NO OCR TEXT 4 10K TRIM POT V ZENER Completed prototype Ace R/C LYD Such unit may mounted transmitter using servo mount tape Printed circuit foil Digital Commander LVD Fig 2 10K Fig 1 4 4 C C C ILL K C C C C -J 10K NE 555 470 LED 49BV 4 0 LOW VOLTAGE WARNING DEVICE LVD OUTPUT FROM LVD DELETE LED Fig 3 1OILf 6V DOWN 470 ED LED TRIM POT V A- geV 10K 10K IN 751A 51V ZENER BANDED END 01 pf Component layout Ace R/C Digital Commander LVD Fig 5 Printed circuit foil add-on audio indi cator rp Fig 7 Printed circuit foil Ace RIC combined LVD-audio warning 96V OUTPUT FROM LVD DELETE LED Component layout add-on audio indicator e 96V b 2N6534 OR 2N6562 C 15 AUDIO WARNING100 0 ov Fig 4 Schematic diagram add-on audio indicator Ace R/C Digital Commander 2N6534 OR 2N6562 OV BLACK WIRE TO AUDIO DEVICE RED WIRE TO Fig 6AUDIO DEVICE ADDING AUDIO WARNING TO THE ACE LVD June1977 13 NO S 15 quires 20-25 milliamperes light properly Charlie Rankin felt would rather have extra drain transmit ter pack switched things around shown Fig 9 see Model Aviation July 1976 have light off until critical voltage reached Id rather since LED could bad wouldnt know push-button test some sort However readers choice article actually began around article submitted Mr C M Duffield also built around Signetics LM555CN Mr Duffields material pre sented paragraphs follow THE LVIs C M Duffield SET SIX GOALS achieve before would satisfied final results goals 1 Low cost 2 Reliabil ity 3 Low current drain 4 Lightweight 5 Simplicity 6 Adaptability last second thought about elec tronic devices operate battery pow er need some means letting know critical voltage reached goals have achieved satis faction two circuits described anyone can build first circuit Fig 10 receiver 48-volt battery pack Low Voltage Indica tor LVI second Fig 11 transmitter Both circuits basically same use Signetic LM555CN Timer light emitting diode capacitor few resistors airborne LVI can wired directly output side battery power switch connector can installed plugged auxiliary channel outlet receiver using just positive negative tertninals transmitter LVI would have wired directly output side power switch air borne LVI light emitting diode LED would have installed dark tube such -in diameter heat-shrink tubing placed fuselage such way can viewed direct sun light Under canopy instrument panel through side bottom fuselage couple suggestions transmitter LVI LED can mounted anywhere transmitter case available using /4-in rubber grommet LED protruding through word cau tion point Any modifications transmitter during warranty peri od may void same both circuits LED comes steadily starts flashing indicate low battery-power state reading power batteries under load since circuit lOpf25V 470 0V%%%%N 2N6534 OR 2N6562 BLACK TO / AUDIO DEVICE / 100 Fig 8 NOTE DOT 10K 10K 1N751A BANDED END DOWN TRIMPOT RED TO AUDIO DEVICE Component layout Ace H/C combined LVD-audio warning Ov POT V Ci 10ftr.4 L7 110K II~12K1 Fig 11 0 IC-i 565 TOP LM 555 CN SIGN ETICS 8 n-I 22K 7 R-2 33K 6 5 -NC 1 Schematic diagram C M Duffields transmitter LVI RECEIVER LVI -v c-iFig 10 10 1d 8 H-i 22K 7 LM 555 CNR-2 56K47KSIGNETIS33K 6 5 NC LED OFF IVOSchematic diagram C M Dufflelds receiver LVI 14 Model Aviation TRANSMITTER LVI power applied Temperature stability LVI de termined temperature stability several components TemperatureVoltage-Current graphs Figs 12 13 show cold day sufficient power will remain after light flashes con tinue flying up 30 minutes very hot day will have stop flying immediately considering fact temperature inside aircraft fuselage can much hotter under hot sun outside air temperature wish discredit circuits commercial circuit electronics operations will vary temperature un less compensated against compensation can add compo nents considerable cost complete circuit Figs 14 15 present PC foil layout receiver LVI transmitter LVI respectively Figs 16 17 pre sent overlays show parts placement component identification following presents construction steps receiver LVI Using Fig 16 guide install jumper wire Install 555 IC Timer taking care jumper wire does touch IC pins number pin IC indi cated small dot next capacitor negative hole Bend leads slightly hold IC place Install other components solder capaci tor installed will lie flat top IC Check no solder bridges Using 22-gauge wire strip small por tion insulation off both ends desired length wires will needed connect unit fuselage Tin lead light-emitting diode LED using heat-sink between LED soldering spots Cut LED leads about /t long Tin end four wires slightly Place about diameter heat-shrink insulating tubing onto red wire black wire Solder two wires LED using heat-sink previously mentioned black wire cathode lead red wire anode lead cathode lead has flat spot notch plastic part next lead Slip tub ing over soldered leads further strengthen connection slip 1-in piece 1/5 diameter heat-shrink sulated tubing over both wires up LED Twist LED wires together place A-in-diameter dark tubing over LED until LED /4 essed Connect red wire LED hole black wire LED hole Twist two remaining black red wires together solder red wire RECEIVER LVITRANSMITTER LVIFig 13 611 FLASH POINT10340p 9SV 0 340F 473V 750F 460V 0 750F 94V 1300F 435V 6789 1011 MILL lAMPS 8 Temperature-Voltage-Current diagram f receiver LVI 12 13 14 15 18 17 18 19 20 21 MILLIAMPS DATA GRAPHS TEMPERATUREVOLTAGE CURRENT TEST EI Fig 14 Printed circuit foil receiver LVI 33 K Fig 15 Printed circuit foil for22 K transmitter LVI ov Component layout receiver LVI June1977 15 V hole black wire V hole time need check set voltage proper operation have access variable DC power supply accurate voltmeter connect positive negative input leads variable power supply can made using freshly charged 48-volt battery pack 500-ohm potentiometer placed positive lead Connect positive lead battery end poten tiometer positive lead LVI center tap potentiometer negative leads battery pack LVI connected directly other accuracy voltmeter can de termined measuring fresh 42-volt mercury battery whichwill close enough application Apply power LVI circuit adjust voltage above 48 volts LED should steady flashing open circuit R-4 and/or R-5 wrong values LED fails light check proper polarity LED connections steady reduce voltage slowly until LED starts flashing Read voltage time should fall between 46 465 volts 75 degrees F LED flashes voltage higher 465 R-5 will have replaced resistor same value R-4 unless 5600-ohm resistor low end tolerance yields proper set voltage LED flashes voltage below 46 method trimming R-5 achieve proper resistance can utilized fol lows Use three-corner file Dremel tool disc grinder file V, sec tion middle resistor shown Fig 18 until carbon part reached Maintain 465 volt supply circuit grind carbon until LED stops flashing Grind little time let resistor cool time until desired set voltage obtained Increase slowly reduce supply volt age until LED starts flashing Read justments supply voltage resistance R-5 can continued until desired set voltage reached Since carbon resistors have 10-percent toler ance stated resistance selection R-4 R-5 proper resistances will give desired results above trimming procedure desired resistance parallel resistors R-4 R-5 about 2600 ohms After desired set voltage obtained satisfied condi tions seal complete unit silicon seal mixture 5-minute epoxy microballoons Now solder input wires unit onto output receiver power switch receiver plug can installed maintaining polarity servo plugs transmitter Low Voltage Indicator LVI constructed using Fig 17 two differences receiver cir cuit jumper wire used under IC R-5 variable resistor trimpot Calibration unit same receiver LVI straightforward simple Connect variable DC power supply accurate voltmeter put leads Two 48 volt battery packs series connected described receiver LVI construction will provide steady DC supply using 500-ohm potenti ometer described above Apply power set voltage desired set volt age Adjust R-5 until LED steady reverse rotation until LED just starts flashing Vary supply voltage un til satisfied LED starts flashing proper voltage Readjust ment R-5 may necessary obtain proper set voltage unit now ready installation transmitter piece servo