Date: Wed, 08 May 2002 16:38:40 -0600

Author: Jerry DiMarco

Subject: Re: Power Supply


I just built one of these. Already had the variac, it is an Ohmite
VT20N. Must have been left over from some project that predates me. Also
had a lot of the other parts, only had to buy the box, meters, breaker and
surge limiter. The surge limiter (not to be confused with 'surge
supressor') was needed because the turn on surge caused by the variac
tripped the breakers in the new building. Maybe you could contact Ohmite
and ask if they know of any manufacturers making power supplies with their

Jerry D.

At 5/6/200212:24 PM, you wrote:
>I would like to buy a 25 volt 25 amp variable DC power supply.
>It should simply consist of an on-off switch, a high current variac,
>a high current bridge, and a filter capacitor.
>Does anyone know where to get a variable DC supply this simple?
>Most power supplies have lower power and a lot more regulation.
>I don't mind having the ripple on the DC. I want 625 Watts power and low
>Mcmaster-Carr has manual battery chargers that are similar to this.
>But they do not have a variac so they're not variable, and they don't have
>a cap so they produce pulsating DC.
>Does anyone know where to get one like I described?
>Can't wait for Boise!


Jerry DiMarco
Manager of Lecture Demonstrations and Instructional Labs
Montana State Univ., Physics Dept.
Bozeman, MT

Our Motto: "We don't use anything the way it was meant to be used."