Cheap self-powering voltage tester
Added 2022-04-18 08:35:43 +0000 UTCThe circuitry in this is quite interesting, and refreshingly simple - although it is divided into four distinct sections.
https://www.youtube.com/watch?v=JSLHxKM-kpw
It's staggeringly cheap for what's inside, and should be OK for lightweight electrical work. But despite its Cat III rating I wouldn't classify it as suitable for use in high current industrial equipment due to the lack of any proper fusible protection, and the closeness of the rectifier diodes.