LCD panel voltmeters and common ground

Discussion in 'General Electronics Chat' started by sleepyMonad, Dec 4, 2010.

  1. sleepyMonad

    Thread Starter New Member

    Aug 18, 2010

    Could someone point to a good reference about panel LCD volt meters, in particular what the rules of the game are for the non common ground types? Should this be taken literally: the ground of the panel lcd must not ever be somehow connected to the ground of the circuit that you want to measure, or can one provide the necessary isolation with a DC-DC convertor, even if the DCDC convertor shares the ground connection between its input and its regulated output? Are there other tricks for decoupling that one may apply?

    Maybe the answers would be obvious if I had some understanding of the internal workings of this kind of devices. Some googling however didn't turn up the expected results :confused: