I have an adjustable 0-400v dc power board and want to add a rectifier to achieve +-dc voltage. Can someone please help me with an appropriate rectifier.

 

I have an adjustable 0-400v dc power board and want to add a rectifier to achieve +-dc voltage. Can someone please help me with an appropriate rectifier.

Can't do that with just a rectifier. Why do you think you can?
All a rectifier can do is allow current flow in one direction, and block in in the reverse direction.

If you want ±400Vdc, you will need to use a switching regulator to convert the +400V to -400V.

If you can settle for ±200Vdc then you might be able to use a virtual ground circuit, depending upon the difference in load current between the plus and minus outputs.

 

Can't do that with just a rectifier. Why do you think you can?
All a rectifier can do is allow current flow in one direction, and block in in the reverse direction.

If you want ±400Vdc, you will need to use a switching regulator to convert the +400V to -400V.

If you can settle for ±200Vdc then you might be able to use a virtual ground circuit, depending upon the difference in load current between the plus and minus outputs.

Thanks for your help. What I am trying to do is get+-80v dc for an audio project. I have lots of carcasses laying around. Ie. Transformers amp boards circuit boards etc. I have adjustable 0 to 400v dc. I need to get a + and - dc with a ground. Can you help. I have many different regulators rectifiers caps diodes resistors.

 

A linear regulator would be too lossy.
You have to use a switching regulator with topology like half-bridge.
Another option is split 400V rail with two capacitors so you get +200V and -200V, make a high voltage amp from this rails and put an transformer between amp output and speaker.

Btw, what is the 400V power supply? Just a mains rectifier?

 

A linear regulator would be too lossy.
You have to use a switching regulator with topology like half-bridge.
Another option is split 400V rail with two capacitors so you get +200V and -200V, make a high voltage amp from this rails and put an transformer between amp output and speaker.

Btw, what is the 400V power supply? Just a mains rectifier?

I have a boost module op amp pcb with irf749 12v dc in and 0 400v dc ou

 

I have a boost module op amp pcb with irf749 12v dc in and 0 400v dc ou

IMHO it would be borderline ridiculous to do what you are trying to do with the components that you have. Even if you have the design chops to conceive of a design it is far from certain that you could realize this design. A boost ratio of 33.33 probably involves a transformer and the specification of transformer to double that for various types of DC-DC converters is far from straightforward depending on your power requirements which you have not specified.

If you want ±80V then start with a mains transformer and produce that. Going from +12V to +400V to ±400 just makes no earthly sense. It makes even less sense for an audio project. for that matter it might be easier to forget the 400 volts altogether and go for ±80 V directly from +12V. The boost ratio is 6.67 which is borderline difficult, but still possible for a direct boost converter.

 

You just need another identical power supply to produce the negative voltage

 

IMHO it would be borderline ridiculous to do what you are trying to do with the components that you have. Even if you have the design chops to conceive of a design it is far from certain that you could realize this design. A boost ratio of 33.33 probably involves a transformer and the specification of transformer to double that for various types of DC-DC converters is far from straightforward depending on your power requirements which you have not specified.

If you want ±80V then start with a mains transformer and produce that. Going from +12V to +400V to ±400 just makes no earthly sense. It makes even less sense for an audio project. for that matter it might be easier to forget the 400 volts altogether and go for ±80 V directly from +12V. The boost ratio is 6.67 which is borderline difficult, but still possible for a direct boost converter.

I can set the boost module to be 80v dc . Then is it possible to get the +-? With a rectifier is that earthly possible?

 

I can set the boost module to be 80v dc . Then is it possible to get the +-? With a rectifier is that earthly possible?

I do have a transformer with 120ac in and 80v ac out 45v ac out and 35 ac out. Can you please tell me how to rectify to dc+-

 

What I am trying to do is get+-80v dc for an audio project.

What power level are we talking about? An audio amp with +- 80V rails, driving an 8 Ohm speaker at max volume would require ~400W !

 

I do have a transformer with 120ac in and 80v ac out 45v ac out and 35 ac out. Can you please tell me how to rectify to dc+-

What you want is a transformer with a 120 VAC primary and a center tapped 120 VAC secondary. Each secondary winding will give 60 VAC which when rectified will give approximately 85 VDC after rectification. Now you can easily make ±80 VDC power supplies with some allowance for losses.

 

I can set the boost module to be 80v dc . Then is it possible to get the +-? With a rectifier is that earthly possible?

No! A rectifier WILL NOT DO WHAT YOU WANT IT TO DO! My apologies for shouting, but you have been told this repeatedly.

 

What power level are we talking about? An audio amp with +- 80V rails, driving an 8 Ohm speaker at max volume would require ~400W !

Yes I know that.

 

So what is the power rating of your transformer, or that boost module?

 

So what is the power rating of your transformer, or that boost module?

0 to 400v dc I think it is 5 amp but not sure. I've uses it to power some vaxume tube amps on the past. Ans thanks for your help