what is the hall sensor used brushless motor controller knows that support the brushless motor controller can cancel the carbon brush of the weight, is the sensor, and on the brushless motor controller with most of the sensor, is the hall sensor. Why hall sensor can make cancel physical carbon brush, brushless motor controller for brushless motor controller to bring the benefits of so much? Can make the brushless motor controller really go into mass production use, can put into normal production and life. Actually this is hall sensor. What is a hall sensor? Hall sensor is a kind of magnetic sensor. Can detect the magnetic field and its changes, it can be used in various situations related to the magnetic field. Hall sensor based on hall effect by hall element and its affiliated circuit composed of integrated sensor. The principle of hall sensor in the magnetic field has a hole, semiconductor, constant current from the horizontal direction, through the film. Under the action of lorentz force, the electron flow through the hall semiconductor offset to one side, the film produced in the vertical direction potential difference, this is the hall voltage. Hall voltage changes along with the change of magnetic field intensity, the stronger the magnetic field, the higher the voltage, the weaker magnetic field, the lower the voltage, the hall voltage is very small, usually only a few millivolts, but by the amplifier amplification in the integrated circuit, can make the output voltage amplification enough strong signal. If make the hall integrated circuit sensor role, need to use mechanical methods to change the magnetic field strength. With a rotation of the rotor shaft as a switch to control the magnetic flux, when the rotor shaft in the air gap between the magnet and hall integrated circuit, the magnetic field deviates from the integration, the hall voltage disappears. In this way, by collecting the output voltage of the hall integrated circuit changes, can be said the position of the rotor shaft a. Brushless motor controller is using the principle of hall sensor, through the hall sensors to know the position of the rotor, and then through the signal control current, make the motor controller axis changing magnetic field, and the magnetic field of permanent magnet interaction, achieve the goal of steering.