How To Do It: Large Pack Slow Charger

LARGE PACK SLOW CHARGER U Bob Kopski rapidly growing interest Electric-powered aeromodels brings diversity model size type well increased use wide-ranging cell counts motor batteries uncommon find batteries ranging few cells 20 cells flightline meet also uncommon find high-tech highcapability fast chargers flightline whats missing seems slow chargers highercell-count packs Two slow-charger versions shown basically same simple easy use inexpensive design version has adjustable output design constant-current charger outputs fixed current value independent cell count up design limit can charge 1-22 cells no significant effect chosen current value over cell-count rangea very convenient feature Circuit Operation Input power Slow Chargers derived AC-to-AC plug-in power module intended use answering machines outputs very safe 13-14 volts AC Referring schematic voltage applied component array made up Dl D2 Cl C2 bridge circuit known full wave doubler converts incoming low AC voltage higher DC voltage charger circuit run off final DC voltage around 40 volts depending July 1997 51 Everything associated two versions Large Pack Slow Charger Plug-in power modules safe use exact line voltage location As shown circuit also has voltage tap between Cl C2 about 20 volts has important use remainder Slow Charger circuit consists primarily transistor Qi its biasing Qi configured electronic current source wherein load battery being charged placed collector circuit battery connected between transistor collector switch-selected positive voltage coming either Cl C2 charging current set voltage across R2 relatively smallabout 14-15 volts fixedcurrent version voltage appears across fixed resistor R2 10 ohms resulting current about 140 150 mA should clear point primary circuit difference between fixed adjustable slow chargers makeup resistor R2 adjustable charger R2 consists two parts fixed R2a variable R2b version has settable output range about 50 mA about 200 mA technically interested transistor emitter voltage derived operation LED D3 Resistor Ri biases D3 normal LED drop 2-22 volts appears Qi base given normal base-emitter drop transistor subsequently appears emitter about 07 volts lower LED acting like low-voltage reference zener Theres however temperature coefficient LED voltage closely matches classic base-emitter diode transistor cancel other out matched temperature LED mounted panel close transistorto track transistor temperature maintain current output stable temperature perfect arrangement does work very well LED also serves charging indicator battery place range switch set too low will no collector current load presented LED inoperative transistor base connection will rob current available Ri LED will light Thus collector circuit closed can LED though charging current per se does flow through LED last circuit feature note switch Si used range switch covering two ranges cell count Its real purpose minimize heat buildup charger selects DC voltage charger circuit operates 20 40 volts DC circuit will operate highest voltage regardless cell count unused voltage difference between circuit voltage pack voltage will appear transistor voltage easy assemble readily available parts 13 VAC INPUT plug module 3/4 5/16 PC BOARD COPPER SIDE UP 7/16 D3 mica insulator R1RO swi Q COMPONENT SIDE VIEW HARDWARE OMITTED FOR CLARITY NOTE Input & Output leads anchored Circuit assy durability see text & photo LARGE PACK FIXED CURRENT SLOW CHARGER C TO BATTERY 0 D2 Dl ALUMINUM PANEL 52 Model Aviation atile charger Inside look fixed version Input Panel view fixed version Leads output leads anchored Double-stick emerge small notches plastic foam tape holds board assembly panel box directly under panel Inside panel adjustable version Wiring point-to-point pc board serves parts holder Sm Dl 20 VOC LEAD VOLTAGE RECTIFIER DOUBLER SUBASSEMBLY COMPONENT VIEW COPPER SIDE DOWN NOT TO SAIE D2 0 VOC LEAD NOTE Thia pae Ia IadrieaIIy 08W 0 0 0 PANEL WIRING BOT VIEW I- hardware details omitted clarity 314- 0 0 I/A110/lal/E eeW0 114Q,114 -lie baeI -2 18 0 PANEL BOTTOM ViEW 2314 LARGE PACK ADJUSTABLE SLOW CHARGER anodecathode 15118 318 transistor current combine make transistor power translates