Fully automatic energy efficient lighting control and method of making same

Abstract

A fully automatic and energy efficient lighting control or light switch comprises different settings, preset by a user, and activates all or a portion of at least one bank of lights upon detecting occupants within a room. In one embodiment, the light switch detects doppler-shifted, reflected ultrasonic waves caused by occupant motion within the room. In an automatic mode, the light switch is configured to automatically switch from an initial sensitivity level for detecting motion within a short range therefrom, to a higher sensitivity level for detecting motion anywhere within the room. After the room is empty or no motion is sensed, the light switch is configured to turn the lights off following a variable time delay. The light switch returns to its initial low sensitivity level following a predetermined grace period which begins once the lights are turned off. The lights can be turned off manually when the light switch is in its automatic mode, in which case, the light switch continues to operate at the higher sensitivity level. When motion is no longer detected, and following the variable time delay and predetermined grace period, the switch automatically returns to an automatic “on” state. In an alternative manual mode, the light switch can be activated manually and deactivated both manually and automatically. In its manual mode, the light switch is configured to deactivate the lights upon sensing no motion and is configured to reactivate the lights automatically within the predetermined grace period upon sensing motion.