Reactor-type ballast circuit
US4914354A · kind A · utility
13Cited by
18References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 8, 1988 |
| Grant date | Apr 3, 1990 |
| Priority date | — |
| Expiry date | Sep 8, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/05
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved, more energy efficient reactor-type ballasting circuit for fluorescent lamps includes an inductive ballasting coil for directly applying an AC line voltage to the cathodes of a lamp without an intermediate autotransformer and also includes a glow type thermal switch in series with a positive temperature coefficient (PTC) resistor for electrical connection across the cathodes of the lamp to conduct pre-heating current to the lamp cathodes. The PTC resistor will effectively remove the glow switch from the ballast circuit if the switch fails to open after an appropriate time delay.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.