transistor heat range switch merely allows use lowest wasted power value given pack size minimize heating transistor mounted larger capable heat sink no switch would needed further word about heat order Both slow charger versions have tested extensively including temperature sensor measurements As shown designs operate safelybut charger panels can get hot depending particular cell count charge current measured normal worst-case panel temperature condition no cells high current setting about l5O F quite hot touch perfecfly safeabout what closed cars interior surfaces might reach hot summer sun average actual use panel temperature will hover around 9O-12O F Construction Notes chargers built entirely Radio Shack parts listed current 1997 catalog no matter get parts strongly suggested follow panel assembly layouts shown have evolved work well version uses some RS universal pc- board material used parts holder circuit thats printed Given simplicity circuitry wiring point-to-point part-to-part minimal interconnecting wire Capacitors Cl C2 relatively large attached boards some 1A6 double-stick foam tape support Dont rely leads alone support parts Size up pc boards parts placements counting holes illustrated accompanying drawings some dimensional flexibility possible whats shown does work well As electronic assembly pay close attention Continued page 57 July1997 53 Above Panel view adjustable version Printed paper overlay dresses up Range switch Si minimizes heating 00 ClC2 C LEAD aitahap rsqirsd Slow ChargerlKopski Continued page 53 parts polarity wiring completeness accuracy Note LEDs polarized cathode negative lead can identified small flat visible base LED Fixed-current version Transistor Qi mechanically mounted electrically isolated mounting hardware thermal conduction electrical insulation qualities mounting kit good used flat panel surface free burrs other words sure clean panel work component pc board subassembly held aluminum panel /16 doublestick foam tape sure no component leads protrude through board holes contact panel Remember pc lands meant anchor points circuit thats printed Its best assemble pc board carefully inspect clean carefully position stick panel shown mount Qi panel transistor base emitter leads lie flat soldered three pc lands middle collector lead merely bent back up over transistor body serves tie point negative output wire positive output wire comes SWi middle post both wires strain-relieved wrapping around body SWi connector comes power module output lead cut off lead wires soldered directly appropriate pe lands wire pair anchored panel assembly plastic landing-gear strap wood spacer block 2-56 x ware spacer measures x 1 input output leads emerge small notches cut plastic boxes just under aluminum panels Adjustable Version Transistor Qi same electrical part used above mechmically different case Qi collector connection hard-mounted panel Thus panel electrically equal negative end motor battery pack approach used because Qi BuAng precision manufactured engine shouldnt send poor house After oil hobby fun financial drain K&B Sport engines have modelers choice over 50 years ore proven economical durable quiet powerful K&B engines designed factory warrantied give top performance years Precision CNC machining hand-fit assembly makes K&B Sportster engine powerful reliable sport engines available K&B Sportster engines feature bronzed bushed crankcase remote needle valve hand fit piston sleeve So want precision powerhouse still have money left over afford fuel make smart invesfrnent Buy K&B Sportster Engine CONTROL LINE C04AERS0N KITS aiabde 284565 520045303579/520045303583 2100 College Dr. Lake Havasu Ciy Arizona 86403 E-mail k&b@Inknefcom SUPV CHAOS SO UTThK CHAOS 62 span Tricycle gear iivIAA L~.xAL 60 size engines Lowest $7995 onlyprice US $500 S&H80 Span Taildragger LARGEST CHAOS EVER $1000 S&H pI@ 5A0 eMplq L FOR CATALOG take G&S Hobbies wwwripperscom/gns/homehtm 167 Hancock 8uIIlad Ofty Az 86442520-758-1100 1-800-628-6065CREDIT CARDS July 1997 57 20 RC Sportster W/ Muffler & Mount 28 RC Sportster45 RC Sportster 45 Control Line Sportster WI Muffler & Mount wI Mufflerwith OIL Conversion Kit shown NEW FROM BRIDI must handle dissipate power fixed-current