低功耗超声波燃气表设计

超声波燃气表受流道结构、管径机械噪声、气体流速等因素影响,造成超声波信号衰减严重、低功耗设计实现难度大。针对这一问题,以超低功耗MSP430微处理器为核心,搭载低功耗芯片超声波模拟前端(TDC1000)和高精度计时芯片(TDC7200),构成了超声波信号发射与接收电路。提出了一种优化激励信号脉冲个数方法,以及采用定时中断和外部中断相结合的系统监控方式来实现低功耗设计,并完成了G2.5超声波燃气表的设计。通过实际测试,优化的激励信号个数能获得较好的超声波回波信号。计算结果表明,使用1节6000mAh的锂电池供电,研制的G2.5超声波燃气表正常计量工作年限可达6年,能够满足企业低功耗技术要求。

The design of low power ultrasonic gas meter

Ultrasonic gas meters are affected by channel structure,pipe diameter mechanical noise,gas velocity and other factors,resulting in serious attenuation of ultrasonic signals,and low power consumption design is difficult to achieve.To solve this problem,the ultra-low power consumption MSP430 microprocessor,equipped with a low-power chip ultrasonic simulation front end (TDC1000) and a high-precision timing chip (TDC7200),constitute the ultrasonic signal transmitting and receiving circuit.A method of optimizing the number of excitation signal pulses is proposed,and the system monitoring method combining timing interrupt and external interrupt is used to realize low power consumption design;furthermore,the design of G2.5 ultrasonic gas meter is completed.Through the actual test,the optimized number of excitation signals can obtain a better ultrasonic echo signal;according to the calculated power consumption data,using a 6000mAh lithium battery for power supply,the developed G2.5 ultrasonic gas meter can normally measure working life of up to 6 years,which can meet the technical requirements of low power consumption of enterprises.