Measuring device and method of rotating speed of brush motor

Abstract

The invention provides a measuring device and method of the rotating speed of a brush motor. The measuring device comprises a current sampling resistor, a signal amplifying device, a signal filtering device, a signal shaping device and a pulse width and frequency measuring device which are sequentially connected, wherein the current sampling resistor is connected with the brush motor. The measuring method comprises the following steps of: converting a current break pulse into a small voltage signal through the current sampling resistor when a current break pulse signal of the brush motor is generated during the commutation of a commutator of the brush motor; amplifying the small voltage signal into a large voltage signal through the signal amplifying device; carrying out bandpass filtering through the signal filtering device to select a sinusoidal signal of a commutating pulse of the commutator; shaping the sinusoidal signal into a rectangular wave pulse signal through the signal shaping device; measuring a pulse width or frequency through the pulse width and frequency measuring device, and carrying out conversion according to the number of pole pairs of the commutator of the brush motor to obtain the final rotting speed of the brush motor. The measuring device can be used for accurately measuring the rotating speed of the brush motor, is easy to operate and can enhance the production efficiency.

Description

technical field [0001] The invention relates to a measuring device and a measuring method for a rotating speed of a brushed motor. Background technique [0002] In the measurement of the speed of the motor, especially on mass-produced products or test equipment for mass-produced products, the general method is to paste a cursor paper for reflecting laser on the motor shaft or the fan connected to the shaft. Then use a laser speedometer to measure the speed. It emits a laser beam, and every time the motor rotates, the laser beam is reflected by the cursor paper once, and a reflected pulse is obtained per circle to calculate the motor speed. There are three problems with this method: one is that every time a motor is measured, there must be two cumbersome actions of sticking the cursor paper and tearing off the cursor paper; second, during the measurement process, the laser must be accurately aligned with the pasted cursor paper; The third is that the laser light is only refl...

AI Technical Summary

Problems solved by technology

There are three problems with this method: one is that every time a motor is measured, there must be two cumbersome actions of sticking the cursor paper and tearing off the cursor paper; second, during the measurement process, the laser must be accurately aligned with the pasted cursor paper; The third is that the laser is only reflected once for each revolution of the motor. Within this revolution, the average speed of this circle is measured, and the fluctuation of the motor speed cannot be measured.

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