Patent ID: 8436602

Claim:
A voltage compensation circuit for receiving an input AC voltage at a first and a second input terminal and for providing an elevated output AC voltage at a first and a second output terminal in the event of an under voltage condition of the input AC voltage, comprising: an autotransformer having a first, second and a third transformer tap with said second transformer tap located between said first and third transformer taps; a first autotransformer winding defined between said first transformer tap and said second transformer tap of said autotransformer; a second autotransformer winding defined between said second transformer tap and said third transformer tap of said autotransformer; a first input connector connecting the first input terminal to the first output terminal; a second input connector connecting the second input terminal to said second transformer tap of said autotransformer; an autotransformer output connector connecting said third transformer tap of said autotransformer to the second output terminal; a switch connected to said first transformer tap of said autotransformer; a first position of said switch connecting said first transformer tap of said autotransformer to said first input connector to provide an elevated output AC voltage between the first and second output terminals; and a second position of said switch connecting said first transformer tap of said autotransformer to said second input connector for shorting said first autotransformer winding to provide a non-elevated output AC voltage between the first and second output terminal.