being pressure-sensitive resistors

Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems > Regulating voltage or current > wherein it is irrelevant whether the variable actually regulated is AC or DC > using variable impedances in series with the load as final control devices > being pressure-sensitive resistors

Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems > Regulating voltage or current (G05F1/02 takes precedence) > wherein it is irrelevant whether the variable actually regulated is AC or DC > using variable impedances in series with the load as final control devices > being pressure-sensitive resistors