HIGH RESOLUTION PULSE WIDTH MODULATION(PWM) FREQUENCY CONTROL USING A TUNABLE OSCILLATOR

A fluorescent lamp light intensity dimming control generates a pulse width modulation (PWM) signal at about a fifty percent duty cycle and has very fine frequency change granularity to allow precise and smooth light dimming capabilities. Intermediate PWM signal frequencies between the frequencies th...

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Bibliographic Details
Main Authors BOWLING STEPHEN, BARTLING JAMES, WOJEWODA IGOR
Format Patent
LanguageEnglish
Korean
Published 15.02.2012
Subjects
ELECTRIC HEATING
ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR
ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
ELECTRICITY
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Summary:A fluorescent lamp light intensity dimming control generates a pulse width modulation (PWM) signal at about a fifty percent duty cycle and has very fine frequency change granularity to allow precise and smooth light dimming capabilities. Intermediate PWM signal frequencies between the frequencies that are normally generated from values in a period register of the PWM generator are provided with a variable frequency clock source to the PWM generator. Selection of each frequency from the plurality of frequencies available from the variable frequency clock source may be determined from a value stored in a variable frequency clock register. A microcontroller may be used to select appropriate frequencies for dimming control of the fluorescent lamp from the variable frequency clock source, and the period and duty cycle values used in generating the PWM signal at about a fifty percent duty cycle.
Bibliography:Application Number: KR20117019872