Energy conserving electrical power control circuit
US4362970A · kind A · utility
Inventor
Key dates
| Filing date | Sep 8, 1980 |
| Grant date | Dec 7, 1982 |
| Priority date | — |
| Expiry date | Sep 8, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/40
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
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 power-off 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.