I. What is an encoder for?
An encoder is a device that encodes and converts signals (such as bitstreams) or data into a signal form that can be used for communication, transmission, and storage; it belongs to the sensor category. Encoders have numerous uses, primarily for measuring the speed, position, angle, distance, or counting of mechanical movements, and are widely used in industrial machinery. Furthermore, there are many types of encoders, each with different functions: 1. Contact encoders: Use brushes for output, with the brush contacting conductive or insulating areas to represent the code state as "1" or "0". 2. Non-contact encoders: Use photosensitive or magnetic sensitive elements; when using photosensitive elements, the light-transmitting and opaque areas represent the code state as "1" or "0". 3. Incremental encoders: Convert displacement into periodic electrical signals, then convert these signals into counting pulses, using the number of pulses to represent the magnitude of the displacement. 4. Absolute encoders: Sensors that directly output digital quantities, commonly used in motor positioning or speed measurement systems. Because each angular position corresponds to a unique digital code, its reading depends only on the starting and ending positions of the measurement, and is independent of the intermediate measurement process. 5. Rotary incremental encoder: It outputs pulses when rotating, and its position is known by a counting device. When the encoder is stationary or the power is off, it relies on the internal memory of the counting device to remember the position.
II. What types of encoders are there?
1. According to shape, encoders can be divided into three types: shaft encoders, through-hole encoders, and blind-hole encoders. 2. According to mechanical structure, encoders can be divided into rotary encoders and linear encoders. 3. According to working principle, encoders can be divided into three types: photoelectric encoders, magnetoelectric encoders, and contact brush encoders. 4. According to signal output type, encoders can be divided into four types: voltage output, open collector output, push-pull complementary output, and long-line drive output. 5. According to the perforation method of the code disk, encoders can be divided into incremental encoders and absolute encoders. 6. According to communication method, encoders can be divided into serial encoders and parallel encoders. 7. According to applicable environment, encoders can be divided into general industrial type, heavy-duty type, and explosion-proof type, etc.
III. Detailed Description of Encoder Models
There are various encoder models to choose from. Since there's no industry-wide standard for encoder model names, each manufacturer creates its own. Therefore, different encoder manufacturers may use different model names. For example, a typical complete encoder model is RE1103IC1-H01-0006 (15P30, AA15F7): 1. RE is the general code for rotary encoder. 2. 11 indicates a key dimension, approximately 11mm in diameter for one surface. 3. 03 indicates a thin base with a switch. 4. E is the shape code for the bushing. 5. C is the bracket code; C bracket indicates a plug-in mounting method. 6. 1 indicates whether the bottom cover has locating posts: 1 means no posts, 2 means two locating posts, 3 means two large locating posts, etc. 7. HO1 indicates the terminal pin type; H01 indicates a vertical plug-in pin. 8. 0006 is an internal serial number, and the information it represents is shown in parentheses: 15 is the number of pulses; P is the direction of pulse output, representing clockwise rotation; 30 is the number of positioning points, representing the number of positioning points in one revolution; the first A is the shaft core shape, representing a D-shaped half-shaft; the second A is the shaft core material, representing aluminum alloy; 15 is the actual installation height; F represents the shaft core opening direction; and 7 represents the length of the shaft core operating part. Encoder selection requires consideration of processing and quality requirements, performance, resolution, space requirements, electrical interfaces, installation dimensions, and price. It is recommended to choose a high-quality encoder.
IV. What signal does the encoder output?
Encoders detect signals by outputting signals. Based on the different output signals, they can be divided into several types. Generally, encoder output signals can be categorized into two types: 1. Analog signals: such as square waves, sine pulses, cosine pulses, etc. 2. Digital signals: i.e., digitally encoded signals, such as binary Gray code, etc.
