What is a Hall sensor?



Hall Sensor - magnetoelectric device gets its name from the surname of Physics Hall, discovered the principle on which, subsequently, was created this sensor.Simply stated - a magnetic field sensor.Now distinguish analog and digital Hall sensors.

  1. Digital sensors detect the presence or absence of the field.That is, if the induction reaches a certain threshold - the sensor produces a field presence in the form of a certain logical unit, if the threshold is not reached - the sensor produces a logic zero.That is, at low induction and thus the sensor sensitivity - the presence of the field can not be fixed.The disadvantage of this sensor - the presence of the dead zone between the thresholds.

    Digital Hall sensors also divided into: bipolar and unipolar.
    • Unipolar - are activated in the presence of a certain polarity of the field and off the field while reducing the induction.
    • Bipolar - react to changing the polarity of the field, that is one polarity - includes a senso
      r, and the other - off.

  2. Analog Hall sensors - convert an induction field in the voltage value of the sensor shown depends on the polarity of the field and its forces.But again, you need to take into account the distance at which the sensor is installed.

Where applicable Hall sensor?



Hall sensors have become part of many appliances.Basically, of course, they are used for their intended purpose and measure the magnetic field strength.They are used in electric motors and even innovations such as ion engines missiles.Most often, a Hall sensor encounter when using the ignition system of the car.

Such simple examples are: proximity switches, liquid level meter, non-contact measurement of current in the conductors, motor control, reading the magnetic codes, and, of course, the Hall sensors could not come to replace the reed switch, because their main advantage - non-contact exposure.

The principle of the Hall sensor



How does the Hall sensor is arranged and where does it hitless impact?Hall noted that if a magnetic field is a plate placed under tension, i.e. with currents flowing through it, the electrons in the direction perpendicular to the plate will deviate the magnetic flux.The direction of this deviation depends on the polarity of the magnetic field.The phenomenon is called - the Hall effect.Thus, the density of electrons on opposite sides of the plate will be different, and that creates a potential difference.It is this difference and capture the Hall sensors.

Below you can clearly see the process of working Hall sensor node is taken as an example of the ignition system of the car.

The principle of the Hall sensor in the ignition system

How to check the hall sensor on the performance?



If you encounter this problem at home, chances are you - the motorist.Of course the easiest way, if the performance of the sensor in doubt - replace it with a known-good.And if the replacement solved the problem - the answer is obvious.

If you do not have serviceable sensor, you can create a simple device that mimics his work.You will need only a piece of wire and strip trĐĹhshtekernaya from the ignition distributor.

for the diagnosis, you can also use a normal tester.If your sensor is defective, the indicator tester is uniquely smaller than 0.4 V.

You can also check for spark at ignition.For this will have to connect the ends of the wires to the specific outputs of the switch.

If you encounter a failure of the Hall sensor out of his car and the other device, most likely you'll need a tester, and everything will depend on the device in which the Hall sensor applied.
Author: Editorial TutKnow.ru | View: open source