mounting tape can used mount unit inside transmitter Cut large enough piece servo tape will enough insulate unit 16 Model Aviation U U transmitter case avoid shorts Connect input leads power switch output observing polarity Drill /4-in hole desired LED mounted Place A-in grommet hole place LED grommet unit now ready opera tion Supplement Mr Duffield has specified Lafayette 555 IC Timer because per forms manner indicated Tem perature-Voltage-Current graphs Another source 555 IC Timer operated directly op posite IC Timer raises set voltage higher temperature vice versa LVI described Mr Duffield somewhat dependent component temperature stability bit less expensive Zener required can calibrated accurately receiver LVI compact draws about 10 milliamps temperature stability 3 percent Components preceding complete units can obtained Ace R/C Higginsville MO 64037 Mr Duf field also will welcome inquiries com plete parts package complete units LVIs PO Box 72 Thomaston TX 77989 Theres no doubt preceding units represent pretty deluxe approach problem satisfied simple on-off indication critical voltage simple LED indicator suffices real problem get sharp repeat able cut off low hysteresis Sig netics data sheets LM339 compara tor show tentative approach Fig 19 presents logic diagram comparator extremely sensitive device VREF can provided Zener divide ever V0 degrades below VREF com parator will swing sharply cutting off LED Hewlett-Packard has provided circuitry shown Fig 19 LED-size package Voltage Sensing Device VSD 5082-4732 Fig 20 shows logic diagram However threshold voltage VTHfor device typically 25 volts directly useful applica tions However range device can readily expanded placing device series external device shown Fig 21 purposes resistor Zener diode can used tests have shown hysteresis using resistor entirely too broad VTH directly proportional temperature stability resistor Zener diode alleviates both pre ceding problems must selected fit particular situation Temperature co efficient combination 1 ener Using suffix Zener eg 1N751A provides 25 per cent accuracy over temperature range following Zener diodes series H-P device permit operation un der conditions shown LVD Zener Trigger Voltage 81 93 10 116 47 1N752A 1N754A 1N755A 1N757A 1N370 Application 9V dry battery 96V nicad pack 1 2V dry battery 12V nicad pack 48V airborne packs can assure would again operate dry battery transmitter least HP device Its matter per sonal preference whether uses air borne device since entirely possible suffer decay below safe limits air borne will least prevent taking off point below safe limits HP device proper Zener available inexpensive unit Ace R/C June1977 17
Edition: Model Aviation - 1977/06
Page Numbers: 12, 13, 14, 15, 16, 17
NO OCR TEXT 4 10K TRIM POT V ZENER Completed prototype Ace R/C LYD Such unit may mounted transmitter using servo mount tape Printed circuit foil Digital Commander LVD Fig 2 10K Fig 1 4 4 C C C ILL K C C C C -J 10K NE 555 470 LED 49BV 4 0 LOW VOLTAGE WARNING DEVICE LVD OUTPUT FROM LVD DELETE LED Fig 3 1OILf 6V DOWN 470 ED LED TRIM POT V A- geV 10K 10K IN 751A 51V ZENER BANDED END 01 pf Component layout Ace R/C Digital Commander LVD Fig 5 Printed circuit foil add-on audio indi cator rp Fig 7 Printed circuit foil Ace RIC combined LVD-audio warning 96V OUTPUT FROM LVD DELETE LED Component layout add-on audio indicator e 96V b 2N6534 OR 2N6562 C 15 AUDIO WARNING100 0 ov Fig 4 Schematic diagram add-on audio indicator Ace R/C Digital Commander 2N6534 OR 2N6562 OV BLACK WIRE TO AUDIO DEVICE RED WIRE TO Fig 6AUDIO DEVICE ADDING AUDIO WARNING TO THE ACE LVD June1977 13 NO S 15 quires 20-25 milliamperes light properly Charlie Rankin felt would rather have extra drain transmit ter pack switched things around shown Fig 9 see Model Aviation July 1976 have light off until critical voltage reached Id rather since LED could bad wouldnt know push-button test some sort However readers choice article actually began around article submitted Mr C M Duffield also built around Signetics LM555CN Mr Duffields material pre sented paragraphs follow THE LVIs C M Duffield SET SIX GOALS achieve before would satisfied final results goals 1 Low cost 2 Reliabil ity 3 Low current drain 4 Lightweight 5 Simplicity 6 Adaptability last second thought about elec tronic devices operate battery pow er need some means letting know critical voltage reached goals have achieved satis faction two circuits described anyone can build first circuit Fig 10 receiver 48-volt battery pack Low Voltage Indica tor LVI second Fig 11 transmitter Both circuits basically same use Signetic LM555CN Timer light emitting diode capacitor few resistors airborne LVI can wired directly output side battery power switch connector can installed plugged auxiliary channel outlet receiver using just positive negative tertninals transmitter LVI would have wired directly output side power switch air borne LVI light emitting diode LED would have installed dark tube such -in diameter heat-shrink tubing placed fuselage such way can viewed direct sun light Under canopy instrument panel through side bottom fuselage couple suggestions transmitter LVI LED can mounted anywhere transmitter case available using /4-in rubber grommet LED protruding through word cau tion point Any modifications transmitter during warranty peri od may void same both circuits LED comes steadily starts flashing indicate low battery-power state reading power batteries under load since circuit lOpf25V 470 0V%%%%N 2N6534 OR 2N6562 BLACK TO / AUDIO DEVICE / 100 Fig 8 NOTE DOT 10K 10K 1N751A BANDED END DOWN TRIMPOT RED TO AUDIO DEVICE Component layout Ace H/C combined LVD-audio warning Ov POT V Ci 10ftr.4 L7 110K II~12K1 Fig 11 0 IC-i 565 TOP LM 555 CN SIGN ETICS 8 n-I 22K 7 R-2 33K 6 5 -NC 1 Schematic diagram C M Duffields transmitter LVI RECEIVER LVI -v c-iFig 10 10 1d 8 H-i 22K 7 LM 555 CNR-2 56K47KSIGNETIS33K 6 5 NC LED OFF IVOSchematic diagram C M Dufflelds receiver LVI 14 Model Aviation TRANSMITTER LVI power applied Temperature stability LVI de termined temperature stability several components TemperatureVoltage-Current graphs Figs 12 13 show cold day sufficient power will remain after light flashes con tinue flying up 30 minutes very hot day will have stop flying immediately considering fact temperature inside aircraft fuselage can much hotter under hot sun outside air temperature wish discredit circuits commercial circuit electronics operations will vary temperature un less compensated against compensation can add compo nents considerable cost complete circuit Figs 14 15 present PC foil layout receiver LVI transmitter LVI respectively Figs 16 17 pre sent overlays show parts placement component identification following presents construction steps receiver LVI Using Fig 16 guide install jumper wire Install 555 IC Timer taking care jumper wire does touch IC pins number pin IC indi cated small dot next capacitor negative hole Bend leads slightly hold IC place Install other components solder capaci tor installed will lie flat top IC Check no solder bridges Using 22-gauge wire strip small por tion insulation off both ends desired length wires will needed connect unit fuselage Tin lead light-emitting diode LED using heat-sink between LED soldering spots Cut LED leads about /t long Tin end four wires slightly Place about diameter heat-shrink insulating tubing onto red wire black wire Solder two wires LED using heat-sink previously mentioned black wire cathode lead red wire anode lead cathode lead has flat spot notch plastic part next lead Slip tub ing over soldered leads further strengthen connection slip 1-in piece 1/5 diameter heat-shrink sulated tubing over both wires up LED Twist LED wires together place A-in-diameter dark tubing over LED until LED /4 essed Connect red wire LED hole black wire LED hole Twist two remaining black red wires together solder red wire RECEIVER LVITRANSMITTER LVIFig 13 611 FLASH POINT10340p 9SV 0 340F 473V 750F 460V 0 750F 94V 1300F 435V 6789 1011 MILL lAMPS 8 Temperature-Voltage-Current diagram f receiver LVI 12 13 14 15 18 17 18 19 20 21 MILLIAMPS DATA GRAPHS TEMPERATUREVOLTAGE CURRENT TEST EI Fig 14 Printed circuit foil receiver LVI 33 K Fig 15 Printed circuit foil for22 