Exit sign having a pulse switching tandem flyback voltage converter and a backup battery
US5847550A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 1997 |
| Grant date | Dec 8, 1998 |
| Priority date | — |
| Expiry date | May 22, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
This invention allows conversion from AC or DC line voltage between 70 and 424 volts to small loads between 2.5V and 18V DC for charging of batteries and operating of small loads. The invention uses a topology including two flyback stages in tandem. This invention has many uses and we are believed to be the first to apply it to battery charging and the operation of small loads. The invention is very cost effective and has feedback both from the input line voltage and output voltage to allow different loads and to allow the universal voltage input. The invention operates at high frequency and thus eliminates large transformers and uses surface mount components. All of this results in its very small size, low heat generation, and high efficiency. The invention draws very little power when connected only to a battery without the AC having been cycled. Primary applications for this invention include low powered uninterrupted power supply (UPS) devices. As disclosed herein, our first application is an emergency lighting device combined with an exit sign. However, we may use the same power supply for lighting equipment, lighting sensors, smoke detectors, burglar alarms, passive receivers…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.