Is there an easy way to convert an LCD panel volt meter that requires an isolated ground to a common ground?? I have this unit:
http://www.mcmelectronics.com/product/72-8100&CAWELAID=220584729
It dosen't like being powered up by the same supply as the voltage I'm trying to monitor, any suggestions?

Thanks,
Eric

 

If it requires a separate ground for the power, then it's not going to change. You may need a different panel meter.

 

It depends on the meter you have. I converted a Martel meter to common ground using an ICL7660 chip to generate +/- voltages. I also have an MPJA meter. It is a pretty tight package and would be difficult to modify. The change I needed to make to extend the range was done on an accessory board.

What information can you give us about your meter? If you have the meter already, can you see which chips are in it?

John

 

The chip they use is covered in a black hard sealant. Guess I'll just use a battery to power it and use a relay to switch it on and off in the car. Thanks.