| 摘要 |
PURPOSE:To prevent a charging resistor from burning out by shortcircuiting a resistor for limiting a charging current by the current of a switching element energized after a smoothing condenser of an inverter arrives at the prescribed voltage, and releasing the inhibit of an operation command. CONSTITUTION:The normal-open contact 88Pa of a relay 88P is connected with both ends of a charging current limiting resistor 11. When a power reactor 1 is started, a capacitor 2 is charged through the resistor 11. The voltage (v) divided from the charging voltage by resistors 3, 4 is input to a comparator 7. A reference voltage divided by resistors 5, 6 is input through a voltage stabilizer 15 from a rectifier 14 to the comparator 7. When the voltage (v) exceeds a reference voltage, the comparator 7 outputs to turn ON a TR18, a relay RY is operated to close a contact RYa. Then, the relay 88P is operated, the contact 88Pa is closed to shortcircuit the resistor 11. A normal-closed contact RYb, not shown, is opened to release the inhibit of the operation command. Thus, even if the operation command switch remains ON and it is started, it can prevent the resistor 11 from burning out. |
