Current Sensors

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  What Are Hall Effect Sensors?

  Nov 24, 2022

  
  Unlike optical sensors, Hall effect sensors are solid-state devices that are immune to dust, moisture, and vibration. They are also non-contact and have a wide range of applications. They can be used for current measurement, proximity detection, and angular movement.

  The Hall effect is a proportional relationship between the magnetic field and current. In this principle, the current passing through the conductor creates a circular electromagnetic field that causes electrons to deviate in a curved path. A Hall voltage is directly proportional to the strength of the magnetic field passing through the semiconductor material.

  The sensitivity of hall effect sensors is high, so they can detect useful magnetic fields from long distances. They also measure electrical currents from milliamps to thousands of amperes. In this way, they can be used in harsh environments, instead of using optical sensors. Depending on the type of device, Hall effect sensors can detect vertical, horizontal, and angular motion.

  There are two types of Hall effect sensors: analog and digital. The analog sensor is comprised of a Hall element, amplifier, and voltage regulator. They are usually manufactured with high-gain amplifiers. The voltage regulator can also be used to increase the output voltage as the magnetic field increases.

  Digital Hall effect sensors incorporate a Schmitt trigger. The Schmitt trigger adjusts the switching threshold on a rising or falling edge of the signal. When the magnetic field increases, the output increases, and when the field decreases, the output decreases. The output switching transistors can be open-collector or NPN sink switches. These can also be used in a push-pull output-type configuration.

  The linear Hall effect sensor is a common type of sensor. The device's output is continuous, and it increases as the magnetic field increases. This type of device has an inherent zero-field point. It can also differentiate between positive and negative magnetic fields. In addition, it can determine the absolute distance between the object and the sensor.

  These types of LEM current sensors are often used for proximity detection. They can also be used to detect the movement of a rotating magnet. In this way, they can count rotational magnets, as well as determine the speed of the motors. The output is also used to calculate RPM.

  Hall effect sensors can be operated by either a permanent magnet or a single magnet attached to a moving shaft. Typically, the sensor has three pins. One pin is used to transmit low-level current, while the other two pins can be used to transmit high-level current.

  A magnetic field must be perpendicular to the Hall effect sensor for the device to generate an output. In addition, the magnetic field must approach the sensor face in a straight line. If the field is not perpendicular, the device will produce an output that is zero. If the magnetic field is perpendicular, it will be in a closed circuit. In addition, the hysteresis between switching points prevents the switch from oscillating due to noise. To get more enlightened on this topic click here: https://en.wikipedia.org/wiki/Resistor.

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