Photo electric methods and apparatus for regulating electrical power consumption in stores

A controller for automatically regulating the consumption of electrical energy in a store, said controller being comprised of;

• photo diode means for placement external to said store to form electrical impedances representative of the ambient light intensity,
• amplifier means having inputs connected to said photo diode and being responsive to the impedance thereof for generating an analog signal having a magnitude indicating said ambient light intensity;
• means for manually selecting first and second reference voltage respectively corresponding to those magnitudes of said analog signal produced by cloudiness and dusk;
• first comparator means having inputs coupled to simultaneously receive said analog signal and said first refererence voltage for generating a first control signal indicating when said ambient light intensity corresponds to cloudy weather;
• second comparator means having inputs coupled to simultaneously receive said analog signal and said second reference voltage for generating a second control signal indicating when said ambient light intensity corresponds to dusk;
• timer means for generating a third control signal after a manually selectable time delay in response to the initial occurrance of said second control signal to indicate full darkness;
• and
• a first electromagnetic switch operable in response to said first control signal for energizing lights near windows in said store, a second electromagnetic switch operable in response to said second control signal for energizing electric signs and parking lot lights for said store, and a third electromagnetic switch operable in response to said third control signal for de-energizing a uniformly distributed portion of all interior overhead lighting in said store.