Step down power management system for LED flashlight
US7394211B1 · kind B1 · utility
3Cited by
8References
9Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 30, 2007 |
| Grant date | Jul 1, 2008 |
| Priority date | — |
| Expiry date | Jan 30, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/345
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A micro-controller and a converter circuit provide constant current to light emitting diode array from a power supply with greater voltage than the forward bias voltage of the light emitting diode. A micro-controller operatively coupled with a semiconductor switch and the converter circuit measures the ability of a DC power supply to charge the inductor. Duty cycles of the semiconductor switch are modified according to the measurement of the voltage across the internal resistor of the semiconductor switch so as to supply substantially constant current to the LED array through an inductor regardless of actual battery voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.