| 摘要 |
PURPOSE:To prevent a rush current suppression function from functioning by maintaining a thyristor to be ON even if power fails momentarily when a load is in constant operation. CONSTITUTION:When thyristor 24 is off, current is supplied to an excitation coil 13b via a current limiting resistor 20 and a relay switch 13 is maintained to be off, thus applying power suppressed by a rush current suppression resistor 14 to an induction motor 16. Also, when a thyristor 24 is turned on, current is supplied to the excitation coil 13b via the thyristor 24, thus turning on the relay switch 13 and hence applying power which is not suppressed by the rush current suppression resistor 14 to the induction motor 16. Then, a capacitor 25b charges via a diode 25a and supplies the discharge electric charge to the thyristor 24 via a resistor 25c when power fails momentarily, thus maintaining the thyristor 24 to be on. |
