Hi, I'm looking to build a small power supply for some LED lighting in my pickup. My main concern is making sure the power stays at or below +12V (if it sags to ~10.5-11V I'm not worried about that) and spikes/noise/etc endemic to automotive power are filtered out.
Would it be sufficient to have a 15V zener across the input along with a couple filter caps (1000μF/50V + 0.33μF/50V), running into an LM7812CT (TO-220) with a 0.1μF/50V bypass cap on the output? Would it be beneficial to add a third mid-range capacitor (~100-220μF) in the filter cap set? The power draw will not exceed 1A, so with the 15V zener, the 7812 should never have to dissipate more than 3W.
I know I could use a LDO regulator to reduce sags when running directly off the battery (~12.8V), but I've tested the LEDs on a 10V power supply and they work just fine, and I have a bucketful of LM7812s on hand already so I figure I'd make use of them if possible.
Thanks!