A position sensor collects information about the movement of an object or its precise position. This information can be obtained remotely from magnetic sensors or by direct contact with the object concerned. This type of sensor can also be used to detect the angle of rotation of a shaft, the level of a fluid or the thickness of a part/object. The presence of position sensors enables machine tools to operate correctly.
Use of a Position Sensor
The position sensor has different ways of operating:
- Depending on the position of the object, it delivers a signal that can vary. The displacement is translated into these signal variations.
- It emits an impulse for each element movement. The position and the displacement are determined from the count of the pulses emitted.
- If there is no mechanical connection between the moving object and the sensor, the sensor emits a signal via a field. This field can be electrostatic for capacitive sensors, electromagnetic for eddy current sensors and a magnetic induction field for magneto-resistive, Hall effect or variable reluctance sensors.
Many position sensors are available:
- The capacitive sensor to detect an object of any kind. This is detected by a change in the capacitive coupling when it is in front of the sensitive face of the sensor. This capacitance change triggers the start of the oscillator. After shaping, an output signal is emitted.
- The optical sensor is based on the emission and reception of a light beam.
- The pneumatic sensor allows non-contact detection of an object at a short distance.
- The inductive sensor. All based on a magnetic phenomenon, different types of sensors can coexist. Among these types of sensors is the Hall effect sensor.
- The ultrasonic sensor, which has a receiver and a transmitter. On the object to be detected, a train of waves is reflected and then returned to the source. The distance to the object is determined by the time the wave train travels back and forth.
- The mechanical sensor is a contact sensor that makes or breaks electrical contact by activating the moving part of the sensor.
Hall Effect Sensor
The Hall effect position sensor reacts in the presence of a magnetic field and allows non-contact detection. It is used for:
- encoding a position,
- multipolar magnets detection,
- motor commutation,
- speed detection.
The advantage of the Hall effect position sensor is its accuracy. It is easy to implement due to its small dimensions. It can be used, for example, by fixing the hall sensor on a magnet to detect the presence of an object and by directly detecting the presence of the magnet.
Logic and amplified outputs can be obtained when the probes are integrated in integrated circuits.
Preparation of a Position Sensor Before Soldering to Modules
Position sensors are cut, formed and soldered to electronic circuits and modules for subsequent use. They are usually supplied by the manufacturers in strip or roll form. Therefore, a special machine is required to prepare them.
Around 100 sensors are installed in a vehicle. This is why car and equipment manufacturers most often need these types of machines, regardless of whether they are automated or not.
The company MGA Technologies designs a special machine to prepare the sensors by cutting and preforming them in a regular and in-line way. This company is a specialist in the creation of special machines dedicated to the pharmaceutical, biotech and automotive industries. The tools of the machines are interchangeable, modular and scalable.