Capacitive Fan speed

Discussion in 'General Electronics Chat' started by dougtheflyboy, Mar 7, 2008.

  1. dougtheflyboy

    Thread Starter New Member

    Mar 5, 2008
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    I am building a capacitive fan speed control using triac's for switching it is giving off excessive RF interfearance does anyone know what can be done to reduce the RF interfearance
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Why don't you post your schematic so that we can take a look at it?

    A photo of the as-built circuit would help a great deal, too.
     
  3. dougtheflyboy

    Thread Starter New Member

    Mar 5, 2008
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    Heres the schematic
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Is that the actual circuit? Your zener and 5 volt regulator should have turned to smoke by now - there is no current limiting for the zener.

    If that's a 115 VAC fan, then VT3 should be able to control the speed if some source for the internal triac is supplied. What VT1 & 2 are supposed to dodo is a bit of a mystery. But you don't get a lot of conduction through a 6.6 uF capacitor (where did you find that value? Are they Ac rated?).

    There must be more circuitry controlling the optocouplers.

    Possibly you could post up a verbal circuit description so we can follow how the circuit is intended to work.
     
  5. dougtheflyboy

    Thread Starter New Member

    Mar 5, 2008
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    they are 250v rated the 6.6 is accually 2, 3.3 Uf in parallel. it is a 3 speed control VT-1 and VT-2 are slow and medium speed it is the accual circuit I have it working it just emits a ton of RF interfearance I have not been able to figure out the source of the interfearance to correct the problem
     
  6. dougtheflyboy

    Thread Starter New Member

    Mar 5, 2008
    7
    0
    I came up with the 3.3 and the 6.6uF as they were the value's used on most ceiling paddle fans to control the speed
     
  7. dougtheflyboy

    Thread Starter New Member

    Mar 5, 2008
    7
    0
    Vt-3 is the highest speed so i was applying it without any limiting capacitance
     
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