OT: Bridge Rectifiers

Predictable? No. As long as the rectifier is rated 25+ percent higher than the actual load, you should expect a long life. High heat is what kills them. So if your rectifier is rated at 100A, Try not to push anymore than 75A through it. You can also put rectifiers in parallel. Since they are sharing the same AC input, they are automatically in phase. This will greatly reduce the heat generated.

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20 years? 50 years? This system is 26 years old. I do not know how much use it actually saw, but it was not a cheap system in its day. I imagine it saw some. It was well beyond the price range of even the most dedicated hobbiests in 1984. Are you saying basically that if it works fine now under the load I plan to use, has a suitable safety margin, and doesn't get hot it should be fine for an indefinite period?

Not a bad idea. There are a couple salvageable modular rectifiers that look the same as this one in the control cabinet, and one that is bread boarded for the lower voltage stuff.

Thanks Jim.

Jim is right Bob. Component mfg's will give you life expectancy values on a general basis, for production type components. For special components they can give you a more specific life expectancy but it's always got an escape clause. Solid state components can be used in too many different applications for a specifice life expectancy to be guaranteed. A resistor for instance could last a lifetime.and longer. But .... on the other hand it could blow .... tomorrow ... just like that light bulb you bought yesterday. However, I've got some of those Ademco keypads used with the 5600 wireless panels still in service. The keypads have an incandescent lamp. That's gotta be about 30 years and still working. I think they were 14 volt bulbs powered by 6 VDC. Go figure.............

Nevermind. I just looked for the heck of it. 400V 25 amps. 2.75 each new. ROFL.

ews.eternal-september.org...

That's hardly worth the skin off your fingers ..... it took to type the question. ;-)

@news.eternal-september.org...

I pulled a Sq-D rectifier out of service for door chime service last year that was still working but not needed that was built in 1934 pretty amazing how long some of that old stuff holds up. I have a 1940s era 1000 watt AM Collins transmitter up at the station we keep in reserve duty and it fires up every few weeks and is strong as ever. I got pictures of it on my face book wall all fired up with the tubes lighted pretty cool.

• That's hardly worth the skin off your fingers ..... it took to type

• the question. ;-)

Well... I have them. I thought no point in buying them if I already have them Then I looked on Ebay and the asking price for the driver boards they are on (which I won't be using) are several hundred dollars each used. I suspect I could list the boards I am pulling with a starting bid of a dollar and more than make back enough to buy new rectifiers, and new caps, and maybe even a couple of the driver boards I do plan to use. LOL.

I pulled a Sq-D rectifier out of service for door chime service last year that was still working but not needed that was built in 1934 pretty amazing how long some of that old stuff holds up. I have a 1940s era 1000 watt AM Collins transmitter up at the station we keep in reserve duty and it fires up every few weeks and is strong as ever. I got pictures of it on my face book wall all fired up with the tubes lighted pretty cool.

Nick, keep those big ole tubes clean, a little hand grease and you'll be looking for a replacement..

keep an eye on those caps too, if they start to fade they can take out a transformer pretty fast.. Hopefully you'll hear the ac buzz first.. ;-)

RTS

=A0and =A0you'll

I take loving care of the Collins