Over-voltage protection

[richard]

That was my first idea, but I don't know just how far a 7805 can take abuse, compared to the TVS, NTC and MOV?

they are pretty tough, i don't go much for linear regs due to their low efficiency and heatsink requirements [ for batt powered stuff].
for low power mains powered roles they served well for years and still can

absolute vin max is 35v but dropping 20v or so across the reg @250mA makes a lot of heat whereas for a switching reg , no heat

[Ioannis]

Maybe I missed the scope but, why are you so worried?

If you have a low current circuit, a 7805 is just fine for up to 35 or so voiltages.

If you have higher currents, then a smps like the expensive Recom that Richard uses or the cheaper https://gr.mouser.com/ProductDetail/490-VXO7805-1000 I use is good enough.

And last but not least, the circuit that you posted for reverse polarity protection with the p-mosfet in post #14 is the best protection with no voltage drop.

Ioannis

[Demon]

Maybe I missed the scope but, why are you so worried?

If you have a low current circuit, a 7805 is just fine for up to 35 or so voiltages.

If you have higher currents, then a smps like the expensive Recom that Richard uses or the cheaper https://gr.mouser.com/ProductDetail/490-VXO7805-1000 I use is good enough.

And last but not least, the circuit that you posted for reverse polarity protection with the p-mosfet in post #14 is the best protection with no voltage drop.

Ioannis

I get crazy power surges and spikes here in thunderstorms, lots of trees messing with lines and transformers.

I might end up using a combination of devices.

Yeah, that diode was costing me .7V and was bugging me like crazy, but with that boost circuit, that's not really a problem. That boost circuit also gives me the choice of splitting my power source: 5V for PIC and other ICs, and what ever I need for more power-hungry circuits.

I have only one major concern, whatever I chose, I have to be able to provide at least 100 within a year, hopefully 1000 over the next few years (gotta have goals in life ).

Robert