View Full Version : reverse voltage protection

01-21-2007, 05:15 AM
I have a stamp circuit that needs reverse voltage protection (it's a slot car arrangement that could be put on backwards pretty easily). Right now I have an in-line diode, but the voltage drop is too great for my purposes.

I found these two solutions and wonder if anyone has any thoughts on which would be better? If I use a fet, how do I choose which one?


Carlos Ferguson



PJ Allen
01-21-2007, 07:00 AM
jcferguson said...
If I use a fet, how do I choose which one?

The www.elecdesign.com (http://www.elecdesign.com) article states that an IRF7342 was used in one and·an IRF7341 was used in the other circuit.

The http://www.chris.org article uses a relay (and they suck current.)

Update --



Post Edited (PJ Allen) : 1/21/2007 2:41:03 AM GMT

01-22-2007, 11:22 AM
thanks PJ,

I guess my question is which method makes more sense for this application - I probably have about 2 amps max at 12v drawn by my circuits, I tried out the relay method, it works fine... I want this to work for a good long time though, do I need to worry about the relay wearing out, and would a fet be better in this respect, or do I have to start worrying about heat with the fet?