Sensors play an important role in different measurement systems. Their purpose is to collect data from physical parameters and provide electrical signal as the system input. Position sensors are among the different types of sensors used in different applications, from aircraft systems to packaging machines.
Resistive sensing principle
Using different sensing principles, position sensors can sense the precise displacement of a unit. The most commonly used position sensor is the potentiometer. An inexpensive and easy-to-use sensor, the potentiometer relies on resistive effect as its sensing principle, with a resistive track as the sensing element. To measure the displacement of a unit or part of a unit accurately, a wiper is attached to it. The wiper must be in contact with the track. When the wiper moves, there would be some changes in the resistance between it and the edge of the track. An electrical signal output is then given. The output has a proportional connection between the wiper’s position on the track and its resistance value. This means that resistance is proportional to position.
One of the most commonly used type of position sensors is the linear potentiometer, which uses a resistive or conductive track. The linear potentiometer position sensor makes changes in the wiper in a linear manner. A constant voltage is typically supplied across the ends of the track. The potentiometer is then used as a voltage divider.
One of the main advantages to think about in choosing a position sensor is the system’s capacity to recover right after a power loss. With potentiometers, there’s no need for the system to reposition back to an origin or index mark. It will simply provide the output voltage corresponding to its current position. Potentiometers are capable of consuming minimal power. In applications that require multiple devices, this advantage is even multiplied.