transformer testing station

[fopoman]

has ever anyone built some sort of jig to wire up an unknown PT. So you can check voltages and all that wonder full stuff.

thannks,
Nathan

[tubesinside]

Assuming that you can identify the heater leads (usually the heaviest wires) you can feed these with 6.3V AC and measure all of the other voltages from here. Be very careful..you will have lethal voltages on several of the windings. No need to load the primaries but remember that measured voltages can be 5% to 10% higher without load.
Good luck and keep safe.
Cyril

[fopoman]

thanks for the reply. I was hunting ideas to build a testing station.

nate

[M Fowler]

I use a wood board with a srew type terminal strip.

Note my paired colored wires and screw the wires to the terminal strip and test the voltages.

I then take a sticky label and write the voltages down and apply to the PT.

[Firestorm]

[quote="M Fowler"]I use a wood board with a srew type terminal strip./quote]

Much more squared away than me: I just use two meters, a signal generator and a rat's nest of test leads and alligator clips.

The challenge is estimating current capabilities. Mostly "How big is it?" "Now much does it weigh?" You can guess what kind of HT current it was wound for, but it's hard to tell whether a heater winding will supply 5 amps or 10. I don't think I've ever heard a precise way to narrow that down short of loading the secondary and seeing what it takes to make the voltage drop.

EDIT: Just saw this posted here by passfan:

http://www.diytube.com/phpBB2/viewtopic ... 65&start=7

Haven't read it yet.

[dynaman]

Just checked some PTs against that chart and it jives. What a huge help! Thanks Firestorm.

[Drumslinger]

very helpful, thanks Firestorm.

[Firestorm]

passfan's the one who found it ...

Thanks passfan.

[Cliff Schecht]

Get a sinusoidal function generator so you don't have to worry about the HV aspect. Set it to 60 Hz and max out the output amplitude, measure this RMS value and attach the primary wires. The secondary windings can be measured and back calculated to figure out the ratios and output voltages (unloaded). Much safer than using wall voltage!

[passfan]

passfan's the one who found it ...

Thanks passfan.

Glad it helped. I know what a pain it is for me scavenging iron from old organ amps and guessing based on weight and size. I knew it would be helpful as soon as I saw it.