Schematic for the relay boxes

[larrykoskie]

Here is a schematic of the relay box. Resistors R1-R6 connect to A8-A13 on the Arduino for continuity. Resistors R7-R13 are the pad and strobe/relay mosfets connected to D2-D8 on the Arduino.. The LEDs on resistor R1-R6 are the continuity lights and are also diodes that prevent the 12volt current from going back to the Arduino during firing the pads. Resistors R1-R13 are 1K ohm and resistors R14-R20 are 10K ohm and drain any voltage off the mosfets so they are off and not firing when the dpdt relay is closed. Putting R14-R20 in the circuit is required for the mosfets as well as R7-R13.
In the diagram the relay is in the off position so power is coming from the Arduino through pins A8-A13 thru the LEDs to the symbol for a neon light but I am using it for the Igniter. Power can't go the other way thru the mosfets because it can't get to ground that way.
When the relay is on the continuity circuits can't get to ground thru the igniter because the relay has removed the ground that way it runs into a +12 volts. The +12 volts can't backfeed the arduino because it can't go backwards thru the LEDs. And the mosfet have to fire for the +12volts to get to ground. The one mosfet is live all the time with the relay in either position because it is the mosfet that turns the relay on. There is a safety switch between the battery and the strobe LED (L7)and the relay coil so the box is disarmed while the pads are being loaded.
So this is a completely redesigned schematic. What do you think?

[ZionPhil]

I think this is going to make a great project write up!

[BeeAmaker]

I think you need to look at your relay connections, I circled in purple. The lower pole of the relay is not connected to anything when the relay is non-energized as well and energized.
Also I over laid a red line on top of a line I don't think is needed, unless you forgot to put something on that line.

[larrykoskie]

Thanks Glen. You were right. I kept making last minute changes and didn't notice some lines got misplaced. So I fixed those mistakes and got this new image.