Analysis of design scheme of speedometer based on stepper motor driver
Compared with analog electronic instruments, stepper motor meters have uniform indexing, good repeatability of pointers, fast response, small jitter, stability and reliability of product quality [1], so stepping Motor-type automobile instruments are gradually popularized in China. Such automotive instruments usually use a microcontroller to drive a stepper motor to drive the meter pointer to rotate. The microcontroller controls the stepping motor generally needs an external driving circuit, and the special automobile instrument stepping motor driving integrated circuit can simplify the software and hardware design of the automobile instrument and improve the stability and reliability of the instrument. This paper introduces and compares the performance characteristics of commonly used drivers in China. Finally, the speedometer is designed with the MC33991 produced by Freescale Semiconductor as an example.
1Common instrument motor driver chip features and performance comparison
Main features of 1.1X12.017 and VID66-06
1.2 Main features of MC33991
2 car speedometer design using MC33991
2 car speedometer design using MC33991
2.1 hardware circuit design
2.1.1 speed pulse detection circuit
2.1.2MC33991 interface circuit
