Ballast circuit for high intensity discharge lamps
AssigneeEG&G, Inc.
InventorLake Lau
Life of this patent
Estimating the term…
Abstract
A ballast circuit for a high intensity discharge lamp includes a boost converter, responsive to a dc input voltage, for providing a boosted dc output voltage; a boost controller, responsive to the boosted dc output voltage, for driving the boost converter to maintain the boosted output voltage at a predetermined level; a buck converter, responsive to the boosted dc output voltage, for providing a reduced dc output voltage; and a buck controller, responsive to the reduced output voltage, for driving the buck converter to operate the discharge lamp in a transition mode and maintaining the reduced dc output voltage at a preselected level for operating the discharge lamp in a steady state mode.
Claims12
A ballast circuit for a high intensity discharge lamp comprising:
- a boost converter, responsive to a dc input voltage, for providing a boosted dc output voltage;
- a boost controller, responsive to the boosted dc output voltage, for driving the boost converter to maintain the boosted dc output voltage at a predetermined level;
- a buck converter, responsive to the boosted dc output voltage, for providing a reduced dc output voltage;
- and
- a buck controller, responsive to the reduced dc output voltage, for driving the buck converter to operate the discharge lamp in a transition mode and maintaining the reduced dc output voltage at a preselected level for operating the discharge lamp in a steady state mode.
A ballast circuit for a high intensity discharge lamp comprising:
- a boost converter, responding to a dc input voltage, for providing a boosted dc output voltage;
- a buck converter, responding to the boosted dc output voltage, for providing a reduced dc output voltage;
- and
- a control circuit, responding to the boosted dc output voltage and the reduced dc output voltage, for driving, respectively, the boost converter to maintain the boosted dc output voltage at a predetermined level and the buck converter to decrease the boosted dc output voltage to the reduced dc output voltage and maintain the reduced dk output voltage at a preselected, steady state level, for operating the discharge lamp.
Dependencies are inferred from the claim text.