OVP's purpose in life is???? - Page 3 - PeachParts Mercedes-Benz Forum

AMG CE 36 · #1 07-03-2004, 06:07 PM

Hi, I have just a few pictures of the engine, nothing else, but I can take some more in a couple of days...

wbain5280 · #2 07-04-2004, 03:31 AM

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.

gschira · #3 03-16-2009, 08:11 PM

Hi y'all,
Is there an OVP on a 1988 300 SE, and if so, where would it be. My car is getting to be hard to start. Seems to be mostly when warm, but not always. This morning's temp here in Texas was about 49- 50 degrees f, and it did not start as quickly as it did at 35 degrees a couple of days ago. And this afternoon, with weather of around 75 was hardest to start, but after normal operating temp started immediately every time. Any Clues?

Jacamo9 · #4 02-11-2013, 04:59 PM

I am trying to diagnose wipers not working. As soon as I turn on washer/wipers they kick out along with the windows and rear seat recline stop working. They came back operational after fifteen minutes or so.
Manual says the wipers are overload protected. Could this be the same OVP relay failure?
Thanks in advance for any advice.

Rando
1988 560SEL

anziani · #5 02-12-2013, 01:27 PM

OVP? Finally a cause for all problems. Now we can retire "second hand smoke", "global warming" and "George W. Bush" as the source of all the worlds ills!
Anziani