Reply With QuoteIf you want to stop the humming I suggest you get one of these:
Fan controller backwards
A couple of years ago I bought one of these fan controllers (second pic) for the ceiling fan I put in my shed. They are very cheap from china.
It works really well so at that time I thought I might get another one for a spare.
Ok so here we are a couple of years later and I decided to change the controller in our bedroom. It has been going hum, hum, hum hum ... ever since it was installed. I was hoping the new controller would stop the humming but I was wrong.
Another strange thing is the new controller operates backwards. Slow and fast are swapped around. These things have a pot with a switch on the shaft (see first pic) so it's the same as a radio volume. Fully anti-clockwise is off then the fan goes faster as it's turned clockwise.
Can you see anything wrong with the circuit or if faulty that might make the speed control operate backwards ? , or what about the fan itself ? .... Of course the silly buggers might have simply wired the pot vice versa yet the new controller hasn't quietened the loud humming either.
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If you want to stop the humming I suggest you get one of these:
Update: A deletion of features that work well and ain't broke but are deemed outdated in order to add things that are up to date and broken.
Compatibility: A word soon to be deleted from our dictionaries as it is outdated.
Humans: Entities that are not only outdated but broken... AI-self-learning-update-error...terminate...terminate...
loopyloo (30-01-18)
That's the exact same controller that it's using now.Originally Posted by nomeat
I assume the humming is coming from the fan and continuous?? The noise is possibly because of crappy motors - We found using PWM controllers we had a hum, and it even worse when Energex send their tariff control signal down the power line... Had to change some of the fans, and ended up run a dedicated fan circuit that had a filter on it.
As for going backwards... Maybe their run a cosine signal in China? I doubt it would matter where it was a leading or trailing edge type of electronic controller so possibly they did wire the it backwards..?!
loopyloo (30-01-18)
Except for one, all my ceiling fans have a directional switch on them to spin either clockwise (Summer) or anti clockwise in Winter.
Two of the fans use what appears to be transformers with multiple taps to select the speeds (5) but my latest is a pot and only has 3 speeds starting at High.
All I know about fans is they use an induction motor and the switch changes how the coil is feed to spin one way or the other, all the controller does is regulate the speed.
I stand unequivicably behind everything I say, I just dont ever remember saying it !!
loopyloo (30-01-18)
Your pictures show a continuous potentiometer.
The one I am referring to is a switch with 3 settings and off position, switching capacitors.
The continuous ones with the triac are notorious for making noise because they chop up the sine wave and create heavy harmonics.
If the fan is still noisy with the capacitor one, then you will have to fix or replace the fan.
I can not sleep with a noisy fan and I have added an additional 2.5µF in series to the motor on several fans to make them almost totally quiet, just with a very light movement of air.
This works well with portable fans in the 50W range but ceiling fans might need a higher value to start up, although I would then assume that the bearings need cleaning.
Do not use the capacitor with a triac controller like you have in the picture.
I understood that you are concerned about the position of the poti starting up with full speed then going to low as you turn clockwise, not actually reverse rotation of the fan as the other posters think. While that wouldn't really bother me, if you can swap the outside lug of the poti where the 2 resistors join to the opposite side that is open circuit, it should work as you want. Usually this is all on a PCB though. I wouldn't really mess with it.
Last edited by Uncle Fester; 30-01-18 at 12:18 PM.
Update: A deletion of features that work well and ain't broke but are deemed outdated in order to add things that are up to date and broken.
Compatibility: A word soon to be deleted from our dictionaries as it is outdated.
Humans: Entities that are not only outdated but broken... AI-self-learning-update-error...terminate...terminate...
loopyloo (30-01-18)
Yes the hum comes from the fan but not continuous. It pulsates speed dependent. I think it's one hum per revolution, low speed is loud, high speed hum is gone but it runs way too fast to use it on high while sleeping. Med is a little quieter but still a bit too fast.
Hum is normally 50Hz. If it is revolution dependent then you have an issue with the fan, imbalance, problem with the bearing, something impeding it's movement.
Last edited by Uncle Fester; 30-01-18 at 12:45 PM.
Update: A deletion of features that work well and ain't broke but are deemed outdated in order to add things that are up to date and broken.
Compatibility: A word soon to be deleted from our dictionaries as it is outdated.
Humans: Entities that are not only outdated but broken... AI-self-learning-update-error...terminate...terminate...
loopyloo (30-01-18)
Yes the original controller is the same as you pictured, 3 positions and off using a multi tapped cap. Both the pics I submitted are the intended new controller.
and Yes the reverse I was referring to is the knob acts reversed on the replacement controller not the fan spins backwards. The pot in the replacement has one of the outside legs removed, so I assume they removed the wrong one and so not repairable. Not really a problem, I can just buy another one, they're only $5 from china.
It is a reversible fan with the switch mounted on the fan hub. also, the fan is well balanced and no bearing noises, in fact the fan looks and runs like a new one except for the disturbing electrical hum hum hum.
When I went to put the new controller in, I tested it only to find it has the exact same hum at low speed, so I put the old controller back in for now.
How do I add a sound file (MP3) here ?
Old motor-rewinder here.
The hum can be shorts in one or more poles in the stator, or a worn bearing that itself doesn't make noise, but allows the rotor laminations to come too close to the stator and produce 'growling' every revolution.
The speed controller is actually correct. The motors used in modern ceiling fans are very small and don't have much start-up torque. The controller is meant to start the fan on the highest speed to give the motor a kick-start. Many of the 3-speed controllers can go either way, and people shorten the lifespan of the fan by starting on the lowest speed, which causes the motor to get very hot while it is trying to get up to operational speed, and over time, this cooks the grease out of the bearings.
loopyloo (30-01-18)
You'll need to upload it on a file sharing site and post the link to it here.
loopyloo (30-01-18)
Yeah got it now.
Had to download a video maker to create something and upload to youtube.
I used Audacity to create a file that sounds the same as the hum, and it's pretty spot on.
100Hz pulsing around every half a second, so This would be assuming the fan is running at 120rpm.
Has anybody thought the reason it hums is because it doesn't know the words ?
Last edited by loopyloo; 30-01-18 at 04:20 PM.
Just like the fans on your Car A/C that also start on HIGH !! I forget one time and turned it on to suddenly remember it blows dust and detritus every where unless the vents are turned away and it did and I copped a face full..........
I stand unequivicably behind everything I say
loopyloo (30-01-18)
Happened to me a couple of times too.....Once i was peppered in the face with bits of glass cos I forgot about the windscreen I just had replaced. Wouldn't happen now days though, as far as I know all the new cars have a filter on the air con.
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