A Hall-effect rotary position sensor is designed for measuring and monitoring the movement of transport vehicles like boats, trucks, buses, and cars and at the same time used in various industrial assemblies.
The working principle of a Hall-effect rotary sensor relies on a magnetic field to detect movement and emit a corresponding signal. The circuitry of this type of sensor is magnetically-biased which detects the rotational displacement of the object’s actuator shaft concerning a predetermined measurement range. As the actuator shaft rotates, the magnet’s position also changes. The resulting change in density gets converted into a linear output used in providing displacement feedback to the machine’s operator or vehicular sub-system.
An RVDT is a type of non-contact rotary sensor which eliminates the effect of friction on the performance of the sensor. One of the main challenges with other sensor technologies like potentiometers is that the wiper and sliding tack mechanism eventually degrade as a result of friction. Non-contact sensors are better for industrial applications which are exposed to harsh environmental elements and conditions.
Specifications to consider in choosing a Hall-effect rotary position sensor
Design engineers need to consider several factors in specifying a rotary position sensor assembly.
- Durability. It is crucial to begin by identifying the exact working conditions the sensor will be exposed to. In most industrial applications subject to harsh conditions, the sensor packaging needs to meet industry standards and qualifications. Such is the case for industrial machines and vehicles.
- Life cycle. The life cycle of a sensor determines how long it will operate reliably under the same conditions. Manufacturers provide buyers with detailed data on the documented life cycle of a rotary sensor. If data is not available, the manufacturer may conduct the testing to save the engineer time and effort.
- Integral connector specification. The need to specify an integral connector depends on the requirements of the assembly. A rotary sensor with an integral connector is compact and has an extended life span. Compared with a rotary sensor with a pigtail connection, a sensor with an integral connector is smaller and suitable for assemblies with limited space.
- Design flexibility. Design flexibility pertains to the available operating voltages and range. In most applications, it is better to have a rotary sensor with a wide range of operating voltages which can apply to various applications.
Other considerations in specifying a rotary sensor include the mounting pitch, AMP termination, and pin-out style.
Applications of a Hall-effect rotary sensor
Suitable applications for Hall-effect rotary sensors are the following:
- In heavy-duty vehicles, a Hall-effect rotary sensor may replace the ordinary mechanical cable connecting the engine and the foot pedal. This replacement will improve the control response of the vehicle
- Hall-effect sensors used in buses sense how the suspension system moves thus improving the vehicle ingress or egress. In trailer trucks, a rotary sensor can monitor the height of the trailer and help in warehouse docking.
Apart from heavy-duty vehicular applications, Hall-effect rotary sensors are also used in food processing plants, beverage manufacturing facilities, power plants, and even in residential HVAC systems.