Try tightening the transformer mounting bolts. This type of problem can range from trivial to maddeningly infuriating.
Early Tektronix 2513 scopes would howl like a banshee and there was no long term fix.
-- Many thanks, Don Lancaster Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552 voice: (928)428-4073 email: don@tinaja.com Please visit my GURU's LAIR web site at http://www.tinaja.com
Custom homes these days often have sound absorbing sheet rock around the bathroom to keep the noise from getting out. Maybe that (not around the BR, of course) and the shock mounts would help.
-- Best Regards, Mike
I recently bought a newly built house with a Carrier A/C system. On move-inday the A/C was quiet whne turning on with little moretha fan hum. I was concerned because the builder placed it outside the wall of my bedroom.
after about 6 months of use in texas (hot) it gradually got a 60Hz humm that is quite noticable in my bedroom. I checked with my neighbors units and there units sound the same so I don't think the A/C is defective (A/C bills are inline)
As there anything I can do to reduce the hum?
Because of the delay in onset, I suggest you look for places near the unit where pipes pass through walls or are clamped to them. They were probably isolated with insulation, but this may have deteriorated or fallen off, and the vibrating pipes now make contact with the wall.
-- John Popelish
Antivibration mountings might be a start, its probably not an "electonically solvable problem"
martin
Serious error. All shortcuts have disappeared. Screen. Mind. Both are blank.
I guess, the humm comes from the mechanics. The motor is an asynchronoeus machine rotating at very close to 60Hz halves, or 1800 revs. Any wear or load sounds like a regular hum. How about mounting shock absorbers or reducing the mechanical coupling to sound ?
Rene
-- Ing.Buero R.Tschaggelar - http://www.ibrtses.com & commercial newsgroups - http://www.talkto.net
Curious, could all the A/C units in the area (inductive loads) be creating a slight phase imbalance, which manefests itself as extraneous noise?
Though a motor can be modelled as a transformer due to its inductive nature , the sound frequencies are rather different from what seems to be the problem. Maybe the presence of harmonics in the load current and voltage contribute, as due to the em forces due to leakage currents in the motor windings that may cause internal vibrations . I'd still think the mechanical component dominates .... but those low frequency em origin noises are also there.
Dont forget magnetostriction, and of course that dead whit guy, Newton - the stator (and rotor) windings are well secured for a good reason.
Cheers Terry
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