| 摘要 |
PURPOSE:To obtain a high-precision timing switch with a small number of parts, by connecting a timing capacitor and a timing resistance to the gate of an N gate thyristor and by connecting a Zener diode to the anode of the thyristor. CONSTITUTION:The connection point between a timing capacitor 14 and a timing resistance 13 is connected to the gate of a PIT11 of an N gate thyristor, and a Zener diode 12 is connected to the anode of the PUT11, and a load relay 3, the other end of the resistance 13, and the negative side of a power source are connected to the cathode of the PUT11. When contacts (a) and (c) of a manual switch 9 are connected, the gate of the PUT11 has a potential higher than that of the anode, and the PUT11 is biased backward and is not conductive. The gate voltage of the PUT11 falls according as the capacitor 14 is chrged; and when the gate voltage becomes lower than the anode voltage, the PUT11 becomes conductive through the diode 12 to operate the load relay 3. When the contact (a) of the switch 9 is switched to the side of a contact (b), electric charge of the capacitor 14 is discharged through a resistance 16 to prepare for the next operation. |