version either case small amount properly applied thermal grease between transistor panel advantageous necessary sure Qi tightly mounted flat undistorted panel surface maximize thermal conductivity other difference version input output lead attachment both connectorized made sense case connectors providing internal wiring tie points course can attach leads permanently desired Operating NotesBoth Versions respect R2 R2a some selection effort may needed service particular application also because limitations RS resistor inventory fixed-current version outputs 140-150 mA use packs having 12 14 17 Ah cells As above current controlled 10 ohm emitter resistor can lower current non-adjustable version larger value R2 RS choices limited get around can series-parallel available resistors get desired value too much get assistance local electronics hobby expert find better parts source resistor fudging may used adjustable version too Mine has R2a made up two 10 ohm resistors series third wired across two threeresistor combination calculates 67 ohms Its what needed used electrically series variable resistor R2b current adjustment range covered about 50-200 mA several variables collectively affect final current current range values including exact LED voltage transistor E-B drop resistor tolerances Thus having some flexibility R2 R2a very useful case exceed 150 mA fixed-current version 200 mA adjustable CheckoutBoth Versions thats needed multimeter some test leads temporary load resistor see parts list Connect ohmmeter function fixed-current version panel transistor collector should open circuit Verify open circuit between panel other random circuit pointsthere should no contact between circuit node panel course should solid contact 0 ohms between panel collector adjustable versionits made way no load connected charger output connect DC voltmeter between 0 40 volt points bottom C2 top Cl plug power module LED should lit should read close 40 volts DC Confirm voltage across C2 should close 20 volts Unplug module Note voltage readings dependent exact AC line voltage doing test Temporarily connect 100 ohm test load resistor charger output DC voltmeter across resistor Plug module LED should now light fixed-current version resistor voltage should around 14-15 volts chose lower current value resistor voltage will vary accordingly voltage reading should remain close same value range switch either position LED brightness should also constant youre testing adjustable version resistor voltage should vary about 5-20 volts over adjustment range may see need fudge R2a 20 volt level may achieved range switch set 10-22 position checks out unplug module remove test resistor connect candidate battery its place charge Temporarily connect current meter series circuit Choose current range allow verification chosen charge-current levels either fixed variable Plug module confirm correct current level can substitute packs differing cell count during test verify constancy chosen current level Neat huh Try charging some packs overnight think youll very pleased Kopski 25 West End Dr Lansdale PA 19446 IKON NWST Since 1977 IKON offers largest selection giant scale kits world order kits call 1-800-327-7198 catalog fine kits send $4 00 Idaho Residesta Add 5% State Sales Tax HEADERS Bully 1515 Header Str Bully 0506 Header 75 R Bully 0517 Header 125 R Bully 1517 Header 175 R Bully 15t8 Header 225 R Bully 0519 Header 300 R PIPES Macs 1092 F3A Dbl Quiet Pipe Bolly EQ2002N Carbon Pipe Bolly EQ12OR Carbon Pipe Bolly EQl2ON CarblKevl Pipe Bolly EQ14OR Carbon Pipe Bolly EQ14ON CarblKevl Pipe SOFT MOUNTS 12LS Pattern Soft mount 12LS Pattern Nose Ring 145 Pattern Soft Mount t45 Pattern Nose Ring t2PR Soft Mount SPINNERS Tm Turn 275 12 Slot 2B Tm Turn 300 2 Slot 2B Tm Turn 300 FAI 3B Tm Turn 8x125 Short Nut Tru Turn 8x125 Long Nut Tm Turn Bushing 8mm MUFFLERS Bully 14120 PR Pitts Bully 14121 PR 70 Deg Bully 14122 Pr Sport Bully 14123 PR AT6 Bolly 145 Muffler PROPELLERS APC BOLLY DESAFIO 2000 IN STOCK July1997 59 DOHAVILLAND BEA GIANT SCAI PT-22 1/A EDO FLOATS SHOWN ON BEAVER flM 1/A CAI MONOCOUPE 90A 1/4 SCALE 96 BULLY 12LS Rear Exhaust Pattern/Aerobatic BULLY 12PR Side Exhaust Full Race U AV. Inc PO Box 1548 Bend OR 92709 Call 800-294-9506

