In half-bridge inverter, two capacitors are used to get two voltage sources, each of potentials V/2 from a single voltage source of potential V.
When either of the transistor conduct, the respective capacitor discharge through the load.
But after being discharged, how does the capacitors get charged back to potential V/2? What path does the charging current flow through? If the charging current flows through path Vs-C1-C2, then voltage of the other capacitor would also rise and go above V/2. Why doesn't it happen?
Best Answer
The charging / discharging is intentionally a small fraction of the supply voltage and, providing the duty cycle is 50%, the currents from the load alternate very quickly and the average voltage at the junction of the two capacitors remains largely at Vs/2. The capacitor value has to be sufficient for this to happen of course and the duty cycle needs to be about 50%.