| 摘要 |
PURPOSE:To obtain a prescribed timer operation only by depressing an operation button selectively, by linking operation buttons of a push-button switch, which are locked by depression, and a switch for selecting a time constant of a CR timer circuit with each other. CONSTITUTION:When, a button, for example, 20b out of operation buttons 20a- 20c is depressed, a button projection 24b and a lock plate 23 are engaged with each other to lock the button 20b, and a contact 13b of a switch for selecting a time constant of a CR timer circuit 4 is closed by the projection 27b. Simultaneously, an interlocking plate 25 is pushed in a direction B by the button projection 24b, and a power supply switch 3 is turned on by an operating projection 26 to start supplying power to a load 2, and power is supplied to the CR timer circuit 4 also to start the timer operation. When the voltage of an anode 14 of a thyristor 10 becomes higher than the voltage of a gate 11 with a time constant determined by a resistance 12b and a capacitor 18, thyristors 10 and 15 are turned on, and an electromagnet 17 attracts the lock plate 23 in a direction (c) to release the lock of the button projection 24b. The button 20b is returned to the original state, and the interlocking plate 25 is returned by the force of a spring to open the switch 3. |
