I have a fan I need to control. I tried kit K2636, but it is not reducing the fan speed. Turns out this is a capacitor start motor, so it does not work with the K2536 kit. It may also be brushless, but I can’t find that info anywhere. Is there a Velleman kit that would enable me to control this AC motor?
Sorry, we do not carry controllers that are able to adjust the speed of fans (brushless motors).
An old thread but this might be of assistance - Variacs!
If they are the external rotor type (most small fans are) I’ve had good results with a variac which is basically a transformer with a continuously variable ‘tap’ which allows you to set any voltage between 0-230vac. You can actually wire them to produce a 270vac output if needed. A 1 amp variac can be bought for about £30 but whereas a triac controller weighs barely an ounce or two a 1amp variac pitches up at around 5-6lbs in weight!
They are ‘old tech’ but their beauty is that they produce a pure sine wave reproduction of the input mains at the output tap terminal rather than the “chopped” hard edged waveform that comes out of a triac based unit. It’s those sharp waveform edges that account for most of the buzz associated with them, the sharp transients stresses motor laminations which is the buzzing sound you can hear.
You can think of it like a synthesizer; if you set a synth to produce a pure sine wave it’ll sound rounded and mellow and ‘easy on the ear’ like a flute; switch it to a square wave and it takes on a rasping trumpet like quality that is discomforting to the ear. Motors dislike being fed on square waves. (servos excepted of course) Binning the triacs and switching to variac control of speed shut them up completely and now they run as silent as the grave. If you can live with the weight and bulk I’d say give your fan a treat and buy it a variac for Xmas. There might be an issue with some types of motor not responding to reduced voltage operation but I’ve used them with a lot of different fans (Silavent, RVK etc) and light duty motors with none of the expected issues like rotors overheating as the voltage is reduced.
I also make sure that I program in a 2 sec ‘boost’ at full mains when starting from a standstill as at low speed settings fans can sometimes stall out or fail to start at all if you try to start them at reduced power; they will then just sit there dissipating watts with no cooling airstream, not good. The initial kick at 230vac ensures rotation starts and the changeover relay then switches the fan’s line back to my preset reduced voltage AC output from the variac. Sweet as… 