I've already done all the footwork. After extensively researching this I've found it easier to just go buy the switch glow. But if you just like to tinker here you go. Enjoy
Here is your remote switch.
Parts List:
All resistors 1/4w/5% tolerance, unless otherwise posted.
R1 = 47K IC1 = MC14013B
R2 = 1K Q1 = BUZ11, IRFZ42, NTE2395, or ECG2395
R3 = 10K S1 = on/off switch (optional)
P1 = 100K Servo lead
C1 = 22nF
Parts only KIT available, Click here: R/C Switch
Description:
The circuit, as described above, is a so-called "Radio Controlled Electronic Switch". It can be used to switch on/off anything electrical, whatever it is. Here are a couple of examples: navigation lights, landing gear, sound systems, glowplug driver, bomb release, parachute, search lights, gyros, and so on.
Fig. A shows the regular setup for common accesories such as motors, glowplugs, bomb-doors, relays, etc. If you like to hook it up to a camera, see Fig. B. Note that for the Camera Shutter version the value for R1 and R2 is different (100K). Please note that this system will not work with PCM.
Hart of the circuit is a CMOS Dual 'D' Flip-Flop MC14013B. The input Flip-Flop is designed as a monostable pulse generator by means of R1, P1 and C1 connected between 'Q' and the RESET input, which produces a preset pulse-length set by the adjustable potmeter and starts at the rising edge of the input pulse. When this monostable times out it's inverted 'Q' signal goes high and clocks the output stage of the Flip-Flop, which is used as a normal type 'D', to sample the input pulse. If the duration of the input pulse is longer than the preset monostable pulse, then a logic high level will be clocked to the output of the 'D' type. A shorter input pulse will cause a logic low to be clocked to the output. In short, both halves of the IC perform two different logic funtions.
The output drives the output device which in this circuit is the IRFZ42 TMOS FET. It needs only 2-volt on it's gate to fully turn-on and has an rDS-ON resistance of only 0.028 ohm. To invert the operation of the r/c switch, you can connect R2 either to pin 12 or 13 of the MC14013B. This circuit is easy in design and to built and can easily be done using vector board, vero-board, or whatever. My unit measures 5/8" by 1-1/4" but I know I can do a lot smaller by choosing smd components, probably 3/8" x 1/2". You can use a case or heat-shrink; I used the latter. This unit is NOT ment as a motor-switch for electric flight. For that purpose check out the "R/C Electric Motor Switch".
Adjusting the switch: To test the unit hookup a light and a battery, making sure the + of the battery goes to the Drain of Q1. Adjust the potmeter P1 to somewhere in the middle and set the transmitter function of your choice (say the throttle) to the point where you wish to switch the unit. Now adjust the potmeter P1 to the point the light comes on. If it does, your unit functions properly and you can play with whatever other setup you have in mind. If you intend to use this unit as a on-board glowdriver, make sure to use havy wiring between glowplug, battery and r/s switch. A 'Y'-lead to the throttle servo is required. If you use this unit to switch relays or a small dc-motor, then a 'spark eliminator' diode (1N4001) is required. Cathode of the diode goes to the '+' side of the battery. (See diagram).
Surface Mount Version At the left you see the Surface Mount version (SMT), measuring 15mm x 17mm!
Final Word:
The IRFZ42 is a TMOS Power FET. They can be pricy ($12 Can). Other substitutes like the IRFZ44 will work too. Watch for static discharge with this one!
IC1, the MC14013B, is a CMOS SSI type Dual Flip-Flop. It features a direct pin-for-pin replacement with the CD4013B, NTE4013B, ECG4013B, and others.
The output signal can be inverted by selecting either pin 12 or 13. To make life easier, you could install a miniature on-on switch. The middle contact going to R2, and pin-12 & 13 to the other two contacts.
Original author of the circuit diagram is Ken Hewitt. I modified it somewhat because we can't get the BUK555-60B (Q1). Ken also has a way to put the circuit on a strip-solder board.
And here is your glow ignitor
Parts List:
All resistors, except Rm, (metal-film recommended) 1/8 watt (1/4 watt for carbon)
& no less than 5% tolerance, unless otherwise posted.
