Electronic candle and electronic night lamp
US8368313B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 2009 |
| Grant date | Feb 5, 2013 |
| Priority date | — |
| Expiry date | Sep 3, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B47/155
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to an electronic candle and an electronic night lamp. The electronic candle includes a light-emitting diode (LED), a capacitor and a control circuit. The capacitor has a first terminal coupled to a first terminal of the LED, and a second terminal coupled to a common voltage. The control circuit has a first control terminal coupled to the first terminal of the LED, and a second control terminal coupled to a second terminal of the LED. In a detecting period, the control circuit provides a preset voltage across the first and second terminals of the LED so that the LED is reversely biased for a preset time. Then, the first control terminal of the control circuit is set to high impedance. Next, the control circuit detects a variation of a voltage of the first terminal of the capacitor with respect to time to determine whether to light up the LED.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.