| 摘要 |
PROBLEM TO BE SOLVED: To reduce switching loss and achieve higher efficiency and noise reduction by providing a capacitor for resonance, a backward diode parallel- connected with a switch means, and a second switch means parallel-connected with a rectifier diode. SOLUTION: A direct-current power supply Vi has a choke coil L1 series- connected thereto, and the choke coil L1 has a rectifier diode D2 series- connected thereto. The diode D2 for rectification has a sub-switch element Q2 parallel-connected thereto and further a load resistance RL series-connected thereto. The direct-current power supply Vi has a main switch element Q1, a first diode D1, a first capacitor C1, and a second capacitor CL parallel- connected thereto. As a result, power is always switched on in the valley of resonance where the voltage of the capacitor for resonance is minimized. Therefore, switching loss is reduced, and higher efficiency and noise reduction are achieved. |
