Patent ID: 7084587

Claim:
A control apparatus for starting a load device at full AC line voltage, and for sustained operation of said load device at a reduced operating voltage with no loss of continuity between the line and load during voltage reduction, said control apparatus comprising: an autotransformer having a primary winding including first and second ends, and a secondary winding having respective first and second ends; said primary winding being connected at its first end to one side of said AC line and at its second end being connected to one side of said load device; a SPDT switch having a first switch contact connecting to said first end of said primary winding, and a common contact connecting to said load device so that when said first switch contact and said common contact are connected, said primary winding is shorted and said load device receives full line voltage; said SPDT switch including a second switch contact connecting to a first end of said secondary winding, and a second end of said secondary winding connecting to the other side of said AC line and to the other side of said load device, so that when said second switch contact and said common contact are connected said primary and secondary windings are in series across said AC line and said load device receives reduced voltage.