Analysis of two speed measurement methods for brushless motors

The brushless motor relies on a simple structure and a single current support. It runs at first-rate speed among many motor products. The speed measurement knowledge is introduced as follows. I hope you will read it carefully.

　　 1. Hall effect principle speed measurement method

　　 The rotating shaft of the brushless motor drives the magnet on the shaft to rotate, thereby changing the size of the magnetic field. The change in the magnetic field is converted into a pulse signal through the Hall circuit, which is amplified and shaped to output a rectangular pulse signal. When the speed changes, the frequency of the output pulse will change. So as to get the rotating speed of the DC geared motor.

　　2, photoelectric speed measurement method

　　Use grid disc and photoelectric gate to form a 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 coordinated by two timing/counters of the single-chip microcomputer, one counting and one timing. Calculate the number of pulses per unit time m, after unit conversion, the speed of the motor can be calculated.