Help with any info on this T

[angelodp]

Ok here's what I get with 2v input on the 2.3ohm tap


Outputs below

Red - Red - 35 ohms - 30v
Red - Yl (CT) - 17 ohms - 15v

Gr - Gr - 31 ohms - 31.5v
Gr - short-Gr (CT) 16ohms - 17v

3.6 ohm pair - 8v

3.7 ohm pair - 8.2v

2.6 ohm pair - 1.9v

Not too sure what I can do with this at 120v that would be some very high voltage.

[angelodp]

Phil, so any thoughts on this hunk of metal? 1800VAC yikes

Ange

PS Thank all for the support

[martin manning]

This unit seems to have three pairs of similar windings. Someone suggested above that it might be from an oscilloscope. I'm not too familiar with tube oscilloscope power supplies, but the CRT's commonly used several to tens of kV's.

Gr - Gr - 31 ohms - 31.5v
Gr - short-Gr (CT) 16ohms - 17v

This seems to be an "uncentered" tap, maybe recheck that.

You could try putting 120V on the 8V winding and measure again. In theory you should get something like this:

PTVoltage.png

Using one of those as the primary would produce some useful voltages.

[angelodp]

Thanks Martin, how do you arrive at '4' for the divisor?

So the 31.5ohm now reads 30.4 and side to side is 15.8 and 15.2 - is that what you meant by uncentered? The T is sensitive to temperature. When I put my hands on the core the ohms do move upward.

[martin manning]

Thanks Martin, how do you arrive at '4' for the divisor?

So the 31.5ohm now reads 30.4 and side to side is 15.8 and 15.2 - is that what you meant by uncentered?

I was referring to the voltages. Resistance measurements are good for determining which leads go to which windings, and are a good clue to current capacity.
All the winding voltages will stay more or less in proportion, so applying 120 where you measured 8 will bring all the others up by the same factor, 120/8 = 15, so 2 becomes 30, etc.

I would connect your Variac to the 8V winding and your DMM to one of the others and monitor the voltage on the DMM as you bring the Variac up.

[angelodp]

Confirmed the 3.6ohm tap with 120v in is giving me 459v at the 35ohm pair.

So this T can provide a variety of test voltages on the bench but not good for an amp build.

Nice to use the variac with Sluckeys meter idea installed for very accurate readings.

[angelodp]

Any idea what that single unconnected wire is about. It does not show continuity to anything? That wire has a small tape (looks original to the unit) that has G on it. But I do get continuity to the bell or core.

[martin manning]

Electrostatic shield most likely: https://americas.hammondpowersolutions. ... tic-shield

[angelodp]

Thank Martin, found this on K-factor and harmonic distortion. So that wire helps quell this possible anomaly?

https://powerquality.blog/2022/03/03/k- ... 20currents.