Zero return photoelectric control system

Abstract

A system controls high power devices according to ambient light levels. The system includes a latching relay, a latching relay driver, an ambient light sensor and a relay bulk power supply. The latching relay switches power on and off to the high power devices, and the latching relay driver energizes the latching relay, using power from on-periods when the latching relay is closed. The ambient light sensor controls when the latching relay driver energizes the latching relay, and the relay bulk power supply stores power from the on-periods to be used to energize the latching relay during off-periods when the latching relay is open.

Dependencies are inferred from the claim text.