| 摘要 |
PURPOSE:To obtain the prescribed DC voltage irrespectively of the large variation of an input voltage by automatically altering the electrostatic capacity of a condenser in a time constant circuit in response to an input voltage by a bidirectional switch. CONSTITUTION:When a voltage value of DC power to be intermittently interrupted by a switching element Q1 does not exceed the predetermined voltage value, a bidirectional switch S1 is turned ON by voltage detecting means and switch control means in an electric circuit SWC. The electrostatic capacity of a condenser in the time constant circuit becomes the sum of the electrostatic capacities of condensers C, C1 in this state. When the DC voltage to be intermittently interrupted by the element Q1 exceeds the predetermined voltage value, the switch S1 is turned OFF, and the electrostatic capacity of the condenser in the time constant circuit becomes only the electrostatic capacity of the condenser C. |
