Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
144 words
An apparatus for controlling output illumination level of gas discharge lamps comprising: a source of AC voltage; multiple ballast means for providing operating electrical current to said lamps, each said ballast means coupled in series relationship with at least one said gas discharge lamp; a controlled impedance coupled between an output of each said ballast means and at least one lamp; means for controlling a period of conduction of each said controlled impedance; an isolation transformer, having a primary winding coupled between a neutral and a power supplying terminal of each said ballast means, a voltage tap on said primary winding, and a secondary winding coupled to a cathode of said lamps; and an inductor coupled in parallel relationship with each said controlled impedance providing a current path between said voltage tap and said discharge lamps at least when each said impedance is non-conducting.
Claim 2
Independent Claim
144 words
An apparatus for controlling output illumination level of gas discharge lamps comprising: a source of AC voltage; multiple ballast means for providing operating electrical current to said lamps, each said ballast means coupled in series relationship with at least one said gas discharge lamp; a controlled impedance coupled between an output of each said ballast means and at least one lamp; means for controlling a period of conduction of each said controlled impedance; an isolation transformer, having a primary winding coupled between a neutral and a power supplying terminal of each said ballast means, a voltage tap on said primary winding, and a secondary winding coupled to a cathode of said lamps; and an inductor coupled in parallel relationship with each said controlled impedance providing a current path between said voltage tap and said discharge lamps at least when each said impedance is non-conducting.
Claim 3
Independent Claim
141 words
An apparatus for providing load side control of output illumination levels of gas discharge lamps comprising: a source of AC power; multiple ballast means for providing operating electrical current to said lamps, each said ballast means coupled in series relationship with at least one said gas discharge lamp; a controlled impedance coupled between an output of each said ballast means and said at least one gas discharge lamp; means for controlling a period of conduction of said controlled impedances, said means being responsive to a signal comprising deviation of lamp current from a reference value; and an inductor coupled in parallel relationship with each said controlled impedance providing a current path between said power source and the lamps at least whenever said impedances are substantially non-conducting, each said inductor having a secondary winding coupled to a means for detecting lamp current.
Claim 4
Independent Claim
141 words
An apparatus for providing load side control of output illumination levels of gas discharge lamps comprising: a source of AC power; multiple ballast means for providing operating electrical current to said lamps, each said ballast means coupled in series relationship with at least one said gas discharge lamp; a controlled impedance coupled between an output of each said ballast means and said at least one gas discharge lamp; means for controlling a period of conduction of said controlled impedances, said means being responsive to a signal comprising deviation of lamp current from a reference value; and an inductor coupled in parallel relationship with each said controlled impedance providing a current path between said power source and the lamps at least whenever said impedances are substantially non-conducting, each said inductor having a secondary winding coupled to a means for detecting lamp current.
Claim 5
Dependent Claim
13 words
The apparatus of claim 2 wherein each said controlled impedance comprises a TRIAC.
Claim 6
Dependent Claim
20 words
The apparatus of claim 3 wherein a current detection means is coupled to one load terminal of each said TRIAC.
Claim 7
Dependent Claim
44 words
The apparatus of claim 4 wherein said current detected at the load terminal of each said TRIAC and the current detected in the secondary of each said inductor are coupled to summing means for providing a current regulation signal used to regulate lamp current.
Claim 8
Independent Claim
219 words
An apparatus for providing load side control of output illumination level of gas discharge lamps while maintaining low lamp current crest factor and increased power factor, said apparatus comprising: a source of AC power; multiple ballast means for providing operating electrical current to said lamps, each said ballast means coupled in series relationship with at least one said gas discharge lamp; an input capacitance of less than about six microfarads; a control circuit comprising a first and second control loop arrangement, said first control loop functioning to control lamp current within boundaries of a limiter, said second control loop functioning to compare a signal proportional to said lamp illumination level to a reference signal, and further to provide or deny a drive signal; multiple TRIACS each having a main current conduction path coupled between an output of one said ballast means and at least one of said gas discharge lamps, each said TRIAC being responsive to said drive signal to provide current conduction between one said ballast and at least one of said lamps during at least a portion of each AC voltage half-cycle; and an inductor coupled in parallel relationship with each said TRIAC providing a current path between said power source and said at least one gas discharge lamp at least whenever said TRIAC is substantially non-conducting.
Claim 9
Independent Claim
219 words
An apparatus for providing load side control of output illumination level of gas discharge lamps while maintaining low lamp current crest factor and increased power factor, said apparatus comprising: a source of AC power; multiple ballast means for providing operating electrical current to said lamps, each said ballast means coupled in series relationship with at least one said gas discharge lamp; an input capacitance of less than about six microfarads; a control circuit comprising a first and second control loop arrangement, said first control loop functioning to control lamp current within boundaries of a limiter, said second control loop functioning to compare a signal proportional to said lamp illumination level to a reference signal, and further to provide or deny a drive signal; multiple TRIACS each having a main current conduction path coupled between an output of one said ballast means and at least one of said gas discharge lamps, each said TRIAC being responsive to said drive signal to provide current conduction between one said ballast and at least one of said lamps during at least a portion of each AC voltage half-cycle; and an inductor coupled in parallel relationship with each said TRIAC providing a current path between said power source and said at least one gas discharge lamp at least whenever said TRIAC is substantially non-conducting.