Drive circuit for capacitive electroluminescent panels
US4527096A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 8, 1984 |
| Grant date | Jul 2, 1985 |
| Priority date | — |
| Expiry date | Feb 8, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A drive circuit is disclosed which includes a converter that provides current pulses that charge a capacitive electroluminescent lamp to produce light and a switching circuit that switches a predetermined number of successive current pulses at high frequency for progressively charging the electroluminescent lamp. The switching circuit also reverses the polarity of the electroluminescent lamp at low frequency when the electroluminescent lamp discharges at the end of a predetermined number of successive current pulses and before the electroluminescent lamp charges again by current pulses produced by the converter. The switching circuit is connected to and is responsive to signals provided by the timepiece frequency divider circuit and the converter is connected to the timepiece battery for stepping up the battery voltage to provide for the charging current pulses. The EL lamp is used as its own storage capacitor and receives substantially all of the energy provided by the converter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.