Are you still believe that voltage drip you are seeing on scope is for real? :) I just quickly made illustration of what is most likely going on in your setup, using simple tools - fresh AA battery and wire. 1. Probe/measure power bus of test device with scope 2. Connect wire to earthing terminal of scope. If no avail - then ground terminal of test signal output. 3. For a second or so connect battery between ground of your device and ground of scope. - Yes, battery essentially is shorted through earthing of scope and device, nothing supposedly shall change on the scope screen waveform, right? - Wrong. 4. Finally - take UPS, power scope through it, disconnect UPS from mains so it runs from battery, make sure that only galvanic connection of scope to outside world (your device) is probe leads and see that dip is not there
↧