I own a ceiling fan that has the attached component to regulate the speed of the fan.
The problem I have is that the slowest speed is still too fast for me, ideally I would like it to be 25% slower.
I don't even have the need to be able to select the speed, I would be happy for it to be fixed at a speed 25% slower than the slowest.
With this in mind, what should I replace the component found in the attached images for it to be slower (the fan is 220v, 60hz and 65W).
Many thanks,
Thomas

 

Something to consider with this would be that normally a 3 speed fan starts at high followed by medium and last slow speed. This is done for a good reason. If we try and start the fan at too low of a speed or reduce low speed and just tray and run the fan starting at too low of a speed rotation may not begin and the motor will start humming and get hot. This followed by smoke and a bad sequence begins. This is a good read on the subject. A Google of "fan speed capacitor circuit" will bring up more examples of how using capacitance fan speed is controlled. Just remember trying to start a ceiling fan at too slow of a speed can have bad results. The circuit you have can be modified to work with the switch you have.

Ron

 

Hi Ron, thanks for your note, I understand your point.
In the case of this fan, it has 5 speeds, the dial starts with 0 (the fan is off) and ends in 5 (maximum speed). When you put the dial on 1 which is the slowest speed, it is still very fast.

 

From the picture of the fan speed control, it looks like the speed is set by the number of capacitors in parallel that are put in series with either one of the fan field windings, or in series with the whole fan motor. So one logical thing to try will be to put another capacitor in series with the whole system. The capacitor to try will be one intended for use with AC motors, Rated for probably 400 volts AC and several microfarads.
Another option is to try a lower voltage. If you can borrow an adjustable transformer that would be the easiest way to experiment, But the possibility of the motor not starting when power is applied means that it may not be a working solution.

 

I slowed a 40w 3 speed desk fan down with a 1000 ohm 100w resistor in series. Needed a heat sink but works very well for night time use, the fan is virtually silent.

 

That is a simple Series Capacitor speed regulator.
From the slowest speed, you have a bank of 1.2 uF capacitors added in parallel to the max speed - a direct short.
That is, 1.2, 2.4, 3.6, 6.6, short - the 5 speeds.
If the lowest speed is still too fast, and you do not want to alter the speeds, remove that switch and connect the fan in series with any 2 black wires so you have 0.6 uF instead of 1,2 uF.
If this is still too fast, buy a 0.22 uF / 400 VAC capacitor and put it in series with the fan.

 

This is one way to make a change, rather difficult to undo if it does not produce the desired results. That is why I suggest adding a series capacitor and evaluating the results. A 2 mfd cap added externally will leave enough higher speeds available in case there is a startup problem, as has been described.

 

Many thanks everyone!
I tried what Ramussons suggested and it works perfectly.
thank you!