LARGE PACK SLOW CHARGER U Bob Kopski rapidly growing interest Electric-powered aeromodels brings diversity model size type well increased use wide-ranging cell counts motor batteries uncommon find batteries ranging few cells 20 cells flightline meet also uncommon find high-tech highcapability fast chargers flightline whats missing seems slow chargers highercell-count packs Two slow-charger versions shown basically same simple easy use inexpensive design version has adjustable output design constant-current charger outputs fixed current value independent cell count up design limit can charge 1-22 cells no significant effect chosen current value over cell-count rangea very convenient feature Circuit Operation Input power Slow Chargers derived AC-to-AC plug-in power module intended use answering machines outputs very safe 13-14 volts AC Referring schematic voltage applied component array made up Dl D2 Cl C2 bridge circuit known full wave doubler converts incoming low AC voltage higher DC voltage charger circuit run off final DC voltage around 40 volts depending July 1997 51 Everything associated two versions Large Pack Slow Charger Plug-in power modules safe use exact line voltage location As shown circuit also has voltage tap between Cl C2 about 20 volts has important use remainder Slow Charger circuit consists primarily transistor Qi its biasing Qi configured electronic current source wherein load battery being charged placed collector circuit battery connected between transistor collector switch-selected positive voltage coming either Cl C2 charging current set voltage across R2 relatively smallabout 14-15 volts fixedcurrent version voltage appears across fixed resistor R2 10 ohms resulting current about 140 150 mA should clear point primary circuit difference between fixed adjustable slow chargers makeup resistor R2 adjustable charger R2 consists two parts fixed R2a variable R2b version has settable output range about 50 mA about 200 mA technically interested transistor emitter voltage derived operation LED D3 Resistor Ri biases D3 normal LED drop 2-22 volts appears Qi base given normal base-emitter drop transistor subsequently appears emitter about 07 volts lower LED acting like low-voltage reference zener Theres however temperature coefficient LED voltage closely matches classic base-emitter diode transistor cancel other out matched temperature LED mounted panel close transistorto track transistor temperature maintain current output stable temperature perfect arrangement does work very well LED also serves charging indicator battery place range switch set too low will no collector current load presented LED inoperative transistor base connection will rob current available Ri LED will light Thus collector circuit closed can LED though charging current per se does flow through LED last circuit feature note switch Si used range switch covering two ranges cell count Its real purpose minimize heat buildup charger selects DC voltage charger circuit operates 20 40 volts DC circuit will operate highest voltage regardless cell count unused voltage difference between circuit voltage pack voltage will appear transistor voltage easy assemble readily available parts 13 VAC INPUT plug module 3/4 5/16 PC BOARD COPPER SIDE UP 7/16 D3 mica insulator R1RO swi Q COMPONENT SIDE VIEW HARDWARE OMITTED FOR CLARITY NOTE Input & Output leads anchored Circuit assy durability see text & photo LARGE PACK FIXED CURRENT SLOW CHARGER C TO BATTERY 0 D2 Dl ALUMINUM PANEL 52 Model Aviation atile charger Inside look fixed version Input Panel view fixed version Leads output leads anchored Double-stick emerge small notches plastic foam tape holds board assembly panel box directly under panel Inside panel adjustable version Wiring point-to-point pc board serves parts holder Sm Dl 20 VOC LEAD VOLTAGE RECTIFIER DOUBLER SUBASSEMBLY COMPONENT VIEW COPPER SIDE DOWN NOT TO SAIE D2 0 VOC LEAD NOTE Thia pae Ia IadrieaIIy 08W 0 0 0 PANEL WIRING BOT VIEW I- hardware details omitted clarity 314- 0 0 I/A110/lal/E eeW0 114Q,114 -lie baeI -2 18 0 PANEL BOTTOM ViEW 2314 LARGE PACK ADJUSTABLE SLOW CHARGER anodecathode 15118 318 transistor current combine make transistor power translates transistor heat