Importance

Loading Importance Indicators...

Abstract

An apparatus and method for controlling the voltage applied to a load is taught. The method includes receiving an AC line voltage, generating an operating AC voltage from the AC line voltage and applying this operating AC voltage across the load. A measured signal which is a function of the magnitude of the operating AC voltage is generated, and then averaged to generate an average signal representative of the average value of the measured signal. The operating AC voltage is continually readjusted in response to changes in the average signal. The apparatus implementing this method includes terminal means for receiving an AC line voltage, means for generating an operating AC voltage from the AC line voltage, connector means for applying the operating AC voltage across the load, and voltage detection means for generating a measured signal which is a function of the magnitude of said operating AC voltage. Signal averaging means are provided for generating an average signal representative of the average value of the measured signal. Finally, the apparatus includes AC voltage modulation means for adjusting the operating AC voltage in response to the average signal. In the preferred embodiment of the apparatus of the present invention, the AC voltage modulation means comprises voltage reduction means for switching off the line voltage for a portion of each cycle, the length of the portion being determined by the average value of the measured signal. The voltage modulation means may comprise a phase control integrated circuit device for controlling a triac. The phase control integrated circuit device is responsive to the average signal to generate a control signal operative to control a triac to switch off transmission of the line voltage to the load for the portion of each cycle.

Loading the Abstract Image...

First Claim