Hall Effect Sensor A3144 Magnetic Switch Basics Working & Explanation

Introduction:

In this tutorial we will learn about Hall Effect Sensor A3144 Magnetic Switch Basics Working & Explanation. We will also design a switching circuit using transistor that will help in detecting magnetic north and south pole. It can also be used to detect the presence of magnetic field. A hall-effect sensor as then name suggests works with the principle of hall-effect and is used to detect magnets. Each side of the sensor can detect one particular pole. It can also be easily interfaced with a microcontroller since it works on transistor logic.

Hall Effect Sensor A3144 Magnetic Switch Basics Working & Explanation

What is Hall Effect Sensor:

The A3144 is an integrated Hall effect non-latching sensor. Holding a magnet near the sensor will cause the output pin to toggle. This makes for a robust presence sensor. A Reed Sensor also works nicely, but can be limited by the glass encapsulation and size.

There are two main types of hall-effect sensor, one which gives an analog output and the other which gives a digital output. A3144 is a digital output hall sensor, meaning if it detects a magnet the output will go low else the output will remain high.

A hall effect sensor is much smaller, but can handle less current than a reed switch. The device includes an on-chip Hall voltage generator for magnetic sensing, a comparator that amplifies the Hall voltage, and a Schmitt trigger to provide switching hysteresis for noise rejection, and open-collector output. An internal bandgap regulator is used to provide temperature compensated supply voltage for internal circuits and allows a wide operating supply range. If a magnetic flux density larger than threshold Bop, the output is turned on (low). The output state is held until a magnetic flux density reversal falls below Brp causing the output to be turned off (high).

Featuresof A3144 Hall Effect Sensor

Working of Hall Effect Sensor:

When a beam of charged particles passes through a magnetic field, forces act on the particles and the beam is deflected from a straight path. The flow of electrons through a conductor is known as a beam of charged carriers. When a conductor is placed in a magnetic field perpendicular to the direction of the electrons, they will be deflected from a straight path. As a consequence, one plane of the conductor will become negatively charged and the opposite side will become positively charged. The voltage between these planes is called the Hall voltage.

When the force on the charged particles from the electric field balances the force produced by magnetic field, the separation of them will stop. If the current is not changing, then the Hall voltage is a measure of the magnetic flux density. Basically, there are two kinds of Hall Effect sensors. One is linear which means the output of voltage linearly depends on magnetic flux density; the other is called threshold which means there will be a sharp decrease of output voltage at each magnetic flux density.

Hall Effect Sensor Switch Circuit Diagram

Following components are required for designing Hall Effect Sensor switch using A3144 and transistor.

Now assemble the circuit as shown in the circuit diagram.

Video Tutorial: Hall Effect Sensor A3144 Magnetic Switch Basics Working & Explanation

Here is an application of Hall Effect Sensor: Arduino Water Flow Meter using Hallf Effect Sensor