Bridge rectifier identification

[decoder_82]

Hello,
I found this bridge rectifier. See the picture below. It is an AEG B30/24.
According to what I found online it is a bridge rectifier.
I am wondering from what kind of device it comes from ? Anyone has information?
Many thanks in advance

[soldar]

I remember those. Fifty years ago they were widely used in consumer electronics. Had a very characteristic smell.

https://en.wikipedia.org/wiki/Selenium_rectifier

In the early stage of failure they produce a modest amount of sweet-smelling gas. Sometimes described as 'sickly-sweet'. At that point the rectification properties are almost totally gone, allowing reverse voltage to leak through the rectifier. During catastrophic failure they produced significant quantities of malodorous and highly toxic hydrogen selenide that let the repair technician know what the problem was. By far the most common failure mode was a progressive increase in forward resistance, increasing forward voltage drop and reducing the rectifier's efficiency. During the 1960s they began to be superseded by silicon rectifiers, which exhibited lower forward voltage drop, lower cost, and higher reliability.

[decoder_82]

Thanks ! Do you have example of appliance / device using them ?

[Andy Chee]

[retiredfeline]

I last saw them in valve TVs when I was a kid. But even by then silicon rectifiers had started to displace valve and selinium rectifiers, so I never had to deploy one.

[soldar]

My sister had a record player of the type that was like a portable case with a handle and the lid was the loudspeaker and the base had the turntable and amplifier and it had one of these selenium rectifiers.  I reckon it was around 1967. It was not on any PCB but screwed directly inside the wood case, same as the transformer..

Soon later I saw the first silicon diodes, I believe they were BY127, with bright red body with square section, not round and black like they would be later. I might still even have one of those old ones in my generic diode drawer.