| 摘要 |
PURPOSE:To detect a defect with a simple structure by detecting the input AC current of a thyristor rectifier to detect whether the detecting current is lower than the prescribed value or whether it is a current to be expected in advance or not. CONSTITUTION:A current transformer 12 is provided at the input side of a thyristor rectifier, and a defect detector 13 is provided at the secondary side of the transformer 12. A gate signal provided by a thyristor 5 is transmitted via a phase controlling circuit 10 to the detector 13. The detector 13 has the first detector which detects whether the current detected by the transformer 12 is lower than the prescribed value or not, and the second detector which detects whether the current detected by the transformer 12 is a current to be expected in advance or not, thereby detecting the defect of the thyristor rectifier. |
