| 摘要 |
<p>The present invention relates to a power supply circuit, more specifically, to a power supply circuit using a switching circuit and a multi-level voltage output circuit capable of outputting a plurality of AC voltages differing in amplitude. A power supply circuit according to the present invention comprises: a multi-level voltage output circuit having an input end into which a voltage having a periodically changing magnitude is input and a plurality of output ends from which a plurality of voltages differing in amplitude is output; and a switching circuit which selects one of the voltages output from the multi-level voltage output circuit according to a change in a voltage magnitude or a voltage phase at a front end or a rear end of the multi-level voltage output circuit, and supplies the selected voltage to a load. A power supply circuit according to the present invention applies AC voltage, selected from a plurality of AC voltages differing in amplitude and output from a multi-level voltage output circuit, to a load. As a result, there is an advantage in that it becomes possible to apply a voltage having a substantially constant magnitude to the load even though the magnitude of AC voltage applied by an AC voltage source is continuously changed depending on the phase. [Reference numerals] (2) Load; (3) Multi-level voltage output circuit; (4) Rectifier circuit; (5) Switching circuit; (6) Charge and discharge circuit; (7) Voltage/current limiting circuit</p> |
