I built one of these myself. It burnt out. The problem is how the fan motors work. You can’t just reduce the voltage and expect them to go slower, at least with AC motors.
I currently have 2 fans and achieve 2 levels of wind using Sonoff switches that can connect to wifi so you can adjust using google assistant, Alexa, your phone and IFTTT. Actual customer support is dreadful, but they’re super cheap. Cost about £4 per fan. You need a screwdriver and a knife to wire them in.
I think Sonoff sell a fan inside China. Don’t know if it has variable speeds though. I think if you want variable speeds it’ll need to be built in to the fan, but then I imagine those fans with the feature would turn out to be too wimpy to train with.
If you built a variable speed fan, I thought the acronym might be familiar to you.
PSC = permanant split capacitor. The capacitor is used to start the motor, but remains in the circuit when the motor is running (unlike a capacitor start motor, where the capacitor is used to start the motor, but then switched out of the circuit using a centrifugal switch. Capacitor start motors can not usually be run at variable speed). Many fans use PSC motors, so are suitable for triac control.
I picked up one of those Cleva Vacmaster fans. I am tempted to try it out but I have tweaked something in my knee. I think I have got to the bottom of the niggle but I have to rest it
It sounds promising though.
I have this, it’s very good, I don’t turn it on till I start sweating as it is so powerful and then it stops any perspiration after that. I’ve never really gone beyond the first setting either. I have it on a shelf about a one metre away at head height.
