I WITH THEot modeling projects 1/5 1/4 larger scales lot concern has placed batteries operate airborne control system Weve analyzed conditioned cycled plotted perfor mance Ni-Cds treasure trust power equipment well good Murphys Law says battery can fail flight will Until now Id managed avoid use battery backer system several reasons First personally feel high-vibration environment like model aircraft no place relay also didnt want have switch non standard five-cell packs because charger ESV load set up 48-volt four-cell packs feel com fortable Never having ana lyzed used systems currently available able start project unbiased opinion what specs should S2B2 knew very beginning extremely reliable work standard four-cell packs have negligible effect power available airborne flight system last area prime con cern since loss power could prove catastrophic wrong moment aesign parameters 1-amp ioaa typical two three S-16-size servos doing busy aerobatic maneuvers 15 20-lb aircraft sudden snap roll command might push up 2 amps current #26-gauge wire find radio systems becomes limiting factor especially long leads would introduce serious voltage drop servos design shown has insertion loss 05 volts 1 amp load 1 volt 2 amps far better can achieved bipolar transistor due use two parallel-connected MOSFETs pack de vices exactly cheap trust much relay wont wear out get stuck vibrate Theyre rated 12 amps application just loafing along should last forever S2B2 powered both backup battery primary battery guess could call backup-back up Im taking chances design since plan using Nosen 310 two 0S120 FS engines Robart retracts new Futaba radio system unlikely event either bat tery should fail other will power S2B2 circuitry both quit bets ne system draws about milliamp current thanks use low-power CMOS circuitry An output driver transis tor provided turn remotelymounted LED audio device backup system activated As shown drain goes up 10 mils LED turns indicating backup bat tery being used IC chips has extremely accurate voltage reference used switch backup pack pri mary battery falls below 42 43 volts prefer extra power servo speed five-cell packs changing single resistor value will change switchover point 55 volts can mix four five-cell packs long five-cell pack used backup would advise against sake simplicity Use #22-gauge stranded hookup wire standard Noble DPDT switch two separate charge jacks suggest ed way pack can checked charged cycled separately Once month least primary backup battery packs should switched get equal usage remain reliable Remember bad backup pack like no backup sounds too good true 38 Model Aviation 33 uf OK IC 2 3 71 TV 1GL youre partially right of parasitic diode part ot MOSFET U transistors small compromise made design What boils down simply backup pack must charged good working condition expect work back up pack experiences shorted cell ex ample diode will begin conduct drawing current main pack II course have shorted cell Right Bottom view PC board layout printed twice final size want make own PC board have 50% film ____ negative made layout Parts Layout S2B2 1.1 0 0 C4 e212 CIR9Ri RIO Left Start resistors lumper jumper can made cuttingoff resistors Right Next add four 33 microfared tantalum caps 001 ceramic capacitor photos author Left Solder five Shottky diodes sure orient banded ends shown otherwise unit wont work correctly Note four holes MOSFETs have drilled clear 118-in-dia pop rivets Right two ICs have added Both notches face left properly oriented S2B2 isnt difficult build must pay attention details backup pack isnt worth much anyway sol guess question really just academic no adjustments project either works doesnt doesnt did something wrong youve got bad part want know what makes tick read order properly turn MOS FETs used series pass configuration gate voltage must least 4 6 volts higher source voltage de pending gate characteristics device used nominal 5-volt bat tery means need 9 11 volts cascade voltage tripler provides about 14 volts adequate safety margin 74C14 hex Schmidt trigger inverter package Rl Cl inverter form square wave oscillator running around 10 kilohertz next two gates form 180 out-of-phase push-pull drive diode capacitor ladder composed Dl D2 D3 C2 C3 C4 network steps up voltage three times minus diode losses about 14 volts high voltage provides gate drive MOSFET transistors efficiency con verter very high around 75% really doesnt matter since total cur rent drain about 100 microanlps now some sharp engineers reading might wondering source pair MOSFETs con nected battery drain might expect Well turns out parasitic diode internal power MOSFETs would conduct main pack began discharge causing current flow between back up main pack course really louses up switchover point mention being unacceptable con dition Fortunately MOSFETs reasonably symmetrical operating characteristics allows source drain connections interchanged thus eliminating problem condi tion still exists under unlikely unrealistic situationwhen main pack voltage first discharged during flight will always lower backup pack Im probably making issue deserves believe its necessary us understands equipment works expect make best use its capabilities types MOSFETs available will work very well S2B2 circuit real concern Rds resistance choose should no 1 ohm Since two parallel pack in-line resistance S2B2 max imum 05 ohms what allows use standard four-cell packs drop small youll never notice it wont affect radio system least list suggested MOSFETs Afl Mnr4sl AAir~ Left Last comes power MOSFET devices held place pop rivets rivets installed bottom side board Solder leads after MOSFETs have riveted place avoids stress Right author Joe Utasi home workshop S2B2 hand follQws Supertex VN2306N5 Siemens BUZ-10 BUZ-71 International Rectifier IRF-540 RCA RFP25NO6 Motorola MTP25NOS Other types can used well just re member resistance must no 1 ohm voltage loss will rise undesirable levels ad venturesome builders out dont waste time trying substitute stand ard bipolar transistors because just wont work need much drive cause substantial loss wont match up board layout Capacitors C2 through C5 should dipped tantalum substitute elec trolytics since too leaky up converter gate drive voltage MOSFETs will come up par C5 necessary stabilize diode isolated voltage battery packs against transients occur switching oc curs circuit cant get 33 microfarad tantalums anything up 10 microfarads can substituted long voltage rating least 15 volts C6 mounted bottom PC board between pins 2 8 ICL 8212 IC ensures S2B2 will always come main battery pack line first can considered power reset Once circuit switches over backup pack way will switch back power switch reset main pack comes up above 54 volts Since odds highly un likely overall circuit behavior very similar latching relay Thus airborne system experiences momentary glitch power system its associated wiring switch system will switch over stay until land point will notice LED lit up investigate poten tial problem further remaining gates function simple inverters get correct logic needed drive transistors off Ql turns backup pack comes line remotely-mounted LED gives indica tion backup system Q2 Q3 provide level shifting needed switch 14 volts off MOSFET gates audio buzzer piezo beeper used has resistance 200 ohms higher resistor R6 can replaced wire jumper ulti mate system output transistor can used activate remote telemetry system notify pilot backup condition during flight diodes used 52B2 1N5817 Shottky rectifiers chosen because very low forward voltage drop 1 volt max low reverse leakage current Silicon germanium should substituted since would compromise performance backer circuitry should pointed Out Ni-Cd bat teries have some internal resistance own may trick backer switching over prematurely reason switchover point using resistor values shown ac tually ends up being between 42 43 volts rather 44 volts might expect ensures bat teries have actually discharged reasonably low level dip voltage caused high current demand hasnt caused 52B2 switch over construction 52B2 very difficult sure use good grade solder hot iron Standard precau tions handling CMOS circuitry should observed Insert components following order resistors capacitors transistors diodes integrated circuits lastly MOSFETs Note layout has specifical ly tailored use %-in-diain alumi num pop rivets Trim middle lead off MOSFET bend remaining leads 90 degrees insert leads PC board insert pop rivet bottom board head pop rivet will make intimate contact PC board good solid electrical con tact tab MOSFET Size 6-32 hardware can also used careful short anything out Also ontinued page 141 24 insignia sheets also letters numbers 0 major decals available popular 40 -60sizes plus American Giant Scale size believe major decals have comprehensive assortment available now -with sizes styles coming time pressure sensitive water transfer Well bet line handing line.the complete line decals available model anywhere _OCAG youll love being handed major decals Ostributors nquiries invited TEL 413-525-4110 CONTACT YOUR LOCAL HOBBY SHOP OR WRITE OIREcT NORTHEAST SCREEN GRAPHICS 21 FISHER AVE. EAST LONOMEADOW MA 01020 conversion superhetrodyne affair PCM receiver rejects forms inter ference including direct on-channel transmissions some cases radio tested loaned Bob Aberle before moved Bob Hunt editor Flying Models will no doubt campaigning Pattern events throughout 1984 Bob Aberle get hands others well tell about big subject discussion Toledo Kraft switchable radio frequency SRF RC system MoM people lis tened Jack Albrechts explanation way worked favorably im pressed Some havent seen radio yet havent heard dis cussion calling ban Really guys thats no way business Ban ning system wont solve problem think someone might carelessly shoot down two forthright solutions 1 TrainingTeach newcomer about realities interference teach yourself use what have intel ligently 2 ImpoundingYou really should use impound area John Langes RF Wands primary concern some will shoot down deliberately have cheaper ways go about pocket full crystals Futaba Tower Airtronics transmitter name few sold plug-in crystals will cost less $50 Such being case would anyone spend over five times much job Kraft SRF plan deal problem SRF transmitters 1984 subsequent Nats following manner 1 Owners SRF transmitters wheth er way plug-in crystals modules RF boards synthesizers will asked declare themselves users channels listed AMA Phase-In Plan funny-colored flags 2 The Transmitter Processors will verify operation stated channel within applicable technical specifications correct antenna frequency channel flag mounted 3 The transmitters will sealed duration contest prevent advertent changes resultant poten tial mistakes 4 Impound areas monitors RF Wands will used flight line 5 Some Contest Directors may wish take advantage SRF capabilities resolve conflicts equalize popula tions available RC channels hav ing set-owners switch channels No prob lem takes another pass through transmitter processing line should likewise will productive ban will cost manpower keep trans mitter processing station could simple Airtronics Scanner veri fy transmitter same channel its flag open throughout contest George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 S2B2IUtasi Continued page 41 sure use Loctite threads pre vent backing out pop rivets really much safer 52B2 should wrapped foam RIDDIZ I 042l Ff\j UDLL E 1mm thick Boxed 16 oz rubber per boxSizes Price $1250 per box ppd USA flL KA WAKEFIELErgIsh $3888 pIe UPSBeilding Finished Front Endii end Flying InstruCtion Very Conplete Send SOC 1984/1 985 Oatalog F Al Model Supply It~S7ToeCAf051R 3, 32 1' 1' 3 4 Fine Quality Flying Models Catalog S 150 98 RUBBER POWER KITS plus Gliders C/L R/C Accessories Books 4 4 4 4 4 4 4 4 4 MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 August1984 141 Want REV-VP Props P 4uichie SOD Pattern & Sport 4 carter Midget Nuge Inventory ! New About Custom Tuned Engines P Detailed Drochure Sead 75 TO Kustoin Kuftsmanship RI lox 209 Ique Nuts CR 92654 Ph 714 5305162 NI-STARTER revoluti model engines used boats cars airplanes NI STARTERITMI uses HeadlockiTMI adapter locks onto glow plugs start engine yits pocket comes CItO charger has LED lights up charging Rechargeable hundreds times gives over 50 consecutive starts recharging Acailable charger Send ad along prepayment