| 摘要 |
PURPOSE:To calculate the capacitance of a capacitor even if a power source switch is frequency turned on/off at a short interval. CONSTITUTION:A switching transistor 5 of a DC/DC converter 4 for charging a capacitor C1 is controlled by applying a voltage V1 of the capacitor C1 whose capacitance is to be calculated to a comparator 7 having two reference voltages and controlling a transistor 9 with its output voltage V2 as a control signal. Since the frequency of the control signal depends on the capacitance of the capacitor, its capacitance can be calculated. |