range switch merely allows use lowest wasted power value given pack size minimize heating transistor mounted larger capable heat sink no switch would needed further word about heat order Both slow charger versions have tested extensively including temperature sensor measurements As shown designs operate safelybut charger panels can get hot depending particular cell count charge current measured normal worst-case panel temperature condition no cells high current setting about l5O F quite hot touch perfecfly safeabout what closed cars interior surfaces might reach hot summer sun average actual use panel temperature will hover around 9O-12O F Construction Notes chargers built entirely Radio Shack parts listed current 1997 catalog no matter get parts strongly suggested follow panel assembly layouts shown have evolved work well version uses some RS universal pc- board material used parts holder circuit thats printed Given simplicity circuitry wiring point-to-point part-to-part minimal interconnecting wire Capacitors Cl C2 relatively large attached boards some 1A6 double-stick foam tape support Dont rely leads alone support parts Size up pc boards parts placements counting holes illustrated accompanying drawings some dimensional flexibility possible whats shown does work well As electronic assembly pay close attention Continued page 57 July1997 53 Above Panel view adjustable version Printed paper overlay dresses up Range switch Si minimizes heating 00 ClC2 C LEAD aitahap rsqirsd Slow ChargerlKopski Continued page 53 parts polarity wiring completeness accuracy Note LEDs polarized cathode negative lead can identified small flat visible base LED Fixed-current version Transistor Qi mechanically mounted electrically isolated mounting hardware thermal conduction electrical insulation qualities mounting kit good used flat panel surface free burrs other words sure clean panel work component pc board subassembly held aluminum panel /16 doublestick foam tape sure no component leads protrude through board holes contact panel Remember pc lands meant anchor points circuit thats printed Its best assemble pc board carefully inspect clean carefully position stick panel shown mount Qi panel transistor base emitter leads lie flat soldered three pc lands middle collector lead merely bent back up over transistor body serves tie point negative output wire positive output wire comes SWi middle post both wires strain-relieved wrapping around body SWi connector comes power module output lead cut off lead wires soldered directly appropriate pe lands wire pair anchored panel assembly plastic landing-gear strap wood spacer block 2-56 x ware spacer measures x 1 input output leads emerge small notches cut plastic boxes just under aluminum panels Adjustable Version Transistor Qi same electrical part used above mechmically different case Qi collector connection hard-mounted panel Thus panel electrically equal negative end motor battery pack approach used because Qi BuAng precision manufactured engine shouldnt send poor house After oil hobby fun financial drain K&B Sport engines have modelers choice over 50 years ore proven economical durable quiet powerful K&B engines designed factory warrantied give top performance years Precision CNC machining hand-fit assembly makes K&B Sportster engine powerful reliable sport engines available K&B Sportster engines feature bronzed bushed crankcase remote needle valve hand fit piston sleeve So want precision powerhouse still have money left over afford fuel make smart invesfrnent Buy K&B Sportster Engine CONTROL LINE C04AERS0N KITS aiabde 284565 520045303579/520045303583 2100 College Dr. Lake Havasu Ciy Arizona 86403 E-mail k&b@Inknefcom SUPV CHAOS SO UTThK CHAOS 62 span Tricycle gear iivIAA L~.xAL 60 size engines Lowest $7995 onlyprice US $500 S&H80 Span Taildragger LARGEST CHAOS EVER $1000 S&H pI@ 5A0 eMplq L FOR CATALOG take G&S Hobbies wwwripperscom/gns/homehtm 167 Hancock 8uIIlad Ofty Az 86442520-758-1100 1-800-628-6065CREDIT CARDS July 1997 57 20 RC Sportster W/ Muffler & Mount 28 RC Sportster45 RC Sportster 45 Control Line Sportster WI Muffler & Mount wI Mufflerwith OIL Conversion Kit shown NEW FROM BRIDI must handle dissipate power fixed-current version either