How to select the applicable potentiometer

1. The characteristics of wire wound potentiometer are:; High temperature resistance, high rated power, low resistance temperature coefficient, good resistance stability, small contact resistance change, low current noise and reliable contact, and can realize various output function characteristics. It is easy to control and ensure the high output characteristic accuracy of linear and nonlinear; At the same time, due to the recent development of wire wound potentiometers in material, structure, process and technology, the reliability has been further improved and the service life has been extended.

The disadvantages of wire wound potentiometer are:; Because the output is stepped broken line, it has stepped error, low resolution, poor wear resistance, especially when the resistance is high, it is easy to break the line, short service life, high dynamic noise, narrow resistance range (10 ohm - 30 ohm), poor high-frequency performance, and high price.

2. The characteristics of metal film potentiometer are:; The resistance temperature coefficient is small, the resolution is high, the temperature resistance is high, the friction torque is small, and the high-frequency characteristic is good. The disadvantages are:; The rated power consumption is low, the wear resistance is poor, and the resistance range is narrow. "50 Ohm-20K" is expensive.

The characteristics of synthetic carbon film potentiometer are:; With high resolution, it can adjust the voltage step by step with Wu, good wear resistance, long service life, easy to make linear and nonlinear potentiometers, strictly control the thickness and width of the resistor body, and can obtain high output characteristic accuracy. The linearity is generally about 1%, which can be raised to about 0.1% after etching. The resistance range is generally 100 ohm-5M. The potentiometer has low price and simple manufacturing process. It is widely used.

The disadvantages of synthetic carbon film potentiometer are:; Because the synthetic carbon film resistor contains organic junction phase in the body, its temperature resistance is poor, and it is easy to age under the action of high temperature, so the working temperature can not be too high, and the rated power consumption is small; In addition, because the proportion of bonding phase and conductive phase in the synthetic carbon film resistor, the size of particles, and the uniformity of the slurry have an impact on the noise, the contact resistance is large, the dynamic noise is large, the resistance temperature is large, and the working temperature is low.

3. Characteristics of conductive plastic potentiometer; 

Ａ； The resistor can be made into solid or thin film, which is curved or straight. The surface is as smooth as a mirror, with good smoothness and resolution.

Ｂ； There is almost no friction between the contact brush and the resistance body, the rotating torque is small and constant, there is almost no wear problem, the service life is very long, the rotating noise is small, and the reliability is high.

ｃ ； The resistance range is wide, and the resistance temperature coefficient is 110 °. Ｄ； The independent linearity is usually the most practical linear accuracy, with an accuracy of more than 0.1-0.5%.

Ｅ； Rated power consumption is 2-3WF; Resistance to chemical corrosion and atomic radiation.

Ｇ； The production process is simple and less polluted by the environment,

The disadvantages of conductive plastic potentiometer are:; The temperature resistance is poor, the contact resistance is large, the pressure relief is required to be large, the accuracy is not easy to be very high, and the operating temperature range is; - ５５°－７０°。

4. The characteristics of photoelectric potentiometer are:; Mechanical contact brush without conventional potentiometer, no mechanical friction. No wear, long wear life, up to hundreds of millions of weeks, high resolution, low noise, high sensitivity, continuous output signal. High reliability, resistance range, 500 ohm-15M. The working angle is applicable to a wide range.

The disadvantages of photoelectric potentiometer are:; The contact resistance is large, and because the photoconductive material is not a pure conductor, the contact resistance at the photoelectric contact is quite high, which can reach 10K Ω., It is difficult to output large current because of the hysteresis characteristic, poor high-speed response, high output impedance, narrow operating temperature range, large resistance temperature coefficient, and high linearity, which can only reach about 1% after etching