Re: [CAD_CAM_EDM_DRO] Constant voltage transformer

Hi Dave,

I seem to recall a load resistor on the old hard-drive power supplies
that had the ferro-resonant transformers. I'd leave 'em. Should give
you a nice, droop-proof supply for your motors.

Alan KM6VV

dave_ace_me wrote:

>
> Hi all,
>
> Thanks to you who advised me that what I have is a constant voltage
> transformer or as some called it, ferro-resonant (sp) transformer.
>
> In doing some further checking, and going by the size of the frame
> and using the sq cm as the basis, it is of the same capacity as
> the 'standard' transformer that was in the same unit.
>
> My question is whether there is any plus (or minus) of using this
> constant voltage transformer over the standard transformer.
>
> The second question is to the reason why there is a 100 ohm
> (measured) resistor across the taps of the cap. Does the constant
> voltage transformer require a minum load or something ? I would have
> expected a much smaller bleed resistor over such a large cap.
>
> The resistor is a 100 ohm, 55 watt connected directly across the
> 68,000 / 75 volt capacitor.
>
> Dave