This circuit was found in the February 1970 issue of Radio Electronics magazine. The integrated circuit is a type of the time. It consists of a high-gain differential amplifier.
It can be obtained from Mouser Electronics new superFETs III from Fairchild for voltages of 700 V...
This circuit was found in a 1969s American documentation. With modern components, it can be used...
The figure shows how to change the frequency of a 5 V LED blinking. The capacitor can have other...