Hey there,
I have a question about center tapped primaries on used, old-style PT's.
The transfrormer in question has a black start, black/yellow ct, and a black/red end.
For 120v mains, should I use the black and black/yellow, or black and black/red?
Could I hook up a signal generator to the secondary and gleen something from the primary that way?
When I first bought it, I thought it had 2 primary winding you could put in parallel since there is a white lead, but it turns out that the white wire is the bias tap on the secondary 😵.
I have a question about center tapped primaries on used, old-style PT's.
The transfrormer in question has a black start, black/yellow ct, and a black/red end.
For 120v mains, should I use the black and black/yellow, or black and black/red?
Could I hook up a signal generator to the secondary and gleen something from the primary that way?
When I first bought it, I thought it had 2 primary winding you could put in parallel since there is a white lead, but it turns out that the white wire is the bias tap on the secondary 😵.
No need for a signal generator, go to the experts.
https://www.rfcafe.com/references/electrical/xfr-lead-color-code.htm
Use either the tap or the end, depending on which of them gives the rated secondary output on your line voltage.
https://www.rfcafe.com/references/electrical/xfr-lead-color-code.htm
Use either the tap or the end, depending on which of them gives the rated secondary output on your line voltage.
If you can determine the heater winding, put a heater voltage on that winding (from another transformer). Then measure the voltage on the other windings.
Regards, Gerrit
Regards, Gerrit
The issue is, I don't know what the ratings are on this transformer and it has no code or anything.
Ill give this a try.
If the transformer has more than one winding, their loadings will interact.
But generally full loading will drop the voltage from open circuit by 5% to 10% for a good quality transformer.
You can estimate the VA by comparing with other similar looking units by weight.
But if in any doubt, underestimate the VA.
But generally full loading will drop the voltage from open circuit by 5% to 10% for a good quality transformer.
You can estimate the VA by comparing with other similar looking units by weight.
But if in any doubt, underestimate the VA.
IMO the best way to do the try is taking advantage of a current limited mains: use a filamentary light bulb of, say, 100W in series of proper voltage, and measure secondaries. Usualy the larger diammeter wire will be heater one, 6.3 or 12.6V, and eventualy 5V for rectifier. So you can take an idea if the primary is properly wired. And in case of error, light bulb will alert you. Reject leds and discharge bulbs (fluorrescent) of any kind. Filament must be dark or very slightly brighted.