| 摘要 |
PURPOSE: A power supply unit and a control method thereof are provided to secure a stable operation by limiting an output of a power conversion circuit according to a change of power consumption of the power conversion circuit or impedance of a load. CONSTITUTION: A power conversion circuit(10) converts an input power. A load impedance detecting part(30) detects impedance of the load connected to an output terminal of the power conversion circuit. An impedance comparing part(32) compares the load impedance value detected by the load impedance detecting part with a reference impedance value, and includes a first impedance comparing circuit and a second impedance comparing circuit. The first impedance comparing circuit detects a high impedance state of the load. The second impedance comparing circuit detects a low impedance state of the load. A control part(40) controls an output of a power conversion circuit based on the compared result of the impedance comparing part. |
