What is an angular displacement sensor and what are its classifications
The angular displacement sensor is used to detect the angle. There is a hole in its body to fit the Lego shaft. When connected to the RCX, the angle sensor will count every 1/16 revolution of the shaft. When rotating in one direction, the count increases, when the rotating direction changes, the count decreases. The count is related to the initial position of the angular displacement sensor. When initializing the angle sensor, its count value is set to 0, if necessary, you can reset it by programming.
Angle displacement sensor application
Applicable to the servo system of automobiles, construction machinery, space devices, missiles, aircraft radar antennas, injection molding machines, woodworking machinery, printing presses, electronic rulers, robots, engineering monitoring, computer-controlled sports equipment and other occasions that need to measure displacement.
From the point of view of construction, angle sensors can be divided into two categories: wire-wound angle sensors and non-wire-wound angle sensors.
wirewound angle sensor is a resistance wire wound on a metal, ceramic and plastic frame as a resistance element. Advantages: low temperature coefficient of resistance, good stability of resistance value, high power load, long working life. Disadvantages: the resolution has a certain step, the total resistance range is narrow, and the high frequency performance is poor.
Non-wire wound angle sensors include synthetic film angle sensors, glass glaze angle sensors, conductive plastic angle sensors, etc.
(1) The synthetic film angle sensor is made by mixing carbon black, graphite, organic binders, fillers, etc. on the substrate using a variety of methods (such as screen printing) and then curing the slurry. The resistive film serves as a resistive body. Advantages: large-scale production, low price, low noise during adjustment, superior high-frequency performance, small inductance and distributed capacity, long working life, seldom sudden severe damage, and wide total resistance range .
(2) Glass glaze angle sensor is a slurry made of metal (or its oxide) powder, glass glaze, etc.
Printing and other methods are coated on the ceramic substrate, and the resistance film formed by drying and high temperature sintering is used as the resistance body. Advantages: The total resistance has a wide range, high resolution and good stability, low noise, and very good frequency response, far exceeding 100MHz. The resistance temperature coefficient is small, the surface of the resistance element is hard and wear-resistant, and the working life is long.
(3) The conductive plastic angle sensor is made by coating the slurry of carbon black, graphite and ultrafine metal powder, DAP resin and crosslinking agent on ceramic or special plastic substrate by screen printing and other methods The resistive film serves as a resistive body. Advantages: The contact resistance changes little, and the working life is very long; the surface is smooth and the resolution is very high; even after the moving contact is cyclically moved on the resistor body for millions of times, there will be no obvious friction and wear. The resistance element can be modified to make its linearity reach the level of 0.1%. The dynamic noise is very small, and it has good high-frequency performance and is suitable for high-gain servo systems. Disadvantages: poor moisture resistance, not as stable as glass glaze angle sensors, low rated current for moving contacts, and temperature coefficient between wirewound angle sensors and glass glaze angle sensors.