This indicator circuit used and game machines (arcades) to indicate that the machine is being shaken was found in NASA documentation. The circuit uses as a sensor a container with water and three sensors.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...