| 摘要 |
PURPOSE:To increase the reliability of a protective action by a method wherein an element which is conductive at a voltage over a set voltage is connected in series to a protecting resistance. CONSTITUTION:The protective device is comprised of a coil 1, protecting resistor 2, DC breaker 3, coil source 4, closer 5, transition detector 6, breaker operating signal 7, transition detecting signal 8, closer operating signal 9 and two diodes 10 connected in series oppositely to each other. Even the closer 5 operates badly concurrently with the action of the DC breaker 3, or when the sudden interruption of current supply to the coil is caused by internal accidents in the coil source 4 or accidents on the upstream side of the coil source 4, dielectric break down of diode 10 is caused and the coil 1 is protected. |
