| 摘要 |
PURPOSE:To obtain a limit detection signal before an element is thermally damaged by detecting that power of the prescribed amount or larger is continued over the specified time by detecting the generated power of a static induction thyristor. CONSTITUTION:A voltage detector 6 and a current detector 7 are arranged, a gate voltage and a gate current are detected by the detectors, and a gate power is obtained by a multiplier 8. Further, when the gate power level of the output of the multiplier 8 reaches the reference of the prescribed amount or larger, it is detected by a level discriminator 9 and a time delay circuit 10, and the fact that the level excess state is continued for the prescribed time is detected. Then, a communication limit signal SCF is fed from the delay circuit 10. |