case small amount properly applied thermal grease between transistor panel advantageous necessary sure Qi tightly mounted flat undistorted panel surface maximize thermal conductivity other difference version input output lead attachment both connectorized made sense case connectors providing internal wiring tie points course can attach leads permanently desired Operating NotesBoth Versions respect R2 R2a some selection effort may needed service particular application also because limitations RS resistor inventory fixed-current version outputs 140-150 mA use packs having 12 14 17 Ah cells As above current controlled 10 ohm emitter resistor can lower current non-adjustable version larger value R2 RS choices limited get around can series-parallel available resistors get desired value too much get assistance local electronics hobby expert find better parts source resistor fudging may used adjustable version too Mine has R2a made up two 10 ohm resistors series third wired across two threeresistor combination calculates 67 ohms Its what needed used electrically series variable resistor R2b current adjustment range covered about 50-200 mA several variables collectively affect final current current range values including exact LED voltage transistor E-B drop resistor tolerances Thus having some flexibility R2 R2a very useful case exceed 150 mA fixed-current version 200 mA adjustable CheckoutBoth Versions thats needed multimeter some test leads temporary load resistor see parts list Connect ohmmeter function fixed-current version panel transistor collector should open circuit Verify open circuit between panel other random circuit pointsthere should no contact between circuit node panel course should solid contact 0 ohms between panel collector adjustable versionits made way no load connected charger output connect DC voltmeter between 0 40 volt points bottom C2 top Cl plug power module LED should lit should read close 40 volts DC Confirm voltage across C2 should close 20 volts Unplug module Note voltage readings dependent exact AC line voltage doing test Temporarily connect 100 ohm test load resistor charger output DC voltmeter across resistor Plug module LED should now light fixed-current version resistor voltage should around 14-15 volts chose lower current value resistor voltage will vary accordingly voltage reading should remain close same value range switch either position LED brightness should also constant youre testing adjustable version resistor voltage should vary about 5-20 volts over adjustment range may see need fudge R2a 20 volt level may achieved range switch set 10-22 position checks out unplug module remove test resistor connect candidate battery its place charge Temporarily connect current meter series circuit Choose current range allow verification chosen charge-current levels either fixed variable Plug module confirm correct current level can substitute packs differing cell count during test verify constancy chosen current level Neat huh Try charging some packs overnight think youll very pleased Kopski 25 West End Dr Lansdale PA 19446 IKON NWST Since 1977 IKON offers largest selection giant scale kits world order kits call 1-800-327-7198 catalog fine kits send $4 00 Idaho Residesta Add 5% State Sales Tax HEADERS Bully 1515 Header Str Bully 0506 Header 75 R Bully 0517 Header 125 R Bully 1517 Header 175 R Bully 15t8 Header 225 R Bully 0519 Header 300 R PIPES Macs 1092 F3A Dbl Quiet Pipe Bolly EQ2002N Carbon Pipe Bolly EQ12OR Carbon Pipe Bolly EQl2ON CarblKevl Pipe Bolly EQ14OR Carbon Pipe Bolly EQ14ON CarblKevl Pipe SOFT MOUNTS 12LS Pattern Soft mount 12LS Pattern Nose Ring 145 Pattern Soft Mount t45 Pattern Nose Ring t2PR Soft Mount SPINNERS Tm Turn 275 12 Slot 2B Tm Turn 300 2 Slot 2B Tm Turn 300 FAI 3B Tm Turn 8x125 Short Nut Tru Turn 8x125 Long Nut Tm Turn Bushing 8mm MUFFLERS Bully 14120 PR Pitts Bully 14121 PR 70 Deg Bully 14122 Pr Sport Bully 14123 PR AT6 Bolly 145 Muffler PROPELLERS APC BOLLY DESAFIO 2000 IN STOCK July1997 59 DOHAVILLAND BEA GIANT SCAI PT-22 1/A EDO FLOATS SHOWN ON BEAVER flM 1/A CAI MONOCOUPE 90A 1/4 SCALE 96 BULLY 12LS Rear Exhaust Pattern/Aerobatic BULLY 12PR Side Exhaust Full Race U AV. Inc PO Box 1548 Bend OR 92709 Call 800-294-9506