Electronic ballast for restarting high-pressure discharge lamps in various states of operation
A high-pressure discharge lamp ballast is provided for igniting and re-igniting a high-pressure discharge lamp in various states of operation. A power supply circuit is coupled to a power source and supplies AC power to the lamp. An ignition voltage generating circuit supplies a high-voltage ignitio...
Gespeichert in:
Hauptverfasser: | , |
---|---|
Format: | Patent |
Sprache: | eng |
Online-Zugang: | Volltext bestellen |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | A high-pressure discharge lamp ballast is provided for igniting and re-igniting a high-pressure discharge lamp in various states of operation. A power supply circuit is coupled to a power source and supplies AC power to the lamp. An ignition voltage generating circuit supplies a high-voltage ignition pulse for igniting the lamp. A pulse control circuit alternatively controls the ignition voltage generating circuit in a first control mode to provide the high-voltage ignition pulses for a first time period and in a second control mode to delay the high-voltage ignition pulses for a second time period. An abnormality detection circuit detects an abnormal lighting state of the lamp wherein a measured condition of the lamp corresponds to a predetermined condition. The pulse control circuit increases a ratio of the second time period relative to the first time period upon detection of an abnormal lighting state of the lamp by the abnormality detection circuit. |
---|