WHAT is this amps trafo ?

[ostripper]

I wasn't sure whether to start this in power supplies or solid state , as the "victim" is a classic Altec Lansing 2204a. My question is about the trafo. I never seen one like this. By the photo below , it seems to be 2 completely separate transformers paralleled. On each one , (green-red-yellow-red-green) = 46-38-0-38-46vac. Both "sides" are paralleled (see below).

#1- What would a trafo like this be called ?? (not a EI ? )

#2- Why did they parallel them and could it be used for a dual mono amp even as both windings use the same core ?

#3- what might a 32lb. trafo be rated at (VA ?). The amps were 4 X 75w or 2 X 150w bridged.

I could find no info on this amp AT ALL. Took a gamble for $20usd at Ebay.

I intend to use this for my Cordell triple as it seems to have the DC values after rectification that I desire. reds will give +/-55Vdc and greens will give +/-65Vdc (boosted supply).

PS- all the original amps work perfectly - would literally give them away (few $) to a Altec fanatic.

OS

[jam]

os,

That would be a c-core (or r-core) built with stacked laminatioms like an e-core
Hafler used to use these as well, all in all a pretty nice transformer.

Jam

[jam]

or,

[ostripper]

Originally Posted by jam

os,

That would be a c-core (or r-core) built with stacked laminatioms like an e-core
Hafler used to use these as well, all in all a pretty nice transformer.

Jam

C-core It is different than the picture , each "side" has a primary. Not a separate primary - secondary winding like the picture. at least I know what to google now.Thanks.

OS

[suresh]

it is R-core transformer . for audio it is better than E-I transformer in EMI radiation which will result in humming . it is been used in many japanese audio products long back . now it is absolute and no one manufacturing . for hi-end market is took away by torroidal transformers .
for audio quality
1. torroidal
2. R-core
3. E-I core

[ostripper]

Maybe not ? ... I saw it was "R" not "C" , a lot of chinese R cores !!
American , too !
China -
R-core transformer-DIBAO Transformer
USA-
Products - Custom Magnetics, Inc.

They say it has best qualities of both E-I and toriod , and best efficiency. Two coils cancel each others field.
I got the freakin' best... dang !!
OS

[megajocke]

I've seen them referred to as UI cores. They are often used instead of EI cores from about 1 kVA and up. My 230V/230V isolation transformer for the workbench is of that type.

If the primaries of the two transformer legs are run in series (maybe for European line voltage?) you'd definetely need the windings of both legs to be in either series or parallell, otherwise you'd get high voltage drop and radiated flux because the magnetic couping between the two legs isn't very high.

[ostripper]

The primaries are run in parallel. browns from each bobbin go to live 120V. Black and black/white stripe go to common (return). green/white stripe and white go together and are isolated (I don't know what they are for). All this references to my first picture at the very top

OS

[EWorkshop1708]

Looks like a nice transformer

[Tajzmaj]

Hi Os....
This is UI transformer like someone mentioned......The power can be calculated the same way like for the EI transformer.......It has advantage that it is low if compared to EI.......both coils must be wounded absolutely identical and than you can connect them in parallel on in series.......Such transformers have a lot ,,window,, space so you can wound a lot of wire or in the case of audio amplifier some wire with higher diameter to suck every single watt from the core, because we talk only about pulse consumption.....Those transformers are common in Big power amplifiers made by Crown and Carver.....
Regards, Taj