| 摘要 |
PURPOSE:To suppress the rush current at the starting time and to interrupt a circuit rapidly at the abnormal time by inserting a resistor of the suitable value to a protecting circuit separate from a circuit, through which a main current flows. CONSTITUTION:When an AC power source 1 is applied at the starting time, a charging current flows to a condenser 7 through a circuit protector 2c, a resistor 5 and a rectifier 6, and the voltage across the condenser 7 gradually rises. The value of the resistor 5 is selected to the value so that the rush current becomes one divided by several value of the rated current. When the voltage across the condenser 7 reaches the prescribed value, a relay coil 12 is excited, and its contact 4 is closed. When an AC power source 1 is applied in the state that both ends of the condenser 7 are shortcircuited, a circuit protector 2c is tripped, and circuit protectors 2a, 2b are simultaneously opened. |
