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🔌General Home Automation => Automating Your House => Topic started by: enlite on December 30, 2007, 11:35:48 PM

Title: WS467
Post by: enlite on December 30, 2007, 11:35:48 PM
I just did my first install of a WS467. Works great, but I was wondering if it is normal to hear a very very slight buzzing noise coming from the switch when you put your ear up to it.
Title: Re: WS467
Post by: Puck on December 31, 2007, 09:52:51 AM
As long as you are using incandescent light(s) with the WS467, that buzzing is normal with any Triac dimmer.
Title: Re: WS467
Post by: Dan Lawrence on December 31, 2007, 11:42:07 AM
I just checked all my WS467s and NO BUZZING was heard.
Title: Re: WS467
Post by: Brian H on December 31, 2007, 12:34:37 PM
I believe the coil in the triac circuit sometimes buzzes in both a lamp module and a wall switch. It maybe how it is mounted or how tight this batch got wound on the bobbin.
Title: Re: WS467
Post by: Oldtimer on January 01, 2008, 12:30:01 AM
Mine aren't buzzing whether they're as is or modified for CFLs.
Title: Re: WS467
Post by: JeffVolp on January 01, 2008, 01:01:33 AM
Virtually all triac dimmers contain an inductor to reduce RF interference.  When the dimmer is turned down, the triac switches on with significant voltage across the load.  The resulting current transient induces magnetic forces in the inductor, which can cause the buzz often heard from dimmers.  The buzz is proportional to load current, and is greatest when the dimmer is near mid scale.

Some inductors have a compliant adhesive such as hot-melt glue applied to the windings to damp the vibration.  Whether the buzz is audible depends on how tightly the coils are wound, how well the damping adhesive is applied, load current, and dimmer setting.

The bottom line is that a slight audible buzz from a triac dimmer is no cause for concern.

Jeff
Title: Re: WS467
Post by: Brian H on January 01, 2008, 06:19:05 AM
I have one CFL bulb that also hums softly. I believe the little transformer in it is wound slightly loose or not glued correctly. Others that are the same are quiet.
Title: Re: WS467
Post by: steven r on January 01, 2008, 02:26:45 PM
...Some inductors have a compliant adhesive such as hot-melt glue applied to the windings to damp the vibration.  Whether the buzz is audible depends on how tightly the coils are wound, how well the damping adhesive is applied, load current, and dimmer setting.

The bottom line is that a slight audible buzz from a triac dimmer is no cause for concern....
I've never had one bother me. Maybe my hearing isn't as acute or the TV is too loud or I've been lucky to get good ones.  ;)
(I have had a bulb buzz when dimmed, however, but that's a different problem.)

For someone that it should happen to bother, has anyone tried or would it even be practical to apply more damping adhesive?
(Personally I'd switch the switch before opening it up to modify it.)
Title: Re: WS467
Post by: Jason B on April 22, 2010, 12:03:28 AM
Question, I just replaced 5 normal light switches that used to be full brightness all the time, and run about 3 horus a day. I replaced all 5 with WS467 that I'm going to run at half brightness. Will this cut down on electric costs? I can hear slight buzzing, which is normal, but it just sounds like more power is running through when I hear this sound :)
Title: Re: WS467
Post by: dave w on April 22, 2010, 08:25:25 AM
Will this cut down on electric costs? I can hear slight buzzing, which is normal, but it just sounds like more power is running through when I hear this sound :)

Yes the lights will be using less current but you may not see a big change in your bill. As example: if each bulb was 100 Watt you would be drawing 1.5 kWh per day for the lights.  If your kWh cost was 10 cents then your monthy cost for the lights is about $4.50. So running the lights at 50% would knock off a couple of bucks.

As far as the buzz, like Jeff said in the thread; a triac dimmer tends to buzz the loudest at about mid range, but in this instance, the loudness of the buzz is not directly related to the power going to the bulb. It has to do with the way the dimmer is reducing power to the bulb to dim it.
Title: Re: WS467
Post by: Jason B on April 22, 2010, 12:33:07 PM
Great. Thanks for explaining that, it makes perfect sense now. I'm loving my new switches. I have a bunch of Ws467 and they all have local dimming, and I have some WS477 3 ways, and they have local dimming even the companion switch! Someone told me about this, and everyone I asked said the companion wouldn't dim locally, well it does.

I also just bought the CM15a and an iphone app so I can control everything from my phone. Very cool.