This circuit appears on this site from different sources. This is from documentation from the 1980s. The operating system used is uncommon and can be replaced by a more modern equivalent.
The purpose of this circuit is to automatically turn a water pump on and off. Sensor 1 is the...
This circuit was found in Motorola's 1967 documentation. The circuit makes use of power...
This interesting circuit appeared in the April 1952 Radio Electronics magazine. The circuit is...