What are Position Sensors

What are Position Sensors

• There are many types of position sensors are used in different engineering projects and industrial machines. Some are listed here, we will discuss all of them with detail.
  • Potentiometer
  • Linear Variable Differential Transformer
  • Inductive Proximity Sensors
  • Rotary Encoders

 Potentiometer

• In almost every position detecting circuit or network, the potentiometer is used, due to its less cost, flexibility and easy to install features.
• It consists of the wiper like connected with the cars front screen, this wiper is linked with the shaft like different motors or generators, when the slider moves then its connection point resistance changes that convert into the electrical signal as an output.
• This resistance and the variation in the position of the slider are directly proportional to each other.
• These movement detectors are available in different structure and physical size, normally they are available in the cylindrical shape and flat structure.
• When they are installed in different circuitry the component whose motion to be detected is connected with the shaft of the potentiometer.

  

Linear Variable Differential Transformer

• As we are familiar with the transformer that used the phenomena of the mutual induction for its working.
• The linear variable differential transformer is and such position measurement module that transforms the smooth movement of any device into the current.
• Its construction is very simplest and can be installed in any condition and project.
• The most important part of this position sensor is a transformer and its core. The transformer has 3 windings one is on the primary side and the other 2 are on the secondary side. That is mention as S1 and S2 in the given figure.
• These two secondary windings are wound on the core that is made by the mixture of glass and polymers.
• These three windings are arranged in such a way that the 2 secondary windings are connected with the terminals of the primary windings that primary is in the centre and secondary windings are at left and right side of the primary.
• The other most important part of the linear variable differential transformer is the core that is manufactured by such material that has less resistance for the current movement.
• This core is linked with the non-conductive rod that acts as a shaft and this shaft is attached with the substance whose motion to be measured.

• The working principle of this sensor is that when the voltage provided to the primary side winding this voltage also induce voltage in the other secondary windings.
• The variation in the voltage values of the secondary windings indicates the distance covered by anybody connected with this sensor and angle between the voltages of the secondary windings tells about the direction followed by the substance.

  

Inductive Proximity Sensors

• This position sensor is also known as the eddy current sensor, and these components are not found position variation of anybody while they used to know the existing object near to it.
• These sensors are not connected physically with any other substance but they find the presence of any object by Faraday law.
• This sensor is consist of the core that is constructed by the ferromagnetic materials like iron and windings are wound around the core.
• When any conductive substance comes under the field of the inductive proximity sensor than the voltage induced in that substance is detected by the circuit of the sensor by this way he found the presence of any substance near it.

  

Rotary Encoders

• This position sensor has is similar to the potentiometer that we have discussed, but the difference is that potentiometer is to be connected with the device whose position to be measured but the rotary encoders find position without any connection.
• These sensors detect the movements of the substances and convert them into the electrical signal.
• These sensors are used light-emitting diode and disc that have different codes patterns that are mentioned in the binary system, decimal system or any other related system.

•  When the disc moves its rotation is measured by the photo-detecting modules the rotation than converted into the electrical signal and this electrical signal that transformed to the binary numbers that send to the counter, in this way movement is measured.

  

Applications of the Position Sensors

• These are some important applications of the positions sensors.
• These sensors are used to find the angle of steering of automobiles and location of the gear.
• Clutch position can also st by this sensor.
• Industries the locations of different machine parts are found by using different position sensors.
• These sensors are also used in nuclear plants.
• In industries, it used for the different physical structure testing.
• Positions sensors not only used in industries but also installed in the medical instruments like magnetic imaging machine.
• In the different office, you have seen that the door is closed and open automatically these are controlled by the position sensors.
• To find the movement in the structure of the different bridges in position sensors are employed.