receine tree shipping handling NI-STARTER$2495 charger Itt OV 22tV t2V fast chargert NI-STARTER$1 595 charger Chargers$1295 charger lttOV22tVorl2Vfastchargerl PLEASE SPECIFY WHICH CHARGER WHEN OROERINGf L tucked away neatly aircraft also fits nicely some popular bat tery boxes available Ace R/G Dunhams R&R PC board S2B2 available $750 An assembled unit less switch wiring $4400 Order direct Jomar Products 2028 Knightsbridge Dr Cincinnati OH 45244 Assembled units complete wir ing switch connectors match specific radio system available EMS 6175 Palo Alto Dr Anaheim CA 92807 Write pricing Parts List Rl 100K R2 R3 R4 R7 R8470K R522K R6330 ohm R91OK RlO130K Rl 136K-39K 47K five-cell packs Dl through D51N5817 Ql Q2 Q32N3904 IClCD4584 74C14 1C2ICL8212CPA Cl001 mono C2 C3 C433 mf dipped tantalum 15-volt higher CS C6047 mono Miscellaneous PC board solder wire switch Y-in aluminum pop rivets con$2495 Charger nectors suit radio system LED indicator RC AerobaticslVan Putt Continued page 43 speed Take look Figures 1 2 angle between horizon track airplane relative ground gets larger wind blows stronger So does airplane look like its diving going downwind Its actual ly climbing climb angle stretched out wind see Figure 3 because way eyes work looks like its diving course stronger wind blowing lower climb angle airplane will look like its diving approaches horizon Now know Im going get letters decide write subject please dont assemble tirade about laws conservation kinetic energy conservation momentum high school physics Please stick principles mechanics relative frame reference moving constant velocity Thanks suddenly occurred month ago contest season upon us needed get new Pattern airplane pre pared Since prefabricated allbalsa-fuselage Curare sitting corner decided finish rather start scratch fiberglass-fuselage Phoenix 8 Boy mistake forgot ten much involved finishing balsa fuselage must eight 10 years since did things like putting wing fillets fuselagethere must several mil lion things Id rather Also way up list least-favorite things fiberglassing balsa fuse lage What would very useful some good techniques both jobs problems installing fillets endless Getting fillet material ac cept good contour fast shifting during dry/cure important So us ing material sands well has enough strength manage stress flight everyday rigors handling less importance day epoxy other low-shrink paints surface paint will stick well pull loose during drying Whos got some good ideas fillets absence good technique install ounce per square yard fiber glass cloth fuselage plan brush Dave Brown Mix-A-Matic epoxy through cloth use modified toilet paper roll blot up excess epoxy Since Ive used technique adhere lightweight glass cloth wing skins dont know will work fuselage Does anyone have good ideas alternate techniques received interesting letter Dr John Kallend professor engi neering Illinois university teaches crystallography whatever Anyway also consultant engi neering software capacity has developed RC flight simulator works Apple LIe II puters three-dimensional graphic animation flight RC airplane Control elevator ailerons rudder throttle possible using proportional joysticks See Product Review development March 1984 issue page 91 Dr Kallend claims novice can learn basic control functions over come orientation problems Experienced fliers could practice advanced maneuvers both cases no danger model heard about Dave Brown doing im pressive displays Toledo Conference April Dr Kallend claims Hanno Prettner did too RC Flight Simulator available diskette Dave Brown Products 4560 Layhigh Rd Hamilton OH 45013 have no idea much costs Dave would probably happy discuss little item Sounds like fun Continued page 144 142 Model Aviation MFG OF NI-STARTER 12421 RANSOM DRIVE GLENN DALE MD 20769301464-2260 AT-6 SNI This one flies good looks N ngine 63375 Wingspan 8 lbs Complete List Price $28500 Factory Direct $22800 Michigan residents add 4% sales tax rIU Great Lakes Model Company BmchweWs4cmPO Box 308 Tawas City MI 48763517 362-6078 2 Al Major Components Molded Urethane Foam
Edition: Model Aviation - 1984/08
Page Numbers: 38, 39, 40, 41, 141, 142
I WITH THEot modeling projects 1/5 1/4 larger scales lot concern has placed batteries operate airborne control system Weve analyzed conditioned cycled plotted perfor mance Ni-Cds treasure trust power equipment well good Murphys Law says battery can fail flight will Until now Id managed avoid use battery backer system several reasons First personally feel high-vibration environment like model aircraft no place relay also didnt want have switch non standard five-cell packs because charger ESV load set up 48-volt four-cell packs feel com fortable Never having ana lyzed used systems currently available able start project unbiased opinion what specs should S2B2 knew very beginning extremely reliable work standard four-cell packs have negligible effect power available airborne flight system last area prime con cern since loss power could prove catastrophic wrong moment aesign parameters 1-amp ioaa typical two three S-16-size servos doing busy aerobatic maneuvers 15 20-lb aircraft sudden snap roll command might push up 2 amps current #26-gauge wire find radio systems becomes limiting factor especially long leads would introduce serious voltage drop servos design shown has insertion loss 05 volts 1 amp load 1 volt 2 amps far better can achieved bipolar transistor due use two parallel-connected MOSFETs pack de vices exactly cheap trust much relay wont wear out get stuck vibrate Theyre rated 12 amps application just loafing along should last forever S2B2 powered both backup battery primary battery guess could call backup-back up Im taking chances design since plan using Nosen 310 two 0S120 FS engines Robart retracts new Futaba radio system unlikely event either bat tery should fail other will power S2B2 circuitry both quit bets ne system draws about milliamp current thanks use low-power CMOS circuitry An output driver transis tor provided turn remotelymounted LED audio device backup system activated As shown drain goes up 10 mils LED turns indicating backup bat tery being used IC chips has extremely accurate voltage reference used switch backup pack pri mary battery falls below 42 43 volts prefer extra power servo speed five-cell packs changing single resistor value will change switchover point 55 volts can mix four five-cell packs long five-cell pack used backup would advise against sake simplicity Use #22-gauge stranded hookup wire standard Noble DPDT switch two separate charge jacks suggest ed way pack can checked charged cycled separately Once month least primary backup battery packs should switched get equal usage remain reliable Remember bad backup pack like no backup sounds too good true 38 Model Aviation 33 uf OK IC 2 3 71 TV 1GL youre partially right of parasitic diode part ot MOSFET U transistors small compromise made design What boils down simply backup pack must charged good working condition expect work back up pack experiences shorted cell ex ample diode will begin conduct drawing current main pack II course have shorted cell Right Bottom view PC board layout printed twice final size want make own PC board have 50% film ____ negative made layout Parts Layout S2B2 1.1 0 0 C4 e212 CIR9Ri RIO Left Start resistors lumper jumper can made cuttingoff resistors Right Next add four 33 microfared tantalum caps 001 ceramic capacitor photos author Left Solder five Shottky diodes sure orient banded ends shown otherwise unit wont work correctly Note four holes MOSFETs have drilled clear 118-in-dia pop rivets Right two ICs have added Both notches face left properly oriented S2B2 isnt difficult build must pay attention details backup pack isnt worth much anyway sol guess question really just academic no adjustments project either works doesnt doesnt did something wrong youve got bad part want know what makes tick read order properly turn MOS FETs used series pass configuration gate voltage must least 4 6 volts higher source voltage de pending gate characteristics device used nominal 5-volt bat tery means need 9 11 volts cascade voltage tripler provides about 14 volts adequate safety margin 74C14 hex Schmidt trigger inverter package Rl Cl inverter form square wave oscillator running around 10 kilohertz next two gates form 180 out-of-phase push-pull drive diode capacitor ladder composed Dl D2 D3 C2 C3 C4 network steps up voltage three times minus diode losses about 14 volts high voltage provides gate drive MOSFET transistors efficiency con verter very high around 75% really doesnt matter since total cur rent drain about 100 microanlps now some sharp engineers reading might wondering source pair MOSFETs con nected battery drain might expect Well turns out parasitic diode internal power MOSFETs would conduct main pack began discharge causing current flow between back up main pack course really louses up switchover point mention being unacceptable con dition Fortunately MOSFETs reasonably symmetrical operating characteristics allows source drain connections interchanged thus eliminating problem condi tion still exists under unlikely unrealistic situationwhen main pack voltage first discharged during flight will always lower backup pack Im probably making issue deserves believe its necessary us understands equipment works expect make best use its capabilities types MOSFETs available will work very well S2B2 circuit real concern Rds resistance choose should no 1 ohm Since two parallel pack in-line resistance S2B2 max imum 05 ohms what allows use standard four-cell packs drop small youll never notice it wont affect radio system least list suggested MOSFETs Afl Mnr4sl AAir~ Left Last comes power MOSFET devices held place pop rivets rivets installed bottom side board Solder leads after MOSFETs have riveted place avoids stress Right author Joe Utasi home workshop S2B2 hand follQws Supertex VN2306N5 Siemens BUZ-10 BUZ-71 International Rectifier IRF-540 RCA RFP25NO6 Motorola MTP25NOS Other types can used well just re member resistance must no 1 ohm voltage loss will rise undesirable levels ad venturesome builders out dont waste time trying substitute stand ard bipolar transistors because just wont work need much drive cause substantial loss wont match up board layout Capacitors C2 through C5 should dipped tantalum substitute elec trolytics since too leaky up converter gate drive voltage MOSFETs will come up par C5 necessary stabilize diode isolated voltage battery packs against transients occur switching oc curs circuit cant get 33 microfarad tantalums anything up 10 microfarads can substituted long voltage rating least 15 volts C6 mounted bottom PC board between pins 2 8 ICL 8212 IC ensures S2B2 will always come main battery pack line first can considered power reset Once circuit switches over backup pack way will switch back power switch reset main pack comes up above 54 volts Since odds highly un likely overall circuit behavior very similar latching relay Thus airborne system experiences momentary glitch power system its associated wiring switch system will switch over stay until land point will notice LED lit up investigate poten tial problem further remaining gates function simple inverters get correct logic needed drive transistors off Ql turns backup pack comes line remotely-mounted LED gives indica tion backup system Q2 Q3 provide level shifting needed switch 14 volts off MOSFET gates audio buzzer piezo beeper used has resistance 200 ohms higher resistor R6 can replaced wire jumper ulti mate system output transistor can used activate remote telemetry system notify pilot backup condition during flight diodes used 52B2 1N5817 Shottky rectifiers chosen because very low forward voltage drop 1 volt max low reverse leakage current Silicon germanium should substituted since would compromise performance backer circuitry should pointed Out Ni-Cd bat teries have some internal resistance own may trick backer switching over prematurely reason switchover point using resistor values shown ac tually ends up being between 42 43 volts rather 44 volts might expect ensures bat teries have actually discharged reasonably low level dip voltage caused high current demand hasnt caused 52B2 switch over construction 52B2 very difficult sure use good grade solder hot iron Standard precau tions handling CMOS circuitry should observed Insert components following order resistors capacitors