On 01/14/2011 03:35 PM, Terry wrote:


The rectifier I have is a GBPC1210W; data sheet says 12 amp, 1000 v.
It is rectangular with a hole through the center. It looks like it
ought to be mounted to a heat sink, but the data sheet I saw doesn't
say anything about doing so.

The question is: should a bridge rectifier be heat-sunk (sinked?) in
such an application? If so, how big (roughly) should the heat sink
be? Would it be sufficient to bolt the rectifier to the 4" square
metal enclosure? Thanks for your input.
Yes, it needs to have a heat sink. if the enclosure is 1/8" aluminum,
this may well be enough. If thin steel, then maybe not, but it will be
better than just hanging in the air. You can figure that any time the
bridge is conducting current, there will be two diodes in conduction,
dropping about a volt each. So, at 12 A, you would have about 24 Watts
to get rid of. If the cabinet is too light for removing the heat, a
chunk of 1/8" aluminum would help. Also, you should put heat sink
grease on the back of the bridge to conduct the heat better to the plate.

Jon