Grounding 5v or 12v

Hi,
I want to have a 5v or 12v output on my car project that when grounded I can detect it and not burn anything out, I have a PIC MCU for the logic side whats the simplest way?

Thanks

Scarr said:

Hi,
I want to have a 5v or 12v output on my car project that when grounded I can detect it and not burn anything out, I have a PIC MCU for the logic side whats the simplest way?

Thanks

Click to expand...

How much current do you need to be able to draw from it?, the simplest way would be a series resistor - but it would also have the worst performance. Simple current limited voltage regulators (like the 7805) would make 1A available, but you couldn't use a 7812 for 12V (not enough input voltage).

Umm... you mean that if your 5v or 12v line touches ground you want it to shut off? Just put a fuse on it.. or am I missing something?