Share the potentiometer fault repair method and replacement procedure
The potentiometer is equivalent to a continuously adjustable resistor. It can be understood as a variable resistor with a variable resistance. Simply speaking, by adjusting the rotation axis of the potentiometer, its output potential changes, so it is called a potentiometer. . The resistance unit of the potentiometer is the same as the resistor, which is also Ω. In the circuit, the potentiometer uses the letter “RP” to indicate “W”, which is mainly used for voltage division, shunting and acting as a varistor.
Potentiometer repair method
1. At present, the potentiometer distinguishes a potentiometer without a switch and another potentiometer with a switch. For the use of these two potentiometers, it is easy to cause some malfunctions, such as being related to constant or different. , or the phenomenon of short circuit caused by poor line contact, and some components of the potentiometer fall off and so on. So how do you fix these three types of problems? First of all, in view of the phenomenon that some components of the potentiometer fall off, it is generally recommended to replace the potentiometer. Because the component is detached, it is difficult to recover it. Even if it can be glued back, it is dangerous to use. For some faults such as poor contact, the poor contact of the potentiometer is generally due to the oxidation of the contact. After the contact of the potentiometer is scraped, the fault is eliminated. For another situation, the spring force of the potentiometer is reduced, resulting in poor contact, etc., and the treatment method for this is to replace the new potentiometer spring.
2, generally for the use of potentiometers for a long time will often lead to poor contact between the lines due to carbon film damage. In the event of a poor contact with the potentiometer, first remove the potentiometer housing and check the extent of internal component wear. For reasons such as poor contact caused by slight wear of the potentiometer, some industrial-specific nearby, or carbon tetrachloride can be used to clean the carbon film material of the potentiometer, etc. Adjust the pressure of the slide arm of the potentiometer on the carbon film, and then put it back.
In the nonlinear potentiometer, the leads on the two stators cannot be connected to each other incorrectly, otherwise the control effect of the potentiometer in the circuit will be affected. For example, after the two fixed pin tabs of the volume potentiometer are connected to each other, the volume is already large when the handle is rotated, and the volume is almost no longer increased when the volume knob is turned, and the linear control characteristic of the volume controller is lost. . Amplifier volume potentiometers are various, but the common one is the double potentiometer, which is used to control the volume of the left and right channels, usually single-axis, and occasionally encounter double-layer dual-axis volume potentiometers. The problem with the general volume potentiometer is that there will be noise when the volume is rotated, or the volume of the two channels is different. At this time, the volume potentiometer should be replaced. After the potentiometer is used for a long time, the carbon film ages slightly. Cracks are the main cause of the deterioration of the volume potentiometer quality, which requires a complete replacement of the potentiometer.
Potentiometer replacement step
The potentiometer has multiple pins. In order to prevent the wrong pin from being replaced during replacement, the following specific steps and methods can be used:
In the first step, remove the same set screw of the original potentiometer, but do not solder the lead on the original potentiometer pin piece, and let the lead wire be connected to the potentiometer.
In the second step, the new potentiometer is mounted and fixed.
In the third step, a lead is soldered on the original potentiometer pin piece, and the lead wire is soldered on the corresponding pin piece of the new potentiometer, and the new and old potentiometers are welded.
In the fourth step, the same method is used to solder the pins. This type of soldering can be used to avoid soldering the misalignment between the leads.