| 摘要 |
PROBLEM TO BE SOLVED: To provide a power unit which is capable of being enhanced in DC/AC conversion efficiency and reducing the stresses applied to the switching elements which constitute its first and second amplifier circuits can be reduced. SOLUTION: A power unit is provided with an AC power source AC, a filter circuit F, a rectifier DB, a step-down chopper circuit 8 connected to the output terminal of the rectifier DB, a second amplifier circuit 2a which is connected to the output terminal of the chopper circuit 8, has a switching element Q22, and outputs high-frequency power, a first amplifier circuit 5a which is connected to the output terminal of the chopper circuit 8, has switching elements Q51 and Q52, and outputs high-frequency power, a matching circuit 4, and a load connected to the output terminal of a matching circuit 4. As a result, the DC/AC conversion efficiency of the power unit can be improved and the stresses applied to the switching elements constituting the first and second amplifier circuits 5a and 2a can be reduced. |
