Are Hammond power transformers good enough ?

[ray_moth]

Would the type of rectifier employed affect the temperature of the mains tranny?

It might make a difference, I don't know. The Amplimo 7N607 secondary is not center-tapped, so a bridge is called for. At first, I tried a hybrid bridge, with two SS diodes and a pair of 6D22S TV damper diodes, but the voltage I got from that arrangememnt was a little too low. I discovered that he mains voltage, nominally 220 v, was only 190 v!

I now use a bridge of four Motorola silicon ultra-fast-recovery diodes (MUR4100E). Those are tough little devils! I accidentally had one of them wired the wrong way around in the bridge: the toroid protested with an angry buzzing sound until the fuse blew, but there was no damage to either the tranny or the diodes - just the fuse!

 

[nhuwar]

Wow I never thought Peter W. Dahl would have ever been mentions on this forum at least by someone other then me. I had them make a 3 phase 600kva plate transformer once. Great transfomers built like tanks and good price for good quality. A 600kva 17kv per secondary was only $20,000.
I know that seems like big stats for this forum but it's just my experience with them.


Nick

 

[Dave Cigna]

If you don't mind me asking, what are you doing with a half million watts @ 17 thousand volts?

 

[nhuwar]

I used to work for a tv station they where the beam supply for the 64kw klystron tube amplifiers. One of the original transformer had a short in one phase of the primary and the company that made the power supplies was no longer in buisness so Peter W. Dahl did it. Also got bias and filament transformers from him. 4 tube 50 to 60 percent efficency.

You know I was wrong it wasn't 17 kv it was 9 kv anyway the dc output of usually 27kvdc but was variable from a hipotronics paschel automatic voltage regulator.
These regulator are the stuff if I was rich I would have on on the mains coming into my house if it was 3 phase of course



Nick