Apparatus for operating HID lamp at high frequency with high power factor and for providing standby lighting
US4506195A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 4, 1983 |
| Grant date | Mar 19, 1985 |
| Priority date | — |
| Expiry date | Feb 4, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/2887
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Ballast apparatus operates a HID lamp at high frequency and high power factor. Series-connected current-limiting input inductor and input capacitor connect across apparatus input and are tuned off resonance to pass predetermined lagging current. An additional input capacitor is connected across input terminals to that input power factor approaches unity. Full-wave diode bridge has input connected across series-connected input capacitor and filter capacitor connects across bridge rectifier output. During normal operation, the filter capacitor develops a DC potential which is current limited by series-connected inductor and capacitor. Inverter has input connected across filter capacitor and inverter an output that drives the HID lamp through a high-voltage generating and variable impedance resonant circuit. When HID lamp is not operating, resonant circuit impresses high voltage across lamp to start same in warm or cold condition and resonant circuit exhibits relatively low impedance which decreases current-limited potential across filter capacitor. When HID lamp is normally operating, resonant circuit exhibits relatively high impedance which increases DC potential across filter capac…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.