[2023] All About AC Voltage Controller Explained

    An ac voltage controller or ac voltage regulator is the circuit that is composed of semiconductor (usually thyristor) designed to maintain the desired alternating voltage in an ac circuit. It can supply variable voltage ac power to a electrical load from a fixed voltage ac power source without changing the frequency.

Operation or Working of AC Voltage Controller

    The ac voltage controller operates in two different modes of operation which are listed below.

1. Integral cycle control or ON-FF control
2. Phase control or Phase angle control

Integral Cycle Control or ON-OFF Control

    In integral cycle control or on-off control, ac input power supply is switch ON for some integral cycles and switch OFF for the further same number of cycles. Integral cycle control is usually used where the mechanical time constant and thermal time constant is high by some seconds. For such applications, almost no variation in speed or temperature will be noticed if the control is achieved by connecting the load to the source for some cycles then, disconnecting for further same number of cycles.

    The circuit consists of the two thyristors connected in anti-parallel direction. Anti-parallel connection is done so that one thyristor turn ON for one positive half cycle and another thyristor turn ON for negative half cycle. The firing angle of thyristor may be chosen based on required output voltage. To increase the output voltage, the firing angle should be increased.

 Phase Control or Phase Angle Control

    In this method, thyristor are used to selectively pass the current for only half cycle and turned OFF for remaining cycle. By controlling the phase angle or trigger angle, the RMS output voltage of the load can be varied. Most of the ac voltage controller uses this method.

Classification of AC Voltage Controller

    AC Voltage controllers or ac voltage regulators are classified into two different categories which are listed below.

1. Single phase
2. Three phase

Advantages of AC Voltage Controller

    Some of the important advantages of ac voltage controller or ac voltage regulator has been listed below.

1. Fast control
2. High efficiency
3. Compact size

Application of AC Voltage Controller

    Some of the important application of ac voltage controller or ac voltage regulator has been listed below.

1. Domestic and industrial heating control.
2. Lighting control i.e. dimming the light source.
3. Speed control of ac machines i.e. ac fans and motors.
4. Alternating magnetic field control.
5. On-load transformer tap changing

Conclusion

    Hope, you have clearly understand about the ac voltage controller or ac voltage regulator, their operation or modes of operation, classification, advantages and applications. Make sure to leave your opinion and suggestion about this post in the comment section below.