Universal Motor Speed Control
Full wave controller using triac and demonstrating hysteresis effects improved  by gate slaving techniques. Half wave controller high torque at low speed version – skip cycling operation.
Features:-
The board consists of following built-in parts:
•  A Universal motor of 1/12 H.P. or less capacity.
•  SCR and TRIAC for the speed control of the universal motor.
•  DIAC and two Nos. of diodes.
•  Snubber circuit in parallel with the triac, which helps in improving the Dv/Dt of the device and also helps in reducing the RFI.
•  Adequate no. of other Electronic Components.
•  Mains ON/OFF switch, Fuse and Jewel light.
•  Two potentiometers.
•  Two capacitors to control firing angle of thyristors.