Hall effect sensor Working, specification, and construction

November 16, 2022April 5, 2022 by Mohd Shahid

Magnet sensor is mostly used in projects which require the use of some kind of counter or locking mechanism.

To clear all confusion, This sensor is also known as a Hall effect sensor. It is easily available in the local and online market at a very cheap price.
The sensor gives both output Analog and Digital. But I prefer digital, as analog values can change if the magnet is not lined up correctly to the sensor.
Apart from this, the sensor has the advantage of replacing the component if one gets damaged. The main component, which we’ll discuss in the Hall effect construction section, can be changed.
You can view projects based on the hall effect sensor and its projects with microcontrollers mainly used. Also, here is the link to buy the sensor and the replacing part.

Table of Contents

Construction of hall effect sensor

Above is the schematic which is drawn from a hall effect sensor that I have lying around at my place. This hall effect sensor does not claim 100% accuracy as the schematic can be different for some people.
The main component of the hall sensor is an AH49E Hall effect device, which is similar to a transistor. More information about this can be gathered through datasheet.
Apart from all this, the only drawback of this sensor is that it can only detect the south pole of the magnet. And for SMD(SOT-23-3) package it is North Pole.
The hall effect sensor is also built-in in combination with the LM393 IC, which is a dual voltage comparator. So we can say that this hall sensor is similar to many other sensors which are also built in accordance with L393 IC.
Like another sensor, this hall effect sensor also has a potentiometer and an onboard status led, which are used to trim the values send to the microcontroller and to reflect the status of the detection.

This is the small Transistor device which is the main component of the whole sensor, I’ll explain this in brief in the next few points & for detail, you can view its datasheet attached above.
The working voltage of the transistor is 3V – 6.5V overvoltage or Undervoltage may either lead to frying your IC or a malfunction of the program. Also, the working temp is of quite a large range so there is no issue with it.
It comes in two packages either T)-92 or SOT23 (SMD version), both are easy to use and their hall sensor circuit can be built easily for custom usage. if yu are making any project like magnet detector or cunter then you can choose this sensor.

The working of this hall sensor is similar to another sensor that is included in the basic electronic series and built out of the LM393 IC.
AH49E hall effect sensor device only detects the south pole of the magnet and sends out an analog signal as per the datasheet through its output pin. It is then combined with a 150 Ω resistor as in the schematic. To give a suitable logic level signal to the microcontroller, in combination with a pull-up potentiometer.
The first comparator of the lm393 IC sends out the digital signal through the OUT1 pin to the microcontroller. The 2^nd comparator is connected to the status led to reflect the status of detection by the sensor.
You can replace the AH49E if the one preinstalled is worn out, also the ink to the spare part is provided above. After knowing the working of this sensor you can also learn how to interface magnet sensor with Arduino.