# Full wave rectifier with a high DC offset voltage?

For a full wave rectifier, can it rectify an AC wave with a DC offset above the rated voltage of its diodes rated voltage if the peak to peak voltage of the wave is within its rated voltage? Like if you had a rectifier that with diodes that could work up to 10 volts, and you were rectifying electricity with 100 volts DC and a 5 volt amplitude sine wave ripple, would it work because the AC component is only varying by 10 volts?

• Sounds like a bad idea considering how cheap diodes can be. They should be rated at 3 times the AC voltage to have a 50% safety margin. Remember the peak DC value will be 1.414 times the RMS value.
– user105652
Oct 1, 2018 at 0:06
• There may be a best practice forbidding this, but I suspect it's OK. Each component must be rated for the voltages that will pass across it, so you must make sure the circuit is designed so the offset voltage will never be applied across the components of the rectifier. I won't write this as an answer because I don't possess the necessary degree of certainty.
– K H
Oct 1, 2018 at 0:07
• Why would you need to rectify that? Oct 1, 2018 at 2:49
• You need to draw a schematic of exactly what you intend. I can think of circuits where the answer would be yes, or no, depending on the details. Without those details, there can be only one answer, no. Oct 1, 2018 at 7:23
• An AC voltage with high DC offset is really a DC with some ripple voltage. It makes no sense to rectify DC. Oct 1, 2018 at 7:46

No, you can't do that. If you have 5V peak-to-peak riding on top of 100V dc then two of the rectifier diodes will always be forward biased. The other two diodes will see a combined reverse voltage that varies from 95V to 105V. On the other hand, it really doesn't make sense to use a rectifier when the input voltage is always positive.

To answer this question, we'd need a little bit more background information, but here's a few ideas:

If you wish to simply get rid of the ripple from a powersource for e.g. an audio power amp, a series of RC lowpass filters is a good idea. Here's a link that discusses the subject: http://www.learnabout-electronics.org/PSU/psu12.php

If you're not going to draw much power from the supply, I guess could could go with a diode and a capacitor:

simulate this circuit – Schematic created using CircuitLab

If you really want to do what you're saying, (i.e. a fully rectified ripple wave on top of 100VDC), then the following might work (but no guarantees, I haven't simulated it).

simulate this circuit