| 摘要 |
PURPOSE:To simplify the constitution of a power supply switch device which is used to a remote control device of a TV receiver, etc., by using a time constant circuit in place of a leaf switch. CONSTITUTION:A control circuit 3 gives ON/OFF control to a power supply switch 6 according to an external control signal RC while a power supply VCC is supplied in an ON state of an operating switch 13. A time constant circuit 33 raises up the AC rectified voltage V0 with a prescribed time constant and supplies it to a control terminal P of the circuit 3. The circuit 3 contains a comparator and permits the output of a control signal to the switch 6 when the level of the voltage applied to the terminal P exceeds a prescribed threshold value. Thus it is possible to prevent a malfunction of the circuit 3 without using an expensive leaf switch in such a case where a power failure occurs in an ON state of the switch 13 and then recovered. |
