Method and system to eliminate fluorescent lamp striations by using capacitive energy compensation
AssigneeUniversal Lighting Technologies, Inc.
InventorsWei Xiong, Christopher Radzinski
Life of this patent
Estimating the term…
Abstract
A method and system for reducing and/or eliminating striations from gas discharge lamps powered by an electronic ballast charges a capacitive energy device, which is coupled in parallel with the lamp, when the capacitive energy device detects that a predetermined lamp voltage condition has been satisfied. The system/method supplements the current supplied to the lamp by the electronic ballast with current supplied from the capacitive energy device when the predetermined lamp voltage condition is not satisfied. The supplemental current supplied to the lamp creates a harmonic-rich lamp current waveform that reduces and/or eliminates striations.
Claims17
A method of eliminating striations in a fluorescent lamp powered by an electronic ballast which generates a periodic lamp current to operate the lamp, wherein the lamp has a predetermined lamp voltage condition, comprising:
- providing a capacitive energy circuit in parallel electrical connection with the lamp, the capacitive energy circuit further comprising a resistive element and a capacitive energy source coupled to the resistive element;
- activating a switch, said switch in parallel electrical connection with the resistive element, when the predetermined lamp voltage condition is present so that the capacitive energy circuit charges during a first portion of the periodic lamp current;
- and
- deactivating the switch when the predetermined lamp voltage condition is absent so that the capacitive energy circuit discharges through the lamp during a second portion of the periodic lamp current.
An electronic ballast for a lamp, the lamp having a predetermined signal event, comprising:
- a capacitive energy circuit in parallel electrical connection with the lamp, the capacitive energy circuit further comprising a resistive element and a capacitive energy source coupled to the resistive element;
- and
- a switch in parallel electrical connection with the resistive element, the switch being responsive to the predetermined signal event so that the switch allows the capacitive energy circuit to discharge through the lamp according to the predetermined signal event.
A method of eliminating striations in a lamp powered by an electronic ballast, the lamp having a predetermined lamp voltage condition, comprising:
- charging a capacitive energy device, coupled in parallel with the lamp, when the predetermined lamp voltage condition is satisfied, said capacitive energy device comprising a capacitor, a diode and a resistor in parallel electrical connection with the diode;
- and
- supplementing current supplied to the lamp by the electronic ballast with current supplied from the capacitive energy device when the predetermined lamp voltage condition is not satisfied.
Dependencies are inferred from the claim text.