BLDC Motor with Hall Sensor vs. BLDC Motor without Hall Sensor

If the brushless dc motor without Hall sensor is broken, it cannot be replaced with the brushless dc motor with Hall sensor. The hardware drive circuit of these two motors is different, so is the program code, thus the bldc motors will not work after the replacement. ATO will tell you why.

1. The hardware circuit of a motor with Hall sensor and a motor without Hall sensor is different.

For a three-phase bldc motor, a brushless dc motor with Hall sensors has eight wires: 3 three-phase motor wires, 3 Hall wires, and 2 Hall power wires. There are three Hall chips inside the brushless dc motor with Hall sensor. When the motor is working, the real-time position of the rotor can be displayed to the control board in the form of waveform. Based on the waveform, the position of the rotor and the rhythm to start the brushless dc motor will be determined by the control board.

The brushless DC motor without Hall sensor has only three wires, that is the phase wires of the brushless DC motor. The position of the Hall is determined by the control board through the back-induced electromotive force of the phase line of the brushless DC motor. There is a processing circuit with a comparator as the core on the control board, whose function is to determine the position of the rotor according to the back induced electromotive force.

Therefore, the processing circuit of a DC brushless motor with Hall sensor and a DC brushless motor without Hall sensor are completely different, so they cannot be replaced.

2. The software code of a motor with Hall sensor and a motor without Hall sensor is different.

As mentioned earlier, the hardware circuits of these two motors are different, so the corresponding software codes are also completely different. For brushless DC motors with Hall sensors, the Hall waveform output by the Hall chip can be captured and analyzed by the CCP function of the microcontroller. For brushless DC motors without Hall sensors, the rotor position is determined by back-induced electromotive force, which requires microcontroller to process the output of the comparator, so the code is relatively complicated.

3. The brushless motors and controllers with Hall sensor are stable in use, with large torque at startup and no abnormal noise. The brushless motors and controllers without Hall sensor are not very stable at present due to technical problems, especially in the initial stage, the stability is poor and the power is not enough.

4. Most motors without Hall sensor are brushed motors, which consume a lot of power. Most motors with Hall sensor are brushless motors, which are driven by switches, with energy saving and relatively large drive capacity.

5. The brushless motor with Hall sensor is currently a relatively mature product with more stable operation. However, the Hall element is a component that is liable burn out, so it is particularly important to choose a suitable manufacturer and qualified Hall element.