Static immunity for single touch flash charger control
US5634153A · kind A · utility
6Cited by
28References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 21, 1995 |
| Grant date | May 27, 1997 |
| Priority date | — |
| Expiry date | Dec 21, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/32
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic flash device includes an illumination element, an actuation circuit having a flash capacitor providing energy releasable to illuminate the element, and a self-oscillating charging circuit, having a transistor, for charging the capacitor. The invention is characterized by a resistor located between a base of the transistor and ground for preventing the self-oscillating circuit from charging the capacitor when the flash device is exposed to an external static electric charge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.