一种电能表码轮驱动步进电机堵转检测芯片设计

Design of A Forced Locking Detection Chip for electric energy meter code gear Stepper Motor

电能表码轮驱动步进电机的堵转将漏掉用电计数。为了检测电能表码轮驱动步进电机堵转的状态,设计了专用检测芯片。芯片基于对步进电机检测线圈的脉冲信号宽度的分析,采用模数混合集成电路检测出堵转脉冲数。其中模拟电路主要是比较器,对检测线圈的信号进行数字化变换。这种检测原理对检测系统的时钟误差有较大的容忍度,可达-23%,+45%,检测系统可在电能表中长期稳定可靠地工作。芯片采用0.5um CMOS工艺制造,与用微处理器检测堵转的方案相比,有更低的成本,可大批量使用。芯片已通过电能表企业准入试验。

The forced locking of stepper motor driving the code gear will cause energy meter counting error.In order to detect this forced locking of stepper motor,a dedicated detecting chip has been designed.The chip detects the number of forced locking pulses by mixed signal integrated circuit based on measuring the width of pulses generated from sense coil.The main part of analog circuit is comparator which digitizes the sense coil’s signal.The method used for detection has large tolerance to detection system’s clock error,from-23% to ＋45% of standard clock.The reliability of this chip installed on energy meter is proved.This chip was fabricated using 0.5μm CMOS process.Comparing with MCU forced locking detection method,applying the dedicated IC will greatly lower the cost during mass production.The chip has passed the entrance test of energy meter company.