K transmitter LVI ov Component layout receiver LVI June1977 15 V hole black wire V hole time need check set voltage proper operation have access variable DC power supply accurate voltmeter connect positive negative input leads variable power supply can made using freshly charged 48-volt battery pack 500-ohm potentiometer placed positive lead Connect positive lead battery end poten tiometer positive lead LVI center tap potentiometer negative leads battery pack LVI connected directly other accuracy voltmeter can de termined measuring fresh 42-volt mercury battery whichwill close enough application Apply power LVI circuit adjust voltage above 48 volts LED should steady flashing open circuit R-4 and/or R-5 wrong values LED fails light check proper polarity LED connections steady reduce voltage slowly until LED starts flashing Read voltage time should fall between 46 465 volts 75 degrees F LED flashes voltage higher 465 R-5 will have replaced resistor same value R-4 unless 5600-ohm resistor low end tolerance yields proper set voltage LED flashes voltage below 46 method trimming R-5 achieve proper resistance can utilized fol lows Use three-corner file Dremel tool disc grinder file V, sec tion middle resistor shown Fig 18 until carbon part reached Maintain 465 volt supply circuit grind carbon until LED stops flashing Grind little time let resistor cool time until desired set voltage obtained Increase slowly reduce supply volt age until LED starts flashing Read justments supply voltage resistance R-5 can continued until desired set voltage reached Since carbon resistors have 10-percent toler ance stated resistance selection R-4 R-5 proper resistances will give desired results above trimming procedure desired resistance parallel resistors R-4 R-5 about 2600 ohms After desired set voltage obtained satisfied condi tions seal complete unit silicon seal mixture 5-minute epoxy microballoons Now solder input wires unit onto output receiver power switch receiver plug can installed maintaining polarity servo plugs transmitter Low Voltage Indicator LVI constructed using Fig 17 two differences receiver cir cuit jumper wire used under IC R-5 variable resistor trimpot Calibration unit same receiver LVI straightforward simple Connect variable DC power supply accurate voltmeter put leads Two 48 volt battery packs series connected described receiver LVI construction will provide steady DC supply using 500-ohm potenti ometer described above Apply power set voltage desired set volt age Adjust R-5 until LED steady reverse rotation until LED just starts flashing Vary supply voltage un til satisfied LED starts flashing proper voltage Readjust ment R-5 may necessary obtain proper set voltage unit now ready installation transmitter piece servo mounting tape can used mount unit inside transmitter Cut large enough piece servo tape will enough insulate unit 16 Model Aviation U U transmitter case avoid shorts Connect input leads power switch output observing polarity Drill /4-in hole desired LED mounted Place A-in grommet hole place LED grommet unit now ready opera tion Supplement Mr Duffield has specified Lafayette 555 IC Timer because per forms manner indicated Tem perature-Voltage-Current graphs Another source 555 IC Timer operated directly op posite IC Timer raises set voltage higher temperature vice versa LVI described Mr Duffield somewhat dependent component temperature stability bit less expensive Zener required can calibrated accurately receiver LVI compact draws about 10 milliamps temperature stability 3 percent Components preceding complete units can obtained Ace R/C Higginsville MO 64037 Mr Duf field also will welcome inquiries com plete parts package complete units LVIs PO Box 72 Thomaston TX 77989 Theres no doubt preceding units represent pretty deluxe approach problem satisfied simple on-off indication critical voltage simple LED indicator suffices real problem get sharp repeat able cut off low hysteresis Sig netics data sheets LM339 compara tor show tentative approach Fig 19 presents logic diagram comparator extremely sensitive device VREF can provided Zener divide ever V0 degrades below VREF com parator will swing sharply cutting off LED Hewlett-Packard has provided circuitry shown Fig 19 LED-size package Voltage Sensing Device VSD 5082-4732 Fig 20 shows logic diagram However threshold voltage VTHfor device typically 25 volts directly useful applica tions However range device can readily expanded placing device series external device shown Fig 21 purposes resistor Zener diode can used tests have shown hysteresis using resistor entirely too broad VTH directly proportional temperature stability resistor Zener diode alleviates both pre ceding problems must selected fit particular situation Temperature co efficient combination 1 ener Using suffix Zener eg 1N751A provides 25 per cent accuracy over temperature range following Zener diodes series H-P device permit operation un der conditions shown LVD Zener Trigger Voltage 81 93 10 116 47 1N752A 1N754A 1N755A 1N757A 1N370 Application 9V dry battery 96V nicad pack 1 2V dry battery 12V nicad pack 48V airborne packs can assure would again operate dry battery transmitter least HP device Its matter per sonal preference whether uses air borne device since entirely possible suffer decay below safe limits air borne will least prevent taking off point below safe limits HP device proper Zener available inexpensive unit Ace R/C June1977 17
Edition: Model Aviation - 1977/06
Page Numbers: 12, 13, 14, 15, 16, 17
NO OCR TEXT 4 10K TRIM POT V ZENER Completed prototype Ace R/C LYD Such unit may mounted transmitter using servo mount tape Printed circuit foil Digital Commander LVD Fig 2 10K Fig 1 4 4 C C C ILL K C C C C -J 10K NE 555 470 LED 49BV 4 0 LOW VOLTAGE WARNING DEVICE LVD OUTPUT FROM LVD DELETE LED Fig 3 1OILf 6V DOWN 470 ED LED TRIM POT V A- geV 10K 10K IN 751A 51V ZENER BANDED END 01 pf Component layout Ace R/C Digital Commander LVD Fig 5 Printed circuit foil add-on audio indi cator rp Fig 7 Printed circuit foil Ace RIC combined LVD-audio warning 96V OUTPUT FROM LVD DELETE LED Component layout add-on audio indicator e 96V b 2N6534 OR 2N6562 C 15 AUDIO WARNING100 0 ov Fig 4 Schematic diagram add-on audio indicator Ace R/C Digital Commander 2N6534 OR 2N6562 OV BLACK WIRE TO AUDIO DEVICE RED WIRE TO Fig 6AUDIO DEVICE ADDING AUDIO WARNING TO THE ACE LVD June1977 13 NO S 15 quires 20-25 milliamperes light properly Charlie Rankin felt would rather have extra drain transmit ter pack switched things around shown Fig 9 see Model Aviation July 1976 have light off until critical voltage reached Id rather since LED could bad wouldnt know push-button test some sort However readers choice article actually began around article submitted Mr C M Duffield also built around Signetics LM555CN Mr Duffields material pre sented paragraphs follow THE LVIs C M Duffield SET SIX GOALS achieve before would satisfied final results goals 1 Low cost 2 Reliabil ity 3 Low current drain 4 Lightweight 5 Simplicity 6 Adaptability last second thought about elec tronic devices operate battery pow er need some means letting know critical voltage reached goals have achieved satis faction two circuits described anyone can build first circuit Fig 10 receiver 48-volt battery pack Low Voltage Indica tor LVI second Fig 11 transmitter Both circuits basically same use Signetic LM555CN Timer light emitting diode capacitor few resistors airborne LVI can wired directly output side battery power switch connector can installed plugged auxiliary channel outlet receiver using just positive negative tertninals transmitter LVI would have wired directly output side power switch air borne LVI light emitting diode LED would have installed dark tube such -in diameter heat-shrink tubing placed fuselage such way can viewed direct sun light Under canopy instrument panel through side bottom fuselage couple suggestions transmitter LVI LED can mounted anywhere transmitter case available using /4-in rubber grommet LED protruding through word cau tion point Any modifications transmitter during warranty peri od may void same both circuits LED comes steadily starts flashing indicate low battery-power state reading power batteries under load since