Patent · US Expired

Circuitry for portable lighting devices and portable rechargeable electronic devices

US7723921B2 · kind B2 · utility

5Cited by
75References
20Claims
0Family size

Inventor

Key dates

Filing dateFeb 8, 2006
Grant dateMay 25, 2010
Priority date
Expiry dateFeb 28, 2026

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02J7/0031
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A portable electronic device, such as a flashlight, with a circuit for reducing the initial surge of current that is sent through the lamp filament when a flashlight is turned on is provided. The circuit reduces the stresses placed on the lamp bulb when it is turned on, thereby extending the life expectancy of the lamp bulb. A flashlight with beacon mode that produces light according to a duty cycle of less than 11% is also disclosed.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.