| 摘要 |
PROBLEM TO BE SOLVED: To provide a trip circuit of a protective relay for elongating a life of a testing output circuit as long as that of a circuit element. SOLUTION: Signals 11B and 11A for driving FET in a testing output circuit normally in an off-state and driving the FET in an on-state at a power failure or a testing time of a testing output circuit itself, a logical AND circuit (AND), and a logical OR circuit (OR) are provided. In addition, a pulse transformer, instead of an optical generating element, is used. A driving signal with stopped pulses is used during an off-state of the FET. A constitution for rectifying and smoothing the drive signal through a pulse transformer and driving a semiconductor switch is included. |
