AEG rectifier

[tubee]

I have here from old parts an AEG Rundfunk-Gleichrichter, (broadcasting-rectifier) coded B 250 C 125 L

B should be silicium 250 the voltage, 125 the mA's i think.

It is a black aluminium tube about 11 cm long, and 27mm diameter. Wires come out of bottom like a lytic cap. It has 4 terminals, 2 yellow (AC) and a red (+) and blue (minus)

Has anyone some info about this rectifier. How does it work (silicium, or mercury??) Might use it for a rectifier in a single 6922 line amplifier.

Thanks

[ulibub]

If it is in a can like an electrolytic, than it is an old selenium bridge rectifier. They were often used during the fifties in radio sets.

You are right, B 250 C 125 means "bridge, 250 Volts, for capacitive load (C), 125 mA.

Greetings

Uli

[tubee]

Thanks Uli for reply

If its Selenium, (or maybe Germanium) how is performing in power supply compared to fast shottky like diodes?

[ulibub]

I am sure to 99% that it is Selenium. This was before the age of Germanium and Silicon in Europe, when only copper oxide (the flat aluminium cases) and Se (the colums with many disks, sometime built into a can, like yours) were used as semiconductors. I also have such old things still in my boxes....

Its performance - if you really want to compare it to "modern" diodes, and be it only a simple 1N4004, is almost - non existant.... Very high interior resistance, high voltage drop (easily 30-40 V), just like an old rectifier tube of the 30's... That time (in the 50's) it was an improvement - they needed no heating.

And they are incredibly slow and work only up to a few hundreds Hertz - so usable only for mains rectification. They also have a huge interior capacity.

So if you want to use it, do it for historical reasons - to keep the look of a historic set, or to show the working of an old technique. From an electrical point of view, I would forget them.

Uli

[tubee]

Thanks Uli for your clear reply. Will stack it in my garage again.

[Eli Duttman]

Will stack it in my garage again.

It needs to go to a landfill that handles toxic waste. Selenium rectifiers are ticking time bombs. Sooner or later, they fail. When Selenium rectifiers fail, toxic vapor and toxic dust are produced.

[tubee]

Then i'll stack it in the other corner of my garage, with boxes of old medication, 486 and other pcb's, solvent containing paint leftovers, and replenisched oil to be recycled.

[Tweeker]

Put it next to the cyanide, its more toxic.

[tubee]

I wrapped it in aluminium foil, and stacked above the pcb's. Will recycle it soon, and tell the employee there its seriously toxic.