[sci.electronics] Whisiling power supply

steveh@tasman.cc.utas.edu.au (Steven Howell) (12/18/90)

	Does anyone have any ideas, why a power supply (SMPS) would
create such an irritating high pitch squeal. I thought The chopper may
require replacing, but being a major task, I thought I might get some
options first. 		

					Thanks.... Steve h

teb@uqun38.nixdorf.de (Tobias Brueck) (12/20/90)

steveh@tasman.cc.utas.edu.au (Steven Howell) writes:




>	Does anyone have any ideas, why a power supply (SMPS) would
>create such an irritating high pitch squeal. I thought The chopper may
>require replacing, but being a major task, I thought I might get some
>options first. 		

>					Thanks.... Steve h

First you can try to fix the coil in the power-supply with a little bit
nail-varnish or fix the screws from the coil .
The sound come from the coil which works now like a loudspeaker .
If it doesn't work , control and adjust the switching-frequency by
resistor or capacitor .
Hope that help .

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brooksp@hpcc01.HP.COM (Peter Brooks) (12/21/90)

I trust you mean that the noise is acoustic.  This used to be
a problem in cheap TVs, and the problem was with loose
laminations in the flyback transformer.  considering a
switching supply is similar, you might want to start there.

Pete Brooks