Author Topic: Philips PE1542 transformer hum  (Read 1135 times)

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Offline Bskitter

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Philips PE1542 transformer hum
« on: September 20, 2016, 09:07:40 pm »
Hello Guys,

I purchased a Philips PE1542 of ebay a few months ago and the transformer has a hum/buzz to it.

So I spoke to an old repair guy and he mentioned that sometime boiling wax in a pot and dropping the whole transformer in the boiling wax for 10 minutes could fix it.

I also read that dropping the transformer in wood shellac mixed with methylated spirits could get rid of the hum.

What are your views on this ?

Secondly, can a faulty cap cause a hum on the transformer ?

Byron
 

Offline danadak

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Re: Philips PE1542 transformer hum
« Reply #1 on: September 20, 2016, 11:48:59 pm »
yes to the faulty cap, if it is drawing a lot of excess current above
the reactance value. Eg. shorted or close to it.


Regards, Dana.
Love Cypress PSOC, ATTiny, Bit Slice, OpAmps, Oscilloscopes, and Analog Gurus like Pease, Miller, Widlar, Dobkin, obsessed with being an engineer
 

Offline Bskitter

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Re: Philips PE1542 transformer hum
« Reply #2 on: September 21, 2016, 12:27:56 am »
Thanks for the tip Dana,

Ill disconnect the cap and see if the hum fades away.

These large value caps are quite pricey.
 

Offline oldway

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Re: Philips PE1542 transformer hum
« Reply #3 on: September 21, 2016, 06:18:06 am »
A faulty capacitor can not cause transformer hum.

What fault of the capacitor?

Generally, electrolytic capacitors lose their capacitance and it can not cause the hum of the transformer.

If short circuited, the capacitor will blow the fuse.

High leakage current is also impossible because the capacitor heat up tremendously and explode in a short time.

By cons, this can be caused by a faulty diode bridge with an open diode.

Try to check if the transformer continues to produce hum with secondary connections disconnected.

Does the transformer works abnormally hot without load?

Have you tried to tighten the bolts of the laminations?

To impregnate the transformer again, use a special varnish for this use.
 
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