Re: Bridge rectifier.


John wrote:
How do you check a bridge rectifier in circuit to be absolutely sure it
needs replacing. Conditions: No power applied as 2amp fuse in the
transformer primary blows immediately power is applied. Usual short circuit
procedures followed throughout but I don't place too much reliance on this
test . BTW, the rectifier (B40 C3200/2200)) is in a theatre organ purchased
from an outfit no longer in business and space on the pcb is at a premium
and discourages using single diodes.
Thanks - John

First measure across the + and - leads of the bridge. If it's a steady
LOW, like under 10 ohms, then it could be the bridge or anything after
that. You'll have to cut the + lead of the bridge to isolate the
problem any further.

Then use an ohmmeter on its low ohm or "diode" range and measure the
resistance across each diode, in both directions. It should be very
different each way for each diode.

That part is a 4-amp 100 volt bridge. The rating may have been
marginal so I'd replace it with a somewhat heftier bridge.

.

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