Half-Bridge Inverter for Solid State Lighting Power Conversion

The patent combines the rectifier, boost inverter, and output stage inverter into a single integrated half-bridge circuit. The half-bridge inverter performs multiple functions simultaneously: it rectifies the mains input, provides power factor correction, boosts the voltage, and drives the LED load. This integration eliminates the need for separate circuits for each function, thereby reducing device complexity while maintaining comprehensive power conversion capabilities and wide load range coverage.

The half-bridge inverter is designed as a universal circuit that performs multiple functions: mains rectification, power factor correction, voltage boosting, and LED driver operations. By making the circuit multi-functional, the patent achieves wide load range coverage without adding separate dedicated circuits for each function, thus avoiding increased device complexity.

The patent employs dynamic control of the half-bridge inverter switching based on the instantaneous polarity of the mains input voltage. The control circuit activates different switches (first inverter switch for positive half-cycle, second inverter switch for negative half-cycle) depending on the voltage polarity. This dynamic switching strategy enables the circuit to maintain power factor correction capability across the entire AC cycle while keeping the control logic relatively simple and intuitive.

The control circuit operates in a periodic manner, switching between different inverter switches based on the AC voltage half-cycles. During each positive half-cycle, one switch is activated, and during each negative half-cycle, the other switch is activated. This periodic switching pattern enables continuous power factor correction while maintaining simple control logic that follows the natural periodicity of the AC input.