Types of AC voltage controllers:
- ON-OFF type AC voltage Controller
- Phase angle type AC voltage controller
In this type of controller, the full input voltage is applied to output for some number of cycles and no voltage is applied to output for some number of cycles. In this control, output voltage waveform is discontinuous and contains large ripple.
Phase angle control:
In phase angle control, each half cycle of the source voltage is applied partially or fully to the load. Firing angle of the SCRs is charged to control output voltage. Output voltage waveform is continuous but phase controlled.
The type of AC controller which is highly preferred is Phase angle control, because it contains less ripple and discontinuities in output.