Introducing my new Variable AC isolated Power Supply..

[jpdesroc]

Hi guys,

Because one of my latest passion is vintage radios repairs
I started many years ago to look at some repair GURU’s videos on Youtube.
I discovered that to get efficient at radio repair you need
to own a minimum of RF and metering test equipment.
One of these test equipment would also be an isolated variable power supply
for testing AA5 (All american radio) non isolated radios
that have live chassis..
Because most of these Variable AC supplies are expensives
I decided to build my own with available parts.

This project of mine is viewable here:
http://www.arcenson.com/projects/AC_..._Power_Supply/

I hope this project could help some people to build their own.

Enjoy !
Jean-Pierre

[Diabolical Artificer]

Nice job Jean Pierre, looks well.

Andy.

[John M0GLN]

I built mine a few years ago but I wouldn't like to put it into a competition with yours, mine would come a very poor second, it's an excellent job you've made of it.

John

[Radio Wrangler]

Tres elegant.

There's only one thing I would have added, a large earth terminal on the front.

Sometimes, when running something on an isolated supply I want to be sure some big lump of metal is at a safe potential and that a fault to it will pop a breaker. This action increases some dangers and decreases others but sometimes it's worthwhile. When you attach scope probes you introduce ground connections. I like to know there's one in place strong enough to pop the breaker.

David

[Refugee]

I built mine quite a few years ago in a heavy duty GRP box.
It has moving iron meters and I normally power it from a 1KVA isolating transformer.
If I need 110V I have a smaller 110V isolating transformer yet to be mounted in a box.
I have several non isolating transformers too.

[jpdesroc]

Originally Posted by Diabolical Artificer

Nice job Jean Pierre, looks well.

Thanks Andy !

Originally Posted by John M0GLN

I built mine a few years ago but I wouldn't like to put it into a competition with yours, mine would come a very poor second, it's an excellent job you've made of it.

Thank you John !

Originally Posted by Radio Wrangler

Tres elegant.
There's only one thing I would have added, a large earth terminal on the front.

Sometimes, when running something on an isolated supply I want to be sure some big lump of metal is at a safe potential and that a fault to it will pop a breaker. This action increases some dangers and decreases others but sometimes it's worthwhile. When you attach scope probes you introduce ground connections. I like to know there's one in place strong enough to pop the breaker.

Good suggestion David.. Thanks.

[jpdesroc]

One thing I've been suggested to add is some kind of protection
(fuse or breaker) right in series with the variac's output wiper to limit
the winding current to the variac's current limit even and specially
when the wiper is at low voltages..
ext: 10vac that supplies more than the variac's current limit (here 4.5amp.)
So I will add a 4A fuse in series at the wiper side of the variac.
More protections !!

JP

[usradcoll1]

The Variac you're using is the best one available. I prefer that make myself.
Excellent job on the whole unit. I do a good job on my equipment myself, but not quite that good.

[jpdesroc]

Thank You !!!