This circuit using the CK722 among others came out in a September 1950 Radio Electronics. It was one of the first circuits of this type published with transistors that started to reach the market.
Found in a 1968 US publication, this circuit can operate on any power grid. The thickness of the wire...
In the figure we have a simple timer with the 555 feeding a relay directly. The circuit is from...
A simple electroscope can be made only with a 741, without the need for field effect transistors or other...