Console powersupply extremely ho !!!! but operation is fine

andre tchmil · Mar 31, 2005

I have a very nice Siemens desk here but I notice that my powersupply gets extremely hot.
I mean I can't keep my finger on the transistors for a split second.

transistor typres ar 2N3055.

I know basics in electronics so I'm absolutely sure that there is something wrong here.
Where to look at : 2N3055, caps , resistors ???

thanks

Svart · Mar 31, 2005

heatsinks? those 2n3055s are rated at 115w... 60v@15A.. you must be drawing a lot of current..

i would try to disconnect the output of the PSU and see if your temps go down first.

andre tchmil · Mar 31, 2005

that's what I did, disconnected the output of the PSU,
3055 runs cool that way of course.

could it be one of the transistors?, there are 4 of them , for an output of 2X15V.

gyraf · Mar 31, 2005

You should be able to calculate dissipated power from the transformer voltage and the current drawn.

Compare dissipated power to the expected C/W (tempco) of your heatsinks.

That will show if there's anything wrong.

Jakob E.

BYacey · Mar 31, 2005

Is your AC line voltage perhaps higher than normal, or is there possibly a switch for 100V / 115/ 120V,. If the line voltage is high the series pass transistors will have to drop more voltage and generate more heat than usual.

andre tchmil · Mar 31, 2005

aha

AC input voltage for PSU is rated at 220V.
I have an average mains voltage of 235 V.

Jakob, sounds interesting but could you be a bit more specific ?

Samuel Groner · Apr 1, 2005

AC input voltage for PSU is rated at 220V.
I have an average mains voltage of 235 V.

A well designed PSU will eat 10% overvoltage, as this is pretty common.

Samuel

Console powersupply extremely ho !!!! but operation is fine

Help Support GroupDIY Audio Forum:

andre tchmil

Well-known member

Svart

Well-known member

andre tchmil

Well-known member

gyraf

Well-known member

BYacey

Well-known member

andre tchmil

Well-known member

Samuel Groner

Well-known member

Similar threads

Latest posts

Console powersupply extremely ho !!!! but operation is fine

Help Support GroupDIY Audio Forum:

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Similar threads

Join the conversation!

Join today and get all the highlights of this community direct to your inbox. It's FREE!