Suggested by General Electric in a 1965 publication this circuit uses a light bulb. Can be changed to use LED and capacitor can be 22 uF.
This small blocking oscillator for approximately 1000 Hz was found in an American documentation from the...
This circuit for activating a relay was found in a Radio Electronics magazine from August 1962. The...
In this circuit found in the December 1972 Radio Electronics magazine. R can be from 1k to 22k,...