I'm trying to run a Raspberry Pi as a remote controller and timer for a diesel water pump but it keeps rebooting when the engine cranks. I checked and the supply doesn't drop below 10.5V during cranking so it must be dirty power.
SMPs are sometimes sensitive to supply spikes, so I thought I'd filter the power with a textbook Pi filter.
I built this with C1 and C2 both 4700μF and L1 being 470μH and as soon as power was supplied, C2 boiled, yet C1 didn't even get warm.
From the speed with which failure occurred I imagine there was some kind of resonance between L1 and C2. Before I trawl through old textbooks relearning network analysis I'm hoping the voice of collective experience can tell me whether there ought to be some resistance in the C2 leg, or even whether there are standard values for a Pi filter when you want to arrest spikes from an alternator. VIN is rectified but dirty 12V.