circuit lOpf25V 470 0V%%%%N 2N6534 OR 2N6562 BLACK TO / AUDIO DEVICE / 100 Fig 8 NOTE DOT 10K 10K 1N751A BANDED END DOWN TRIMPOT RED TO AUDIO DEVICE Component layout Ace H/C combined LVD-audio warning Ov POT V Ci 10ftr.4 L7 110K II~12K1 Fig 11 0 IC-i 565 TOP LM 555 CN SIGN ETICS 8 n-I 22K 7 R-2 33K 6 5 -NC 1 Schematic diagram C M Duffields transmitter LVI RECEIVER LVI -v c-iFig 10 10 1d 8 H-i 22K 7 LM 555 CNR-2 56K47KSIGNETIS33K 6 5 NC LED OFF IVOSchematic diagram C M Dufflelds receiver LVI 14 Model Aviation TRANSMITTER LVI power applied Temperature stability LVI de termined temperature stability several components TemperatureVoltage-Current graphs Figs 12 13 show cold day sufficient power will remain after light flashes con tinue flying up 30 minutes very hot day will have stop flying immediately considering fact temperature inside aircraft fuselage can much hotter under hot sun outside air temperature wish discredit circuits commercial circuit electronics operations will vary temperature un less compensated against compensation can add compo nents considerable cost complete circuit Figs 14 15 present PC foil layout receiver LVI transmitter LVI respectively Figs 16 17 pre sent overlays show parts placement component identification following presents construction steps receiver LVI Using Fig 16 guide install jumper wire Install 555 IC Timer taking care jumper wire does touch IC pins number pin IC indi cated small dot next capacitor negative hole Bend leads slightly hold IC place Install other components solder capaci tor installed will lie flat top IC Check no solder bridges Using 22-gauge wire strip small por tion insulation off both ends desired length wires will needed connect unit fuselage Tin lead light-emitting diode LED using heat-sink between LED soldering spots Cut LED leads about /t long Tin end four wires slightly Place about diameter heat-shrink insulating tubing onto red wire black wire Solder two wires LED using heat-sink previously mentioned black wire cathode lead red wire anode lead cathode lead has flat spot notch plastic part next lead Slip tub ing over soldered leads further strengthen connection slip 1-in piece 1/5 diameter heat-shrink sulated tubing over both wires up LED Twist LED wires together place A-in-diameter dark tubing over LED until LED /4 essed Connect red wire LED hole black wire LED hole Twist two remaining black red wires together solder red wire RECEIVER LVITRANSMITTER LVIFig 13 611 FLASH POINT10340p 9SV 0 340F 473V 750F 460V 0 750F 94V 1300F 435V 6789 1011 MILL lAMPS 8 Temperature-Voltage-Current diagram f receiver LVI 12 13 14 15 18 17 18 19 20 21 MILLIAMPS DATA GRAPHS TEMPERATUREVOLTAGE CURRENT TEST EI Fig 14 Printed circuit foil receiver LVI 33 K Fig 15 Printed circuit foil for22 K transmitter LVI ov Component layout receiver LVI June1977 15 V hole black wire V hole time need check set voltage proper operation have access variable DC power supply accurate voltmeter connect positive negative input leads variable power supply can made using freshly charged 48-volt battery pack 500-ohm potentiometer placed positive lead Connect positive lead battery end poten tiometer positive lead LVI center tap potentiometer negative leads battery pack LVI connected directly other accuracy voltmeter can de termined measuring fresh 42-volt mercury battery whichwill close enough application Apply power LVI circuit adjust voltage above 48 volts LED should steady flashing open circuit R-4 and/or R-5 wrong values LED fails light check proper polarity LED connections steady reduce voltage slowly until LED starts flashing Read voltage time should fall between 46 465 volts 75 degrees F LED flashes voltage higher 465 R-5 will have replaced resistor same value R-4 unless 5600-ohm resistor low end tolerance yields proper set voltage LED flashes voltage below 46 method trimming R-5 achieve proper resistance can utilized fol lows Use three-corner file Dremel tool disc grinder file V, sec tion middle resistor shown Fig 18 until carbon part reached Maintain 465 volt supply circuit grind carbon until LED stops flashing Grind little time let resistor cool time until desired set voltage obtained Increase slowly reduce supply volt age until LED starts flashing Read justments supply voltage resistance R-5 can continued until desired set voltage reached Since carbon resistors have 10-percent toler ance stated resistance selection R-4 R-5 proper resistances will give desired results above trimming procedure desired resistance parallel resistors R-4 R-5 about 2600 ohms After desired set voltage obtained satisfied condi tions seal complete unit silicon seal mixture 5-minute epoxy microballoons Now solder input wires unit onto output receiver power switch receiver plug can installed maintaining polarity servo plugs transmitter Low Voltage Indicator LVI constructed using Fig 17 two differences receiver cir cuit jumper wire used under IC R-5 variable resistor trimpot Calibration unit same receiver LVI straightforward simple Connect variable DC power supply accurate voltmeter put leads Two 48 volt battery packs series connected described receiver LVI construction will provide steady DC supply using 500-ohm potenti ometer described above Apply power set voltage desired set volt age Adjust R-5 until LED steady reverse rotation until LED just starts flashing Vary supply voltage un til satisfied LED starts flashing proper voltage Readjust ment R-5 may necessary obtain proper set voltage unit now ready installation transmitter piece servo mounting tape can used mount unit inside transmitter Cut large enough piece servo tape will enough insulate unit 16 Model Aviation U U transmitter case avoid shorts Connect input leads power switch output observing polarity Drill /4-in hole desired LED mounted Place A-in grommet hole place LED grommet unit now ready opera tion Supplement Mr Duffield has specified Lafayette 555 IC Timer because per forms manner indicated Tem perature-Voltage-Current graphs Another source 555 IC Timer operated directly op posite IC Timer raises set voltage higher temperature vice versa LVI described Mr Duffield somewhat dependent component temperature stability bit less expensive Zener required can calibrated accurately receiver LVI compact draws about 10 milliamps temperature stability 3 percent Components preceding complete units can obtained Ace R/C Higginsville MO 64037 Mr Duf field also will welcome inquiries com plete parts package complete units LVIs PO Box 72 Thomaston TX 77989 Theres no doubt preceding units represent pretty deluxe approach problem satisfied simple on-off indication critical voltage simple LED indicator suffices real problem get sharp repeat able cut off low hysteresis Sig netics data sheets LM339 compara tor show tentative approach Fig 19 presents logic diagram comparator extremely sensitive device VREF can provided Zener divide ever V0 degrades below VREF com parator will swing sharply cutting off LED Hewlett-Packard has provided circuitry shown Fig 19 LED-size package Voltage Sensing Device VSD 5082-4732 Fig 20 shows logic diagram However threshold voltage VTHfor device typically 25 volts directly useful applica tions However range device can readily expanded placing device series external device shown Fig 21 purposes resistor Zener diode can used tests have shown hysteresis using resistor entirely too broad VTH directly proportional temperature stability resistor Zener diode alleviates both pre ceding problems must selected fit particular situation Temperature co efficient combination 1 ener Using suffix Zener eg 1N751A provides 25 per cent accuracy over temperature range following Zener diodes series H-P device permit operation un der conditions shown LVD Zener Trigger Voltage 81 93 10 116 47 1N752A 1N754A 1N755A 1N757A 1N370 Application 9V dry battery 96V nicad pack 1 2V dry battery 12V nicad pack 48V airborne packs can assure would again operate dry battery transmitter least HP device Its matter per sonal preference whether uses air borne device since entirely possible suffer decay below safe limits air borne will least prevent taking off point below safe limits HP device proper Zener available inexpensive unit Ace R/C June1977 17
Edition: Model Aviation - 1977/06
