Re: [CAD_CAM_EDM_DRO] Re: Charging Capacitors

Larry, you can run even a 220V Variac across 110VAC without difficulty.

Be aware that Variacs do not provide line isolation, and either output
lead may be "Hot", and essentially connected straight to line voltage.
It would be best to run the output of the variac to an isolation
transformer and then to a diode bridge, and thence to your capacitor.

To measure the leakage current put a DVM configured for current
measurements in series with the charging circuit (between the bridge and
the cap). It will show the charging current as you raise the voltage on
the Variac. (Raise the voltage slowly to avoid blowing the meter). The
leakage current is how much current flows when you are NOT raising the
Variac voltage, in other words, the steady state current that flows (or
leaks) through the cap.

Dave


Larry Olson wrote:

> Or can I run the transformer on 110 (single leg and neutral)?
>
> -----Original Message-----
> From: Larry Olson
> Sent: Friday, June 02, 2006 12:11 PM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: RE: [CAD_CAM_EDM_DRO] Re: Charging Capacitors
>
> I've got a 120VAC variac but my transformer is 220. Can I connect the
> variac to one of the mains legs and vary the voltage that way?
>
> Larry Olson
>