old voltage stabilizer as possible isolation tranformer

[ppavone]

I acquired this heavy monster for next to nothing not really knowing if it would make a good isolation transformer. It has to weight 30 lbs. It has a set of those giant capacitors that look to be coming of a separate winding on the transformer. The unit has a pretty substantial hum.
Is it worth using as an isolation transformer?
If so, i assume the caps are shot and I should just remove them?

 

[Elvee]

The unit has a pretty substantial hum.

That's normal for that kind of equipement: one of the windings resonates with the capacitor, and the resonance current generates a substantial hum, both mechanical and magnetic

Is it worth using as an isolation transformer?

It might, but you have to make sure the secondary is properly isolated from the primary: some cheap models do not have galvanically separated windings.
Also be aware that unless it includes an additional harmonic filter (high-end models have it), the output will be fairly distorted, more trapezoidal than sinewave.

If so, i assume the caps are shot and I should just remove them?

Certainly not: without them, it will not work properly and the output will stay at a few tens of volts

 

[ppavone]

That's normal for that kind of equipement: one of the windings resonates with the capacitor, and the resonance current generates a substantial hum, both mechanical and magnetic

It might, but you have to make sure the secondary is properly isolated from the primary: some cheap models do not have galvanically separated windings.
Also be aware that unless it includes an additional harmonic filter (high-end models have it), the output will be fairly distorted, more trapezoidal than sinewave.

Certainly not: without them, it will not work properly and the output will stay at a few tens of volts

Then for me it sounds like I'd be better off moving on to something else. Thanks

Sent from my SCH-I545 using Tapatalk

 

[Gusser]

One way to make a low cost isolation transformer is to place two surplus transformers back to back.

For example two 24v 4a transformers will make a 100 watt isolation transformer. The VA capacity of the smaller transformer if they are not equal will be the amount of AC watts you can get from it.

IOW, with a 24v at 4a, you don't get 120v at 4 amps back out. You get 100 watts or less than an amp at 120v because that what 24x4 equals in watts (VA) more or less.

(Yes I know watts and VA are not the same in inductive circuits but I'm trying to keep this simple)

 

[Osvaldo de Banfield]

Check with an oscilloscope the output waveform. Possibly, this can be CVT (Constant Voltage Transformers) whose output usually is severely distorted and can damage or overload some apparatus designed to run in a sine wave input.

Once I saw one of them that sourced 60V 50Hz square wave to power the cable TV amplifiers.

 

[basreflex]

you can build one out of two scrap microwave transformers. you have to grind open the iron package and remove the secondary of each tranny. then reassemble one tranny with the 2 primary sections. some have 110, 120, 220 230 and 240 taps. i built one as 120V transformer for US power tools.