Page Numbers: 12, 13, 14, 15, 16, 17
NO OCR TEXT 4 10K TRIM POT V ZENER Completed prototype Ace R/C LYD Such unit may mounted transmitter using servo mount tape Printed circuit foil Digital Commander LVD Fig 2 10K Fig 1 4 4 C C C ILL K C C C C -J 10K NE 555 470 LED 49BV 4 0 LOW VOLTAGE WARNING DEVICE LVD OUTPUT FROM LVD DELETE LED Fig 3 1OILf 6V DOWN 470 ED LED TRIM POT V A- geV 10K 10K IN 751A 51V ZENER BANDED END 01 pf Component layout Ace R/C Digital Commander LVD Fig 5 Printed circuit foil add-on audio indi cator rp Fig 7 Printed circuit foil Ace RIC combined LVD-audio warning 96V OUTPUT FROM LVD DELETE LED Component layout add-on audio indicator e 96V b 2N6534 OR 2N6562 C 15 AUDIO WARNING100 0 ov Fig 4 Schematic diagram add-on audio indicator Ace R/C Digital Commander 2N6534 OR 2N6562 OV BLACK WIRE TO AUDIO DEVICE RED WIRE TO Fig 6AUDIO DEVICE ADDING AUDIO WARNING TO THE ACE LVD June1977 13 NO S 15 quires 20-25 milliamperes light properly Charlie Rankin felt would rather have extra drain transmit ter pack switched things around shown Fig 9 see Model Aviation July 1976 have light off until critical voltage reached Id rather since LED could bad wouldnt know push-button test some sort However readers choice article actually began around article submitted Mr C M Duffield also built around Signetics LM555CN Mr Duffields material pre sented paragraphs follow THE LVIs C M Duffield SET SIX GOALS achieve before would satisfied final results goals 1 Low cost 2 Reliabil ity 3 Low current drain 4 Lightweight 5 Simplicity 6 Adaptability last second thought about elec tronic devices operate battery pow er need some means letting know critical voltage reached goals have achieved satis faction two circuits described anyone can build first circuit Fig 10 receiver 48-volt battery pack Low Voltage Indica tor LVI second Fig 11 transmitter Both circuits basically same use Signetic LM555CN Timer light emitting diode capacitor few resistors airborne LVI can wired directly output side battery power switch connector can installed plugged auxiliary channel outlet receiver using just positive negative tertninals transmitter LVI would have wired directly output side power switch air borne LVI light emitting diode LED would have installed dark tube such -in diameter heat-shrink tubing placed fuselage such way can viewed direct sun light Under canopy instrument panel through side bottom fuselage couple suggestions transmitter LVI LED can mounted anywhere transmitter case available using /4-in rubber grommet LED protruding through word cau tion point Any modifications transmitter during warranty peri od may void same both circuits LED comes steadily starts flashing indicate low battery-power state reading power batteries under load since circuit lOpf25V 470 0V%%%%N 2N6534 OR 2N6562 BLACK TO / AUDIO DEVICE / 100 Fig 8 NOTE DOT 10K 10K 1N751A BANDED END DOWN TRIMPOT RED TO AUDIO DEVICE Component layout Ace H/C combined LVD-audio warning Ov POT V Ci 10ftr.4 L7 110K II~12K1 Fig 11 0 IC-i 565 TOP LM 555 CN SIGN ETICS 8 n-I 22K 7 R-2 33K 6 5 -NC 1 Schematic diagram C M Duffields transmitter LVI RECEIVER LVI -v c-iFig 10 10 1d 8 H-i 22K 7 LM 555 CNR-2 56K47KSIGNETIS33K 6 5 NC LED OFF IVOSchematic diagram C M Dufflelds receiver LVI 14 Model Aviation TRANSMITTER LVI power applied Temperature stability LVI de termined temperature stability several components TemperatureVoltage-Current graphs Figs 12 13 show cold day sufficient power will remain after light flashes con tinue flying up 30 minutes very hot day will have stop flying immediately considering fact temperature inside aircraft fuselage can much hotter under hot sun outside air temperature wish discredit circuits commercial circuit electronics operations will vary temperature un less compensated against compensation can add compo nents considerable cost complete circuit Figs 14 15 present PC foil layout receiver LVI transmitter LVI respectively Figs 16 17 pre sent overlays show parts placement component identification following presents construction steps receiver LVI Using Fig 16 guide install jumper wire Install 555 IC Timer taking care jumper wire does touch IC pins number pin IC indi cated small dot next capacitor negative hole Bend leads slightly hold IC place Install other components solder capaci tor installed will lie flat top IC Check no solder bridges Using 22-gauge wire strip small por tion insulation off both ends desired length wires will needed connect unit fuselage Tin lead light-emitting diode LED using heat-sink between LED soldering spots Cut LED leads about /t long Tin end four wires slightly Place about diameter heat-shrink insulating tubing onto red wire black wire Solder two wires LED using heat-sink previously mentioned black wire cathode lead red wire anode lead cathode lead has flat spot notch plastic part next lead Slip tub ing over soldered leads further strengthen connection slip 1-in piece 1/5 diameter heat-shrink sulated tubing over both wires up LED Twist LED wires together place A-in-diameter dark tubing over LED until LED /4 essed Connect red wire LED hole black wire LED hole Twist two remaining black red wires together solder red wire RECEIVER LVITRANSMITTER LVIFig 13 611 FLASH POINT10340p 9SV 0 340F 473V 750F 460V 0 750F 94V 1300F 435V 6789 1011 MILL lAMPS 8 Temperature-Voltage-Current diagram f receiver LVI 12 13 14 15 18 17 18 19 20 21 MILLIAMPS DATA GRAPHS TEMPERATUREVOLTAGE CURRENT TEST EI Fig 14 Printed circuit foil receiver LVI 33 K Fig 15 Printed circuit foil for22 K transmitter LVI ov Component layout receiver LVI June1977 15 V hole black wire V hole time need check set voltage proper operation have access variable DC power supply accurate voltmeter connect positive negative input leads variable power supply can made using freshly charged 48-volt battery pack 500-ohm potentiometer placed positive lead Connect positive lead battery end poten tiometer positive lead LVI center tap potentiometer negative leads battery pack LVI connected directly other accuracy voltmeter can de termined measuring fresh 42-volt mercury battery whichwill close enough application Apply power LVI circuit adjust voltage above 48 volts LED should steady flashing open circuit R-4 and/or R-5 wrong values LED fails light check proper polarity LED connections steady reduce voltage slowly until LED starts flashing Read voltage time should fall between 46 465 volts 75 degrees F LED flashes voltage higher 465 R-5 will have replaced resistor same value R-4 unless 5600-ohm resistor low end tolerance yields proper set voltage LED flashes voltage below 46 method trimming R-5 achieve proper resistance can utilized fol lows Use three-corner file Dremel tool disc grinder file V, sec tion middle resistor shown Fig 18 until carbon part reached Maintain 465 volt supply circuit grind carbon until LED stops flashing Grind little time let resistor cool time until desired set voltage obtained Increase slowly reduce supply volt age until LED starts flashing Read justments supply voltage resistance R-5 can continued until desired set voltage reached Since carbon resistors have 10-percent toler ance stated resistance selection R-4 R-5 proper resistances will give desired results above trimming procedure desired resistance parallel resistors R-4 R-5 about 2600 ohms After desired set voltage obtained satisfied condi tions seal complete unit silicon seal mixture 5-minute epoxy microballoons Now solder input wires unit onto output receiver power switch receiver plug can installed maintaining polarity servo plugs transmitter Low Voltage Indicator LVI constructed using Fig 17 two differences receiver cir cuit jumper wire used under IC R-5 variable resistor trimpot Calibration unit same receiver LVI straightforward simple Connect variable DC power supply accurate voltmeter put leads Two 48 volt battery packs series connected described receiver LVI construction will provide steady DC supply using 500-ohm potenti ometer described above Apply power set voltage desired set volt age Adjust R-5 until LED steady reverse rotation until LED just starts flashing Vary supply voltage un til satisfied LED starts flashing proper voltage Readjust ment R-5 may necessary obtain proper set voltage unit now ready