放电灯驱动控制电路

Discharge lamp drive control circuit

Abstract

Abnormal operation of a discharge lamp is detected using a small number of circuit elements by detecting load open circuit abnormality and load short circuit abnormality of the discharge lamp operating on a high frequency drive voltage through a single comparison circuit. The discharge lamp drive control circuit comprises an inverter control circuit, a positive side potential variation detecting circuit for detecting a positive side potential variation occurring in the secondary coil of a drive transformer, a negative side potential variation detecting circuit for detecting a negative side potential variation occurring in the secondary coil of the drive transformer, and a comparison circuit connected with the inverter control circuit. Outputs from the positive side potential variation detecting circuit and the negative side potential variation detecting circuit are superposed to be supplied to the comparison circuit and compared with a reference voltage, and an abnormal operation control signal is provided from the comparison circuit to the inverter control circuit during abnormal operation.
通过利用单一的比较电路来检测在高频驱动电压下进行动作的放电灯的负载开路异常和负载短路异常,以较少的电路元件来检测放电灯的异常动作。放电灯驱动控制电路具备:变换器控制电路;正侧电位变化检测电路,其检测驱动变压器的次级线圈中产生的正侧的电位变化;负侧电位变化检测电路,其检测驱动变压器的次级线圈中产生的负侧的电位变化;及比较电路,其连接在变换器控制电路上,其中,所述放电灯驱动控制电路将正侧电位变化检测电路和负侧电位变化检测电路的输出叠加并提供给比较电路从而与基准电压进行比较,在异常动作时从比较电路向变换器控制电路提供异常动作控制信号。

Claims

Description

Topics

Download Full PDF Version (Non-Commercial Use)

Patent Citations (0)

    Publication numberPublication dateAssigneeTitle

NO-Patent Citations (0)

    Title

Cited By (0)

    Publication numberPublication dateAssigneeTitle