High voltage detector

Simple high voltage detector based on JFET.

Used JFET: KP103I made in USSR:
KP103 transistor
Transistor can be tested with multimeter - its channel resistance is ~700 ohm and it increases to few kOhms and more in electric field (eg. near the mains cord).

Schematic:
High voltage detector schematic

Due to simplicity detector can be soldered directly on 6F22 battery socket:
High voltage detector


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