installation transmitter piece servo mounting tape can used mount unit inside transmitter Cut large enough piece servo tape will enough insulate unit 16 Model Aviation U U transmitter case avoid shorts Connect input leads power switch output observing polarity Drill /4-in hole desired LED mounted Place A-in grommet hole place LED grommet unit now ready opera tion Supplement Mr Duffield has specified Lafayette 555 IC Timer because per forms manner indicated Tem perature-Voltage-Current graphs Another source 555 IC Timer operated directly op posite IC Timer raises set voltage higher temperature vice versa LVI described Mr Duffield somewhat dependent component temperature stability bit less expensive Zener required can calibrated accurately receiver LVI compact draws about 10 milliamps temperature stability 3 percent Components preceding complete units can obtained Ace R/C Higginsville MO 64037 Mr Duf field also will welcome inquiries com plete parts package complete units LVIs PO Box 72 Thomaston TX 77989 Theres no doubt preceding units represent pretty deluxe approach problem satisfied simple on-off indication critical voltage simple LED indicator suffices real problem get sharp repeat able cut off low hysteresis Sig netics data sheets LM339 compara tor show tentative approach Fig 19 presents logic diagram comparator extremely sensitive device VREF can provided Zener divide ever V0 degrades below VREF com parator will swing sharply cutting off LED Hewlett-Packard has provided circuitry shown Fig 19 LED-size package Voltage Sensing Device VSD 5082-4732 Fig 20 shows logic diagram However threshold voltage VTHfor device typically 25 volts directly useful applica tions However range device can readily expanded placing device series external device shown Fig 21 purposes resistor Zener diode can used tests have shown hysteresis using resistor entirely too broad VTH directly proportional temperature stability resistor Zener diode alleviates both pre ceding problems must selected fit particular situation Temperature co efficient combination 1 ener Using suffix Zener eg 1N751A provides 25 per cent accuracy over temperature range following Zener diodes series H-P device permit operation un der conditions shown LVD Zener Trigger Voltage 81 93 10 116 47 1N752A 1N754A 1N755A 1N757A 1N370 Application 9V dry battery 96V nicad pack 1 2V dry battery 12V nicad pack 48V airborne packs can assure would again operate dry battery transmitter least HP device Its matter per sonal preference whether uses air borne device since entirely possible suffer decay below safe limits air borne will least prevent taking off point below safe limits HP device proper Zener available inexpensive unit Ace R/C June1977 17
Edition: Model Aviation - 1977/06
Page Numbers: 12, 13, 14, 15, 16, 17
NO OCR TEXT 4 10K TRIM POT V ZENER Completed prototype Ace R/C LYD Such unit may mounted transmitter using servo mount tape Printed circuit foil Digital Commander LVD Fig 2 10K Fig 1 4 4 C C C ILL K C C C C -J 10K NE 555 470 LED 49BV 4 0 LOW VOLTAGE WARNING DEVICE LVD OUTPUT FROM LVD DELETE LED Fig 3 1OILf 6V DOWN 470 ED LED TRIM POT V A- geV 10K 10K IN 751A 51V ZENER BANDED END 01 pf Component layout Ace R/C Digital Commander LVD Fig 5 Printed circuit foil add-on audio indi cator rp Fig 7 Printed circuit foil Ace RIC combined LVD-audio warning 96V OUTPUT FROM LVD DELETE LED Component layout add-on audio indicator e 96V b 2N6534 OR 2N6562 C 15 AUDIO WARNING100 0 ov Fig 4 Schematic diagram add-on audio indicator Ace R/C Digital Commander 2N6534 OR 2N6562 OV BLACK WIRE TO AUDIO DEVICE RED WIRE TO Fig 6AUDIO DEVICE ADDING AUDIO WARNING TO THE ACE LVD June1977 13 NO S 15 quires 20-25 milliamperes light properly Charlie Rankin felt would rather have extra drain transmit ter pack switched things around shown Fig 9 see Model Aviation July 1976 have light off until critical voltage reached Id rather since LED could bad wouldnt know push-button test some sort However readers choice article actually began around article submitted Mr C M Duffield also built around Signetics LM555CN Mr Duffields material pre sented paragraphs follow THE LVIs C M Duffield SET SIX GOALS achieve before would satisfied final results goals 1 Low cost 2 Reliabil ity 3 Low current drain 4 Lightweight 5 Simplicity 6 Adaptability last second thought about elec tronic devices operate battery pow er need some means letting know critical voltage reached goals have achieved satis faction two circuits described anyone can build first circuit Fig 10 receiver 48-volt battery pack Low Voltage Indica tor LVI second Fig 11 transmitter Both circuits basically same use Signetic LM555CN Timer light emitting diode capacitor few resistors airborne LVI can wired directly output side battery power switch connector can installed plugged auxiliary channel outlet receiver using just positive negative tertninals transmitter LVI would have wired directly output side power switch air borne LVI light emitting diode LED would have installed dark tube such -in diameter heat-shrink tubing placed fuselage such way can viewed direct sun light Under canopy instrument panel through side bottom fuselage couple suggestions transmitter LVI LED can mounted anywhere transmitter case available using /4-in rubber grommet LED protruding through word cau tion point Any modifications transmitter during warranty peri od may void same both circuits LED comes steadily starts flashing indicate low battery-power state reading power batteries under load since circuit lOpf25V 470 0V%%%%N 2N6534 OR 2N6562 BLACK TO / AUDIO DEVICE / 100 Fig 8 NOTE DOT 10K 10K 1N751A BANDED END DOWN TRIMPOT RED TO AUDIO DEVICE Component layout Ace H/C combined LVD-audio warning Ov POT V Ci 10ftr.4 L7 110K II~12K1 Fig 11 0 IC-i 565 TOP LM 555 CN SIGN ETICS 8 n-I 22K 7 R-2 33K 6 5 -NC 1 Schematic diagram C M Duffields transmitter LVI RECEIVER LVI -v c-iFig 10 10 1d 8 H-i 22K 7 LM 555 CNR-2 56K47KSIGNETIS33K 6 5 NC LED OFF IVOSchematic diagram C M Dufflelds receiver LVI 14 Model Aviation TRANSMITTER LVI power applied Temperature stability LVI de termined temperature stability several components TemperatureVoltage-Current graphs Figs 12 13 show cold day sufficient power will remain after light flashes con tinue flying up 30 minutes very hot day will have stop flying immediately considering fact temperature inside aircraft fuselage can much hotter under hot sun outside air temperature wish discredit circuits commercial circuit electronics operations will vary temperature un less compensated against compensation can add compo nents considerable cost complete circuit Figs 14 15 present PC foil layout receiver LVI transmitter LVI respectively Figs 16 17 pre sent overlays show parts placement component identification following presents construction steps receiver LVI Using Fig 16 guide install jumper wire Install 555 IC Timer taking care jumper wire does touch IC pins number pin IC indi cated small dot next capacitor negative hole Bend leads slightly hold IC place Install other components solder capaci tor installed will lie flat top IC Check no solder bridges Using 22-gauge wire strip small por tion insulation off both ends desired length wires will needed connect unit fuselage Tin lead light-emitting diode LED using heat-sink between LED soldering spots Cut LED leads about /t long Tin end four wires slightly Place about diameter heat-shrink insulating tubing onto red wire black wire Solder two wires LED using heat-sink previously mentioned black wire cathode lead red wire anode lead cathode lead has flat spot notch plastic part next lead Slip tub ing over soldered leads further strengthen connection slip 1-in piece 1/5 diameter heat-shrink sulated tubing over both wires up LED Twist LED wires together place A-in-diameter dark tubing over LED until LED /4 essed Connect red wire LED hole black wire LED hole Twist two remaining black red wires together solder red wire RECEIVER LVITRANSMITTER LVIFig 13 611 FLASH POINT10340p 9SV 0 340F 473V 750F 460V 0 750F 94V 1300F 435V 6789 1011 MILL lAMPS 8 Temperature-Voltage-Current diagram f receiver LVI 12 13 14 15 18 17 18 19 20 21 MILLIAMPS DATA GRAPHS TEMPERATUREVOLTAGE CURRENT TEST EI Fig 14 Printed circuit foil receiver LVI 