transistors diodes integrated circuits lastly MOSFETs Note layout has specifical ly tailored use %-in-diain alumi num pop rivets Trim middle lead off MOSFET bend remaining leads 90 degrees insert leads PC board insert pop rivet bottom board head pop rivet will make intimate contact PC board good solid electrical con tact tab MOSFET Size 6-32 hardware can also used careful short anything out Also ontinued page 141 24 insignia sheets also letters numbers 0 major decals available popular 40 -60sizes plus American Giant Scale size believe major decals have comprehensive assortment available now -with sizes styles coming time pressure sensitive water transfer Well bet line handing line.the complete line decals available model anywhere _OCAG youll love being handed major decals Ostributors nquiries invited TEL 413-525-4110 CONTACT YOUR LOCAL HOBBY SHOP OR WRITE OIREcT NORTHEAST SCREEN GRAPHICS 21 FISHER AVE. EAST LONOMEADOW MA 01020 conversion superhetrodyne affair PCM receiver rejects forms inter ference including direct on-channel transmissions some cases radio tested loaned Bob Aberle before moved Bob Hunt editor Flying Models will no doubt campaigning Pattern events throughout 1984 Bob Aberle get hands others well tell about big subject discussion Toledo Kraft switchable radio frequency SRF RC system MoM people lis tened Jack Albrechts explanation way worked favorably im pressed Some havent seen radio yet havent heard dis cussion calling ban Really guys thats no way business Ban ning system wont solve problem think someone might carelessly shoot down two forthright solutions 1 TrainingTeach newcomer about realities interference teach yourself use what have intel ligently 2 ImpoundingYou really should use impound area John Langes RF Wands primary concern some will shoot down deliberately have cheaper ways go about pocket full crystals Futaba Tower Airtronics transmitter name few sold plug-in crystals will cost less $50 Such being case would anyone spend over five times much job Kraft SRF plan deal problem SRF transmitters 1984 subsequent Nats following manner 1 Owners SRF transmitters wheth er way plug-in crystals modules RF boards synthesizers will asked declare themselves users channels listed AMA Phase-In Plan funny-colored flags 2 The Transmitter Processors will verify operation stated channel within applicable technical specifications correct antenna frequency channel flag mounted 3 The transmitters will sealed duration contest prevent advertent changes resultant poten tial mistakes 4 Impound areas monitors RF Wands will used flight line 5 Some Contest Directors may wish take advantage SRF capabilities resolve conflicts equalize popula tions available RC channels hav ing set-owners switch channels No prob lem takes another pass through transmitter processing line should likewise will productive ban will cost manpower keep trans mitter processing station could simple Airtronics Scanner veri fy transmitter same channel its flag open throughout contest George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 S2B2IUtasi Continued page 41 sure use Loctite threads pre vent backing out pop rivets really much safer 52B2 should wrapped foam RIDDIZ I 042l Ff\j UDLL E 1mm thick Boxed 16 oz rubber per boxSizes Price $1250 per box ppd USA flL KA WAKEFIELErgIsh $3888 pIe UPSBeilding Finished Front Endii end Flying InstruCtion Very Conplete Send SOC 1984/1 985 Oatalog F Al Model Supply It~S7ToeCAf051R 3, 32 1' 1' 3 4 Fine Quality Flying Models Catalog S 150 98 RUBBER POWER KITS plus Gliders C/L R/C Accessories Books 4 4 4 4 4 4 4 4 4 MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 August1984 141 Want REV-VP Props P 4uichie SOD Pattern & Sport 4 carter Midget Nuge Inventory ! New About Custom Tuned Engines P Detailed Drochure Sead 75 TO Kustoin Kuftsmanship RI lox 209 Ique Nuts CR 92654 Ph 714 5305162 NI-STARTER revoluti model engines used boats cars airplanes NI STARTERITMI uses HeadlockiTMI adapter locks onto glow plugs start engine yits pocket comes CItO charger has LED lights up charging Rechargeable hundreds times gives over 50 consecutive starts recharging Acailable charger Send ad along prepayment receine tree shipping handling NI-STARTER$2495 charger Itt OV 22tV t2V fast chargert NI-STARTER$1 595 charger Chargers$1295 charger lttOV22tVorl2Vfastchargerl PLEASE SPECIFY WHICH CHARGER WHEN OROERINGf L tucked away neatly aircraft also fits nicely some popular bat tery boxes available Ace R/G Dunhams R&R PC board S2B2 available $750 An assembled unit less switch wiring $4400 Order direct Jomar Products 2028 Knightsbridge Dr Cincinnati OH 45244 Assembled units complete wir ing switch connectors match specific radio system available EMS 6175 Palo Alto Dr Anaheim CA 92807 Write pricing Parts List Rl 100K R2 R3 R4 R7 R8470K R522K R6330 ohm R91OK RlO130K Rl 136K-39K 47K five-cell packs Dl through D51N5817 Ql Q2 Q32N3904 IClCD4584 74C14 1C2ICL8212CPA Cl001 mono C2 C3 C433 mf dipped tantalum 15-volt higher CS C6047 mono Miscellaneous PC board solder wire switch Y-in aluminum pop rivets con$2495 Charger nectors suit radio system LED indicator RC AerobaticslVan Putt Continued page 43 speed Take look Figures 1 2 angle between horizon track airplane relative ground gets larger wind blows stronger So does airplane look like its diving going downwind Its actual ly climbing climb angle stretched out wind see Figure 3 because way eyes work looks like its diving course stronger wind blowing lower climb angle airplane will look like its diving approaches horizon Now know Im going get letters decide write subject please dont assemble tirade about laws conservation kinetic energy conservation momentum high school physics Please stick principles mechanics relative frame reference moving constant velocity Thanks suddenly occurred month ago contest season upon us needed get new Pattern airplane pre pared Since prefabricated allbalsa-fuselage Curare sitting corner decided finish rather start scratch fiberglass-fuselage Phoenix 8 Boy mistake forgot ten much involved finishing balsa fuselage must eight 10 years since did things like putting wing fillets fuselagethere must several mil lion things Id rather Also way up list least-favorite things fiberglassing balsa fuse lage What would very useful some good techniques both jobs problems installing fillets endless Getting fillet material ac cept good contour fast shifting during dry/cure important So us ing material sands well has enough strength manage stress flight everyday rigors handling less importance day epoxy other low-shrink paints surface paint will stick well pull loose during drying Whos got some good ideas fillets absence good technique install ounce per square yard fiber glass cloth fuselage plan brush Dave Brown Mix-A-Matic epoxy through cloth use modified toilet paper roll blot up excess epoxy Since Ive used technique adhere lightweight glass cloth wing skins dont know will work fuselage Does anyone have good ideas alternate techniques received interesting letter Dr John Kallend professor engi neering Illinois university teaches crystallography whatever Anyway also consultant engi neering software capacity has developed RC flight simulator works Apple LIe II puters three-dimensional graphic animation flight RC airplane Control elevator ailerons rudder throttle possible using proportional joysticks See Product Review development March 1984 issue page 91 Dr Kallend claims novice can learn basic control functions over come orientation problems Experienced fliers could practice advanced maneuvers both cases no danger model heard about Dave Brown doing im pressive displays Toledo Conference April Dr Kallend claims Hanno Prettner did too RC Flight Simulator available diskette Dave Brown Products 4560 Layhigh Rd Hamilton OH 45013 have no idea much costs Dave would probably happy discuss little item Sounds like fun Continued page 144 142 Model Aviation MFG OF NI-STARTER 12421 RANSOM DRIVE GLENN DALE MD 20769301464-2260 AT-6 SNI This one flies good looks N ngine 63375 Wingspan 8 lbs Complete List Price $28500 Factory Direct $22800 Michigan residents add 4% sales tax rIU Great Lakes Model Company BmchweWs4cmPO Box 308 Tawas City MI 48763517 362-6078 2 Al Major Components Molded Urethane Foam
Edition: Model Aviation - 1984/08
Page Numbers: 38, 39, 40, 41, 141, 142
I WITH THEot modeling projects 1/5 1/4 larger scales lot concern has placed batteries operate airborne control system Weve analyzed conditioned cycled plotted perfor mance Ni-Cds treasure trust power equipment well good Murphys Law says battery can fail flight will Until now Id managed avoid use battery backer system several reasons First personally feel high-vibration environment like model aircraft no place relay also didnt want have switch non standard five-cell packs because charger ESV load set up 48-volt four-cell packs feel com fortable Never having ana lyzed used systems currently available able start project unbiased opinion what specs should S2B2 knew very beginning extremely reliable work standard four-cell packs have negligible effect power available airborne flight system last area prime con cern since loss power could prove catastrophic wrong moment aesign parameters 1-amp ioaa typical two three S-16-size servos doing busy aerobatic maneuvers 15 20-lb aircraft sudden snap roll command might push up 2 amps current #26-gauge wire find radio systems becomes limiting factor especially long leads would introduce serious voltage drop servos design shown has insertion loss 05 volts 1 amp load 1 volt 2 amps far better can achieved bipolar transistor due use two parallel-connected MOSFETs pack de vices exactly cheap trust much relay wont wear out get stuck vibrate Theyre rated 12 amps application just loafing along should last forever S2B2 powered both backup battery primary battery guess could call backup-back up Im taking chances design since plan using Nosen 310 two 0S120 FS engines Robart retracts new Futaba radio system unlikely event either bat tery should fail other will power S2B2 circuitry both quit bets ne system draws about milliamp current thanks use low-power CMOS circuitry An output driver transis tor provided turn remotelymounted LED audio device backup system activated As shown drain goes up 10 mils LED turns indicating backup bat tery being used IC chips has extremely accurate voltage reference used switch backup pack pri mary battery falls below 42 43 volts prefer extra power servo speed five-cell packs changing single resistor value will change switchover point 55 volts can mix four five-cell packs long five-cell pack used backup would advise against sake simplicity Use #22-gauge stranded hookup wire standard Noble DPDT switch two separate charge jacks suggest ed way pack can checked charged cycled separately Once month least primary backup battery packs should switched get equal usage remain reliable Remember bad backup pack like no backup sounds too good true 38 Model Aviation 33 uf OK IC 2 3 71 TV 1GL youre partially right of parasitic diode part ot MOSFET U transistors small compromise made design What boils down simply backup pack must charged good working condition expect work back up pack experiences shorted cell ex ample diode will begin conduct drawing current main pack II course have shorted cell Right Bottom view PC board layout printed twice final size want make own PC board have 50% film ____ negative made layout Parts Layout S2B2 1.1 0 0 C4 e212 CIR9Ri RIO Left Start resistors lumper jumper can made cuttingoff resistors Right Next add four 33 microfared tantalum caps 001 ceramic capacitor photos author Left Solder five Shottky diodes sure orient banded ends shown otherwise unit wont work correctly Note four holes MOSFETs have drilled clear 118-in-dia pop rivets Right two ICs have added Both notches face left properly oriented S2B2 isnt difficult build must pay attention details backup pack isnt worth much anyway sol guess question really just academic no adjustments project either works doesnt doesnt did something wrong youve got bad part want know what makes tick read order properly turn MOS FETs used series pass configuration gate voltage must least 4 6 volts higher source voltage de pending gate characteristics device used nominal 5-volt bat tery means need 9 11 volts cascade voltage tripler provides about 14 volts adequate safety margin 74C14 hex Schmidt trigger inverter package Rl Cl inverter form square wave oscillator