Mixer or Sewing Machine Motor Speed Control
It will be effective to use simple half wave motor speed control with small universal ac/dc motors. Two amps RMS is the maximum current capability. The control gives excellent torque characteristics to the motor because speed dependent feedback is provided, even at low rotation speeds. By closing switch S1, thus bypassing the SCR, we can achieve normal operation at maximum speed.
[Circuit’s schematic diagram source: seekic.com]