Displacement Sensor – Operation and Preforming Machine

A displacement sensor tracks the movement of an element relative to a reference position. With Hall effect components, integration into an electronic assembly may require preparing the pins before soldering. MGA Technologies offers a cutting and bending machine to adjust their length and orientation to the intended layout. MGA Technologies developed a lead cutting and forming machine for components and sensors, designed to prepare these parts before assembly.

Although they play a strategic role, these sensors are barely visible in installations. They perform many detection tasks, such as dimensional measurements, fluid levels or the thickness of a part. Many constraints and requirements come into play when choosing the right displacement sensor for an application.

Operation of a Displacement Sensor

Displacement sensors provide reliable information on the position and movement of elements in a reference space.

There are different types of displacement sensors on the market:

• Mechanical sensor: these sensors are used less and less. Through mechanical action, they can, for example, open an electrical contact.
• Optical sensor: based on light emission and detection. Different systems are available: through-beam (for opaque materials), reflex (for non-reflective elements) and proximity (for transparent and translucent elements).
• Capacitive sensor: a non-contact sensor that detects metal objects as well as other materials (wood, plastic, glass, leather, fluids, etc.). When the object reaches the face where the sensor’s electric field is located, the oscillator starts and the change is translated into an output signal.
• Inductive sensor: the most widely used sensors in robotics and production lines. Inductive sensors only detect metal objects and measure the variation of a magnetic field.

Pneumatic sensors (using air pressure) and ultrasonic sensors (using acoustic waves) are also available.

Eddy Current Sensors

Eddy current sensors are also very robust. They work on an inductive principle and consist of a coil supplied with alternating current. The coil emits a high-frequency magnetic field that induces eddy currents in nearby conductive objects. The field generated by these induced currents opposes that of the coil, which changes the coil’s impedance. This change depends on the distance between the object and the sensor: measuring it gives the desired displacement value.

Eddy current sensors essentially “see” electrically conductive materials and remain insensitive to everything else. They can operate in harsh environments (oil, dust, humidity, etc.), at temperatures above 150°C and under high pressure. Accuracy is high as long as the measuring distance remains short.

In many applications, eddy current sensors remain essential. They are generally used to measure very small displacements at high speed in particularly harsh environments. Their robustness also makes them suitable for engine test benches and machine tools. A typical application is automated test benches that check the dimensional quality of welds on moving parts: only eddy current sensors can withstand the electromagnetic interference generated by the welding robot.

This measurement method offers many advantages: very good resolution and accuracy, a wide bandwidth to measure fast displacements, and operation in extreme environments.

Hall Effect Displacement Sensors

A Hall effect displacement sensor uses a magnetic field to detect a position or track a movement without contact. Widely used in the automotive, precision engineering, aerospace and manufacturing sectors, these sensors are inexpensive, accurate and durable. The choice of component depends on the application and the required measurement performance.

They are delivered in strips of several tens or even hundreds of sensors. Before soldering, some components require their pins to be cut and bent to match the geometry of the assembly. This preparation must be defined from the package, the pin dimensions and the drawing after forming. The MGA Technologies machine is specifically designed for this sensor preparation step, and it can be automated within an integrated manufacturing line.

Cutting and Bending Machine for Hall Effect Sensors

A machine for cutting and bending displacement sensors prepares them before soldering onto electronic circuits. This machine is modular and scalable, and it can be integrated into an automated assembly line such as our Hall effect sensor assembly line.

Features of the MGA Technologies Cutting / Bending Machine

The characteristics of the MGA Technologies cutting and bending machine:

• Noise level < 70 dB,
• Cutting accuracy: ±0.1 mm,
• Bending accuracy < 2°,
• Magnetic or non-magnetic sensors with 3 to 5 legs,
• Throughput: 900 sensors cut and bent per hour.

The MGA Technologies machine can be:

• interconnected with an existing machine,
• integrated into an automated line,
• configured with a shuttle, bins or a belt conveyor.

Sensor Accuracy vs. Forming Accuracy: What Is the Difference?

The measurement accuracy of a sensor and the accuracy with which its pins are prepared are two different requirements. The first concerns the measurement of displacement. The second describes compliance with the dimensions and angles required for assembly.

For its machine, MGA Technologies states a cutting accuracy of ±0.1 mm and a bending accuracy of less than 2°. These values describe the operations performed on the pins; they do not describe the sensing performance of the component.

To prepare your displacement sensor, specify separately the lengths after cutting, the bending angles and the expected tolerances. This makes it possible to compare the requirements of your drawing with the stated capabilities of the machine. See also our custom inspection, testing and identification machines.

Discover the MGA Technologies displacement sensor cutting and bending machine by downloading the brochure, or contact our technical teams directly to obtain a personalized quote.