Hello to you all, I have seen something at a friends work place and did not understand how it worked? after asking I didn’t get an answer that satisfied me. The company produce voltage detectors and test them on a single phase 50kV transformer. One output post is connected to earth and the other is producing up to 50kV depending on the input voltage. They then offer the voltage detector to the high voltage output terminal. If the voltage detector reaches a pre determined voltage then the detector will light up and whistle, indicating that the line is live, my question is if this detector is put onto a 50kV line then why does it not blow up, the unit goes straight to a PCB so surly the transistor would pop??? The detector is battery operated if this helps? surly the detector must only be taking 1-12v as not to blow the transistor up, I’m confused and have not been told why this wouldnt blow the voltage detector up??? thanks all, I hope to hear from someone soon.