This simple injector circuit can actually be powered by voltages from 3 to 9 V. The frequency is given by C1 which can be between 4.7 and 10 nF. The CMOS can also be 4011.
Using a voltage comparator, we find this AND gate on a Popular Electronics from the 90s. The...
We found this circuit in an old documentation from the 70s. Its purpose is to indicate the...
This circuit appeared in the June 1990 issue of Radio Electronics magazine. Integrated circuits must...