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公开(公告)号：US4396868A
公开(公告)日：1983-08-02
申请号：US238116
申请日：1981-02-25
CPC分类号： G01R31/44 , H05B37/03 , H05B37/036
摘要： A lamp circuit is provided having a constant current-type AC power source and a plurality of isolation transformers coupled in series with the AC power source. The secondary circuit of each isolation transformer is connected to an electric lamp. The output voltage of the constant current-type AC power source is detected to determine the times when the output voltage crosses the zero voltage level. A disconnected lamp in the circuit results in a distortion of the output voltage waveform due to the magnetic-saturation characteristics of the isolation transformer coupled to the disconnected lamp. The output voltage waveform is integrated over time between the time periods when the output voltage signal crosses the zero axis. The result of the integration is compared with a reference value. When the integrated value exceeds the reference value, an alarm signal is generated. The number of disconnected lamps may also be determined and displayed. The circuit includes a device for supplying a small current to the plurality of isolation transformers such that the status of the lamps in a circuit can be determined without illuminating any of the lamps in the circuit.
摘要翻译： 提供了具有恒流型AC电源和与AC电源串联耦合的多个隔离变压器的灯电路。 每个隔离变压器的次级电路连接到电灯。 检测恒流型AC电源的输出电压，以确定输出电压跨越零电压电平的时间。 由于耦合到断开的灯的隔离变压器的磁饱和特性，电路中断开的灯导致输出电压波形的失真。 输出电压波形在输出电压信号穿过零轴的时间段之间随时间积分。 将积分的结果与参考值进行比较。 当积分值超过参考值时，产生报警信号。 也可以确定并显示断开的灯的数量。 电路包括用于向多个隔离变压器提供小电流的装置，使得可以确定电路中的灯的状态而不照亮电路中的任何灯。
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公开(公告)号：US5168198A
公开(公告)日：1992-12-01
申请号：US670780
申请日：1991-03-19
申请人： Toshisuke Watanabe
发明人： Toshisuke Watanabe
CPC分类号： H05B37/038
摘要： A lamplight failure detection system for detecting lamplight failure in a lamplight circuit, the lamplight circuit having a plurality of lamplight units connected with the secondary side circuits of each of a plurality of current transformers, the current transformers having their primary side circuits connected in series to an alternating current power supply. The lamplight failure detecting system includes a plurality of lamplight failure detectors fitted to each lamplight unit for detecting lamplight failure in the corresponding lamplight unit, a power control unit for repeatedly performing the momentary interruption of the output of the alternating power supply when there is no fault in the lighting of the lamplight unit, a plurality of lamplight circuit control units fitted to each lamplight failure detector for electrically closing the secondary side circuit of the current transformer when a lamplight failure is detected by the lamplight failure detector and for opening the secondary side circuit for a fixed time when a predetermined number of momentary interruptions of the alternating current power supply which occur after the lamplight failure is detected, a lamplight failure judgement unit for detecting lamplight failure based on variations in the outputs of alternating current power supply, and a lamplight failure locator unit for deciding which lamplight units have failed based on the comparison between the number of momentary interruptions from the time when a first lamplight failure is detected to when the next lamplight failure is detected with the predetermined number of momentary interruptions for each of lamplight unit.
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