Re: [CAD_CAM_EDM_DRO] Power supply

Mina,

A simple solution would be to find a 12 volt transformer with a 10 amp
or so output rating, and wire its output winding in series with the
primary of your original transformer so that the 12 volt output of the
new transformer opposes the line voltage going onto the original
transformer. This will reduce the primary voltage by 10% (assuming that
the original transformer runs on 120 VAC), and thus lower the output
voltage by the same proportion. No winding cutting or removal required
that way.

This arrangement is called a buck transformer in industrial parlance,
and you can find boost/buck transformers on eBay easily. Depending on
the polarity of the wiring, they can boost or buck the line voltage by a
certain amount.

You have a 50/50 chance of connecting the setup right the first time.
If you have the wrong relative polarity, then the supplemental
transformer will raise the voltage by 10%. Just reverse the polarity of
any pair of the transformer primary leads to change things around.

HTH,
Dave

>>>
>>> I'm trying to rebuild the power supply that came with an old lathe,
>>> the Transformer is good I took 65 AC from the output fed it to a
>>> bridge to get the DC and then on to a Capacitor.
>>> The thing is the DC voltage after the bridge is stable at 65 VDC but
>>> after the Capacitor it grows up to 90 VDC which is too high for my
>>> Geckos 320.
>>>
>>> Any advise?
>>>
>>> Mina F.
>>>
>