Dimmer on oscillating fan

[zeroseven]

On its lowest setting our fan was too much, noisy too so I placed an in line dimmer switch into the cable.

The motor made a strange noise whenever the dimmer was on anything other than 100%, and eventually the fan motor died.

Can anyone explain what I did wrong?

 

[IanDB]

Dimmer switches are fine for lights as these are completely passive electrical beasts. Unfortunately the same cannot be said for motors which love nice, steady 50 cycle per second sine waves. A dimmer does not provide this sort of supply so your fan motor died a very slow painful death.

The closest analogy I can think of is of a bike where the chain links are too small to grip the sprockets properly. You may get away with cycling on the flat but as soon as you start going uphill things will slip and break.

Still, you know now.

 

[breezer]

its also to do with the way the motor is wiund, but we wont go there. but basically not all motors can be speed varied

 

[zeroseven]

Thanks, is there a proper way to lower the RPM of an (presumably cheap) electric motor?

 

[plugwash]

depends on the fan...

you could try putting a couple of 100W lightbulbs (in some kind of METAL box if you don't want them visible in parallel with each other and in series with the fan)

like

[code:1]
live-----100w lightbulb----fan----neutral
| |
'-100w lightbulb-'
[/code:1]

just make sure you dont cut down the voltage so much that the fan stops spinning or you may damage it

lighting dimmers are generally phase cutters and some types of motor don't like being fed from theese

 

[zeroseven]

Thanks for the idea but not too practical!!

The fan has three preset speeds, how then do these presets control the fans speed? Is it not possible to use the same method?

 

[ban-all-sheds]

Thanks for the idea but not too practical!!

The fan has three preset speeds, how then do these presets control the fans speed? Is it not possible to use the same method?

I'm sure it is.

You'll have to open up the fan controller, work out what it does to control the fan speed, and either change the values of some of the components or add extra ones and a switch with more positions.

Or you could see if a proper fan speed controller does the trick.

Or you could console yourself that it's less than a week until the nights start drawing in...

 

[zeroseven]

Or you could console yourself that it's less than a week until the nights start drawing in...

Aha a man like myself. I have great pleasure telling people at the beginning of May "another six weeks and....."

Cheers them up no end...

 

[dingbat]

Why not just buy a new fan that does exactly what you want? By the time you've tried all the possible fixes for your dilemma you'll have probably spent as much if not more than the cost of replacement.

 

[zeroseven]

Yes I've done that ta - just wanted to learn for 'next time'. If i'm responsible for causing something a "very slow painful death", its nice to know how to avoid it next time

 

[ban-all-sheds]

Aha a man like myself. I have great pleasure telling people at the beginning of May "another six weeks and....."

Cheers them up no end...

Even better - on Christmas Eve, when everybody's nerves are shot, and tempers frayed etc, point out that it's less than 6 months...

Talking of which, did you know that there are only 27 Saturdays left before Christmas?

 

[zeroseven]

Talking of which, did you know that there are only 27 Saturdays left before Christmas?

But at least most of them will have some 'proper' football

 

[securespark]

B*gger off, all you pro-winter peeps!!
There's nothing wrong in trying to prolong thar summer warmth & length of day.

Be glass half full, not glass half empty.....

 

[dingbat]

Ah, takes me back to my armed forces days - ROMFT (Roll On My 'Flipping' Time) - when everybody would start a tick-off sheet of days to go till the end of a tour of duty. S*d today, let's get to the end of this and get it behind us!

Only last night I told a friend who waxed lyrical about the coming summer that he'd better make the most of it as after Monday it was all downhill! I like to think I've spread a little joy!