Toroid Toroidal Power Transformer Installation

[1885]

I just purchased a

Toroid Toroidal Power Transformer T140 0-20-24-27V 5A

Noobie I am!

I need help hooking it up.

There are two black red leads for input.
? Am I save hooking both up to 120 VAC in parallel?

? On the output end I've got 0-20-24-27V
black, blue , green yellow

How do I get 27VAC (black and yellow)

How do I get 24VAC (black and green)

How do I get 20VAC (black and blue)
This is a lot of amps to play with.

Thanks,
1885

[AndrewT]

This transformer will only give (high power) single polarity supplies.
Many Power Amplifier Projects require dual polarity supplies and for these you need a dual secondary transformer or a Centre Tapped secondary transformer.

Is that transformer fitted with dual primaries? What is the voltage rating of the primary/ies

[1885]

Originally Posted by AndrewT

This transformer will only give (high power) single polarity supplies.
Many Power Amplifier Projects require dual polarity supplies and for these you need a dual secondary transformer or a Centre Tapped secondary transformer.

Is that transformer fitted with dual primaries? What is the voltage rating of the primary/ies

I do believe it has dual primaries. 2 black and 2 red.

It s for a power amp with a rectifier that provides 27VDC + and 27DVC -

thank you

[AndrewT]

You can half wave rectify from your single secondary transformer to give a low power dual polarity supply. But, this is not recommended for higher power use.

The transformer you have is, basically, wrong.
For a +-27Vdc supply you need an 0-18, 0-18 dual secondary or a 18-0-18Vac centre tapped secondary (sometimes specified as 36Vac Centre Tapped). You may find that a 20Vac dual or 40Vac centre tapped will also give close to +-27Vdc.

[1885]

Originally Posted by AndrewT

You can half wave rectify from your single secondary transformer to give a low power dual polarity supply. But, this is not recommended for higher power use.

The transformer you have is, basically, wrong.
For a +-27Vdc supply you need an 0-18, 0-18 dual secondary or a 18-0-18Vac centre tapped secondary (sometimes specified as 36Vac Centre Tapped). You may find that a 20Vac dual or 40Vac centre tapped will also give close to +-27Vdc.

Well this is what I purchased:
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

for this kit:

power:
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

amp:
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

If I got the wrong transformers I spent a lot of money for nothing

[AndrewT]

you have the wrong transformer.
But, fortunately you have choices.

The regulators can be used to reduce the "too high" supply voltage. The regs will also smooth the high ripple voltage that the half wave rectifiers must inevitably produce.
The amplifiers can accept upto +-38Vdc.
The amplifiers are configurable for Bridged and non-Bridged modes.

You should be able to use the half wave rectified solution if you keep the current demand low. Don't bridge the amplifiers. Don't use low impedance speaker/s.

Spend money on good capacitors with adequate ripple capability for the half wave rectified duty.

Far from the best way, but that minimises wastage and allows project completion. If at a later date you can use the transformer for another more suitable duty, then at that time buy the correct transformer.
In the meantime it will work and will produce music.

[CBS240]

If I had received the wrong transformer for that project and could not return or refund it, I would just re-wind the secondary for what the project requires. It is not terribly difficult to do with large toroids. BTW, that core is around the size where you might consider a 'slow start' circuit.

[1885]

Originally Posted by AndrewT

you have the wrong transformer.
But, fortunately you have choices.

The regulators can be used to reduce the "too high" supply voltage. The regs will also smooth the high ripple voltage that the half wave rectifiers must inevitably produce.
The amplifiers can accept upto +-38Vdc.
The amplifiers are configurable for Bridged and non-Bridged modes.

You should be able to use the half wave rectified solution if you keep the current demand low. Don't bridge the amplifiers. Don't use low impedance speaker/s.

Spend money on good capacitors with adequate ripple capability for the half wave rectified duty.

Far from the best way, but that minimises wastage and allows project completion. If at a later date you can use the transformer for another more suitable duty, then at that time buy the correct transformer.
In the meantime it will work and will produce music.

Thank you so much for the help. Live and learn . I'll learn a lot getting thing built.
I purchased the transformers from the same person I got the amp from.