| 摘要 |
<p>PURPOSE:To ensure the control of conductive state and to prevent malfunction, by back-biasing the part between the gate and cathode of the photo thyristor. CONSTITUTION:To the gate electrode of the photo thyristor 17, the resistor 19 and the cathode electrode of the photodiode 30 are connected. Another end of the resistor 19 and the anode electrode of the photodiode 30 are connected to the cathode electrode of the photo thyristor 17. The photodiode 30 is activated with radiation light of the light emitting diode 31, back-biasing the part between the gate and cathode of the photo thyristor 17. Thus, positive voltage is fed to the terminal 15 and negative one is to the terminal 16, and even if the light from the light emitting diode 20 is fed to the photo thyristor 17, since the photo thyristor 17 is unconductive with the presence of the light radiation from the photodiode 31, the input signal at the terminals 32, 33 is controlled to control the conductive state.</p> |
