Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Energy conserving electrical power control circuit

Patent ·
OSTI ID:6392726
An energy conserving circuit for controlling supply of electrical power to various loads such as a street lamp or a hot water heater comprises a photoelectric device for starting a timer when a change from daylight to dark is sensed at sundown, and a load power control responsive to the timer to switch between power-off and power-on states. With a street lamp the timer and power control means are connected to switch the power control means to power-on state at the beginning of the delay period at sundown and later, well before sunrise, to switch to power-off state. In the case of a household hot water heater the switching of the power control to power-on state is delayed until the peak demand hours have ended after sundown. The photoelectric device will normally cause the power control to switch to poweroff state at sunrise. But a second timer may be added which is responsive to the photoelectric device to start a second timing period ending after normal sunrise so that switching to power-off will occur if the photoelectric device does not or cannot respond to sunrise.
Assignee:
EDB-83-057346
Patent Number(s):
US 4362970
OSTI ID:
6392726
Country of Publication:
United States
Language:
English