| 摘要 |
PURPOSE:To speed up the selective operation, by shortening the base and emitter with the SW circuit, when the photo Tr is interrupted, by constituting the selection circuit through the provision of the switching SW circuit to the base circuit of photo transistor Tr. CONSTITUTION:The base of the photo detection transistor Tr 31 is commonly connected to the collector of the selection Tr 33 via the diode 32. The first group selection signl is fed to the base of Tr33 and the emitter is grounded. The emitter of the photo Tr 31 is grounded via the diode 34, and it is connected to the power supply V2 via the resistor 35 and output signal group is picked up from the collector. When Tr33 is turned on, the base and emitter of all photo transistors 31 are shortened and compulsively turned off, then no signal delivery is made. When Tr33 is turned off, the base emitter of Tr 31 is opened, photo transistor Tr31 is operated according to the presence of the input signal to the light emitting diode 21, enabling signal delivery. |
