Just finished writing the code for my car's push to start system. I'm using a BS2 Rev. J from a Boe Bot kit I had lying around. I have everything working on a breadboard using LED's to simulate the components but now I have no idea how to make it work inside the car.
I'll be powering 2 ignition relays (IG1 & IG2), a starter relay and an ACC relay. I can't find a data sheet for my specific relays but most 12V 30A relays I saw draw 130mA to switch them. The IG1, IG2 and ACC circuit will all be continuous while the car is on and the starter won't be powered for more than 1-2 seconds. I need to find a way to amplify the current from the microcontroller to be able to power the relays.
I looked into MOSFET's but from my super limited understanding it looks like they are controlled by the voltage difference between the gate and the source and when that happens, the source connects to the drain. I saw a lot of 'hey use this transistor' etc. but not too much on how to wire them up. I do have 2 car amplifiers for parts so I'm sure I have all kinds of transistors to toy around with.
Any help would be greatly appreciated!