| 摘要 |
PURPOSE:To enable to continue the operation of a thyristor converter even if one component such as a light emitting element becomes defective by providing at least two groups of a plurality of light emitting elements connected in series with each other, and further providing a switching element for controlling the light emitting elements of each group. CONSTITUTION:When light emitting elements La1-Lan and Lb1-Lbn of light emitting element groups are normal, the same light gate signal is transmitted to a light thyristor to control to fire the thyristor. If the light emitting element Lb1 becomes defective and open state, a current detector 12b applies a light emitting element current abnormal signal to a switching circuit 11a, which switches to a circuit having current limiting resistors 6-2, 7-2 and a capacitor 8-2. In this manner, the light gate signal of the normal light emitting element group 3a is intensified, thereby enabling to transmit a light gate sufficient to fire the thyristor. |
