| 摘要 |
PURPOSE:To increase the trigger light amount of a photothyristor by devising the pulse drive current waveform of a light emitting diode. CONSTITUTION:A light emitting diode is driven by a pulse with a current waveform which stepwisely or continuously decreases with sufficient current value at the initial drive in the pulse drive time duration of the diode which is determined under the circuit conditions of a system. Accordingly, a light output which is larger than the conventional one can be obtained in the case that large light output is necessary at the initial pulse of the case of driving the diode with a pulse, and the pertinent light output is obtained in the case that small light output is thereafter needed. In this manner, since the large increase of the trigger light amount of the photothyristor can be expected, the dv/dt and di/dt withstand values of the photothyristor can be improved. |
