External PSU for preamp

Tyimo

Member
2002-11-16 3:43 pm
Hungary
Hi!

Could somebody help me how to make a symmetrical +/-24VDC PSU from a simple 24V AC?
I would like to use an external transformer and the bridge rectifier and caps etc. inside the case of the preamp.
I find something like what I need, but I don't need regulated, only passive PSU.

Thanks:

Tyimo
 

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Hi,
get your reference books out and find a voltage doubler.
Compare to your schematic top half & then bottom half.
I have not seen the idea of using reverse polarity to generate dual voltage and central ground before. Nice one if it works.
Build up a quick test circuit without any regulators and test the output voltages without a load. Should be about 2* sqrt2 * V or about +-30Vdc. All this from a single 12Vac secondary!!!
If it comes out this big then I will be very surprised.
Give us some feedback after you try it.