What Is a Potentiometer?

A potentiometer is a resistance element with three lead-out terminals whose resistance can be adjusted according to a certain change law. A potentiometer usually consists of a resistor and a movable brush. When the brush moves along the resistor, a resistance value or voltage having a certain relationship with the displacement is obtained at the output end.

Potentiometer (English: Potentiometer) is

Further analysis of the right waveform and expansion according to the time axis can be seen, although the left and right waveforms of the pulse potentiometer are the same. However, when left-handed, in the first state, foot 1 becomes lower than foot 2; in the second state, foot 2 also becomes

The degree of compliance is also called compliance, which refers to the correspondence between the actual output function characteristics of the potentiometer and the required theoretical function characteristics.

Resolution depends on the theoretical accuracy of the potentiometer. for

slide

The mechanical life of a potentiometer is also called the wear life, which is often expressed by mechanical durability. Mechanical durability refers to the total number of times the moving contact moves reliably under the specified test conditions. The mechanical life is related to the type, structure, material and manufacturing process of the potentiometer, and the difference is quite large.

In addition to the above characteristics, the potentiometer also has

The key parts that make up the potentiometer are the resistor body and

The main functions of the potentiometer in the circuit are as follows

1. used as

1. Potentiometer resistors are mostly made of polycarbonate-based synthetic resins. Avoid contact with the following items: ammonia, other amines, alkaline aqueous solutions, aromatic hydrocarbons, ketones, lipid hydrocarbons, Strong chemicals (excessive pH value), etc., otherwise it will affect its performance.

2. Avoid using water-capacitive flux when soldering the terminals of the potentiometer. Otherwise, it will promote metal oxidation and material mold. Avoid using poor quality solder. Poor solder may cause difficulty in soldering, resulting in poor contact or open circuit.

3. If the terminal of the potentiometer is soldered, the welding temperature is too high or the time is too long may cause damage to the potentiometer. Pin-type terminals should be soldered at 235 ° C ± 5 ° C within 3 seconds. Welding should be more than 1.5MM away from the potentiometer body. Do not use solder flow through during soldering.

The main parameters of the potentiometer are the nominal resistance,

Potentiometer

1) The naming rules of potentiometers are the same as the method of naming resistors, except that they begin with the letter W.

2) Potentiometer labeling method: Generally, potentiometers use the direct standard method. Letters and numbers are used on the potentiometer housing to indicate their model, nominal power, resistance, and the relationship between the resistance and the angle of rotation. For example: WT--1-1k-X potentiometer is shown as single carbon film potentiometer type , power is 1W, resistance value is 1k, curve is linear ^[1]

The main requirements for the potentiometer are: The resistance value meets the requirements. The contact between the center sliding end and the resistor is good, and the rotation is smooth. For potentiometers with switches, the switching part should be accurate, reliable, and flexible. Therefore, the performance of the potentiometer must be checked before use ^[1] .

1) Measurement of resistance value: First select the appropriate resistance range of the multimeter according to the resistance value of the measured potentiometer, and measure the resistance value, that is, the resistance value between the two ends of the AC, and compare it with the nominal resistance value See if they are the same. Rotate the sliding contact at the same time, and its value should be fixed. If the resistance is infinite, the potentiometer is damaged.

2) Then measure the contact between the central end and the resistor, that is, the resistance value between the two ends of the BC. The method is that the ohm range of the multimeter is in the proper range. During the measurement, slowly rotate the rotating shaft, pay attention to observe the reading of the multimeter. Under normal conditions, the reading changes smoothly in one direction. Bad contact failure.

3) When the center end slides to the head end or the end, the resistance value of the center end and the coincident end in the ideal state is 0. In actual measurement, there will be a certain residual value (generally depends on the nominal, generally less than 5) Normal phenomenon ^[1] .