DISCHARGE LAMP LIGHTING DEVICE

PURPOSE:To improve a lighting device which operates via an inverter by providing a load current detecting circuit for a discharge lamp; a circuit which stops an inverter when the load current is no greater than the specified current value: and a circuit which disables the former circuit for present...

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Bibliographic Details
Main Authors YAMAGUCHI GORO, SHIBATA MITSUO
Format Patent
LanguageEnglish
Published 28.05.1992
Subjects
ELECTRIC HEATING
ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR
ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
ELECTRICITY
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Summary:PURPOSE:To improve a lighting device which operates via an inverter by providing a load current detecting circuit for a discharge lamp; a circuit which stops an inverter when the load current is no greater than the specified current value: and a circuit which disables the former circuit for present period after the power supply is switched on. CONSTITUTION:A load current detecting circuit 24 which detects the load current flowing through a discharge lamp 15, and an inverter stopping circuit 32 which stops the operation of an inverter 18 when the current detected by the circuit is no greater than e specified current value on at least one pole side of either positive or negative electrode are provided. Thus, either when the discharge lamp 15 is not kept on or when end of life causes nits-lighting or half wave discharge state, lighting abnormality can be detected with a simple circuit configuration so as to surely stop the operation of the inverter 18, so that dangers or damages, etc., of electrical parts which might occur because of the lighting abnormality can be prevented from happening. And, since a timing circuit 38 which disables operation of the circuit 32 after turning-on of the power supply until lighting comes on is provided, normal lighting can not be disabled.
Bibliography:Application Number: JP19900282898