PIEZOELECTRICALLY ACTUATED VARIABLE CAPACITOR

A variable capacitor comprises a fixed conductive plate and a movable conductive plate with a dielectric disposed between them. A piezoelectric actuator is used to vary the distance between the conductive plates by moving the movable plate with respect to the fixed plate, with capacitance changing i...

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Bibliographic Details
Main Authors BOROWIEC, JOSEPH C, HAMASY, SAYED - AMR A
Format Patent
LanguageEnglish
Korean
Published 07.06.1994
Edition5
Subjects
BASIC ELECTRIC ELEMENTS
CAPACITORS
CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES ORLIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
ELECTRIC HEATING
ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR
ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
ELECTRICITY
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Summary:A variable capacitor comprises a fixed conductive plate and a movable conductive plate with a dielectric disposed between them. A piezoelectric actuator is used to vary the distance between the conductive plates by moving the movable plate with respect to the fixed plate, with capacitance changing in inverse proportion to distance moved. In an electrodeless high intensity discharge lamp ballast, such a variable capacitor is situated in series with the excitation coil of the lamp. When a control voltage is applied to the piezoelectric actuator, the movable plate is moved from a starting position to a running position so as to maintain the ballast load in tune under both starting and running conditions, respectively, resulting in higher efficiency operation.
Bibliography:Application Number: KR19910009291