hot miniature transformer

[Tony Williams]

Unfortunately yes. I've measured a few of these

[Dave Plowman (News)]

Quick correction on that. The RCD feeding the Safeblock had tripped. It does get hot - near enough too hot to touch.

[N. Thornton]

That might be the case, but it usually isnt, and we certainly cant assume it is - therefore we can not conclude its safe, and it probably isnt. Therefore a risk is present. If its the PSu case thats that hot. Even if its the TF itself, 60C no load is still a far call from 'we're confident its safe.'

Regards, NT

[Dave Plowman (News)]

Some actual results from a 9-0-9 250mA chassis transformer - brand new.

Open circuit after approx 1 hour measured on the top of the clamp - 68 C Approx half load (136 ohm resistors)""""""""""""""""""""""""""""" - 55 C

[The Natural Philosopher]

They do indeed run hot. If its not over 100C its probably safe to run tho - insulation tends to go at 200-400C and most irons start to get dodgy magnetic wise at over 150C.

[The Natural Philosopher]

I agree 100%.

[Steven Briggs]

In message , "Dave Plowman (News)" writes

You had me worried with your previous post ;-)

So there you go, small transformers run hot.

[Scott Mills]

I am not surprised by this result.

[BillV]

Thats not a very good design then.. How would the designer know if the transformer was always going to be loaded or not?

[The Natural Philosopher]

Woukd sem to be a bit pointless if not loaed.

Why not leave it out altogether.