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Friday, September 10, 2021
CONTINUITY: Selenium Rectifiers—When They Blow Up, It’s Like a Rectal Fire
You'll find these in all kinds of electrical and electronic gear dating from the 1930s through the 1960s. They were the first (kind of) practical solid state rectifier, but had limited reverse voltage capability and required a stack of individual junctions for mains and higher voltage applications. They had a forward voltage drop of around one volt, which would increase as the unit aged. In high voltage and current applications, this could eventually lead to thermal runaway as heat dissipation and resistance increased, ending with a bang and release of hideously malodorous and toxic smoke. At least, when this happened, there was no question about what was wrong.
Posted at September 10, 2021 14:11