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  1. #1
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    Speed control of single phase induction motor of a fan

    I want to design a circuit to control the speed of the motor of a single phase induction motor of ceiling fan into three level( max tourque -2800 rpm ). I want to do it by controlling voltage, in that case how should I do it?

    I know that one way is to provide several connecting points or taps on the motor winding and another one is by using light dimmer type circuit. The dimmer varies the effective voltage by chopping the waveform with a triac.

    Which one is more efficient and cost effective?

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  2. #2
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    Re: Speed control of single phase induction motor of a fan

    I suggest triac dimmer..

    If you only need three steps you can use resistor's. You can find it in conventional fan regulators.


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  3. #3
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    Re: Speed control of single phase induction motor of a fan

    Speed control of single phase induction motor of a fan. Induction motors lock onto the frequency of the mains, if the voltage is low, they slow down, take more current and finally stop. Only brush type (universal motors) can be controlled by reducing the voltage into them.
    Frank



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  4. #4
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    Re: Speed control of single phase induction motor of a fan

    I would not recommend using a triac dimmer for a single phase induction motor. This solution is only valid for universal motors. You should rather vary frequency using a rectifier + inverter.



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