| 摘要 |
An overvoltage protection circuit is provided for protecting a load against overload damage, including a coarse protection device for dissipating the major portion of the energy of the trouble event, a plurality of fine protection devices for limiting the remaining portion of the trouble energy to a safe value, a diagnostic arrangement for determining the operating condition of the destructible fine protection devices, and a disconnect arrangement for disconnecting from the protection circuit at least one of the fine protection devices that has been determined to be faulty. A trouble event identifying arrangement compares with a reference voltage standard a measured voltage existing at a measuring junction between the fine protection devices, and generates a fault signal in the event of destruction of a fine protection device. A display arrangement indicates whether or not a fine protection device has been determined to be faulty. |
