PORTABLE FLUORESCENT LAMP AND INVERTER THEREFOR
US3953768A · kind A · utility
Inventors
Key dates
| Filing date | May 22, 1973 |
| Grant date | Apr 27, 1976 |
| Priority date | — |
| Expiry date | May 22, 1993 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A portable battery-operated fluorescent light with an inverter having a single transistor Class C oscillator and a gapped-core nonsaturating reactor transformer with a parallel capacitance in the secondary circuit to cause the secondary circuit to act as a resonant tank circuit for the oscillator. The lamp is capacitor-ballasted, and the batteries are rechargeable. A large capacitance is connected in parallel with the batteries to decrease effective battery impedance. The light has an automatic shutoff circuit using a zener diode to shut off the inverter when the batteries are discharged to the safe limit and a self-contained constant voltage current-taper charging circuit for the cells, with the same zener diode as a voltage reference. A jam-in lamp socket is shown which allow the lamp to be inserted straight into the socket without rotation, and a method for pulsing the filament at one end of the lamp to improve startup of aging lamps is disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.