Design Of The Analog Temperature Alarm Device For The EMU Based On Digital Potentiometer

In July 2015, CSR CO.,LTD and CNR Co., LTD formally merged into CRRC. the merger further brought orders increased significantly. a large number of production orders brought more assembly debugging tasks. In addition, the service number of vehicles is increasing year by year, and the number of EMUs that requiring maintenance is also increasing. Both of all need to improve debugging efficiency.According to the test problems of alarm module used for CRH ATMS(axle temperature monitoring system) of the CSR Qingdao Sifang CO.,LTD. Considering the limitations of traditional test scheme: temperature rising slowly, low efficiency, damaging the peripheral equipment. This paper takes the digital potentiometer as the temperature compensation component.We can change the resistance of PT100 temperature sensor by setting the temperature parameters of system manually through the touch screen and MCU, to simulate the axel temperature rising. Therefore we can verify the performance of the ATMS, through whether the alarm or the emergency brake is triggered.The original physical heating mode is replaced by the non-destructive embedded method witch complete the test of alarm function of the ATMS.In this paper, we analyzed the temperature sensor circuit of ATMS. And according to the actual circuit, formulated the design scheme: the adjustable resistor module string into the circuit to simulate temperature rise. Finally, we add the temperature acquisition unit, to feedback the simulation temperature to the device display interface. Due to it is a battery powered equipment, the design elements of low power consumption are considered, both in hardware design and software design. At the meantime complex operation environment is also considered.At the stage of site tests, we verified the basic function of device, and tested the accuracy. Then, we got the MTBF(Mean Time Between Failures), and according to the feedback of site staff we corrected the bug and improved the function. Finally the device was put into into use in the CSR field debugging, and it was proved with high practical value.