running around 10 kilohertz next two gates form 180 out-of-phase push-pull drive diode capacitor ladder composed Dl D2 D3 C2 C3 C4 network steps up voltage three times minus diode losses about 14 volts high voltage provides gate drive MOSFET transistors efficiency con verter very high around 75% really doesnt matter since total cur rent drain about 100 microanlps now some sharp engineers reading might wondering source pair MOSFETs con nected battery drain might expect Well turns out parasitic diode internal power MOSFETs would conduct main pack began discharge causing current flow between back up main pack course really louses up switchover point mention being unacceptable con dition Fortunately MOSFETs reasonably symmetrical operating characteristics allows source drain connections interchanged thus eliminating problem condi tion still exists under unlikely unrealistic situationwhen main pack voltage first discharged during flight will always lower backup pack Im probably making issue deserves believe its necessary us understands equipment works expect make best use its capabilities types MOSFETs available will work very well S2B2 circuit real concern Rds resistance choose should no 1 ohm Since two parallel pack in-line resistance S2B2 max imum 05 ohms what allows use standard four-cell packs drop small youll never notice it wont affect radio system least list suggested MOSFETs Afl Mnr4sl AAir~ Left Last comes power MOSFET devices held place pop rivets rivets installed bottom side board Solder leads after MOSFETs have riveted place avoids stress Right author Joe Utasi home workshop S2B2 hand follQws Supertex VN2306N5 Siemens BUZ-10 BUZ-71 International Rectifier IRF-540 RCA RFP25NO6 Motorola MTP25NOS Other types can used well just re member resistance must no 1 ohm voltage loss will rise undesirable levels ad venturesome builders out dont waste time trying substitute stand ard bipolar transistors because just wont work need much drive cause substantial loss wont match up board layout Capacitors C2 through C5 should dipped tantalum substitute elec trolytics since too leaky up converter gate drive voltage MOSFETs will come up par C5 necessary stabilize diode isolated voltage battery packs against transients occur switching oc curs circuit cant get 33 microfarad tantalums anything up 10 microfarads can substituted long voltage rating least 15 volts C6 mounted bottom PC board between pins 2 8 ICL 8212 IC ensures S2B2 will always come main battery pack line first can considered power reset Once circuit switches over backup pack way will switch back power switch reset main pack comes up above 54 volts Since odds highly un likely overall circuit behavior very similar latching relay Thus airborne system experiences momentary glitch power system its associated wiring switch system will switch over stay until land point will notice LED lit up investigate poten tial problem further remaining gates function simple inverters get correct logic needed drive transistors off Ql turns backup pack comes line remotely-mounted LED gives indica tion backup system Q2 Q3 provide level shifting needed switch 14 volts off MOSFET gates audio buzzer piezo beeper used has resistance 200 ohms higher resistor R6 can replaced wire jumper ulti mate system output transistor can used activate remote telemetry system notify pilot backup condition during flight diodes used 52B2 1N5817 Shottky rectifiers chosen because very low forward voltage drop 1 volt max low reverse leakage current Silicon germanium should substituted since would compromise performance backer circuitry should pointed Out Ni-Cd bat teries have some internal resistance own may trick backer switching over prematurely reason switchover point using resistor values shown ac tually ends up being between 42 43 volts rather 44 volts might expect ensures bat teries have actually discharged reasonably low level dip voltage caused high current demand hasnt caused 52B2 switch over construction 52B2 very difficult sure use good grade solder hot iron Standard precau tions handling CMOS circuitry should observed Insert components following order resistors capacitors transistors diodes integrated circuits lastly MOSFETs Note layout has specifical ly tailored use %-in-diain alumi num pop rivets Trim middle lead off MOSFET bend remaining leads 90 degrees insert leads PC board insert pop rivet bottom board head pop rivet will make intimate contact PC board good solid electrical con tact tab MOSFET Size 6-32 hardware can also used careful short anything out Also ontinued page 141 24 insignia sheets also letters numbers 0 major decals available popular 40 -60sizes plus American Giant Scale size believe major decals have comprehensive assortment available now -with sizes styles coming time pressure sensitive water transfer Well bet line handing line.the complete line decals available model anywhere _OCAG youll love being handed major decals Ostributors nquiries invited TEL 413-525-4110 CONTACT YOUR LOCAL HOBBY SHOP OR WRITE OIREcT NORTHEAST SCREEN GRAPHICS 21 FISHER AVE. EAST LONOMEADOW MA 01020 conversion superhetrodyne affair PCM receiver rejects forms inter ference including direct on-channel transmissions some cases radio tested loaned Bob Aberle before moved Bob Hunt editor Flying Models will no doubt campaigning Pattern events throughout 1984 Bob Aberle get hands others well tell about big subject discussion Toledo Kraft switchable radio frequency SRF RC system MoM people lis tened Jack Albrechts explanation way worked favorably im pressed Some havent seen radio yet havent heard dis cussion calling ban Really guys thats no way business Ban ning system wont solve problem think someone might carelessly shoot down two forthright solutions 1 TrainingTeach newcomer about realities interference teach yourself use what have intel ligently 2 ImpoundingYou really should use impound area John Langes RF Wands primary concern some will shoot down deliberately have cheaper ways go about pocket full crystals Futaba Tower Airtronics transmitter name few sold plug-in crystals will cost less $50 Such being case would anyone spend over five times much job Kraft SRF plan deal problem SRF transmitters 1984 subsequent Nats following manner 1 Owners SRF transmitters wheth er way plug-in crystals modules RF boards synthesizers will asked declare themselves users channels listed AMA Phase-In Plan funny-colored flags 2 The Transmitter Processors will verify operation stated channel within applicable technical specifications correct antenna frequency channel flag mounted 3 The transmitters will sealed duration contest prevent advertent changes resultant poten tial mistakes 4 Impound areas monitors RF Wands will used flight line 5 Some Contest Directors may wish take advantage SRF capabilities resolve conflicts equalize popula tions available RC channels hav ing set-owners switch channels No prob lem takes another pass through transmitter processing line should likewise will productive ban will cost manpower keep trans mitter processing station could simple Airtronics Scanner veri fy transmitter same channel its flag open throughout contest George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 S2B2IUtasi Continued page 41 sure use Loctite threads pre vent backing out pop rivets really much safer 52B2 should wrapped foam RIDDIZ I 042l Ff\j UDLL E 1mm thick Boxed 16 oz rubber per boxSizes Price $1250 per box ppd USA flL KA WAKEFIELErgIsh $3888 pIe UPSBeilding Finished Front Endii end Flying InstruCtion Very Conplete Send SOC 1984/1 985 Oatalog F Al Model Supply It~S7ToeCAf051R 3, 32 1' 1' 3 4 Fine Quality Flying Models Catalog S 150 98 RUBBER POWER KITS plus Gliders C/L R/C Accessories Books 4 4 4 4 4 4 4 4 4 MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 August1984 141 Want REV-VP Props P 4uichie SOD Pattern & Sport 4 carter Midget Nuge Inventory ! New About Custom Tuned Engines P Detailed Drochure Sead 75 TO Kustoin Kuftsmanship RI lox 209 Ique Nuts CR 92654 Ph 714 5305162 NI-STARTER revoluti model engines used boats cars airplanes NI STARTERITMI uses HeadlockiTMI adapter locks onto glow plugs start engine yits pocket comes CItO charger has LED lights up charging Rechargeable hundreds times gives over 50 consecutive starts recharging Acailable charger Send ad along prepayment receine tree shipping handling NI-STARTER$2495 charger Itt OV 22tV t2V fast chargert NI-STARTER$1 595 charger Chargers$1295 charger lttOV22tVorl2Vfastchargerl PLEASE SPECIFY WHICH CHARGER WHEN OROERINGf L tucked away neatly aircraft also fits nicely some popular bat tery boxes available Ace R/G Dunhams R&R PC board S2B2 available $750 An assembled unit less switch wiring $4400 Order direct Jomar Products 2028 Knightsbridge Dr Cincinnati OH 45244 Assembled units complete wir ing switch connectors match specific radio system available EMS 6175 Palo Alto Dr Anaheim CA 92807 Write pricing Parts List Rl 100K R2 R3 R4 R7 R8470K R522K R6330 ohm R91OK RlO130K Rl 136K-39K 47K five-cell packs Dl through D51N5817 Ql Q2 Q32N3904 IClCD4584 74C14 1C2ICL8212CPA Cl001 mono C2 C3 C433 mf dipped tantalum 15-volt higher CS C6047 mono Miscellaneous PC board solder wire switch Y-in aluminum pop rivets con$2495 Charger nectors suit radio system LED indicator RC AerobaticslVan Putt Continued page 43 speed Take look Figures 1 2 angle between horizon track airplane relative ground gets larger wind blows stronger So does airplane look like its diving going downwind Its actual ly climbing climb angle stretched out wind see Figure 3 because way eyes work looks like its diving course stronger wind blowing lower climb angle airplane will look like its diving approaches horizon Now know Im going get letters decide write subject please dont assemble tirade about laws conservation kinetic energy conservation momentum high school physics Please stick principles mechanics relative frame reference moving constant velocity Thanks suddenly occurred month ago contest season upon us needed get new Pattern airplane pre pared Since prefabricated allbalsa-fuselage Curare sitting corner decided finish rather start scratch fiberglass-fuselage Phoenix 8 Boy mistake forgot ten much involved finishing balsa fuselage must eight 10 years since did things like putting wing fillets fuselagethere must several mil lion things Id rather Also way up list least-favorite things fiberglassing balsa fuse lage What would very useful some good techniques both jobs problems installing fillets endless Getting fillet material ac cept good contour fast shifting during dry/cure important So us ing material sands well has enough strength manage stress flight everyday rigors handling less importance day epoxy other low-shrink paints surface paint will stick well pull loose during drying Whos got some good ideas fillets absence good technique install ounce per square yard fiber glass cloth fuselage plan brush Dave Brown Mix-A-Matic epoxy through cloth use modified toilet paper roll blot up excess epoxy Since Ive used technique adhere lightweight glass cloth wing skins dont know will work fuselage Does anyone have good ideas alternate techniques received interesting letter Dr John Kallend professor engi neering Illinois university teaches crystallography whatever Anyway also consultant engi neering software capacity has developed RC flight simulator works Apple LIe II puters three-dimensional graphic animation flight RC airplane Control elevator ailerons rudder throttle possible using proportional joysticks See Product Review development March 1984 issue page 91 Dr Kallend claims novice can learn basic control functions over come orientation problems Experienced fliers could practice advanced maneuvers both cases no danger model heard about Dave Brown doing im pressive displays Toledo Conference April Dr Kallend claims Hanno Prettner did too RC Flight Simulator available diskette Dave Brown Products 4560 Layhigh Rd Hamilton OH 45013 have no idea much costs Dave would probably happy discuss little item Sounds like fun Continued page 144 142 Model Aviation MFG OF NI-STARTER 12421 RANSOM DRIVE GLENN DALE MD 20769301464-2260 AT-6 SNI This one flies good looks N ngine 63375 Wingspan 8 lbs Complete List Price $28500 Factory Direct $22800 Michigan residents add 4% sales tax rIU Great Lakes Model Company BmchweWs4cmPO Box 308 Tawas City MI 48763517 362-6078 2 Al Major Components Molded Urethane Foam
Edition: Model Aviation - 1984/08
