German AST sensors, AST models, AST prices

AST sensors, also known as torque sensors, torsion sensors, torque transducers, and torque meters, are divided into two main categories: dynamic and static. Dynamic torque sensors are also referred to as torque sensors, torque-speed sensors, non-contact torque sensors, and rotary torque sensors. Torque sensors detect the twisting moment on various rotating or non-rotating mechanical components. They convert the physical changes in torque into precise electrical signals. Torque sensors can be used in the manufacture of viscometers and electric (pneumatic, hydraulic) torque wrenches. They offer advantages such as high precision, fast frequency response, good reliability, and long service life.

AST sensor classification

1) Laser speed measurement: With the rise of precision manufacturing and the need for cost savings, non-contact speed sensors are gradually replacing contact speed sensors. The most common and highly accurate non-contact laser speed sensors on the market today are ZLS-Px aberration speed sensors. Aberration speed sensors have two ports: one emission port that emits a LED light source, and one high-speed imaging port that achieves high-speed CCD area imaging comparison. By comparing images taken at two points in time within an extremely short interval, the distance moved by the object is determined. Combined with internal algorithms, the sensor outputs the object's speed in real time. As shown in the figure, (1) is the LED light emission port, (2) is the camera reception port, (3) and (4) are the terminal blocks, and (5) are the mounting screw holes. (1) The LED light emission port directs a laser beam at the target object; the reflected light reaches the (2) camera reception port. Upon receiving the signal, it is transmitted to the signal processor, which calculates the speed using algorithms. ZLS-Px aberration speed sensors can simultaneously measure speed and length in two directions. They can detect not only whether the object has stopped but also its direction of motion. Mount the sensor on a stable bracket to ensure that excessive vibration does not occur during the rotation of the object, thereby allowing measurement of the rotational angle and speed of the rotating object. 2) Radar speed measurement: Traditional speed measurement mostly involves rotary motion speed and linear motion speed. However, industrial automation often requires irregular speed measurements, such as athlete speed measurement, traffic vehicle speed measurement, and golf ball speed measurement. Radar speed sensors can meet these requirements.

AST sensor principle

A transmissive speed sensor consists of a slotted or apertured disk, a light source, and a phototube. When the disk rotates with the shaft under test, light can only reach the phototube through the holes or slots. When the phototube is illuminated, its reverse resistance is very low, thus outputting an electrical pulse signal. When the light source is blocked by the disk, the reverse resistance of the phototube is very high, and there is no signal output at the output terminal. In this way, based on the number of holes or slots on the disk, the rotational speed of the shaft under test can be measured. The number of holes or slots on the disk is usually set to sixty, so that for each revolution of the shaft under test, the photoelectric converter outputs 60 pulse signals. If the time base signal of the electronic counter is set to 1s, the rotational speed of the shaft under test can be read directly. The principle of a reflective speed sensor is the same as that of a transmissive one; it converts changes in received light into changes in electrical signals via a phototube, but it obtains pulse signals through light reflection, typically by adhering reflective material to the measurement area of the shaft under test to form a reflective surface. Commonly used reflective materials are special-purpose speed-measuring reflective paper tapes (adhesive tapes); aluminum foil or other reflective materials may also be used as substitutes; sometimes white paint can be applied to the measurement area to serve as a reflective surface. The emitter and the reflective surface must be properly configured, typically with a distance of 5-15M between them. When the measured shaft rotates, the photoelectric element receives pulsed light, and outputs the corresponding electrical signal to the electronic counter, thereby measuring the rotational speed of the measured shaft. The waveform of the output signal from the photoelectric speed sensor is relatively regular, close to a standard square wave, with almost no interference signals generated. However, for the transmissive type, vibration can reduce the lifespan of the light source, so it is not suitable for use in conditions with strong vibration. The reflective type has no mechanical connection with the measured shaft, making it convenient to use.

AST sensor industry applications

1) Modern vehicles are generally equipped with engine control, autonomous driving, ABS, TRC, automatic door locking, active suspension, guidance systems, electronic instruments, and other devices, all of which require vehicle speed signals. Therefore, the accuracy and stability of the output signals from speed sensors greatly impact these control units. Automotive speed sensors often adopt a Hall-effect structure. Hall speed sensors are magnetoelectric sensors based on the Hall effect, featuring high magnetic field sensitivity, stable output signals, high frequency response, strong electromagnetic interference immunity, simple structure, and ease of use. They mainly consist of permanent magnets with a specific number of pole pairs (typically 4 or 8 pairs), Hall elements, a rotating mechanism, and input/output connectors. Their working principle is that when the sensor's rotating mechanism is driven externally, it rotates the permanent magnet, causing periodic changes in the magnetic field passing through the Hall element. This induces changes in the Hall element's output voltage, which is processed by subsequent circuits to form stable pulse voltage signals as the output of the speed sensor. Key electrical technical parameters for Hall-structure speed sensors include high/low output voltage, duty cycle, period, rise time, fall time, and pulses per period. To ensure product performance and reliability, these parameters must be quantitatively tested before factory release. Test systems featuring integration and intelligence, efficient automatic measurement, software calculation, and graphical or tabular display of results are increasingly favored by automotive speed sensor manufacturers. A comprehensive testing device has been developed for measuring the performance of common Hall-effect vehicle speed sensors. Considering cost, the high-speed counter port of a microprocessor is used for data acquisition from the speed sensor, while software control handles data calculation and graphical display. The completed testing device offers high test accuracy, reliable data communication, a user-friendly graphical interface, strong anti-interference capability, simple and intuitive testing processes, and low system development costs. It has good market potential, indicating significant application prospects for speed sensors in vehicle speed detection. 2) Speed sensors for belt conveyors use Hall sensors, which utilize the Hall effect for magnetoelectric conversion. The Hall effect was discovered in 1879 and has over 100 years of development history. However, its application gained attention and widespread adoption in the 50s of this century due to the rapid development of microelectronics, leading to the continuous development of various Hall elements. China began increasing research on Hall elements in the 20s of the 70th century. After decades of research and development, it is now possible to produce Hall elements with various performances, such as standard, high-sensitivity, low-temperature-coefficient, temperature/magnetic-field-measuring, and switching types. Due to their high sensitivity, good linearity, high stability, small size, and high-temperature resistance, Hall sensors are widely used in industrial fields such as non-electrical quantity measurement, automatic control, computer devices, and modern military technology.

Weidou Intelligent Technology specializes in selling German AST sensors, AST proximity sensors, AST distance sensors, AST vision sensors, AST displacement sensors, AST torque sensors, AST speed sensors, AST photoelectric sensors, AST position sensors, AST angle sensors, AST tactile sensors, AST temperature sensors, AST pressure sensors, AST flow sensors, AST level sensors, AST motion sensors, and AST process sensors. All products are original imports from Germany. Customers are welcome to inquire and place orders.