C1 = 100uF/16V Electrolytic R1 = 100 Ohm, 1/2 watt 1 red jack
C2 = 10nF, ceramic R2 = 1K 1 black jack
C3,C4 = 10nF, mica R3 = 1K 1 amp meter, 1 to 6-amp (dc)
Q1 = TIP42C R4 = 4K7 1 knob for potentiometer
Q2 = NTE123AP R5 = 750K 1 coolrib for Q1
D2 = 1N5401 Rm = .2 ohm/10W
D1,D3 = 1N4002 P1 = 100K
D4 = 1N4148F Here is a suggestion for a complete Power Panel
IC1 = LM555
A couple possible substitutes, use at your disgression, no guarantees:
For Q1: TIP32C, TIP42, TIP42A (or B), NTE332, ECG332.
For Q2: 2N3904, BC547, (or A or B), BC550, European TUN.
For D1,3: NTE116, ECG116, try others.
For D2: NTE5801, try others.
For D4: NTE519, ECG519, other 1N4148x types worked also.
For IC1: NE555, TLC555, MC1455, HC555, NTE955M, ECG955, etc.
The NTE123A did not seem to work and is not quite the same as the 'AP' type.
The 2N2222(A) did not work in the prototype and shorted out the circuit.
The ECG and NTE/ECG substitutes are made by Sylvania (Philips). I build two units
and both working fine.
pin connections
Printed Circuit Board Component layout
[Click here] to print an original size pcb (3 x 6cm).
Notes:
An on/off switch is not required for the glowplug driver since it only draws current when a glowplug is attached. As a matter of fact, the circuit is only powered (via Q1) via a connected glowplug. Just in case you were wondering how the positive (+) side of the circuit is connected. The starter motor runs directly from the flight box battery, via the jacks on the power-panel, and has it's own on/off switch. Same scenario for the fuel pump, but includes a reverse switch to pump the fuel in or out the tank/cannister.
For all components, substitutes are fine. D1 and D3 are regular 1N4002 diodes. You may substitute with the 1N4001, or 1N4003. D4 (1N4148F) is an ultra-fast switching silicon diode with a 100V prv. The regular and more familiar 1N4148 seems to work also.
D2 (1N5401) is a 3A/100V prv power diode.
Q1 is a PNP power transistor/switch with a TO-220 case, 6A, 80/100V, 65 watts. Don't be afraid to experiment, and don't forget the coolrib on the TIP42, it may be needed. I strongly recommend a power supply if you're gonna experiment and turn up the voltage slowly while watching the ampmeter. My own experiments resulted in 3 burned out glowplugs, 2 TIPs, and 2 NTE123AP. Q2 is a NPN silicon, AF/RF Amp/Driver, transistor to drive Q1. If you substitute, stick with the 'driver' type, other may burn-out the very second you apply power. Again, try using whatever you have in your parts-box first, but try to match the current/voltage parameters as close as you can and make sure it is able to drive Q1. Whatever transistor you use for Q1 or Q2, watch the orientation of the the emitter, base and collector and don't assume it is the same as the original or as shown in the component layout. The tab for the metal case transistors (Q2) is always the emitter. Remember, Q2, as mentioned before, should be a driver-type-transistor (or close to it) in order for it to supply enough current to Q1.
All this circuit does, is providing enough controlled current (via P1) to make/keep a plug glowing under various conditions.
In regards to the 750K value of R5, it is fine to combine different resistors to get to that value. I used two 1M5 resistors in parallel myself. Works fine! So does 680K+6M8 (754K).
The CMOS timer,
MC1455P, can be substituted for the ordinary LM or NE555 and are pin-for-pin compatible. The CMOS version uses much less power and its operating voltage is 2 - 18 volt versus the regular 555 type 4.5 - 18volt. On the other hand, the MC1455P is not as robust as the regular 555 type. The amp meter is not mandatory, but gives you a nice visual indicator. It can easily be constructed from a salvaged panel amp meter.
When a glowplug is hooked up (the plug act as an on/off switch to power the circuit), Q2 switches on and biases Q1, which in turn provides enough current, adjusted with potentiometer P1, to make the plug glow. C2, C3, & C4 are filtering capacitors while C1 keeps the voltage over the glowplug steady, like when the plug gets wet with fuel and draws more current. Diodes D1/D3 are feedback blocking diodes preventing signal feedback.
CAUTION! The '-' of the glow plug jack connects to the emitter of Q1 only!Waiting for parts
bmapope
krashtagain
billiano