Page Numbers: 38, 39, 40, 41, 141, 142
I WITH THEot modeling projects 1/5 1/4 larger scales lot concern has placed batteries operate airborne control system Weve analyzed conditioned cycled plotted perfor mance Ni-Cds treasure trust power equipment well good Murphys Law says battery can fail flight will Until now Id managed avoid use battery backer system several reasons First personally feel high-vibration environment like model aircraft no place relay also didnt want have switch non standard five-cell packs because charger ESV load set up 48-volt four-cell packs feel com fortable Never having ana lyzed used systems currently available able start project unbiased opinion what specs should S2B2 knew very beginning extremely reliable work standard four-cell packs have negligible effect power available airborne flight system last area prime con cern since loss power could prove catastrophic wrong moment aesign parameters 1-amp ioaa typical two three S-16-size servos doing busy aerobatic maneuvers 15 20-lb aircraft sudden snap roll command might push up 2 amps current #26-gauge wire find radio systems becomes limiting factor especially long leads would introduce serious voltage drop servos design shown has insertion loss 05 volts 1 amp load 1 volt 2 amps far better can achieved bipolar transistor due use two parallel-connected MOSFETs pack de vices exactly cheap trust much relay wont wear out get stuck vibrate Theyre rated 12 amps application just loafing along should last forever S2B2 powered both backup battery primary battery guess could call backup-back up Im taking chances design since plan using Nosen 310 two 0S120 FS engines Robart retracts new Futaba radio system unlikely event either bat tery should fail other will power S2B2 circuitry both quit bets ne system draws about milliamp current thanks use low-power CMOS circuitry An output driver transis tor provided turn remotelymounted LED audio device backup system activated As shown drain goes up 10 mils LED turns indicating backup bat tery being used IC chips has extremely accurate voltage reference used switch backup pack pri mary battery falls below 42 43 volts prefer extra power servo speed five-cell packs changing single resistor value will change switchover point 55 volts can mix four five-cell packs long five-cell pack used backup would advise against sake simplicity Use #22-gauge stranded hookup wire standard Noble DPDT switch two separate charge jacks suggest ed way pack can checked charged cycled separately Once month least primary backup battery packs should switched get equal usage remain reliable Remember bad backup pack like no backup sounds too good true 38 Model Aviation 33 uf OK IC 2 3 71 TV 1GL youre partially right of parasitic diode part ot MOSFET U transistors small compromise made design What boils down simply backup pack must charged good working condition expect work back up pack experiences shorted cell ex ample diode will begin conduct drawing current main pack II course have shorted cell Right Bottom view PC board layout printed twice final size want make own PC board have 50% film ____ negative made layout Parts Layout S2B2 1.1 0 0 C4 e212 CIR9Ri RIO Left Start resistors lumper jumper can made cuttingoff resistors Right Next add four 33 microfared tantalum caps 001 ceramic capacitor photos author Left Solder five Shottky diodes sure orient banded ends shown otherwise unit wont work correctly Note four holes MOSFETs have drilled clear 118-in-dia pop rivets Right two ICs have added Both notches face left properly oriented S2B2 isnt difficult build must pay attention details backup pack isnt worth much anyway sol guess question really just academic no adjustments project either works doesnt doesnt did something wrong youve got bad part want know what makes tick read order properly turn MOS FETs used series pass configuration gate voltage must least 4 6 volts higher source voltage de pending gate characteristics device used nominal 5-volt bat tery means need 9 11 volts cascade voltage tripler provides about 14 volts adequate safety margin 74C14 hex Schmidt trigger inverter package Rl Cl inverter form square wave oscillator running around 10 kilohertz next two gates form 180 out-of-phase push-pull drive diode capacitor ladder composed Dl D2 D3 C2 C3 C4 network steps up voltage three times minus diode losses about 14 volts high voltage provides gate drive MOSFET transistors efficiency con verter very high around 75% really doesnt matter since total cur rent drain about 100 microanlps now some sharp engineers reading might wondering source pair MOSFETs con nected battery drain might expect Well turns out parasitic diode internal power MOSFETs would conduct main pack began discharge causing current flow between back up main pack course really louses up switchover point mention being unacceptable con dition Fortunately MOSFETs reasonably symmetrical operating characteristics allows source drain connections interchanged thus eliminating problem condi tion still exists under unlikely unrealistic situationwhen main pack voltage first discharged during flight will always lower backup pack Im probably making issue deserves believe its necessary us understands equipment works expect make best use its capabilities types MOSFETs available will work very well S2B2 circuit real concern Rds resistance choose should no 1 ohm Since two parallel pack in-line resistance S2B2 max imum 05 ohms what allows use standard four-cell packs drop small youll never notice it wont affect radio system least list suggested MOSFETs Afl Mnr4sl AAir~ Left Last comes power MOSFET devices held place pop rivets rivets installed bottom side board Solder leads after MOSFETs have riveted place avoids stress Right author Joe Utasi home workshop S2B2 hand follQws Supertex VN2306N5 Siemens BUZ-10 BUZ-71 International Rectifier IRF-540 RCA RFP25NO6 Motorola MTP25NOS Other types can used well just re member resistance must no 1 ohm voltage loss will rise undesirable levels ad venturesome builders out dont waste time trying substitute stand ard bipolar transistors because just wont work need much drive cause substantial loss wont match up board layout Capacitors C2 through C5 should dipped tantalum substitute elec trolytics since too leaky up converter gate drive voltage MOSFETs will come up par C5 necessary stabilize diode isolated voltage battery packs against transients occur switching oc curs circuit cant get 33 microfarad tantalums anything up 10 microfarads can substituted long voltage rating least 15 volts C6 mounted bottom PC board between pins 2 8 ICL 8212 IC ensures S2B2 will always come main battery pack line first can considered power reset Once circuit switches over backup pack way will switch back power switch reset main pack comes up above 54 volts Since odds highly un likely overall circuit behavior very similar latching relay Thus airborne system experiences momentary glitch power system its associated wiring switch system will switch over stay until land point will notice LED lit up investigate poten tial problem further remaining gates function simple inverters get correct logic needed drive transistors off Ql turns backup pack comes line remotely-mounted LED gives indica tion backup system Q2 Q3 provide level shifting needed switch 14 volts off MOSFET gates audio buzzer piezo beeper used has resistance 200 ohms higher resistor R6 can replaced wire jumper ulti mate system output transistor can used activate remote telemetry system notify pilot backup condition during flight diodes used 52B2 1N5817 Shottky rectifiers chosen because very low forward voltage drop 1 volt max low reverse leakage current Silicon germanium should substituted since would compromise performance backer circuitry should pointed Out Ni-Cd bat teries have some internal resistance own may trick backer switching over prematurely reason switchover point using resistor values shown ac tually ends up being between 42 43 volts rather 44 volts might expect ensures bat teries have actually discharged reasonably low level dip voltage caused high current demand hasnt caused 52B2 switch over construction 52B2 very difficult sure use good grade solder hot iron Standard precau tions handling CMOS circuitry should observed Insert components following order resistors capacitors transistors diodes integrated circuits lastly MOSFETs Note layout has specifical ly tailored use %-in-diain alumi num pop rivets Trim middle lead off MOSFET bend remaining leads 90 degrees insert leads PC board insert pop rivet bottom board head pop rivet will make intimate contact PC board good solid electrical con tact tab MOSFET Size 6-32 hardware can also used careful short anything out Also ontinued page 141 24 insignia sheets also letters numbers 0 major decals available popular 40 -60sizes plus American Giant Scale size believe major decals have comprehensive assortment available now -with sizes styles coming time pressure sensitive water transfer Well bet line handing line.the complete line decals available model anywhere _OCAG youll love being handed major decals Ostributors nquiries invited TEL 413-525-4110 CONTACT YOUR LOCAL HOBBY SHOP OR WRITE OIREcT NORTHEAST SCREEN GRAPHICS 21 FISHER AVE. EAST LONOMEADOW MA 01020 conversion superhetrodyne affair PCM receiver rejects forms inter ference including direct on-channel transmissions some cases radio tested loaned Bob Aberle before moved Bob Hunt editor Flying Models will no doubt campaigning Pattern events throughout 1984 Bob Aberle get hands others well tell about big subject discussion Toledo Kraft switchable radio frequency SRF RC system MoM people lis tened Jack Albrechts explanation way worked favorably im pressed Some havent seen radio yet havent heard dis cussion calling ban Really guys thats no way business Ban ning system wont solve problem think someone might carelessly shoot down two forthright solutions 1 TrainingTeach newcomer about realities interference teach yourself use what have intel ligently 2 ImpoundingYou really should use impound area John Langes RF Wands primary concern some will shoot down deliberately have cheaper ways go about pocket full crystals Futaba Tower Airtronics transmitter name few sold plug-in crystals will cost less $50 Such being case would anyone spend over five times much job Kraft SRF plan deal problem SRF transmitters 1984 subsequent Nats following manner 1 Owners SRF transmitters wheth er way plug-in crystals modules RF boards synthesizers will asked declare themselves users channels listed AMA Phase-In Plan funny-colored flags 2 The Transmitter Processors will verify operation stated channel within applicable technical specifications correct antenna frequency channel flag mounted 3 The transmitters will sealed duration contest prevent advertent changes resultant poten tial mistakes 4 Impound areas monitors RF Wands will used flight line 5 Some Contest Directors may wish take advantage SRF capabilities resolve conflicts equalize popula tions available RC channels hav ing set-owners switch channels No prob lem takes another pass through transmitter processing line should likewise will productive ban will cost manpower keep trans mitter processing station could simple Airtronics Scanner veri fy transmitter same channel its flag open throughout contest George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 S2B2IUtasi Continued page 41 sure use Loctite threads pre vent backing out pop rivets really much safer 52B2 should wrapped foam RIDDIZ I 042l Ff\j UDLL E 1mm thick Boxed 16 oz rubber per boxSizes Price $1250 per box ppd USA flL KA WAKEFIELErgIsh $3888 pIe UPSBeilding Finished Front Endii end Flying InstruCtion Very Conplete Send SOC 1984/1 985 Oatalog F Al Model Supply It~S7ToeCAf051R 3, 32 1' 1' 3 4 Fine Quality Flying Models Catalog S 150 98 RUBBER POWER KITS plus Gliders C/L R/C Accessories Books 4 4 4 4 4 4 4 4 4 MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 August1984 141 Want REV-VP Props P 4uichie SOD Pattern & Sport 4 carter Midget Nuge Inventory ! New About Custom Tuned Engines P Detailed Drochure Sead 75 TO Kustoin Kuftsmanship RI lox 209 Ique Nuts CR 92654 Ph 714 5305162 NI-STARTER revoluti model engines used boats cars airplanes NI STARTERITMI uses HeadlockiTMI adapter locks onto glow plugs start engine yits pocket comes CItO charger has LED lights up charging Rechargeable hundreds times gives over 50 consecutive starts recharging