LED driver circuit
US9155142B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 2013 |
| Grant date | Oct 6, 2015 |
| Priority date | — |
| Expiry date | Jan 30, 2034 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention is to provide an LED driver circuit which includes a capacitor and at least one LED respectively connected in parallel to a power source through a switch device, and a controller having an input end connected to a line between the switch device and the power source and being configured for detecting an input voltage applied to the LED. When the controller detected that the input voltage is unable to drive the LED to emit light, the controller activates the switch device to make only the connection between the capacitor and the at least one LED, such that the capacitor discharges a voltage stored therein to the at least one LED to continuously emit light. Since the driver circuit only needs a small-capacity, low-cost capacitor for increasing the light emission time of the at least one LED, the cost of the driver circuit can be lowered effectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.