Bridge rectifier failure question

[labb]

If a bridge rectifier with a capacitor input load fails will it fail completely ie: no output voltage, or can it fail partially where you have some output but reduced voltage. Tks. My mind does not want to work today.

[sluckey]

There are 4 diodes in the bridge. They work in pairs. One pair works on a half cycle, the other pair works on the other half cycle. **IF** one or two diodes in a pair fail open, then the bridge will still work as a half cycle rectifier with reduced output.

But if any one of the diodes shorts it's likely to take out the complement diode in the other pair and also put your PT and filter caps at risk.