Acailable charger Send ad along prepayment receine tree shipping handling NI-STARTER$2495 charger Itt OV 22tV t2V fast chargert NI-STARTER$1 595 charger Chargers$1295 charger lttOV22tVorl2Vfastchargerl PLEASE SPECIFY WHICH CHARGER WHEN OROERINGf L tucked away neatly aircraft also fits nicely some popular bat tery boxes available Ace R/G Dunhams R&R PC board S2B2 available $750 An assembled unit less switch wiring $4400 Order direct Jomar Products 2028 Knightsbridge Dr Cincinnati OH 45244 Assembled units complete wir ing switch connectors match specific radio system available EMS 6175 Palo Alto Dr Anaheim CA 92807 Write pricing Parts List Rl 100K R2 R3 R4 R7 R8470K R522K R6330 ohm R91OK RlO130K Rl 136K-39K 47K five-cell packs Dl through D51N5817 Ql Q2 Q32N3904 IClCD4584 74C14 1C2ICL8212CPA Cl001 mono C2 C3 C433 mf dipped tantalum 15-volt higher CS C6047 mono Miscellaneous PC board solder wire switch Y-in aluminum pop rivets con$2495 Charger nectors suit radio system LED indicator RC AerobaticslVan Putt Continued page 43 speed Take look Figures 1 2 angle between horizon track airplane relative ground gets larger wind blows stronger So does airplane look like its diving going downwind Its actual ly climbing climb angle stretched out wind see Figure 3 because way eyes work looks like its diving course stronger wind blowing lower climb angle airplane will look like its diving approaches horizon Now know Im going get letters decide write subject please dont assemble tirade about laws conservation kinetic energy conservation momentum high school physics Please stick principles mechanics relative frame reference moving constant velocity Thanks suddenly occurred month ago contest season upon us needed get new Pattern airplane pre pared Since prefabricated allbalsa-fuselage Curare sitting corner decided finish rather start scratch fiberglass-fuselage Phoenix 8 Boy mistake forgot ten much involved finishing balsa fuselage must eight 10 years since did things like putting wing fillets fuselagethere must several mil lion things Id rather Also way up list least-favorite things fiberglassing balsa fuse lage What would very useful some good techniques both jobs problems installing fillets endless Getting fillet material ac cept good contour fast shifting during dry/cure important So us ing material sands well has enough strength manage stress flight everyday rigors handling less importance day epoxy other low-shrink paints surface paint will stick well pull loose during drying Whos got some good ideas fillets absence good technique install ounce per square yard fiber glass cloth fuselage plan brush Dave Brown Mix-A-Matic epoxy through cloth use modified toilet paper roll blot up excess epoxy Since Ive used technique adhere lightweight glass cloth wing skins dont know will work fuselage Does anyone have good ideas alternate techniques received interesting letter Dr John Kallend professor engi neering Illinois university teaches crystallography whatever Anyway also consultant engi neering software capacity has developed RC flight simulator works Apple LIe II puters three-dimensional graphic animation flight RC airplane Control elevator ailerons rudder throttle possible using proportional joysticks See Product Review development March 1984 issue page 91 Dr Kallend claims novice can learn basic control functions over come orientation problems Experienced fliers could practice advanced maneuvers both cases no danger model heard about Dave Brown doing im pressive displays Toledo Conference April Dr Kallend claims Hanno Prettner did too RC Flight Simulator available diskette Dave Brown Products 4560 Layhigh Rd Hamilton OH 45013 have no idea much costs Dave would probably happy discuss little item Sounds like fun Continued page 144 142 Model Aviation MFG OF NI-STARTER 12421 RANSOM DRIVE GLENN DALE MD 20769301464-2260 AT-6 SNI This one flies good looks N ngine 63375 Wingspan 8 lbs Complete List Price $28500 Factory Direct $22800 Michigan residents add 4% sales tax rIU Great Lakes Model Company BmchweWs4cmPO Box 308 Tawas City MI 48763517 362-6078 2 Al Major Components Molded Urethane Foam
Edition: Model Aviation - 1984/08
Page Numbers: 38, 39, 40, 41, 141, 142
I WITH THEot modeling projects 1/5 1/4 larger scales lot concern has placed batteries operate airborne control system Weve analyzed conditioned cycled plotted perfor mance Ni-Cds treasure trust power equipment well good Murphys Law says battery can fail flight will Until now Id managed avoid use battery backer system several reasons First personally feel high-vibration environment like model aircraft no place relay also didnt want have switch non standard five-cell packs because charger ESV load set up 48-volt four-cell packs feel com fortable Never having ana lyzed used systems currently available able start project unbiased opinion what specs should S2B2 knew very beginning extremely reliable work standard four-cell packs have negligible effect power available airborne flight system last area prime con cern since loss power could prove catastrophic wrong moment aesign parameters 1-amp ioaa typical two three S-16-size servos doing busy aerobatic maneuvers 15 20-lb aircraft sudden snap roll command might push up 2 amps current #26-gauge wire find radio systems becomes limiting factor especially long leads would introduce serious voltage drop servos design shown has insertion loss 05 volts 1 amp load 1 volt 2 amps far better can achieved bipolar transistor due use two parallel-connected MOSFETs pack de vices exactly cheap trust much relay wont wear out get stuck vibrate Theyre rated 12 amps application just loafing along should last forever S2B2 powered both backup battery primary battery guess could call backup-back up Im taking chances design since plan using Nosen 310 two 0S120 FS engines Robart retracts new Futaba radio system unlikely event either bat tery should fail other will power S2B2 circuitry both quit bets ne system draws about milliamp current thanks use low-power CMOS circuitry An output driver transis tor provided turn remotelymounted LED audio device backup system activated As shown drain goes up 10 mils LED turns indicating backup bat tery being used IC chips has extremely accurate voltage reference used switch backup pack pri mary battery falls below 42 43 volts prefer extra power servo speed five-cell packs changing single resistor value will change switchover point 55 volts can mix four five-cell packs long five-cell pack used backup would advise against sake simplicity Use #22-gauge stranded hookup wire standard Noble DPDT switch two separate charge jacks suggest ed way pack can checked charged cycled separately Once month least primary backup battery packs should switched get equal usage remain reliable Remember bad backup pack like no backup sounds too good true 38 Model Aviation 33 uf OK IC 2 3 71 TV 1GL youre partially right of parasitic diode part ot MOSFET U transistors small compromise made design What boils down simply backup pack must charged good working condition expect work back up pack experiences shorted cell ex ample diode will begin conduct drawing current main pack II course have shorted cell Right Bottom view PC board layout printed twice final size want make own PC board have 50% film ____ negative made layout Parts Layout S2B2 1.1 0 0 C4 e212 CIR9Ri RIO Left Start resistors lumper jumper can made cuttingoff resistors Right Next add four 33 microfared tantalum caps 001 ceramic capacitor photos author Left Solder five Shottky diodes sure orient banded ends shown otherwise unit wont work correctly Note four holes MOSFETs have drilled clear 118-in-dia pop rivets Right two ICs have added Both notches face left properly oriented S2B2 isnt difficult build must pay attention details backup pack isnt worth much anyway sol guess question really just academic no adjustments project either works doesnt doesnt did something wrong youve got bad part want know what makes tick read order properly turn MOS FETs used series pass configuration gate voltage must least 4 6 volts higher source voltage de pending gate characteristics device used nominal 5-volt bat tery means need 9 11 volts cascade voltage tripler provides about 14 volts adequate safety margin 74C14 hex Schmidt trigger inverter package Rl Cl inverter form square wave oscillator running around 10 kilohertz next two gates form 180 out-of-phase push-pull drive diode capacitor ladder composed Dl D2 D3 C2 C3 C4 network steps up voltage three times minus diode losses about 14 volts high voltage provides gate drive MOSFET transistors efficiency con verter very high around 75% really doesnt matter since total cur rent drain about 100 microanlps now some sharp engineers reading might wondering source pair MOSFETs con nected battery drain might expect Well turns out parasitic diode internal power MOSFETs would conduct main pack began discharge causing current flow between back up main pack course really louses up switchover point mention being unacceptable con dition Fortunately MOSFETs reasonably symmetrical operating characteristics allows source drain connections interchanged thus eliminating problem condi tion still exists under unlikely unrealistic situationwhen main pack voltage first discharged during flight will always lower backup pack Im probably making issue deserves believe its necessary us understands equipment works expect make best use its capabilities types MOSFETs available will work very well S2B2 circuit real concern Rds resistance choose should no 1 ohm Since two parallel pack in-line resistance S2B2 max imum 05 ohms what allows use standard four-cell packs drop small youll never notice it wont affect radio system least list suggested MOSFETs Afl Mnr4sl AAir~ Left Last comes power MOSFET devices held place pop rivets rivets installed bottom side board Solder leads after MOSFETs have riveted place avoids stress Right author Joe Utasi home workshop S2B2 hand follQws Supertex VN2306N5 Siemens BUZ-10 BUZ-71 International Rectifier IRF-540 RCA RFP25NO6 Motorola MTP25NOS Other types can used well just re member resistance must no 1 ohm voltage loss will rise undesirable levels ad venturesome builders out dont waste time trying substitute stand ard bipolar transistors because just wont work need much drive cause substantial loss wont match up board layout Capacitors C2 through C5 should dipped tantalum substitute elec trolytics since too leaky up converter gate drive voltage MOSFETs will come up par C5 necessary stabilize diode isolated voltage battery packs against transients occur switching oc curs circuit cant get 33 microfarad tantalums anything up 10 microfarads can substituted long voltage rating least 15 volts C6 mounted bottom PC board between pins 2 8 ICL 8212 IC ensures S2B2 will always come main battery pack line first can considered power reset Once circuit switches over backup pack way will switch back power switch reset main pack comes up above 54 volts Since odds highly un likely overall circuit behavior very similar latching relay Thus airborne system experiences momentary glitch power system its associated wiring switch system will switch over stay until land point will notice LED lit up investigate poten tial problem further remaining gates function simple inverters get correct logic needed drive transistors off Ql turns backup pack comes line remotely-mounted LED gives indica tion backup system Q2 Q3 provide level shifting needed switch 14 volts off MOSFET gates audio buzzer piezo beeper used has resistance 200 ohms higher resistor R6 can replaced wire jumper ulti mate system output transistor can used activate remote telemetry system notify pilot backup condition during flight diodes used 52B2 1N5817 Shottky rectifiers chosen because very low forward voltage drop 1 volt max low reverse leakage current Silicon germanium should substituted since would compromise performance backer circuitry should pointed Out Ni-Cd bat teries have some internal resistance own may trick backer switching over prematurely reason switchover point using resistor values shown ac tually ends up being between 42 43 volts rather 44 volts might expect ensures bat teries have actually discharged reasonably low level dip voltage caused high current demand hasnt caused 52B2 switch over construction 52B2 very difficult sure use good grade solder hot iron Standard precau tions handling CMOS circuitry should observed Insert components