| 摘要 |
PROBLEM TO BE SOLVED: To shorten the discharging time without decreasing the filter capacitor or the discharging resistor by providing a circuit for substantially short-circuiting first and second terminals in response to a power turn off signal. SOLUTION: An shorting circuit 28 comprising a series circuit of an FET Q2 functioning as a switching element and a resistor R1 is connected between first and second terminals 24a and 26a. When the shorting circuit 28 functions and a current flow through the current limiting resistor R1, residual charges in capacitors C11, C12, C21 and C22 are consumed, as heat energy, by the resistor R1 and eventually go to zero. Consequently, the discharging time of 15 V and -7.5 V is shortened to about 7.5 mS, for example. According to the arrangement, the discharging time can be shortened without modifying the filter capacitor or the discharging resistor. |
