High output power quasi-square wave inverter circuit

A high output power inverter circuit coupled to obtain power from a voltage source (Vb) such as a battery service, the voltage source having a ground return line (Vr), the high output power inverter comprising:

• a toroidal transformer having a primary and a secondary winding, the primary winding having a first end and a second end and a center tap, the center tap being coupled to the voltage source,
• a first and second switch to conductively couple the first end and the second end of the transformer alternately to the ground return line (Vr) during alternate half cycles of successive power cycles for respective and successive first and second on-time intervals, the toroidal transformer secondary providing a quasi-square wave output voltage,
• a pulse-width modulator and driver circuit for driving the first and second switch into conduction for each on-times during alternate half cycles of successive power cycles, and for interposing a dead-time or non-conductive interval between the first and second on-time intervals and during the interval preceding the start of any subsequent first on-time interval,
• a control circuit for sensing an on-time voltage on a non-conducting second end or non-conducting first end of the primary winding during each on-time of the respective conducting first or conducting second switch and formodulating the on-time of the first and second switch to maintain the quasi-square wave output voltage within a predetermined range, and
• a shunt switching circuit for connecting the first end of the primary winding to the second end to the primary winding during a dead-time between each respective on-time.

A high output power inverter circuit coupled to obtain power from a voltage source (Vb) such as a battery service, the voltage source having a ground return line (Vr), the high output power inverter comprising:

• a toroidal transformer having a primary and a secondary winding, the primary winding having a first end and a second end and a center tap, the center tap being coupled to the voltage source,
• a first and second switch to conductively couple the first end and the second end of the transformer alternately to the ground return line (Vr) during alternate half cycles of successive power cycles for respective and successive first and second on-time intervals, the toroidal transformer secondary providing a quasi-square wave output voltage,
• a pulse-width modulator and driver circuit for driving the first and second switch into conduction for first and second on-times during alternate half cycles of successive power cycles, and for interposing a dead-time or non-conductive interval between the first and second on-time intervals and during the interval preceding the start of any subsequent first on-time interval,
• a control circuit for sensing an on-time voltage on a non-conducting second end or non-conducting first end of the primary winding during each first and second on-time of the respective conducting first or conducting second switch and for modulating the first and second on-time of the first and second switch to maintain the quasi-square wave output voltage within a predetermined range,
• an output current-voltage sensing circuit means for measuring the load current by measuring a first and second on-time voltage on the conducting first end or second end of the primary winding with respect to the ground return line (Vr) during the on-time of the respective first or second switch, and for terminating the first and second on-time in response to a predetermined on-time voltage threshold being exceeded and
• a shunt switching circuit for connecting the first end of the primary winding to the second end to the primary winding during a dead-time between each respective on-time.