Re: PWM motor noise

Bart wrote:
Hi all, bought a PWM kit ( http://kitsrus.com/pdf/k67v3.pdf ), but put in an
IRF840 & a 630V .1uF cap to run a 108VDC (nom) motor with
rectified/filtered line voltage (~160VDC).
The motor makes a rather loud (pwm) noise when running, is this
normal?
Any way of quieting it down?
Yes, I know I shouldn't be rectifying mains, but this is a test & I'll
use a stepdown/ isolation Xformer if & when it's working well.
TIA!
Bart

High pitched at low speeds,and it gradually gets higher pitched at faster speeds? Pretty normal.
.

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