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.
We found this circuit in the May 1972 issue of Radio Electronics magazine. Its purpose is to teach...
This circuit is from 1985 documentation. The integrated circuit used is not very common today, but...
This circuit consists of a simple continuity test with two transistors forming a relaxation...