Alright, lets get back to this project. Last I left it, I had fried my dc-dc converter. It can only handle 18V for 100ms, and is really only meant to handle 13.2V which is kind of low. When the alternator kicks on, it boots the voltage up to 14.4V. When you switch back to the dc-dc converter, that is too high and it will eventually fry as mine did. This simply won't work for the next phase of this project. So, we have to revisit the design and make things a bit more robust.
This is what we started with:
This is what we're now going to. I've added a 7805 linear voltage regulator before the dc-dc converter. This linear voltage regulator will take 7-35V and convert it down to a regulated 5V. So, a voltage spike of 14.4V is nothing for this puppy to handle. It then spits out 5V to the new dc-dc convter which converts 5V to 15V. The old one took 12V and converted to 15V. This design will be a lot more robust and should really never have issues with frying components, yay!
