Please notice modifications to post #37.
And, yes, that time I was joking with you.
I think your unconventional terms feel British. i.e. Even an American Nerd would not use the range of vocabulary you exhibit.

 

My fave is "The Poison Belt":

" Our Gardener is, in my opinion, about to dip the solar system, and the human bacillus, the little mortal vibrio which twisted and wriggled upon the outer rind of the earth, will in an instant be sterilized out of existence..."

Great stuff!...

Best regards
HP

As much as I enjoy good old-fashioned, classical English, its American counterpart has its beauty too:

"And all my days are trances, and all my nightly dreams, are where thy dark eye glances, and where thy footstep gleams, in what ethereal dances... by what eternal streams"
E.A. Poe

 

As much as I enjoy good old-fashioned, classical English, its American counterpart has its beauty too:

"And all my days are trances, and all my nightly dreams, are where thy dark eye glances, and where thy footstep gleams, in what ethereal dances... by what eternal streams"
E.A. Poe

I do not have a feel for poetry but my suggestion anyway: try Whitman one of these days.

Or take the time (and I mean it) to read Possession by Antonia Byatt.

 

FWIW I'd just use a diode...

I hope you're joking? If the OP tries that the fan will die due to coil saturation.

 

I hope you're joking? If the OP tries that the fan will die due to coil saturation.

Hence my amendment in the post script...

 

Woow, Guys. You are amazing!
Thank you for all the inputs, hehe...
Since there was also no objections to using a light bulb, I will test it right now before and after the switch..

 

Woow, Guys. You are amazing!
Thank you for all the inputs, hehe...
Since there was also no objections to using a light bulb, I will test it right now before and after the switch..

Sounds like a plan!

Whatever you do --- Please DO NOT take my STUPID advice (in post #10) in regards to use of a diode as a '∏θ phase control'! --- Doing so would certainly result in overheating with subsequent damage and, possibly, fire! -- Sorry about that! - Seems my brain wasn't 'set' for 'induction motor'

Contritely
HP

 

If the fan has a simple induction motor, adding resistance just reduces the current and the torque.

The fan's air resistance applies a counter torque on the motor so the fan speed will decrease until the motor and fan torque reach equilibrium. However if the frequency remains at 60 Hz. while the RPM decreases, the "slip" of the induction motor will increase. I get a sneaking feeling that there's a "Rat In The Woodpile" and something's going wrong somewhere.

 

If the fan has a simple induction motor, adding resistance just reduces the current and the torque.

The fan's air resistance applies a counter torque on the motor so the fan speed will decrease until the motor and fan torque reach equilibrium. However if the frequency remains at 60 Hz. while the RPM decreases, the "slip" of the induction motor will increase. I get a sneaking feeling that there's a "Rat In The Woodpile" and something's going wrong somewhere.

I've used phase angle control circuits in small single phase ac induction motors in the past with no problem. Specifically for a sump pump... but maybe the TS is looking for a much simpler solution...

 

Phase angle control on an AC line is the same principle as a light dimmer and it lowers the average voltage to the load.

In the case of an induction motor, lowering the voltage (and subsequently the current) will have the same result as a resistive control, but without the heat dissipation in the controller.

Once again, starving the induction motor of current may have some detrimental effects.

 

I've used phase angle control circuits in small single phase ac induction motors in the past with no problem. Specifically for a sump pump... but maybe the TS is looking for a much simpler solution...

Indeed, symmetrical phase control, although expedient, may briefly function satisfactorily on low power induction motors -- That said, inasmuch as the upshot is merely reduction of mean power to the motor, the considerations/concerns rased in post #48 apply!

The definitive solution, apart from an appropriately wound motor, is a VFD --- control of an induction motor via 'slip' is a 'losing game'...

Best Regards
HP

EDIT: Seems I 'doubled' with post #50 --- anyway it's all good!

 

Just as word of caution, using an inverter to control fan speed may cause problems with the motor winding's insulation.

Most inverters use IGBTs which have very sharp rise and fall characteristics and they contain harmonics in the RF range. These harmonics can puncture the insulation of a conventional line operated motor.

Before connecting it to an inverter, the motor should have a label that says something to the effect that it is "Inverter Compatible".

 

Just as word of caution, using an inverter to control fan speed may cause problems with the motor winding's insulation.

Most inverters use IGBTs which have very sharp rise and fall characteristics and they contain harmonics in the RF range. These harmonics can puncture the insulation of a conventional line operated motor.

Before connecting it to an inverter, the motor should have a label that says something to the effect that it is "Inverter Compatible".

So now we've evolved from a simple resistor to a diode to an inductor to phase angle control to an inverter... and nothing seems to be 100% adequate to control the speed of a simple fan

 

If you want "infinite resolution" for speed control of an induction motor, the only theoretically correct solution is to use an inverter.

 

If you want "infinite resolution" for speed control of an induction motor, the only theoretically correct solution is to use an inverter.

Agreed! --- That said, I feel the OP's best (i.e. most practical) solution is purchase of a multi-speed fan...

Best regards
HP

 

Agreed! --- That said, I feel the OP's best (i.e. most practical) solution is purchase of a multi-speed fan...

Best regards
HP

That'll probably be cheaper than an inverter!

 

I think you guys can turn off the lights and sirens now. TS only asked where to place a light bulb, got his answers, and said, "Thank You".

 

Much appreciated #12, et al.!

I ended up putting the 40W light bulb in front of the FAN switch with additional SPDT switch, in case I would need to bypass the light bulb and get original speeds somewhere in the future.

Agreed! --- That said, I feel the OP's best (i.e. most practical) solution is purchase of a multi-speed fan...

Best regards
HP

Definitely, and it actually is a multi speed fan, the problem is, that I sit 1m bellow it, and all four speeds are way to fast. I tried with another cheap ebay FAN multi switch, and the speeds were the same. And for 3 bucks I got also ton of extra HUM.

Sounds like a plan!

Whatever you do --- Please DO NOT take my STUPID advice (in post #10) in regards to use of a diode as a '∏θ phase control'! --- Doing so would certainly result in overheating with subsequent damage and, possibly, fire! -- Sorry about that! - Seems my brain wasn't 'set' for 'induction motor'

Contritely
HP

No worries Bud, only diodes i used so far in my projects are those shiny LED ones, so no worries there. TY!

Anyhow..I have no hum now, complete silence. It starts more slowly of course, but that was expected.
There is still retained a difference between speeds. 1 still moves the air just a little, and 4 is still fast enough to be useful for faster room refreshing.
The 'brightness' of the bulb also changes from one speed to another. At 1 it barely shines, and i can actually touch/hold it without burning my fingers. So I will be able to put it out of sight without worrying about heat i guess. :w00t

Overall power consumption looks like this;

As for RPM, much more enjoyable

/me thankfully waving to all!!