solid state rectifier differences

[wsaraceni]

what are the differences between the solid state rectifiers used for amps.

i've seen a bridge rectifier, used for amps without center taps. and then i've seen two other. one with two diodes and one with 4 (2 in series off of each transformer pair.

what's the difference between those two?

[surfsup]

http://www.hammondmfg.com/pdf/5c007.pdf

[martin manning]

...and then I've seen two other. One with two diodes and one with 4 (2 in series off of each transformer pair).

What's the difference between those two?

Putting two or even three diodes in series in place of a single diode is a way to increase the PIV (peak inverse voltage) capacity. The operation of the circuit is the same as with a single diode for each phase, and it allows a failure of one or more diodes without losing overall function. To some extent this is probably a hold-over from times when 1kV rectifiers were not as easily available or reliable as they are today.

[Bob S]

Early in my career I was always told that diodes (and capacitors) should be rated for a minimum of 2.5x the voltage they will see.
Easy nowadays for diodes.
The filter caps we use would have to be 1000v rated though.
Electrolytics have come a long way since back then.