trying to figure out xformer wiring...

[cowanrg]

i have a pair of 1.7kva transformers that im trying to use for an amp, but i dont have a wiring schematic. i was told when i bought them that they were dual 45v secondaries, with a 12v secondary.

that seems pretty simple, and i can kinda verify that. but the primaries are confusing me. i have attached a couple pics to help out. i am in the US, and have 115v mains here. how would you go about testing this, hooking it up to find out what wires are 115v primaries? thanks a WHOLE lot. i dont know nearly enough about transformers to figure this one out on my own.

from the picture, the wire colors are from left to right: black, green, grey, purple, blue, white (those are the assumed primaries). then, the secondaries are brown, brown, red, yellow, red.

the green is two wires tied together, and so is the blue and yellow.

[cowanrg]

here is a schematic i drew up. i simply took a meter and checked continuity of the wires. so, white is connected to blue is connected to purple. same with grey, green, and black.

the wires are in the same order as the picture above. im thinking it has dual secondaries and the yellows are just tied together to make a single secondary. but, the primaries confuse me, ive not seen enough transformers to know whats going on...

any help is appreciated!

[cowanrg]

nobody?

is there at least an online tutorial someone can point me to so i can figure out how to hook this thing up?

[rpapps]

Hi
At first glance, I would assume the Brown/Brown to be the primary but I'd check with the ohmmeter first.
Can you post the actual resistance of each winding as this may give a clue.
Cheers
Rob

[cowanrg]

i can post actual resistance...

the brown/brown isnt primaries because its like 32ga or so. im almost sure it is the 12v tap.

i can post resistances though.

[cowanrg]

ok, ive metered it all and have the actual resistances for you all:

between red and yellow, its 0.4 ohm, and between red and red, 0.4 ohm.

between grey and black, there is around 0.9 ohm, and 0.9 ohm between green and black and grey and green.

between purple and blue, 0.3 ohms, between blue and white, 0.6ohm, and 0.6 ohms between whte and purple.

these values vary a whole lot though... i tested multiple times to try and see what was a valid value and what wasnt. sometimes i would get lower or higher values, it was very random.

[rpapps]

What does it measure between the browns?

[cowanrg]

it measured around 0.2 - 0.3.

[mpmarino]

I always have fun with this, and blow a lot of fuses .

Are the yellows and reds thinner than the cloth covered wires..do they seem to be buried deeper? If so I would guess that the reds and yellows are dual primaries and the secondaries are dual-dual (layout=measure??). I bet you are right about the browns.

I like buying single secondary toroids for cheap , finding the center of the secondary and soldering my own center tap in..DIY!

I have attached my guess, Truly a guess.

B careful..!

[rpapps]

I think my next step would be to connect 12 volts AC to the brown winding and measure what voltage comes out of the others. That should get us close to the final answer.