following order resistors capacitors transistors diodes integrated circuits lastly MOSFETs Note layout has specifical ly tailored use %-in-diain alumi num pop rivets Trim middle lead off MOSFET bend remaining leads 90 degrees insert leads PC board insert pop rivet bottom board head pop rivet will make intimate contact PC board good solid electrical con tact tab MOSFET Size 6-32 hardware can also used careful short anything out Also ontinued page 141 24 insignia sheets also letters numbers 0 major decals available popular 40 -60sizes plus American Giant Scale size believe major decals have comprehensive assortment available now -with sizes styles coming time pressure sensitive water transfer Well bet line handing line.the complete line decals available model anywhere _OCAG youll love being handed major decals Ostributors nquiries invited TEL 413-525-4110 CONTACT YOUR LOCAL HOBBY SHOP OR WRITE OIREcT NORTHEAST SCREEN GRAPHICS 21 FISHER AVE. EAST LONOMEADOW MA 01020 conversion superhetrodyne affair PCM receiver rejects forms inter ference including direct on-channel transmissions some cases radio tested loaned Bob Aberle before moved Bob Hunt editor Flying Models will no doubt campaigning Pattern events throughout 1984 Bob Aberle get hands others well tell about big subject discussion Toledo Kraft switchable radio frequency SRF RC system MoM people lis tened Jack Albrechts explanation way worked favorably im pressed Some havent seen radio yet havent heard dis cussion calling ban Really guys thats no way business Ban ning system wont solve problem think someone might carelessly shoot down two forthright solutions 1 TrainingTeach newcomer about realities interference teach yourself use what have intel ligently 2 ImpoundingYou really should use impound area John Langes RF Wands primary concern some will shoot down deliberately have cheaper ways go about pocket full crystals Futaba Tower Airtronics transmitter name few sold plug-in crystals will cost less $50 Such being case would anyone spend over five times much job Kraft SRF plan deal problem SRF transmitters 1984 subsequent Nats following manner 1 Owners SRF transmitters wheth er way plug-in crystals modules RF boards synthesizers will asked declare themselves users channels listed AMA Phase-In Plan funny-colored flags 2 The Transmitter Processors will verify operation stated channel within applicable technical specifications correct antenna frequency channel flag mounted 3 The transmitters will sealed duration contest prevent advertent changes resultant poten tial mistakes 4 Impound areas monitors RF Wands will used flight line 5 Some Contest Directors may wish take advantage SRF capabilities resolve conflicts equalize popula tions available RC channels hav ing set-owners switch channels No prob lem takes another pass through transmitter processing line should likewise will productive ban will cost manpower keep trans mitter processing station could simple Airtronics Scanner veri fy transmitter same channel its flag open throughout contest George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 S2B2IUtasi Continued page 41 sure use Loctite threads pre vent backing out pop rivets really much safer 52B2 should wrapped foam RIDDIZ I 042l Ff\j UDLL E 1mm thick Boxed 16 oz rubber per boxSizes Price $1250 per box ppd USA flL KA WAKEFIELErgIsh $3888 pIe UPSBeilding Finished Front Endii end Flying InstruCtion Very Conplete Send SOC 1984/1 985 Oatalog F Al Model Supply It~S7ToeCAf051R 3, 32 1' 1' 3 4 Fine Quality Flying Models Catalog S 150 98 RUBBER POWER KITS plus Gliders C/L R/C Accessories Books 4 4 4 4 4 4 4 4 4 MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 August1984 141 Want REV-VP Props P 4uichie SOD Pattern & Sport 4 carter Midget Nuge Inventory ! New About Custom Tuned Engines P Detailed Drochure Sead 75 TO Kustoin Kuftsmanship RI lox 209 Ique Nuts CR 92654 Ph 714 5305162 NI-STARTER revoluti model engines used boats cars airplanes NI STARTERITMI uses HeadlockiTMI adapter locks onto glow plugs start engine yits pocket comes CItO charger has LED lights up charging Rechargeable hundreds times gives over 50 consecutive starts recharging Acailable charger Send ad along prepayment receine tree shipping handling NI-STARTER$2495 charger Itt OV 22tV t2V fast chargert NI-STARTER$1 595 charger Chargers$1295 charger lttOV22tVorl2Vfastchargerl PLEASE SPECIFY WHICH CHARGER WHEN OROERINGf L tucked away neatly aircraft also fits nicely some popular bat tery boxes available Ace R/G Dunhams R&R PC board S2B2 available $750 An assembled unit less switch wiring $4400 Order direct Jomar Products 2028 Knightsbridge Dr Cincinnati OH 45244 Assembled units complete wir ing switch connectors match specific radio system available EMS 6175 Palo Alto Dr Anaheim CA 92807 Write pricing Parts List Rl 100K R2 R3 R4 R7 R8470K R522K R6330 ohm R91OK RlO130K Rl 136K-39K 47K five-cell packs Dl through D51N5817 Ql Q2 Q32N3904 IClCD4584 74C14 1C2ICL8212CPA Cl001 mono C2 C3 C433 mf dipped tantalum 15-volt higher CS C6047 mono Miscellaneous PC board solder wire switch Y-in aluminum pop rivets con$2495 Charger nectors suit radio system LED indicator RC AerobaticslVan Putt Continued page 43 speed Take look Figures 1 2 angle between horizon track airplane relative ground gets larger wind blows stronger So does airplane look like its diving going downwind Its actual ly climbing climb angle stretched out wind see Figure 3 because way eyes work looks like its diving course stronger wind blowing lower climb angle airplane will look like its diving approaches horizon Now know Im going get letters decide write subject please dont assemble tirade about laws conservation kinetic energy conservation momentum high school physics Please stick principles mechanics relative frame reference moving constant velocity Thanks suddenly occurred month ago contest season upon us needed get new Pattern airplane pre pared Since prefabricated allbalsa-fuselage Curare sitting corner decided finish rather start scratch fiberglass-fuselage Phoenix 8 Boy mistake forgot ten much involved finishing balsa fuselage must eight 10 years since did things like putting wing fillets fuselagethere must several mil lion things Id rather Also way up list least-favorite things fiberglassing balsa fuse lage What would very useful some good techniques both jobs problems installing fillets endless Getting fillet material ac cept good contour fast shifting during dry/cure important So us ing material sands well has enough strength manage stress flight everyday rigors handling less importance day epoxy other low-shrink paints surface paint will stick well pull loose during drying Whos got some good ideas fillets absence good technique install ounce per square yard fiber glass cloth fuselage plan brush Dave Brown Mix-A-Matic epoxy through cloth use modified toilet paper roll blot up excess epoxy Since Ive used technique adhere lightweight glass cloth wing skins dont know will work fuselage Does anyone have good ideas alternate techniques received interesting letter Dr John Kallend professor engi neering Illinois university teaches crystallography whatever Anyway also consultant engi neering software capacity has developed RC flight simulator works Apple LIe II puters three-dimensional graphic animation flight RC airplane Control elevator ailerons rudder throttle possible using proportional joysticks See Product Review development March 1984 issue page 91 Dr Kallend claims novice can learn basic control functions over come orientation problems Experienced fliers could practice advanced maneuvers both cases no danger model heard about Dave Brown doing im pressive displays Toledo Conference April Dr Kallend claims Hanno Prettner did too RC Flight Simulator available diskette Dave Brown Products 4560 Layhigh Rd Hamilton OH 45013 have no idea much costs Dave would probably happy discuss little item Sounds like fun Continued page 144 142 Model Aviation MFG OF NI-STARTER 12421 RANSOM DRIVE GLENN DALE MD 20769301464-2260 AT-6 SNI This one flies good looks N ngine 63375 Wingspan 8 lbs Complete List Price $28500 Factory Direct $22800 Michigan residents add 4% sales tax rIU Great Lakes Model Company BmchweWs4cmPO Box 308 Tawas City MI 48763517 362-6078 2 Al Major Components Molded Urethane Foam
Edition: Model Aviation - 1984/08
Page Numbers: 38, 39, 40, 41, 141, 142
I WITH THEot modeling projects 1/5 1/4 larger scales lot concern has placed batteries operate airborne control system Weve analyzed conditioned cycled plotted perfor mance Ni-Cds treasure trust power equipment well good Murphys Law says battery can fail flight will Until now Id managed avoid use battery backer system several reasons First personally feel high-vibration environment like model aircraft no place relay also didnt want have switch non standard five-cell packs because charger ESV load set up 48-volt four-cell packs feel com fortable Never having ana lyzed used systems currently available able start project unbiased opinion what specs should S2B2 knew very beginning extremely reliable work standard four-cell packs have negligible effect power available airborne flight system last area prime con cern since loss power could prove catastrophic wrong moment aesign parameters 1-amp ioaa typical two three S-16-size servos doing busy aerobatic maneuvers 15 20-lb aircraft sudden snap roll command might push up 2 amps current #26-gauge wire find radio systems becomes limiting factor especially long leads would introduce serious voltage drop servos design shown has insertion loss 05 volts 1 amp load 1 volt 2 amps far better can achieved bipolar transistor due use two parallel-connected MOSFETs pack de vices exactly cheap trust much relay wont wear out get stuck vibrate Theyre rated 12 amps application just loafing along should last forever S2B2 powered both backup battery primary battery guess could call backup-back up Im taking chances design since plan using Nosen 310 two 0S120 FS engines Robart retracts new Futaba radio system unlikely event either bat tery should fail other will power S2B2 circuitry both quit bets ne system draws about milliamp current thanks use low-power CMOS circuitry An output driver transis tor provided turn remotelymounted LED audio device backup system activated As shown drain goes up 10 mils LED turns indicating backup bat tery being used IC chips has extremely accurate voltage reference used switch backup pack pri mary battery falls below 42 43 volts prefer extra power servo speed five-cell packs changing single resistor value will change switchover point 55 volts can mix four five-cell packs long five-cell pack used backup would advise against sake simplicity Use #22-gauge stranded hookup wire standard Noble DPDT switch two separate charge jacks suggest ed way pack can checked charged cycled separately Once month least primary backup battery packs should switched get equal usage remain reliable Remember bad backup pack like no backup sounds too good true 38 Model Aviation 33 uf OK IC 2 3 71 TV 1GL youre partially right of parasitic diode part ot MOSFET U transistors small compromise made design What boils down simply backup pack must charged good working condition expect work back up pack experiences shorted cell ex ample diode will begin conduct drawing current main pack II course have shorted cell Right Bottom view PC board layout printed twice final size want make own PC board have 50% film ____ negative made layout Parts Layout S2B2 1.1 0 0 C4 e212 CIR9Ri RIO Left Start resistors lumper jumper can made cuttingoff resistors Right Next add four 33 microfared tantalum caps 001 ceramic capacitor photos author Left Solder five Shottky diodes sure orient banded ends shown otherwise unit wont work correctly Note four holes MOSFETs have drilled clear 118-in-dia pop rivets Right two ICs have added Both notches face left properly oriented S2B2 isnt difficult build must pay attention details backup pack isnt worth much anyway sol guess question really just academic no adjustments project either works doesnt doesnt did something wrong youve got bad part want know what makes tick read order properly turn MOS FETs used series pass configuration gate voltage must least 4 6 volts higher source voltage de pending gate characteristics device used nominal 5-volt bat tery means need 9 11 volts cascade voltage tripler provides about 14 volts adequate safety margin 74C14 hex Schmidt trigger inverter package Rl