As I´m going to convert my nitro engine to an electric starter I need to be able to control when the glowplug ignites. Does anyone know how this could be done?
Thanks 
Hi,
The glow plug (used for starting only) is, as I recall from my 6th grade modelling days, (65 years ago) is 1.5 to 2.0V at ?? What, 3 amps or so, right? SO you COULD probably control it with a good power N-FET if you have a source for the 1.5..2.0V, maybe a couple AA batteries in parallel?
OH: Update, maybe you can PWM the FET and run it off a 5 or 6V or 8.4V battery??
Can you handle the weight for that??
Oh, BTW is that an aircraft or an (Intentional?) ground vehicle??
The simplest method is to attach a microswitch to the throttle linkage , such that at tickover the plug is powered . Just connect a single nicad cell.
The plug is then ready for a restart .
Gives a more reliable tickover as a bonus .
Oh terry. What do you mean with PMW the FET?
What do you mean with PMW the FET?
Oh you know, we Nerds need to throw words around like we KNOW something...
Pulse Width Modulation turns a circuit on and off rapidly and can change the percentage of time it is on.
So if you want to run that ~ 2 volt Glowplug from a 7.4V battery, for example, you could use a power Field Effect Transistor in the circuit to turn it on for only a portion of some very fast cycles. The "Duty Cycle" would be approximately 2/7.4 = 27% in that case.
Even better, you can also turn it off, since usually a glow plug is electrically heated only for starting the motor.