CT transformer question

[phalanger]

Even though the answer to this is probably straightforward, I could not find it with a little searching so I'll venture to ask:

Can a CT transformer of say, 300-0-300 @ 250mA be used to supply two separate (single-ended) powersupplies with 300V@250mA each? Does that work, and if so, should the CT be grounded or not? How to wire the 0? In this arrangement, the powersupplies probably run in counter-phase, would that be of any consequence when powering two channels of an amplifier with it?

I hope someone can enlighten me on this.

Thanks in advance.
Alexander

 

[abraxalito]

When a CT'd trafo is used the two supplies won't be separate, they'll be cojoined at the CT.

Normally rectification will result in the peak (not RMS) voltage on the reservoir caps so with your trafo you'll end up with DC rails of roughly +420V - 0 - -420V assuming perfect regulation.

The CT will normally be grounded yes, because its a safety requirement to have exposed metal parts (i.e. input socket grounds) earthed.

 

[TonyTecson]

the 250mA rating of for a ct type psu into a resistor load, something like 420 volts unloaded assuming a capacitor input filter....i am not even sure that your idea will work....

 

[DF96]

There is a general rule in electronics: two things cannot be both joined and separate.

Some CT transformers actually have two secondaries which are externally joined. In this case you can undo the join and use them as separate secondaries. If it is a genuine CT then you can't do this.

 

[TonyTecson]

^i learned that the hard way, glad that it is all behind me now...