Emergency lighting circuit for shunt-regulated battery charging and lamp operation
US5646502A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 28, 1995 |
| Grant date | Jul 8, 1997 |
| Priority date | — |
| Expiry date | Aug 28, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S320/22
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Battery charging circuits configured as a combination of current limited charging sources and a shunt regulating path to bypass current from a battery charging path through a low impedance path so that charge current can be regulated and terminated or controlled, the invention further includes combination of the circuits in emergency lighting systems utilizing conventional AC mains power in a non-emergency mode and DC battery power in an emergency mode, the battery being charged with regulation of charge current effected by said circuits when in the non-emergency mode. In the present circuits, current is by-passed from that portion of the circuit used for battery charging by provision of a low impedance alternate path through which current may also be supplied to non-emergency lamps, the alternate path supplanting prior art circuits which function by continuously turning a single path on and off for charge regulation. In primary embodiments, the circuits use the charging path to also drive the non-emergency lamps. Current through the alternate shunt regulating path drives the non-emergency lamps in the normal non-emergency mode without passing of the current through the battery.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.