| 摘要 |
PROBLEM TO BE SOLVED: To provide a power unit for which the DC/AC conversion efficiency of its second amplifier circuit can be improved, circuit design can be made regardless of the input voltage of the second amplifier circuit, and then the stress applied to the switching element constituting the amplifier circuit can be reduced. SOLUTION: A power unit is provided with DC power sources E1 and E2, a first amplifier circuit 5a which is connected to both ends of the power source E1, has a switching element Q53, and outputs high-frequency power, a load circuit 7 which is connected to the output terminal of the amplifier circuit 5a through a matching circuit 4, and a second amplifier circuit 2a composed of a class-D amplifier circuit which is connected to both ends of the power source E2 and drives the switching element Q53. Therefore, the DC/AC conversion efficiency of the second amplifier circuit 2a can be improved and circuit design can be made, regardless of the input voltage of the circuit 2a. In addition, the stress applied to the switching element Q53 constituting the circuit 2a can be reduced. |
