Electric lamp and discharge devices: systems – Condenser in the supply circuit – Condenser in shunt to the load device and the supply
Patent
1985-01-14
1987-02-17
Chatmon, Saxfield
Electric lamp and discharge devices: systems
Condenser in the supply circuit
Condenser in shunt to the load device and the supply
315DIG7, 315241R, 315244, 361113, 361 71, 363 50, H05B 3700, H05B 3900, H05B 4114
Patent
active
046442286
ABSTRACT:
A source of high-frequency voltage is applied directly across a series-resonant L-C circuit. A fluorescent lamp and a Varistor are both connected in parallel with the capacitor of this L-C circuit. The Varistor is operative: (i) to prevent the series-resonant L-C circuit from ever overloading the voltage source, and (ii) to limit the magnitude of the voltage provided across the lamp to a level appropriate for rapid-starting thereof. When power is initially applied, the lamp's cathodes are cold and the lamp does not conduct; which implies that a significant amount of power is dissipated in the Varistor. For sake of cost-effectivity and energy conservatiion, if the lamp fails to conduct for about 25 milli-seconds, a control means provides a short circuit across the capacitor. The resulting short circuit current is used for heating the fluorescent lamp cathodes. After about 1.5 second, the short circuit is removed for about 25 milli-seconds, thereby permitting the voltage across the capacitor to grow to an magnitude sufficient to ignite and operate the lamp. If lamp current does not then flow, or if at any time it ceases to flow, the short circuit will be re-applied within about 25 milli-seconds. Thereafter, until power is removed or until an operable lamp is connected, the control means will continuously repeat the cycle of 1.5 second short circuit and 25 milli-seconds open circuit.
REFERENCES:
patent: 4259614 (1981-03-01), Kohler
patent: 4392087 (1983-07-01), Zansky
patent: 4398126 (1983-08-01), Zuchtriegel
patent: 4406976 (1983-09-01), Wisbey et al.
patent: 4413313 (1983-11-01), Robinson
patent: 4503363 (1985-03-01), Nilssen
patent: 4554487 (1985-11-01), Nilssen
LandOfFree
Series-resonant parallel-loaded fluorescent lamp ballast does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Series-resonant parallel-loaded fluorescent lamp ballast, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Series-resonant parallel-loaded fluorescent lamp ballast will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1939254