33 K Fig 15 Printed circuit foil for22 K transmitter LVI ov Component layout receiver LVI June1977 15 V hole black wire V hole time need check set voltage proper operation have access variable DC power supply accurate voltmeter connect positive negative input leads variable power supply can made using freshly charged 48-volt battery pack 500-ohm potentiometer placed positive lead Connect positive lead battery end poten tiometer positive lead LVI center tap potentiometer negative leads battery pack LVI connected directly other accuracy voltmeter can de termined measuring fresh 42-volt mercury battery whichwill close enough application Apply power LVI circuit adjust voltage above 48 volts LED should steady flashing open circuit R-4 and/or R-5 wrong values LED fails light check proper polarity LED connections steady reduce voltage slowly until LED starts flashing Read voltage time should fall between 46 465 volts 75 degrees F LED flashes voltage higher 465 R-5 will have replaced resistor same value R-4 unless 5600-ohm resistor low end tolerance yields proper set voltage LED flashes voltage below 46 method trimming R-5 achieve proper resistance can utilized fol lows Use three-corner file Dremel tool disc grinder file V, sec tion middle resistor shown Fig 18 until carbon part reached Maintain 465 volt supply circuit grind carbon until LED stops flashing Grind little time let resistor cool time until desired set voltage obtained Increase slowly reduce supply volt age until LED starts flashing Read justments supply voltage resistance R-5 can continued until desired set voltage reached Since carbon resistors have 10-percent toler ance stated resistance selection R-4 R-5 proper resistances will give desired results above trimming procedure desired resistance parallel resistors R-4 R-5 about 2600 ohms After desired set voltage obtained satisfied condi tions seal complete unit silicon seal mixture 5-minute epoxy microballoons Now solder input wires unit onto output receiver power switch receiver plug can installed maintaining polarity servo plugs transmitter Low Voltage Indicator LVI constructed using Fig 17 two differences receiver cir cuit jumper wire used under IC R-5 variable resistor trimpot Calibration unit same receiver LVI straightforward simple Connect variable DC power supply accurate voltmeter put leads Two 48 volt battery packs series connected described receiver LVI construction will provide steady DC supply using 500-ohm potenti ometer described above Apply power set voltage desired set volt age Adjust R-5 until LED steady reverse rotation until LED just starts flashing Vary supply voltage un til satisfied LED starts flashing proper voltage Readjust ment R-5 may necessary obtain proper set voltage unit now ready installation transmitter piece servo mounting tape can used mount unit inside transmitter Cut large enough piece servo tape will enough insulate unit 16 Model Aviation U U transmitter case avoid shorts Connect input leads power switch output observing polarity Drill /4-in hole desired LED mounted Place A-in grommet hole place LED grommet unit now ready opera tion Supplement Mr Duffield has specified Lafayette 555 IC Timer because per forms manner indicated Tem perature-Voltage-Current graphs Another source 555 IC Timer operated directly op posite IC Timer raises set voltage higher temperature vice versa LVI described Mr Duffield somewhat dependent component temperature stability bit less expensive Zener required can calibrated accurately receiver LVI compact draws about 10 milliamps temperature stability 3 percent Components preceding complete units can obtained Ace R/C Higginsville MO 64037 Mr Duf field also will welcome inquiries com plete parts package complete units LVIs PO Box 72 Thomaston TX 77989 Theres no doubt preceding units represent pretty deluxe approach problem satisfied simple on-off indication critical voltage simple LED indicator suffices real problem get sharp repeat able cut off low hysteresis Sig netics data sheets LM339 compara tor show tentative approach Fig 19 presents logic diagram comparator extremely sensitive device VREF can provided Zener divide ever V0 degrades below VREF com parator will swing sharply cutting off LED Hewlett-Packard has provided circuitry shown Fig 19 LED-size package Voltage Sensing Device VSD 5082-4732 Fig 20 shows logic diagram However threshold voltage VTHfor device typically 25 volts directly useful applica tions However range device can readily expanded placing device series external device shown Fig 21 purposes resistor Zener diode can used tests have shown hysteresis using resistor entirely too broad VTH directly proportional temperature stability resistor Zener diode alleviates both pre ceding problems must selected fit particular situation Temperature co efficient combination 1 ener Using suffix Zener eg 1N751A provides 25 per cent accuracy over temperature range following Zener diodes series H-P device permit operation un der conditions shown LVD Zener Trigger Voltage 81 93 10 116 47 1N752A 1N754A 1N755A 1N757A 1N370 Application 9V dry battery 96V nicad pack 1 2V dry battery 12V nicad pack 48V airborne packs can assure would again operate dry battery transmitter least HP device Its matter per sonal preference whether uses air borne device since entirely possible suffer decay below safe limits air borne will least prevent taking off point below safe limits HP device proper Zener available inexpensive unit Ace R/C June1977 17
Edition: Model Aviation - 1977/06
Page Numbers: 12, 13, 14, 15, 16, 17
NO OCR TEXT 4 10K TRIM POT V ZENER Completed prototype Ace R/C LYD Such unit may mounted transmitter using servo mount tape Printed circuit foil Digital Commander LVD Fig 2 10K Fig 1 4 4 C C C ILL K C C C C -J 10K NE 555 470 LED 49BV 4 0 LOW VOLTAGE WARNING DEVICE LVD OUTPUT FROM LVD DELETE LED Fig 3 1OILf 6V DOWN 470 ED LED TRIM POT V A- geV 10K 10K IN 751A 51V ZENER BANDED END 01 pf Component layout Ace R/C Digital Commander LVD Fig 5 Printed circuit foil add-on audio indi cator rp Fig 7 Printed circuit foil Ace RIC combined LVD-audio warning 96V OUTPUT FROM LVD DELETE LED Component layout add-on audio indicator e 96V b 2N6534 OR 2N6562 C 15 AUDIO WARNING100 0 ov Fig 4 Schematic diagram add-on audio indicator Ace R/C Digital Commander 2N6534 OR 2N6562 OV BLACK WIRE TO AUDIO DEVICE RED WIRE TO Fig 6AUDIO DEVICE ADDING AUDIO WARNING TO THE ACE LVD June1977 13 NO S 15 quires 20-25 milliamperes light properly Charlie Rankin felt would rather have extra drain transmit ter pack switched things around shown Fig 9 see Model Aviation July 1976 have light off until critical voltage reached Id rather since LED could bad wouldnt know push-button test some sort However readers choice article actually began around article submitted Mr C M Duffield also built around Signetics LM555CN Mr Duffields material pre sented paragraphs follow THE LVIs C M Duffield SET SIX GOALS achieve before would satisfied final results goals 1 Low cost 2 Reliabil ity 3 Low current drain 4 Lightweight 5 Simplicity 6 Adaptability last second thought about elec tronic devices operate battery pow er need some means letting know critical voltage reached goals have achieved satis faction two circuits described anyone can build first circuit Fig 10 receiver 48-volt battery pack Low Voltage Indica tor LVI second Fig 11 transmitter Both circuits basically same use Signetic LM555CN Timer light emitting diode capacitor few resistors airborne LVI can wired directly output side battery power switch connector can installed plugged auxiliary channel outlet receiver using just positive negative tertninals transmitter LVI would have wired directly output side power switch air borne LVI light emitting diode LED would have installed dark tube such -in diameter heat-shrink tubing placed fuselage such way can viewed direct sun light Under canopy instrument panel through side bottom fuselage couple suggestions transmitter LVI LED can mounted anywhere transmitter case available using /4-in rubber grommet LED protruding through word cau tion point Any modifications transmitter during warranty peri od may void same both circuits LED comes steadily starts flashing indicate low battery-power state reading