Cl inverter form square wave oscillator running around 10 kilohertz next two gates form 180 out-of-phase push-pull drive diode capacitor ladder composed Dl D2 D3 C2 C3 C4 network steps up voltage three times minus diode losses about 14 volts high voltage provides gate drive MOSFET transistors efficiency con verter very high around 75% really doesnt matter since total cur rent drain about 100 microanlps now some sharp engineers reading might wondering source pair MOSFETs con nected battery drain might expect Well turns out parasitic diode internal power MOSFETs would conduct main pack began discharge causing current flow between back up main pack course really louses up switchover point mention being unacceptable con dition Fortunately MOSFETs reasonably symmetrical operating characteristics allows source drain connections interchanged thus eliminating problem condi tion still exists under unlikely unrealistic situationwhen main pack voltage first discharged during flight will always lower backup pack Im probably making issue deserves believe its necessary us understands equipment works expect make best use its capabilities types MOSFETs available will work very well S2B2 circuit real concern Rds resistance choose should no 1 ohm Since two parallel pack in-line resistance S2B2 max imum 05 ohms what allows use standard four-cell packs drop small youll never notice it wont affect radio system least list suggested MOSFETs Afl Mnr4sl AAir~ Left Last comes power MOSFET devices held place pop rivets rivets installed bottom side board Solder leads after MOSFETs have riveted place avoids stress Right author Joe Utasi home workshop S2B2 hand follQws Supertex VN2306N5 Siemens BUZ-10 BUZ-71 International Rectifier IRF-540 RCA RFP25NO6 Motorola MTP25NOS Other types can used well just re member resistance must no 1 ohm voltage loss will rise undesirable levels ad venturesome builders out dont waste time trying substitute stand ard bipolar transistors because just wont work need much drive cause substantial loss wont match up board layout Capacitors C2 through C5 should dipped tantalum substitute elec trolytics since too leaky up converter gate drive voltage MOSFETs will come up par C5 necessary stabilize diode isolated voltage battery packs against transients occur switching oc curs circuit cant get 33 microfarad tantalums anything up 10 microfarads can substituted long voltage rating least 15 volts C6 mounted bottom PC board between pins 2 8 ICL 8212 IC ensures S2B2 will always come main battery pack line first can considered power reset Once circuit switches over backup pack way will switch back power switch reset main pack comes up above 54 volts Since odds highly un likely overall circuit behavior very similar latching relay Thus airborne system experiences momentary glitch power system its associated wiring switch system will switch over stay until land point will notice LED lit up investigate poten tial problem further remaining gates function simple inverters get correct logic needed drive transistors off Ql turns backup pack comes line remotely-mounted LED gives indica tion backup system Q2 Q3 provide level shifting needed switch 14 volts off MOSFET gates audio buzzer piezo beeper used has resistance 200 ohms higher resistor R6 can replaced wire jumper ulti mate system output transistor can used activate remote telemetry system notify pilot backup condition during flight diodes used 52B2 1N5817 Shottky rectifiers chosen because very low forward voltage drop 1 volt max low reverse leakage current Silicon germanium should substituted since would compromise performance backer circuitry should pointed Out Ni-Cd bat teries have some internal resistance own may trick backer switching over prematurely reason switchover point using resistor values shown ac tually ends up being between 42 43 volts rather 44 volts might expect ensures bat teries have actually discharged reasonably low level dip voltage caused high current demand hasnt caused 52B2 switch over construction 52B2 very difficult sure use good grade solder hot iron Standard precau tions handling CMOS circuitry should observed Insert components following order resistors capacitors transistors diodes integrated circuits lastly MOSFETs Note layout has specifical ly tailored use %-in-diain alumi num pop rivets Trim middle lead off MOSFET bend remaining leads 90 degrees insert leads PC board insert pop rivet bottom board head pop rivet will make intimate contact PC board good solid electrical con tact tab MOSFET Size 6-32 hardware can also used careful short anything out Also ontinued page 141 24 insignia sheets also letters numbers 0 major decals available popular 40 -60sizes plus American Giant Scale size believe major decals have comprehensive assortment available now -with sizes styles coming time pressure sensitive water transfer Well bet line handing line.the complete line decals available model anywhere _OCAG youll love being handed major decals Ostributors nquiries invited TEL 413-525-4110 CONTACT YOUR LOCAL HOBBY SHOP OR WRITE OIREcT NORTHEAST SCREEN GRAPHICS 21 FISHER AVE. EAST LONOMEADOW MA 01020 conversion superhetrodyne affair PCM receiver rejects forms inter ference including direct on-channel transmissions some cases radio tested loaned Bob Aberle before moved Bob Hunt editor Flying Models will no doubt campaigning Pattern events throughout 1984 Bob Aberle get hands others well tell about big subject discussion Toledo Kraft switchable radio frequency SRF RC system MoM people lis tened Jack Albrechts explanation way worked favorably im pressed Some havent seen radio yet havent heard dis cussion calling ban Really guys thats no way business Ban ning system wont solve problem think someone might carelessly shoot down two forthright solutions 1 TrainingTeach newcomer about realities interference teach yourself use what have intel ligently 2 ImpoundingYou really should use impound area John Langes RF Wands primary concern some will shoot down deliberately have cheaper ways go about pocket full crystals Futaba Tower Airtronics transmitter name few sold plug-in crystals will cost less $50 Such being case would anyone spend over five times much job Kraft SRF plan deal problem SRF transmitters 1984 subsequent Nats following manner 1 Owners SRF transmitters wheth er way plug-in crystals modules RF boards synthesizers will asked declare themselves users channels listed AMA Phase-In Plan funny-colored flags 2 The Transmitter Processors will verify operation stated channel within applicable technical specifications correct antenna frequency channel flag mounted 3 The transmitters will sealed duration contest prevent advertent changes resultant poten tial mistakes 4 Impound areas monitors RF Wands will used flight line 5 Some Contest Directors may wish take advantage SRF capabilities resolve conflicts equalize popula tions available RC channels hav ing set-owners switch channels No prob lem takes another pass through transmitter processing line should likewise will productive ban will cost manpower keep trans mitter processing station could simple Airtronics Scanner veri fy transmitter same channel its flag open throughout contest George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 S2B2IUtasi Continued page 41 sure use Loctite threads pre vent backing out pop rivets really much safer 52B2 should wrapped foam RIDDIZ I 042l Ff\j UDLL E 1mm thick Boxed 16 oz rubber per boxSizes Price $1250 per box ppd USA flL KA WAKEFIELErgIsh $3888 pIe UPSBeilding Finished Front Endii end Flying InstruCtion Very Conplete Send SOC 1984/1 985 Oatalog F Al Model Supply It~S7ToeCAf051R 3, 32 1' 1' 3 4 Fine Quality Flying Models Catalog S 150 98 RUBBER POWER KITS plus Gliders C/L R/C Accessories Books 4 4 4 4 4 4 4 4 4 MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 August1984 141 Want REV-VP Props P 4uichie SOD Pattern & Sport 4 carter Midget Nuge Inventory ! New About Custom Tuned Engines P Detailed Drochure Sead 75 TO Kustoin Kuftsmanship RI lox 209 Ique Nuts CR 92654 Ph 714 5305162 NI-STARTER revoluti model engines used boats cars airplanes NI STARTERITMI uses HeadlockiTMI adapter locks onto glow plugs start engine yits pocket comes CItO charger has LED lights up charging Rechargeable hundreds times gives over 50 consecutive starts recharging Acailable charger Send ad along prepayment receine tree shipping handling NI-STARTER$2495 charger Itt OV 22tV t2V fast chargert NI-STARTER$1 595 charger Chargers$1295 charger lttOV22tVorl2Vfastchargerl PLEASE SPECIFY WHICH CHARGER WHEN OROERINGf L tucked away neatly aircraft also fits nicely some popular bat tery boxes available Ace R/G Dunhams R&R PC board S2B2 available $750 An assembled unit less switch wiring $4400 Order direct Jomar Products 2028 Knightsbridge Dr Cincinnati OH 45244 Assembled units complete wir ing switch connectors match specific radio system available EMS 6175 Palo Alto Dr Anaheim CA 92807 Write pricing Parts List Rl 100K R2 R3 R4 R7 R8470K R522K R6330 ohm R91OK RlO130K Rl 136K-39K 47K five-cell packs Dl through D51N5817 Ql Q2 Q32N3904 IClCD4584 74C14 1C2ICL8212CPA Cl001 mono C2 C3 C433 mf dipped tantalum 15-volt higher CS C6047 mono Miscellaneous PC board solder wire switch Y-in aluminum pop rivets con$2495 Charger nectors suit radio system LED indicator RC AerobaticslVan Putt Continued page 43 speed Take look Figures 1 2 angle between horizon track airplane relative ground gets larger wind blows stronger So does airplane look like its diving going downwind Its actual ly climbing climb angle stretched out wind see Figure 3 because way eyes work looks like its diving course stronger wind blowing lower climb angle airplane will look like its diving approaches horizon Now know Im going get letters decide write subject please dont assemble tirade about laws conservation kinetic energy conservation momentum high school physics Please stick principles mechanics relative frame reference moving constant velocity Thanks suddenly occurred month ago contest season upon us needed get new Pattern airplane pre pared Since prefabricated allbalsa-fuselage Curare sitting corner decided finish rather start scratch fiberglass-fuselage Phoenix 8 Boy mistake forgot ten much involved finishing balsa fuselage must eight 10 years since did things like putting wing fillets fuselagethere must several mil lion things Id rather Also way up list least-favorite things fiberglassing balsa fuse lage What would very useful some good techniques both jobs problems installing fillets endless Getting fillet material ac cept good contour fast shifting during dry/cure important So us ing material sands well has enough strength manage stress flight everyday rigors handling less importance day epoxy other low-shrink paints surface paint will stick well pull loose during drying Whos got some good ideas fillets absence good technique install ounce per square yard fiber glass cloth fuselage plan brush Dave Brown Mix-A-Matic epoxy through cloth use modified toilet paper roll blot up excess epoxy Since Ive used technique adhere lightweight glass cloth wing skins dont know will work fuselage Does anyone have good ideas alternate techniques received interesting letter Dr John Kallend professor engi neering Illinois university teaches crystallography whatever Anyway also consultant engi neering software capacity has developed RC flight simulator works Apple LIe II puters three-dimensional graphic animation flight RC airplane Control elevator ailerons rudder throttle possible using proportional joysticks See Product Review development March 1984 issue page 91 Dr Kallend claims novice can learn basic control functions over come orientation problems Experienced fliers could practice advanced maneuvers both cases no danger model heard about Dave Brown doing im pressive displays Toledo Conference April Dr Kallend claims Hanno Prettner did too RC Flight Simulator available diskette Dave Brown Products 4560 Layhigh Rd Hamilton OH 45013 have no idea much costs Dave would probably happy discuss little item Sounds like fun Continued page 144 142 Model Aviation MFG OF NI-STARTER 12421 RANSOM DRIVE GLENN DALE MD 20769301464-2260 AT-6 SNI This one flies good looks N ngine 63375 Wingspan 8 lbs Complete List Price $28500 Factory Direct $22800 Michigan residents add 4% sales tax rIU Great Lakes Model Company BmchweWs4cmPO Box 308 Tawas City MI 48763517 362-6078 2 Al Major Components Molded Urethane Foam