| 摘要 |
<p>PURPOSE:To increase the delaying time when a phototransistor changes from OFF to ON, by connecting a capacitor between the base and emitter of the phototransistor. CONSTITUTION:An input signal is applied to a light emitting diode 3-1 of a photocoupler 3 via a resistor 1. The collector of a phototransistor 3-1 is connected to a power supply +V via a resistor 4, and an integration network consisting of a resistor 5 and a capacitor 6 is connected, and a delay signal is obtained from the output of the said capacitor 6. When the phototransistor 3-2 changes from ON to OFF, a delay is given with the integration network, connected to the collector output. Since the rise of the bias voltage given to the base by a capacitor 7 has a delay when the phototransistor 3-2 changes from OFF, to ON, the time from the light irradiation to the turning-on of the transistor has a delay.</p> |
