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.
This thermometer, which uses common diodes as sensors, was found in a 1975 magazine -...
This circuit is from American documentation from the 70s. This configuration appears in this...
We found this Japanese commercial radio diagram of three transistors in a documentation of the...