Why is a transformer overheating


Transformer (electronics)

written by Kendiman, 06.10.2013, 5:33 pm

" Hello,
“I have a (stupid?) Question.
»How warm can a transformer get?
“A few weeks ago I was given an amplifier as a gift. The
»The amplifier is from the company" RIM "and the name is" Imperator
» 1000".
“The amplifier works, except for some hum.
»But: The transformer gets very warm. Already uncomfortable when you have one
“Hand on. Is that normal?
“Maybe I'll be lucky enough to have someone living around here
»And can check the amplifier?
" See you,


the temperature measurement with the hand lay-on method is extremely inaccurate.
Insulation suffers if the temperature is too high.
Since enameled copper wires are used, the enamel insulation is crucial.
There is hardly any concern for a paint temperature of up to 150 degrees.
Today there are also wires with a temperature index greater than 300 degrees.
Given the age of the transformer, I would assume 120 degrees to be reasonable.
This is the maximum temperature inside the transformer.
Outside it can get up to 60-70 degrees warm (hot) without being damaged.
You will burn your fingers.
A specialist should convert the push-pull output stages with 2 x 2 EL84 to the
Examine the working point setting to be absolutely sure
that there is no error.
As long as you can still touch the transformer for a long time,
everything seems to be fine.
Of course, the amplifier must first be under load (volume)
operated for some time.

Greetings Kendiman

Entire thread:

Transformer - Frank (from Lübeck), 06.10.2013, 4:45 pm (electronics)
Transformer - Kendiman, 06.10.2013, 17:33