We found this circuit in the Texas Instruments optoelectronics manual. Field effect transistors can be BF245 and bipolar BC548. The sensor is a photodiode in the photo-generator mode.
To obtain an AND gate we have the configuration shown in the figure. With the values indicated for the...
This circuit has been removed from the component's datasheet. In it we have a monostable or...
Here we have the way to activate two common cathode displays with 4026 integrated circuits. The...