Very hot power transformer on a JLM Dual 99v

Ive finally finished racking the Dual 99v modules I built some time ago. Im happy to say it appears to work with minimal issues.
Except, the powertransformer seems to be getting pretty hot, and fairly quickly (a few minutes).

The powertransfomer is a 240V to 25V + 25V 160VA torodial unit from Jaycar. It is housed in a seperate (minimally ventilated) metal box from the rest of the unit. The AC/DC pcb is mounted in the main rack case, and is being fed from one secondary. The other secondary is presently unloaded.

Is this imbalance of the secondaries likely to be part of the problem?

Other than measuring current flowing to the AC/DC pcb, where else should I look, and what for?

Or should I quit worrying and accept it as part of normal operation?

Thanks kindly,

Phillip

[quote author="tall_phill"]....It is housed in a seperate (minimally ventilated) metal box from the rest of the unit. .... where else should I look, and what for?..[/quote]
http://www.groupdiy.com/index.php?topic=6564&postdays=0&postorder=asc&start=0

Hi Phillip
You haven't got a short around the toroid transformer by connecting the top of the toroid bolt to ground etc as this is the only thing that would heat it up so quick? As a 160va is way way way overkill and should be stone cold and not getting warm at all. You only need 30VA. Send me a couple of photo's to my jlmaudio email and I will check it over for you.

Joe,

Indeed I think you must be spot on. The bolt screws into the metal box housing the tranfomer, which is connected to earth.

Reading though the other thread explains it somewhat.

Unfortunately I only have a 30mm film camera, so posting pics is a bit tricky.

I will look at it on friday, if that doest solve the problem you'll hear more.

I used that transfomer because it was the closest appriopriate that was stock at my local jaycar.

Futhermore, since it has two secondaries, can I connect them in series and run it to the the AC/DC board as AC - 0v - AC as is listed for a 25v-0v-25v transformer (with the centre tap going to 0v)?

Thanks for the speedy reply,

Phillip