Timer on reduced-frequency circuit

maybe, but the easy fix is to put the timer before the speed control. you don't need to power the speed control when not using the fan.

Bye. Jasen

Firstly, a variable speed control does not affect the 'frequency' of the supply current. It does, however, have a profound effect on the waveshape, if it is electronic rather than passive, and this may well affect an electronic timer's ability to work correctly, as opposed to keeping time, which I presume is your reason for asking about frequency. If you put the timer ahead of the speed control, there will be no such issues, as the timer will only be fed with 'standard' line power, which it will then pass thru' to the speed control during one of its 'on' periods.

Arfa

I assume you mean a common thyristor phase control, not one that actually changes the frequency of the power, though the same comments apply.

If you mean put the timer first which plugs into a wall socket and then the switched output of the timer goes to a variable speed control, there should be no problem. The timer will run off the unmodified power.

However, if it is an electronic timer that is in series with the load ONLY then this is probably not a good idea unless the timer manufacturer specicially states that it is permissible.

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Probably. A guy at an electric store said it changes the frequency, which sounded weird to me. But no, it would be an ordinary speed control. I vaguely remember reading about phase affecting power delivery in a physics book.

I see - that makes sense.

Thanks Laura

Some speed controls do (a device called a variable frequency drive), but that is for large industrial motors, small fan speed controllers just reduce the voltage that the fan gets.

Bye. Jasen