Weird problem in Full wave (FW) bridge rectifier

Are you sure you are actually measuring the voltage across the load and not the voltage from one side of the load to one side of the input? Eg. single-ended input (one scope probe) with the other side at earth.

Best regards, Spehro Pefhany

Is the centre tap earthed?

If the parts are working correctly, then the circuit, simple though it is, must be wrong. Go back to the very basics and check everything - less time spent saying "it can't be" is less time wasted on the way to making it work.

Either it's wired up incorrectly, or something that looks connected is not actually connected.

This is the configuration I am using. (+) (-) represents the source. Now I am taking the +-10 Volt source from function generator embedded in CRO. One CRO for measurement and one for generating sine wave.

--------------------------- | | | | D D | | | | | C (+ probe RED ) (+) | | R | | R O | (-) | | (GND probe BLACK) D D | | | | | | | | | | ------------------------------

Cleaning up that gibberish:

---(+)--------------------- | | | | _ _ | | ^ ^ | | (+ probe RED ) | | | C (~) (~) \\ R (Oscilloscope, in elderly TLA) | | / R O _ _ \\ | (GND probe BLACK) ^ ^ | | | | | | | | | | ----(-)----------------------

If you are feeding it a signal (~) that goes from oscilloscope ground to a positive voltage, there will be no negative part of the waveform - this is perhaps what is happening if you are using a scope probe test signal as your AC source. Try a plain old transformer. Diodes have polarity, so drawing them as "D" is not useful.

Thanks Lawrence you are correct. Circuit is behaving as it should behave with plain old transformer. Regards Deepak