LED driver operating from unfiltered mains on a half-cycle by half-cycle basis
US9706613B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 16, 2015 |
| Grant date | Jul 11, 2017 |
| Priority date | — |
| Expiry date | Apr 16, 2035 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An analog electronic circuit for driving a string of LEDs including input terminals for accepting connection to AC voltage, a current regulation circuit operatively coupled to receive an AC voltage from the input terminals and to provide an output for connection to drive the string of LEDs. Included is a current regulation circuit configured to limit the current flow through the string of LEDs on a half-cycle basis to a predetermined value. Also disclosed are an overvoltage circuit configured to switch off electrical connection between the AC voltage and the string of LEDs upon the AC reaching a predetermined high voltage value on a half-cycle basis in order to limit power. Overtemperature and power factor correction are also addressed. Also improving efficiency by shorting part of the LED string during the lower voltage phase of the input AC voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.