How does a variable reluctance sensor work?

How does a variable reluctance sensor work?

The variable reluctance sensor consists of a permanent magnet and a ferromagnetic pole piece surrounded by a coil of wire. The sensor generates an analog voltage output signal when a ferromagnetic material passes by the tip of the pole piece.

What is the need of demodulator in variable reluctance accelerometer?

78) What is the need of demodulator in Variable Reluctance Accelerometer? To detect motion on both sides of zero, a fairly involved phase- sensitive demodulator would be required.

What is meant by variable reluctance?

externally energized transducer, called the variable-reluctance type, is one in which the magnetic circuit is broken by an air gap. The mechanical movement to be measured is used to change this air gap, thus changing the reluctance, or opposition, to the production of a magnetic field in the circuit.

How do magnetoresistive sensors work?

A magnetoresistive sensor uses the fact that the electrical resistance in a ferromagnetic thin film alloy is changed through an external magnetic field. “Ferrum” is Latin and stands for “iron”. These sensors are exceptionally small, and due to their special material, they are robust and consume very little energy.

What is a variable reluctance pressure sensor?

A variable reluctance sensor (commonly called a VR sensor) is a transducer that measures changes in magnetic reluctance. When combined with basic electronic circuitry, the sensor detects the change in presence or proximity of ferrous objects.

What is a sensor used for?

A sensor is a device that detects the change in the environment and responds to some output on the other system. A sensor converts a physical phenomenon into a measurable analog voltage (or sometimes a digital signal) converted into a human-readable display or transmitted for reading or further processing.

What is the other name for variable reluctance transducers?

VR sensor
A variable reluctance sensor (commonly called a VR sensor) is a transducer that measures changes in magnetic reluctance.

What is the unit of reluctance?

ampere-turns per weber
Reluctance(S) is the property of a magnetic circuit opposing the passage of magnetic flux lines, equal to the ratio of the magnetomotive force to the magnetic flux. It is measured in AT/weber. The unit of reluctance is ampere-turns per weber i.e., (Henry)-1.

What is a magnetoresistive sensor?

What is a magnetoresistive sensor? A magnetoresistive sensor uses the fact that the electrical resistance in a ferromagnetic thin film alloy is changed through an external magnetic field. “Ferrum” is Latin and stands for “iron”. Generally, mixed alloys are used, for example iron and nickel.

What is the purpose of a variable reluctance sensor?

A variable reluctance sensor (commonly called a VR sensor) is a transducer that measures changes in magnetic reluctance. When combined with basic electronic circuitry, the sensor detects the change in presence or proximity of ferrous objects. With more complex circuitry and the addition…

How is the output of a VR sensor readable?

VR sensor interface circuits VR sensors need waveform shaping for their output to be digitally readable. The normal output of a VR sensor is an analog signal, shaped much like a sine wave. The frequency and amplitude of the analog signal is proportional to the target’s velocity.

How is the amplitude of a VR sensor proportional to velocity?

The frequency and amplitude of the analog signal is proportional to the target’s velocity. This waveform needs to be squared up, and flattened off by a comparator like electronic chip to be digitally readable. While discrete VR sensor interface circuits can be implemented, the semiconductor industry also offers integrated solutions.

Which is an example of a VR sensor interface circuit?

While discrete VR sensor interface circuits can be implemented, the semiconductor industry also offers integrated solutions. Examples are the MAX9924 to MAX9927 VR sensor interface IC from Maxim Integrated products, LM1815 VR sensor amplifier from National Semiconductor and NCV1124 from ON semiconductor.