Just bought a Transformer of ebay for £1.60 - what use is it

Torroidal - Avel
Primary 120 v + 120v
Secondary 18v + 18v

Built 1992

found a datasheet on the web
60VA
Secondary current 1.67
13% temp rise at 50

Is this way overspecced for any of the DIY projects

A few questions on transformers...
If you buy a big one - do the modules just draw the current they want ?
what happens to tthe rest of the current?
Or does it give you just more "headroom" ?

There is no mounting plate - just a hole in the middle of it - can you buy these separately - the data sheet says M5 screw

As long as you can accommodate the physical size of the transformer,this will be ideal for many +/-15V projects.
Make sure you understand the important mounting restrictions:mounting pin/plate to connect to one chassis surface only.

the rest is reasonable assumptions,no one knows the truth about instanteous peaks....

Robert

> If you buy a big one

Then you pay too much and need too much space. It may run a bit cooler, but there is some heat at no-load.

At 2 bucks, the "pay too much" is a non issue. And many systems can spare space for an oversized transformer.

That's enough for 50V or +/-25V DC at 0.6A DC. Not really right for an 8 ohm loudspeaker amp. Ideal for regulating to +/-18VDC if you have less than about 100 chip op-amps to power. For a more typical 10-chip project, a 20VA transformer is ample, an inch or two smaller, and at market price for iron, about 5 or 10 bucks cheaper.

Oh, and you have to pick your rectifiers to be bigger than the transformer. If you use a little 20VA job, you can get away with 1N1004 1A rectifiers. With a 60VA transformer, even if you only draw 0.020A steady, you need 3A or larger rectifiers to handle the high current available to charge the filter caps. At $2 for the iron, you can buy 3A rectifers and still come out ahead. (And in practice, 1A rects will probably last many-many start-ups, but if they fail short they burn up your transformer, no bargain.)