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Changing AC heaters to DC

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You will have to take care of the current rating of the transformer.

If you have a 1A 6.3v transformer and use a full wave rectifier
and a big cap you should get ~ 6.8v dc . 6.3 x 1.41 = 8.82
but you will lose ~2v in the bridge rectifier more important
is that your avaliable current is now ~ .5A not 1A.
 
It should not be any trouble. Just recitfy the ac, filter it with a CRC and adjust the resistance to get the right voltage. Be careful to calculate the power dropped over the resistor and make the margin like 50% or so. The resistor will be hot anyhow, but just control that it is not too hot when operating the circuit.

A big powerresistor or one of these resistors that you can mount on a cooling device might be an idea.
 
Hi Bereanbill

What are you trying to achieve? In some cases making DC out of AC can give more problems than solutions - and one such case is plain rectification and CRC filtering. Have a look at this site

If you are, for example, having HUM problems using AC I don't think you will solve them by simply rectifying and CRC filtering it.
 
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