Fried my power supply by doing a bad thing

[dlgoff]

There used to be chargers that would tell you almost instantly if you connected a battery backwards.

The rectifier was a few metal plates coated with Selenium, a high current would of course overheat the rectifier.

The aroma was rather strong and reminiscent of rotten eggs... not something you would soon forget.

https://www.google.com/search?q=selenium+rectifier+smell

IIRC they were used in the high voltage supplies for TV picture tubes.
From: https://en.wikipedia.org/wiki/Selenium_rectifier#:~:text=A selenium rectifier is a,rectifiers in the late 1960s.

 

[Averagesupernova]

I seem to recall seeing those in old tube radios. Rectifier for the plate supply. Maybe I'm thinking of something else. I recall working on a record player that used just two tubes they each had 35 volt filaments. Wired in series and burned up the remainder in a power resistor. Must have had a selenium rectifier for the plate supply.

 

[dlgoff]

35 volt filaments.

Some old sets I remember working on had 117 volt filaments.

 

[Tom.G]

IIRC they were used in the high voltage supplies for TV picture tubes.

Nah... A Selenium plate is only good for 20V or so.

The TV high voltage rectifer was the 1B3 vacuum tube, peak plate voltage of 26,000V and a 1.25V filament. The filament was also fed from a winding on the flyback transformer, which of course was floating at the rectified HV DC.

1B3 data sheet at:
https://www.google.com/url?sa=t&rct.../1/1G3GT.pdf&usg=AOvVaw2nEe3LzCQJ3fW69uU8LwQN

 

[Baluncore]

IIRC they were used in the high voltage supplies for TV picture tubes.

High-voltage stick rectifiers were made from silicon rectifier pellets, stacked end to end. I don't believe HV "stick rectifiers" were ever made from selenium diodes.

Selenium was used in some lower voltage "metal rectifiers" which needed a stack of oxide coated cooling fins.

 

[Averagesupernova]

High-voltage stick rectifiers were made from silicon rectifier pellets, stacked end to end.

I recall those. You could lose a few and get by. But too many go missing from the stack and that is inviting trouble.

 

[Baluncore]

I recall those. You could lose a few and get by. But too many go missing from the stack and that is inviting trouble.

Each diode pellet was similarly leaky, like having a parallel resistor, so the reverse voltage was shared equally by all the diodes in the stack. The least leaky diode would drop the most voltage and so go short first, followed by a cascade of failures as each carried a greater voltage burden than before.

The 1S2 EHT tripler tube had much going for it. It wore an aluminium cap, that made the dust stand on end.