Advantages and disadvantages of several common absolute encoders such as synthetic binary encoders

Absolute Encoderis a common component, today to introduce the market commonly used several kinds ofAbsolute Encoderand the advantages and disadvantages of these absolute encoders.

I. Synthetic Binary Encoder

The resistor body of the synthetic binary encoder is made of carbon film, graphite, quartz powder, and organic powder composite, etc., which is formulated into a kind of suspension and coated on vitreous enameled fiberboard or adhesive paper. The production process is simple, is currently the most widely used absolute value encoder. Advantages of synthetic binary encoder: wide range of resistance, high resolution, can be made into a variety of types of absolute value encoder, long life, low price, more models. Disadvantages: power is not too high, high temperature resistance, moisture resistance is poor, low resistance absolute value encoder is not easy to make.

II. Organic solid core absolute encoders

Organic solid core absolute encoder is a new type of absolute encoder, which uses the method of heating and molding to press the organic resistive powder into the groove (meaning: groove recessed on the surface of the object) of the insulator. Multi-turn absolute encoders are used if you want to measure rotations beyond the 360-degree range. Encoder manufacturers use the principle of clock and watch gear machinery, when the center of the code disk rotation, through the gear drive another set of code disk (or multi-group gear, multi-group code disk), in the single-turn encoding on the basis of the number of turns of the code, in order to expand the encoder's measurement range, such an absolute encoder is known as a multi-turn absolute encoder, which is likewise determined by the mechanical position of the code, the code of each position is unique and not repeatable, while the There is no need to memorize. Organic solid core absolute encoders have the advantages of good heat resistance, high power, high reliability and good wear resistance compared to binary encoders. However, the temperature coefficient is large, the dynamic noise is large, the moisture resistance is poor, the manufacturing process is complicated, and the resistance accuracy (precision) is poor. It is used to regulate voltage and current in miniaturized, highly reliable and wear-resistant equipment as well as AC and DC circuits.

III. Metal Film Absolute Encoders

Metal film absolute encoders are made of several materials such as metal synthetic film, metal oxide film, metal alloy film and oxidized button film deposited on a ceramic (raw material: non-metallic minerals) substrate by vacuum technology. Advantages: good heat resistance, high resolution, distribution inductance and distribution capacitance is small, the noise potential is very low. Disadvantages: wear resistance is not good, resistance range is small 10 Ω -100K Ω.

IV. Wire-wound absolute encoders

Wire-wound absolute encoders are made by using a copper or nickel-chromium alloy wire as a resistor and winding it around an insulating skeleton. Multiturn Absolute Encoders Multiturn absolute encoders are used if you want to measure rotations beyond the 360-degree range. Encoder manufacturers use the principle of clock and watch gear machinery, when the center code disk rotation, through the gear drive another set of code disk (or multiple sets of gears, multiple sets of code disks), in the single-turn encoding on the basis of the encoding of the number of additional laps to expand the encoder's measurement range, such an absolute encoder is known as a multi-turn absolute encoder, which is likewise determined by the mechanical position of the encoding, the unique code for each position does not repeat, and There is no need to memorize. Advantages of wirewound absolute encoders: low contact resistance, high accuracy, small temperature coefficient. Disadvantages: poor resolution, low resistance, poor high frequency characteristics. It is mainly used as a voltage divider, transformer, instrument zero and adjust the working point.

V. Digital Absolute Encoders

The digital absolute encoder eliminates the pieces and is a semiconductor integrated circuit. Singleturn absolute encoders measure the various engraved lines of the optical code disk in rotation to obtain a unique code. When the rotation exceeds 360 degrees, the code returns to the origin, which does not comply with the principle of absolute code uniqueness, so that the encoder can only be used for measurements within a rotational range of 360 degrees, known as a singleturn absolute encoder. Advantages are: high regulation accuracy (precision), no noise, extremely long working life, no mechanical wear (a basic type of component failure), data can be read/written, with a configuration register and data register, multi-level volume storage function, easy software control, small size, easy to assemble. It is suitable for home theater systems, audio surround control, audio amplifiers and cable TV equipment.