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AC voltage ControllersAC voltage ControllersConverts fixed AC to a variable ACNo change in frequencyHigh efficiencyCompact sizeLess maintenanceApplicationsUsed for Domestic & Industrial heatingLighting ControlSpeed control of single phase and three phase ac drivesStarting of induction motors

2For Regulating power in ac controllers two methods are there:Phase ControlIntegral Control

Single Phase Half wave AC Voltage controller

Single Phase Full wave AC Voltage controller

Integral Control Used in several industrial applications where the mechanical or the thermal time constants are of the order of several seconds. Eg. Mechanical time constants for some speed control drives and thermal time constants for heating loads is quite high.No change will be noticed if load is disconnected from the supply for some off cycles.

Principle of integral cycle control

Only Resistive Load

RL load

Two Stage sequence controlled

Multistage Controller