An improved AC power supply is described. The supply identifies the load through monitoring the current and voltage wave forms and phase relations with the AC Mains. The comparison is done in conditions where the power to the load is programmably varied through use of a control switch located in the line and neutral between the AC mains and the load. The program of controlling the switch is varied to optimize the ability to distinguish similar load types. The switch can be further used to control power to the load that varies according to a set of rules based upon the identity of the load. In a preferred embodiment, the design enables high efficiency with minimal components that may be fully integrated onto silicon.