Transformer identification

[The Dark force of dance]

Y-ellow Ingo 'n' y'all.
	
At 09:35 AM 08/13/99 +0200, Ingo Debus wrote:

>Maybe these are transformers that don't need a low current fuse on the
>primary side, they are safe enough with the 16A which is there anyway.
>Here those transformers are often used for doorbells.

Yes quite likely something along those lines. though I've seen fuse rated
transformers -or whatever they call them/as used in plug-pack/wall-warts-
of similar ratings and they are tiny by comparison. You could fit at least
5 300ma/24 volt transformers in the space that these things take up. In
fact you could probably fit 3 in the volume of the core alone. We're
talking huge.

First of all. These are power transformers. No two ways about it. They come
out of old Telecom PSUs. There is a mains fuse mounted on the primary end
and the secondary is not only fused but also the rectifier section as well.
Very neat little plastic plug-in arrangements which hold standard 3AG
fuses. Along with 3 banks of spares. Presumably for a quick turn around.

I don't know exactly what these are used for in the telephone network but I
would presume they're made that way for high reliability. The thing that
gets me is that if you just wanted to over engineer them you could simply
use a transformer with 2 or more times the required VA. However this
doesn't seem to be quite the case. They can probably put out 600ma but are
5 times the size. The winding wire does not appear to be thick enough to
support anything more than perhaps an amp.

When I first scrounged them, I looked at them and felt the weight and
thought. "Hell if I put two of these things together I'd have enough VA to
run a couple of 50watt Power Amps. We had lots of them at the time so I
scooped up 8 of them and brought them home. (I use to work for a salvage
place at the time.) But when I pulled them apart I could see the windings
attached to the transformer posts and they were way too thin. Comparing
them to a transformer which was rated to run -and indeed does run- a couple
of 50 watt amps, I found there to be a huge and obvious difference.

So my guess is something along the lines Ingo mentioned. That they were
designed for high-reliablity and/or safety. Which is a big bloody shame. :(

In this particular case it's very obvious that they're not going to deliver
the current required for an amp application or what ever, but I'm just
curious. I'd like to find out what kind of current I could expect to draw
off them.

And one final note:
It was the entire powersupply which was rated at 300ma. The transformers
themselves carry little or no identification on them. The diodes forming
the bridge were 1N4004s so the limitations weren't there. And that was
about it as  far  as the contents of the PSU. Transformer-bridge-caps ---
end of story.

I'm not worried about them or even desperate to use them by any means but
simply pointing out that size and weight alone aren't necessarily a guide
to total VA.

Curiouser and Curiouser.

Thanks for that.

be absolutely icebox.

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