High pressure sodium lamp starter controller
First Claim
1. A starter controller for a gas discharge lamp, in which the lamp has a pair of lamp input terminals connected across the output of a ballast, in which a lamp starter supplies starting signals to the lamp, and in which a starter controller is coupled to the lamp starter for controlling the starting signals to the lamp, the starter controller comprising:
- state-change detector means having input terminals for connection across the input terminals of the lamp for detecting an electrical signal proportional to the state of the lamp voltage normally present across the lamp input terminals, wherein said lamp voltage undergoes a rapid rise when a lamp drop-out condition occurs either as a result of a power line transient condition sufficient to cause a normally operating lamp to drop out, or as a result of a lamp aging condition, and the electrical signal detected across the input terminals of the state-change detector means measures the presence of said rapid rise in lamp voltage;
means responsive to the electrical signals present across the input terminals of the lamp for measuring and processing the detected electrical signals from the lamp, following a detection of said lamp drop-out condition by the state-change detector means, said electrical signal being proportional to the state of the lamp voltage wherein a first lamp voltage level is produced when the lamp drop-out condition was caused by a power line transient condition and a second lamp voltage level is produced when the lamp drop-out condition was caused by a lamp aging condition;
means for generating a start signal to the lamp starter for enabling restarting of the lamp in response to the processed electrical signal producing a first indication that the lamp drop-out condition was caused by power line transient conditions; and
means for preventing restarting of the lamp in response to the processed electrical signal producing a second indication that the lamp drop-out condition was caused by the lamp aging condition.
1 Assignment
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Accused Products
Abstract
A starter controller for a multiple parallel ballast for high pressure sodium lamps detects lamp "drop-out" or '"'"'cycling" and enables restarting of the lamp if the drop-out was causded by line transients of a level sufficent to cause normally operating lamps to drop-out. If the detected lamp drop-out was caused by normal end-of-life conditions, the controller does not allow restarting of the lamp. In one embodiment, the starter controller constantly monitors the voltage across the lamp terminals. When lamp drop-out occurs, this voltage rises rapidly to the ballast open-circuit secondary voltage. This voltage is detected by a level detector and rate detector which then processes lamp voltage level and rate of change of voltage after the initial drop-out is sensed. If the drop-out was caused by a sudden line transient, a relatively low maximum voltage level occurs after a high rate of change of lamp voltage, and this sensed combination of voltage level and rate of change triggers a timing circuit to enable the starter to restart the lamp. If a relatively high voltage level is sensed in combination with a high rate of change of lamp voltage, this indicates that drop-out was caused by lamp aging and the lamp is not restarted.
15 Citations
29 Claims
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1. A starter controller for a gas discharge lamp, in which the lamp has a pair of lamp input terminals connected across the output of a ballast, in which a lamp starter supplies starting signals to the lamp, and in which a starter controller is coupled to the lamp starter for controlling the starting signals to the lamp, the starter controller comprising:
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state-change detector means having input terminals for connection across the input terminals of the lamp for detecting an electrical signal proportional to the state of the lamp voltage normally present across the lamp input terminals, wherein said lamp voltage undergoes a rapid rise when a lamp drop-out condition occurs either as a result of a power line transient condition sufficient to cause a normally operating lamp to drop out, or as a result of a lamp aging condition, and the electrical signal detected across the input terminals of the state-change detector means measures the presence of said rapid rise in lamp voltage; means responsive to the electrical signals present across the input terminals of the lamp for measuring and processing the detected electrical signals from the lamp, following a detection of said lamp drop-out condition by the state-change detector means, said electrical signal being proportional to the state of the lamp voltage wherein a first lamp voltage level is produced when the lamp drop-out condition was caused by a power line transient condition and a second lamp voltage level is produced when the lamp drop-out condition was caused by a lamp aging condition; means for generating a start signal to the lamp starter for enabling restarting of the lamp in response to the processed electrical signal producing a first indication that the lamp drop-out condition was caused by power line transient conditions; and means for preventing restarting of the lamp in response to the processed electrical signal producing a second indication that the lamp drop-out condition was caused by the lamp aging condition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A starter circuit for a gas discharge lamp having a pair of lamp terminals connected across the output of a ballast, and a lamp starter for supplying starting signals to the lamp, and in which the starter controller is coupled to the lamp starter for controlling the starting signals to the lamp, the starter controller comprising:
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state-change detector means having input terminals for connection across the input terminals of the lamp for detecting the state of the voltage which is normally present across the terminals of the lamp, wherein said lamp voltage undergoes a rapid rise when a lamp drop-out condition occurs either as a result of a power line transient condition sufficient to cause a normally operating lamp to drop out, or as a result of a lamp aging condition; the state-change detector means including means for measuring the rate of change of the lamp voltage and the level of the lamp voltage following detection of said rapid rise in lamp voltage; means for generating a starting signal to the lamp starter for enabling restarting of the lamp in response to the measured lamp voltage level and rate of change of lamp voltage, in combination, producing a first indication that lamp drop-out was caused by the line transient conditions; and means for preventing restarting of the lamp in response to the measured lamp voltage level and rate of change of lamp voltage, in combination, producing a second indication that lamp drop-out was caused by the lamp aging condition. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. In a starter circuit for a gas-discharge lamp having lamp terminals and the lamp starter both connected in parallel across a lamp ballast, a starter controller coupled to the lamp starter for detecting lamp drop-out, and thereafter controlling the lamp starter for either enabling or preventing restarting of the lamp, depending upon the condition of the lamp at drop-out, the starter controller comprising:
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state-change detector means having input terminals for connection across the input terminals of the lamp for detecting an electrical signal proportional to the state of the lamp voltage normally present across the lamp input terminals, wherein said lamp voltage undergoes a rapid rise when a lamp drop-out condition occurs either as a result of a power line transient condition sufficient to cause a normally operating lamp to drop out, or as a result of a lamp aging condition, and the electrical signal detected across the input terminals of the state-change detector means measures the presence of said rapid rise in lamp voltage; means responsive to the electrical signal present across the input terminals of the lamp for measuring and processing the detected electrical signal from the lamp, following a detection of said lamp drop-out condition by the state-change detector means, said electrical signal being proportional to the state of the lamp voltage wherein a first lamp voltage level is produced when the lamp drop-out condition was caused by a power line transient condition and a second lamp voltage level is produced when the lamp drop-out condition was caused by a lamp aging condition; means for generating a start signal to the lamp starter for enabling restarting of the lamp in response to the processed electrical signal producing a first indication that the lamp drop-out condition was caused by power line transient conditions; and means for preventing restarting of the lamp in response to the processed electrical signal producing a second indication that the lamp drop-out condition was caused by the lamp aging condition. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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Specification