Re: [CAD_CAM_EDM_DRO] Best way to vary output of 24V transformer?

Hi Donald,

What you want is a VARIAC. A variable transformer. Other then that,
try your 24V transformer with a "bucking" transformer in series with the
primary. ANOTHER 24V (12V for less effect) secondary connected in
series (opposing) with the supply 24V transformer primary will lower the
output by about 20%. I don't think a light dimmer would be advisable.
They typically "chop" the duty cycle of the AC waveform, NOT the P-P
voltage.

Alan KM6VV


Donald Brock wrote:

>
> Hello all,
>
> I have a power supply board minus the transformer (2.25" x 4"
> footprint) robbed from a broken down Panasonic copy machine. I know
> the voltage output on it is no more than 24V. The input is fused at
> 1.6 amps. It has 1 input and 2 outputs. One of the outputs is simply
> rectified and unfiltered. The other output is well filtered. I want
> to vary the output of a 24V transformer to find the output voltage of
> the board starting with a low voltage and working up to the voltage
> the regulator circuit is set for. The board appears to use a
> darlington configuration for the voltage regulation and a variable
> pot resistor for fine adjustment of the voltage.
>
> My guess is that a reastat (spelling?) is the answer but I'm not sure
> just how to go about hooking this up to handle both sides of the
> transformer output or what value it should be.
>
> OR
>
> Would I simply be able to use a light dimmer on the 110V side of the
> transformer to vary the output voltage? I've never tried this and
> would have to purchase the dimmer switch.
>
> Does any one have an answer?
>
> Looks like I could use it for powering relays or a dc fan if the
> output voltage is right.
>
> Thanks,
>
> Donald Brock