hi AltairLabs, hi Ran Talbott
We are worried that your diagram does not show any independent mechanical interlock as a safety backup for software.
actualy, i have a lot of other things plugged into the arduino.
I have 1 switch to open the circuit of the Battery (12V +), that means the battery don't feed any fet with its (+) until i switch it. I will switch it only when all my check routine is OK.
I have an other switch that goes in the ARduino, and act as a sofware switch, if it is off the code can not fire any igniter, and i did the condition in many place in the code.
I cannot put a switch just before the N-channel gate as Ran Talbott said because i have 20 channels of that circuit, i would need 20 switch right ? maybe you think about a way to do it ?
I would add code that flashes an LED distinctively so I'd know the sketch is running properly before I flipped the "arming" switch.
Yes, I did something like this. I have a LCD that show me some important information, and a little star is blinking in the corner when the code is running in the good place. that tells me "ALL is good, you can arm". i also have a led that blink to tell that the communication between the 2 Arduino is OK.
because when N FET turns on the drain goes to ground, the top end of resistor or igniter is at +12V.
So You think it could damage the P_FET if i do it the way i draw that's right ? I replace this Resistor by the igniter between the Gate and the source ? I don't need this Resistor ?
by Dammage you mean in case of a short with an igniter that don't burst ?
the P FET is 60V 27A ..., I use a battery 12V 1800mAH, and i open the FET only 10ms, do you think the FET will handle a short in this conditions ?
I will draw a new circuit with the switchs and your way to place the igniter. It should be on the new Forum, ... migration is coming.