Multi-stage LED lighting systems
US9426855B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 2014 |
| Grant date | Aug 23, 2016 |
| Priority date | — |
| Expiry date | Aug 7, 2034 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Multi-stage LED drivers and lighting systems are disclosed. The lighting system comprises a bridge rectifier receiving power from an AC power line source, two or more current limiting devices, and a string of LEDs having a corresponding number of LED lamps connected in electrical series. Each of the current limiting devices is coupled to and provides current to the corresponding LED. When the instantaneous voltage of the alternating current source is near zero volts, no significant current flows through the string of LEDs. As the instantaneous voltage from the bridge rectifier increases beyond the forward voltages of the LEDs in the string, the current limiting devices energize and provide current to the corresponding LEDs as well as the LEDs connected to the cathode of the corresponding LED. The equivalent circuits of the lighting system vary throughout the power cycle of the AC line power source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.