Support Forum (EN/FR)

Hi! I'm using the PMLCD and PMLED 2000 counts panel meters (200 mV sensitivity) in a project. For some reason I did not manage to get them to work, but I soon discovered that the meters works just fine with power separated from input. As my project powers the meters from the same power nets (on my PCB) that I try to measure, my IN- is (kelvin-)connected to GND and my IN+ is connected to a mV-source on my PCB that gets its power from the same power I use to drive the PMLED/PMLCD.

Is this possible somehow, or do I need an isolated power source for the meters? The manual doesn't say.

Edit: For clarification, "doesn't work" means that the meters indicates overrange ("1") regardless of the input potential on IN+/- when powered from the same source that provides the signal to be measured (0-200 mV).

Velleman Projects items only please. See forum rules. For all other items of the Velleman group please use the online support form.
http://www.velleman.eu/support/contact/?product=19215