Cheap way to test HV sections with out Variac

[ElectronTubesRule]

Ok so I have an old 6/12 2,5,10 amp batter charger. I took it apart cleaned the Transformer with iso/alcohol then backed it the over at 180 degree's F. Then I mixed up some resin and poured into the transformer. I replaced some of the diodes and cap's since I intend to return it to being a batter charger. So I am taking the 12V output from this before it get's rectified and I am going to use that to feed circuit's for testing. I figured that at 12 volts I should be able to test the circuits for sound design and performance. Since 12 volts is 1/10 the primary supply voltage I thought it would be perfect for testing the circuits with out having H.V. going through the parts.

I do not know if this is a good idea but I thought it might be helpful someone else on here that might not have a variac for testing.

If this is a bad idea do let me know.

 

[wavrider]

fuse the secondary output or put a light bulb in the secondary in case the HV circuit under test has a short or malfunction, besides that should work fine for a no load test of a hv circuit test.

 

[Captain Kilowatt]

Be sure and verify the exact voltage output from the transformer. Battery chargers are sort of a "close enough" type thing.

Why bake the transformer and seal it with resin BTW? No need to bake it because moisture will not harm it because it is not HV. Same goes for the resin idea.

 

[ElectronTubesRule]

The paper used was not in the best shape and this battery charger is at least 50 years old. I thought that since this things sits outside in my pole barn and is often outside in the winter that it might be wise to stop it from decaying any more. So I baked it at 180° to get any residual moisture out of the paper. Then I taped the one side so it would not leak out and poured resin in. I have resin on hand because I do body work with fiber glass and carbon fiber etc....My goal was to keep the paper from decaying any more. I was afraid that if I did not do something then in a few more years the paper would have disintegrated. It looks like they used just plain unwaxed paper no wax no tar no resin nothing. So it was just an attempt to slow the rotting and break down of the paper. Now the paper is translucent yellow and it is hard and prob. close to moisture proof. I use this battery charger all the time I have had it for at least 15-20 years myself. So when I say how bad the transformer was I just wanted to slow down the ravages of time! If not in a few more year's I am sure I would have had to re-wrap it or replace it with a new part!

Yes, it is going to be for no load testing just to check that all solder joints are good and all the parts are allowing electricity to flow as it should through the circuit. I always check small parts like diodes and resistors before I put them in since it is easier to do it before you put them in place. It seems like if I do not check a part before I put in in place that will be the one problem in the entire thing! My Dad used to tell me as a kid I had "Buzzard Luck" so now I just check since I do not do a lot of electrical work not like I am spending my time just checking parts all day. It never hurts though to check a completed rectifier board for instance before you decide to put it in a box and send HV through it!!! I am not a chicken of live testing but I do like to minimize my risk when ever I can do so with out hurting the final outcome!

I will definitely use the light bulb idea! Thanks.