I was asked to investigate over-voltage protection for aftermarket gauges for older cars. Not sure if we have to protect against load dump, or maybe that protection happens elsewhere in the cars (circa 1960-2005).
Proposed design has 18V max DC MOVs (AMCV-0805-180-C101N-T) in front of a 50V ceramic 10uF capacitor, that goes into a 5V linear regulator, then another 50v cap and an 8v max DC varistor. The “data” lines, mostly analog resistive sensors have large resistances and caps, so seem less of a problem.
Any advice, specific or general, would be welcomed.