The Research And Development Of Emergency Lighting Circuit Monitoring System

This article embarks from the practical application of emergency lighting system, designs a monitoring system for emergency lighting circuit. This system can monitor the voltage and current of the lighting circuit, via analyzing and processing the data to judge the lamp circuit whether has lamp break down, so as to be able to repair timely. At the same time of reducing maintenance workload, ensure the emergency lighting is still working on reliable state.Firstly, the paper analyzed the function requirement of monitoring system in a practical application, then designed two kinds of schemes, through comparison, selected the special energy measuring chip ATT7022E and MCU dsPIC combining one. In addition, designed the hardware and the software on the basis of the target. The design of the hardware part includes power module, MCU module, voltage and current signal acquisition module, circuit on-off controlling module, memory module, serial communication module, light-emitting diode displaying module, and introduces the hardware design of the whole process of each part. The software design includes MCU program and PC controlling interface program. MCU part introduces the design of hardware interface layer. The upper compute part introduces that use serial communication to develop the control interface, realize a number of parameters setting and controlling. The micro controller uses the SPI interface to get the measured results of the effective value of current and voltage in ATT7022E, with a linear fitting in measurement by using the least square method in PC through the serial port communication, and deposits the parameters of linear model into MCU’s storage system. According to the sampling value we can measure actual size of the voltage and current. The micro controller processes and analyzes the real-time data, including the software filter, differential, correlation operation and so on to search the maximum order of the current decline hop, by comparing the quantity of step voltage, current changes before and after, and combining with the related parameters to judge whether it has lighting circuit break down. The system also realizes lighting circuit on-off control by magnetic latching relay. Finally, testing the lighting circuit monitoring system, and sum up the whole design. The results show that, the system is stable and reliable, can meet the basic functional requirements.