Flashlight with soft turn on control
US4855647A · kind A · utility
4Cited by
8References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1987 |
| Grant date | Aug 8, 1989 |
| Priority date | — |
| Expiry date | Apr 14, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B39/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A flashlight is provided with a special circuit for limiting the surge current through the flashlight bulb. The circuit includes a secondary incandescent filament used to energize a transistor gradually upon the activation of flashlight. The transistor in turn gradually energizes the main bulb.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.