Power Supply Rectifier question

[john65b]

First, forgive me for asking this as it may be quite basic, but better safe than sorry...

Can I use a standard 25A Bridge Rectifier without the neg connected?

For example, I only need the positive side of this Dual Rail amp power supply.

The rectifier will have AC connected to both sides, but only have the + and Tranny Centertap as ground. The - of the rectifier would be unused...Am I pushing the limits of the existing rectifier positive side, assuming I am not exceeding volt/amp rating?

I know I can just get two diodes and make the right rectifier, but already have the FWBR and its in the chassis...

Just thought I would check with some "experts"

 

[nigelwright7557]

Yes that's a standard full wave rectifier with two diodes.

 

[wwenze]

You won't "push the limits" of the rectifier... In its intended application, xxx amperes of current will flow through two diodes in series, now you have xxx amperes flowing through one diode while the other does nothing, the working diode won't complain to the trade union.

 

[Rundmaus]

If you leave out the "-" connection the circuit is a standard full wave rectifier, as nigelwright7557 already wrote. Depending on the intended application, a bridge rectifier configuration might be more useful: leave the center tap of the transformer unconnected and take your output voltage from the "+" and "-" connection. This gives approx. 2 times the voltage of the full-wave rectifier and makes use of all four diodes.

Regards,
Andreas

 

[john65b]

Problem is I can't use 2x the secondary voltage... that would be 140VDC - 0.

Maybe a bit more info is in order - this is a transformer that was salvaged from an amp that had +70VDC- 0 -70VDC dual rails. It has a complete tranny, FWBR and caps. Transformer secondary is 50VAC -0 -50VAC

I have an ICEPower amp that does not use dual rails, but single 70VDC - 0 rail.

I wanted to see if I could use the existing transformer, FWBR and caps using the positive rail only, as discussed above.

I could just FWBR the CT-50VAC (or half of secondary winding), but I think I would lose (or only use half) the full VA of secondary winding. Just disconnecting the neg rail I should have available the entire VA of the full secondary winding, correct? Or am I missing something basic?

 

[AndrewT]

use the "full wave rectifier" . This uses the whole transformer and needs only two Power Diodes.
The bridge rectifier has a full wave rectifier inside, but the other half is unused.

 

[Rundmaus]

If you need only the 70V, it is perfectly ok to use the full wave configuration. Maybe with two single diodes, or use the existing bridge. The "-" connection remains unused then.

Regards,
Andreas

 

[john65b]

Yup. I got it. Thanks!!