| 摘要 |
PURPOSE:To shorten the OFF time of an output TR by discharging charge applied at the ON of an FET through a bipolar TR connected between the source and drain of the FET in parallel. CONSTITUTION:A diode is used for a photovoltatic element 1, the charged capacity of the bipolar TR4 is sufficiently low as compared to that of an FE type output TR2 and the threshold voltage of the base is lower than that of the TR2. When light is interrupted, the capacity stored in the TR4 starts to be discharged. The discharged current flows through the diode 1 at first, but positive voltage is applied to the base of the TR4 because a diode 5 exists, the TR4 is turned to the connected status and the charge of the TR2 acted as a capacitor is discharged through the TR4. The time from the start of the discharge of the TR2 to the ON of the TR4 is shortened and the charge of the TR2 is discharged through the diode 1 and the TR4. |
