Pressure / Temp sender switch

Thread Starter


Joined Feb 28, 2012
Hi. I've got a couple of automotive sender units, one for pressure, and one for temp. I'm hoping to setup a 'switch' action in addition to gauges. Aside from a spot of soldering, I'm pretty unskilled with electronics, but have done some reading and come up with this

The comparitor I'd use would be a lm339 I think... there's two sender units I'd like to do this for. One sender operates from 10-180 ohms, and the other is 23-287ohms.

I think my real concerns is about burning out the comparitor... I don't really know what I'm doing, and am not running large resistance there. Don't think I can with the gauge in parallel, and the low resistance of the senders?

Am I heading down the right track? Sorry I don't have any real simulators etc.