Patent ID: 8120307

Claim:
A method for providing constant loading in AC power applications using a modulating sine wave having a constant first root mean squared voltage and positive half cycles and negative half cycles, said method comprising the steps of: selecting randomly a plurality of turn-on points along said modulating sine wave, wherein each of said turn-on points is paired with a turn-off point that immediately precedes said turn-on point, and wherein said selection of said turn-on points is made via at least one insulated gate bipolar transistor; determining said turn-off points; removing slices from said modulating sine wave wherein each of said slices is between one of said pairs of turn-off points and turn-on points; reducing said constant first root mean squared voltage to a constant second root mean squared voltage during said step of removing; controlling said positive half cycles with a first IGBT device; controlling said negative half cycles with a second IGBT device; routing said positive half cycles to said first IGBT device with a first diode connected across said first IGBT device; and routing said negative half cycles to said second IGBT device with a second diode connected across said second IGBT device; wherein a first IGBT shunt control transistor is placed in a shunt configuration with said first IGBT device, and wherein a second IGBT shunt control transistor is placed in a shunt configuration with said second IGBT device.