Quote:
Originally posted by Strife
I THINK (don't know for sure) that the OVP is like a "crowbar" circuit on a switching power supply - that is, when voltage goes over, say, +16 volts, a big SCR (a cheap, high current semiconductor) latches in and presents a dead short - which will then deliberately blow the fuse (and maybe the semiconductor, which is designed to fail shorted). Depending on how the circuit is made, the circuit might NOT latch so the circuit can survive short overvoltages.
This "cheap" (in the relative term) part sacrifices itself (or its fuse) for the sake of other stuff.
Of all the magic MB modules, this one is the most promising to reverse-engineer!
|
That's an excellent description. The OVP's purpose in life is to protect the electronic control units. If the voltage goes too high, the zener conducts causing the fuse to blow.TV electronics use spark gaps around the picture tubes to protect it from voltage spikes.
It's the sacrificial anode of our cars.
__________________
Regards
Warren
Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor
Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL
ENTER > = (HP RPN)
Not part of the in-crowd since 1952.
|