The brushless motor
relies on a simple structure and a single current support, and it runs faster in many motor products. The speed measurement knowledge is as follows:
1. Hall effect principle speed measurement method
The brushless motor shaft drives the magnetic steel on the shaft to rotate, thereby changing the size of the magnetic field, converting the magnetic field change into a pulse signal through the Hall circuit, and amplifying and shaping to output a rectangular pulse signal. When the speed changes, the frequency of the output pulse changes. Thereby, the speed at which the DC geared motor rotates is obtained.
2, photoelectric speed measurement method
The grid speed and photogate are used to form the speed measurement system. When the brushless motor drives the grid disc to rotate through the transmission part, the speed measuring photoelectric gate obtains a series of pulse signals. These pulse signals are matched by two timing/counters of the single chip microcomputer, one counting one timing. Calculate the number m of pulses per unit time, and after unit conversion, the speed at which the motor rotates can be calculated.