G PHYSICS
G05 CONTROLLING; REGULATING
G05F SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
1/00 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
G05F1/10 Regulating voltage or current
G05F1/46 wherein the variable actually regulated by the final control device is DC
G05F1/56 using semiconductor devices in series with the load as final control devices