power batteries under load since circuit lOpf25V 470 0V%%%%N 2N6534 OR 2N6562 BLACK TO / AUDIO DEVICE / 100 Fig 8 NOTE DOT 10K 10K 1N751A BANDED END DOWN TRIMPOT RED TO AUDIO DEVICE Component layout Ace H/C combined LVD-audio warning Ov POT V Ci 10ftr.4 L7 110K II~12K1 Fig 11 0 IC-i 565 TOP LM 555 CN SIGN ETICS 8 n-I 22K 7 R-2 33K 6 5 -NC 1 Schematic diagram C M Duffields transmitter LVI RECEIVER LVI -v c-iFig 10 10 1d 8 H-i 22K 7 LM 555 CNR-2 56K47KSIGNETIS33K 6 5 NC LED OFF IVOSchematic diagram C M Dufflelds receiver LVI 14 Model Aviation TRANSMITTER LVI power applied Temperature stability LVI de termined temperature stability several components TemperatureVoltage-Current graphs Figs 12 13 show cold day sufficient power will remain after light flashes con tinue flying up 30 minutes very hot day will have stop flying immediately considering fact temperature inside aircraft fuselage can much hotter under hot sun outside air temperature wish discredit circuits commercial circuit electronics operations will vary temperature un less compensated against compensation can add compo nents considerable cost complete circuit Figs 14 15 present PC foil layout receiver LVI transmitter LVI respectively Figs 16 17 pre sent overlays show parts placement component identification following presents construction steps receiver LVI Using Fig 16 guide install jumper wire Install 555 IC Timer taking care jumper wire does touch IC pins number pin IC indi cated small dot next capacitor negative hole Bend leads slightly hold IC place Install other components solder capaci tor installed will lie flat top IC Check no solder bridges Using 22-gauge wire strip small por tion insulation off both ends desired length wires will needed connect unit fuselage Tin lead light-emitting diode LED using heat-sink between LED soldering spots Cut LED leads about /t long Tin end four wires slightly Place about diameter heat-shrink insulating tubing onto red wire black wire Solder two wires LED using heat-sink previously mentioned black wire cathode lead red wire anode lead cathode lead has flat spot notch plastic part next lead Slip tub ing over soldered leads further strengthen connection slip 1-in piece 1/5 diameter heat-shrink sulated tubing over both wires up LED Twist LED wires together place A-in-diameter dark tubing over LED until LED /4 essed Connect red wire LED hole black wire LED hole Twist two remaining black red wires together solder red wire RECEIVER LVITRANSMITTER LVIFig 13 611 FLASH POINT10340p 9SV 0 340F 473V 750F 460V 0 750F 94V 1300F 435V 6789 1011 MILL lAMPS 8 Temperature-Voltage-Current diagram f receiver LVI 12 13 14 15 18 17 18 19 20 21 MILLIAMPS DATA GRAPHS TEMPERATUREVOLTAGE CURRENT TEST EI Fig 14 Printed circuit foil receiver LVI 33 K Fig 15 Printed circuit foil for22 K transmitter LVI ov Component layout receiver LVI June1977 15 V hole black wire V hole time need check set voltage proper operation have access variable DC power supply accurate voltmeter connect positive negative input leads variable power supply can made using freshly charged 48-volt battery pack 500-ohm potentiometer placed positive lead Connect positive lead battery end poten tiometer positive lead LVI center tap potentiometer negative leads battery pack LVI connected directly other accuracy voltmeter can de termined measuring fresh 42-volt mercury battery whichwill close enough application Apply power LVI circuit adjust voltage above 48 volts LED should steady flashing open circuit R-4 and/or R-5 wrong values LED fails light check proper polarity LED connections steady reduce voltage slowly until LED starts flashing Read voltage time should fall between 46 465 volts 75 degrees F LED flashes voltage higher 465 R-5 will have replaced resistor same value R-4 unless 5600-ohm resistor low end tolerance yields proper set voltage LED flashes voltage below 46 method trimming R-5 achieve proper resistance can utilized fol lows Use three-corner file Dremel tool disc grinder file V, sec tion middle resistor shown Fig 18 until carbon part reached Maintain 465 volt supply circuit grind carbon until LED stops flashing Grind little time let resistor cool time until desired set voltage obtained Increase slowly reduce supply volt age until LED starts flashing Read justments supply voltage resistance R-5 can continued until desired set voltage reached Since carbon resistors have 10-percent toler ance stated resistance selection R-4 R-5 proper resistances will give desired results above trimming procedure desired resistance parallel resistors R-4 R-5 about 2600 ohms After desired set voltage obtained satisfied condi tions seal complete unit silicon seal mixture 5-minute epoxy microballoons Now solder input wires unit onto output receiver power switch receiver plug can installed maintaining polarity servo plugs transmitter Low Voltage Indicator LVI constructed using Fig 17 two differences receiver cir cuit jumper wire used under IC R-5 variable resistor trimpot Calibration unit same receiver LVI straightforward simple Connect variable DC power supply accurate voltmeter put leads Two 48 volt battery packs series connected described receiver LVI construction will provide steady DC supply using 500-ohm potenti ometer described above Apply power set voltage desired set volt age Adjust R-5 until LED steady reverse rotation until LED just starts flashing Vary supply voltage un til satisfied LED starts flashing proper voltage Readjust ment R-5 may necessary obtain proper set voltage unit now ready installation transmitter piece servo mounting tape can used mount unit inside transmitter Cut large enough piece servo tape will enough insulate unit 16 Model Aviation U U transmitter case avoid shorts Connect input leads power switch output observing polarity Drill /4-in hole desired LED mounted Place A-in grommet hole place LED grommet unit now ready opera tion Supplement Mr Duffield has specified Lafayette 555 IC Timer because per forms manner indicated Tem perature-Voltage-Current graphs Another source 555 IC Timer operated directly op posite IC Timer raises set voltage higher temperature vice versa LVI described Mr Duffield somewhat dependent component temperature stability bit less expensive Zener required can calibrated accurately receiver LVI compact draws about 10 milliamps temperature stability 3 percent Components preceding complete units can obtained Ace R/C Higginsville MO 64037 Mr Duf field also will welcome inquiries com plete parts package complete units LVIs PO Box 72 Thomaston TX 77989 Theres no doubt preceding units represent pretty deluxe approach problem satisfied simple on-off indication critical voltage simple LED indicator suffices real problem get sharp repeat able cut off low hysteresis Sig netics data sheets LM339 compara tor show tentative approach Fig 19 presents logic diagram comparator extremely sensitive device VREF can provided Zener divide ever V0 degrades below VREF com parator will swing sharply cutting off LED Hewlett-Packard has provided circuitry shown Fig 19 LED-size package Voltage Sensing Device VSD 5082-4732 Fig 20 shows logic diagram However threshold voltage VTHfor device typically 25 volts directly useful applica tions However range device can readily expanded placing device series external device shown Fig 21 purposes resistor Zener diode can used tests have shown hysteresis using resistor entirely too broad VTH directly proportional temperature stability resistor Zener diode alleviates both pre ceding problems must selected fit particular situation Temperature co efficient combination 1 ener Using suffix Zener eg 1N751A provides 25 per cent accuracy over temperature range following Zener diodes series H-P device permit operation un der conditions shown LVD Zener Trigger Voltage 81 93 10 116 47 1N752A 1N754A 1N755A 1N757A 1N370 Application 9V dry battery 96V nicad pack 1 2V dry battery 12V nicad pack 48V airborne packs can assure would again operate dry battery transmitter least HP device Its matter per sonal preference whether uses air borne device since entirely possible suffer decay below safe limits air borne will least prevent taking off point below safe limits HP device proper Zener available inexpensive unit Ace R/C June1977 17