Power supply apparatus for discharge lamp and control method for the same
AssigneeRubycon Corporation
InventorMitsuru Nomizo
Life of this patent
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Abstract
An apparatus supplies power to at least one discharge lamp. The apparatus includes a buck converter for regulating power supplied to at least one discharge lamp having a switching element driven by PWM pulses, and a control unit for supplying PWM pulses to the buck converter. The control unit includes a function for controlling an output power of the buck converter so as to be constant using PWM pulses of a first frequency; and a function for controlling an output voltage of the buck converter so as to be maximum using PWM pulses of a second frequency that is lower than the first frequency. The buck converter is capable of operating in discontinuous mode based on the PWM pulses of the second frequency.
Claims10
A method of controlling an apparatus, the apparatus including a buck converter for regulating power supplied to at least one discharge lamp, the buck converter including a switching element driven by PWM pulses,
- the method comprising:
- regulating an output power of the buck converter so as to be constant using PWM pulses of a first frequency;
- and
- regulating, prior to the regulating the output power, an output voltage of the buck converter so as to be a target voltage using PWM pulses of a second frequency that is lower than the first frequency and operating the buck converter in discontinuous mode.
A method of controlling an apparatus, the apparatus including a buck converter for regulating power supplied to at least one discharge lamp, the buck converter including a switching element driven by PWM pulses,
- the method comprising:
- regulating an output power of the buck converter so as to be constant using PWM pulses of a first frequency;
- and
- regulating, prior to the regulating the output power, an output voltage of the buck convert so as to be maximum using PWM pulses of a second frequency that is lower than the first frequency and operating the buck converter in discontinuous mode.
An apparatus comprising:
- a buck converter for regulating power supplied to at least one discharge lamp, the buck converter including a switching element driven by PWM pulses;
- and
- a control unit for supplying PWM pulses to the buck converter, the control unit including:
- a function for controlling an output power of the buck converter so as to be constant using PWM pulses of a first frequency;
- and
- a function for controlling an output voltage of the buck converter so as to be maximum using PWM pulses of a second frequency that is lower than the first frequency, the buck converter being capable of operating in discontinuous mode based on the PWM pulses of the second frequency.
A program product for controlling an apparatus, the apparatus including:
- a buck converter with a switching element driven by PWM pulses for regulating power supplied to at least one discharge lamp;
- and a control unit for supplying PWM pulses to the buck converter,
- the program product comprising:
- regulating, by the control unit, an output power of the buck converter so as to be constant using PWM pulses of a first frequency;
- and
- regulating, prior to the regulating the output power, by the control unit, an output voltage of the buck converter so as to be maximum using PWM pulses of a second frequency that is lower than the first frequency and operating the buck converter in discontinuous mode.
Dependencies are inferred from the claim text.