How to detect the potentiometers?

Last Update Time: 2019-07-02 16:15:02

1. The method of detecting the good or bad of the ordinary potentiometer is visual inspection.


When using the pointer multimeter to detect the quality of the ordinary potentiometer, first turn the spinor handle of the detected potentiometer to see if the rotating handle is smooth, and whether the switch is flexible or not. If the "clatter" sound of the switch is crisp or not when it is turned on and off, listen carefully-listen to the sound of internal contact, friction between points and resistors when the potentiometer handle rotates, and if there is an obvious "rustling" sound, it shows that its performance is not good.


Second, the detection method.

When the ordinary potentiometer is good or bad, according to the detected electricity first

The resistance value of the bit meter, using the pointer multimeter to detect the universal or to make a square meter suitable for the electrical barrier. For ease of explanation, the only boundary of the electricity, that is, the circuit  number, is shown in figure 1. The specific detection methods are as follows.


Schematic diagram of three pin numbers of potentiometer.


1. Detection of resistance values.

The two pens of the multimeter are connected to the "1" and "3" ends of the potentiometer, respectively, to detect the resistance value of the potentiometer, the reading of which should be the nominal resistance value of the potentiometer. If the pointer of the multimeter is fixed or the resistance value is different from the nominal value, the detected potentiometer is damaged or bad.


2. Detect the contact between the movable arm of the potentiometer and the resistor.

The two pens of the multimeter are connected to the "1" and "2" ends of the potentiometer respectively, and then rotate the displacement of the potentiometer so that it can be rotated counterclockwise to the position close to off, and the smaller the resistance, the better. Then rotate the potentiometer crank clockwise slowly, the resistance value should gradually increase, and in the resistance value gradually increased, the multimeter's pointer should move smoothly. When the potentiometer handle is rotated to the extreme position of "3", the resistance value should be close to the nominal value of the potentiometer.


3. Issues that need to be explained.

The method of detecting "2" and "3" pins of potentiometer with multimeter is similar to that when "1" and "2" pins are detected.

In the above detection, if the pointer of the multimeter jumps during the rotation of the shaft handle of the potentiometer, then the detected potentiometer active contact has a bad contact phenomenon, It can be cleaned with gasoline or anhydrous alcohol containing more than 95%. New parts should be replaced when cleaning is not effective.


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