This circuit is from a 1976 amateur radio manual. The transistor can be the BD136 and the frequency adjustment is done in a potentiometer. The supply can be done with voltages from 6 to 15 V.
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...