Found in a 1966 documentation, this circuit monitors the operation of an air conditioning system. Transistors are from the time.
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...