• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Transformer question

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I have a quick noob question about a PT I have. It's secondaries are labeled like this:

250V/100mA - 0V - 250V/100mA

I'm not certain what this means the current rating is. I'm guessing another way to show this is 500VCT/200mA, correct?

Or is it 500VCT / 100mA ?


TIA!
 
On the same subject, I never got this really clear.
If I for example have a 500VCT @100mA TX what can I expect it to handle if used for bridge rectification instead of the (I suppose) expected full wave rectification.
Can I actually pull 100mA @ 500V?

/Olof
 
No, you can't get 100 mA since you have to supply capacitor ripple current as well as dc current - 60-70 mA would be more like it. With choke input you could get 90 mA or so. Duncan Amps PSU designer can give a good idea of the RMS transformer current for a given DC current.

Hi there
Yes I am aware of this, it was late and I did not express myself very clear. I refered to actual AC current to be drawn from the secondary.
What I really wonder is; if a TX is spec'd at 500VCT@100mA, is this for use in a full wave circuit where you actually can draw approx 60-70 mA at 350VDC?
Or can it be used in a bridge circuit to supply 60-70mA @ 700VDC?

It is quite a difference.

/Olof
 
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