How to use the potentiometer correctly

The potentiometer is a resistance element with three lead-out ends and the resistance value can be adjusted according to a certain change rule. The potentiometer is usually composed of a resistor and a movable brush. When the brush moves along the resistor body, the resistance value or voltage that has a certain relationship with the displacement is obtained at the output end.

Potentiometer has the characteristics of small size, long life, high reliability, simple structure, etc. According to the difference of output function, potentiometer can be divided into exponential potentiometer, linear potentiometer and logarithmic potentiometer.

The potentiometer is a kind of precision electronic component. How can we guarantee the normal use and the potentiometer's service life? These all require some tricks, so let's learn and observe together, how to use the potentiometer correctly?

1. For potentiometers with grounding pads, the pads must be grounded to prevent external interference.

2. The voltage drop generated when the current flows through the high-resistance potentiometer shall not exceed the maximum working voltage allowed by the potentiometer.

3. In order to prevent the potentiometer's contact and conductive layer from deteriorating or burning, the working current of the small resistance potentiometer must not exceed the maximum current allowed by the contact.

4. Various trimming potentiometers can be installed directly on the printed circuit board, but attention should be paid to the arrangement of adjacent components to ensure that the potentiometer is convenient to adjust without affecting adjacent components.

5. The potentiometer must be firm and reliable during installation, and the nut that should be tightened should be tightened with sufficient torque to prevent loosening and displacement during long-term use and collision with other components and causing circuit failure.

6. Since some parts of the potentiometer are made of synthetic resin such as polycarbonate, do not use high concentrations of chemicals such as ammonia, amines, alkali solutions, aromatic hydrocarbons, ketones, and halogenated hydrocarbons. Use in the environment to extend the service life of the potentiometer.

7. Check the quality of the potentiometer before use. The shaft handle of the potentiometer should be able to rotate flexibly, with proper elasticity, and no mechanical noise. Check the nominal resistance value with a multimeter, and it should meet the requirements. If you use a multimeter to measure the resistance between the fixed end and the sliding end of the potentiometer, when you slowly rotate the potentiometer shaft, the needle should rotate smoothly without jumping.

8. Unsealed potentiometers are most prone to noise failures, which are mainly caused by oil stains and wear. At this time, do not use lubricating oil to solve this problem. Lubricating oil will increase the accumulation of internal dust and conductive particles. The correct way to deal with it is to use a cotton ball dipped in absolute alcohol to gently wipe the dirt on the resistor, and to remove the oil on the contact brush and the lead-out reed.

9. Do not overload the potentiometer, use it within the rated value. When the potentiometer is used as a rheostat to adjust the current, the allowable power consumption should be reduced in proportion to the stroke of the moving contact contact brush to ensure that the current flowing does not exceed the rated value of the potentiometer to prevent the potentiometer from being caused by partial overload. Invalidate. In order to prevent the current when the resistance of the potentiometer is adjusted close to zero from exceeding the maximum allowable value, it is best to connect a current-limiting resistor in series to avoid damage to the potentiometer due to overcurrent.

10. When the potentiometer is seriously damaged, a new potentiometer needs to be replaced. At this time, it is best to choose a potentiometer with the same model and resistance as the original potentiometer. Also, note that the shaft length and shaft end shape of the potentiometer should match the original knob. If you can't find the potentiometer of the original model and resistance, you can replace it with a potentiometer of similar resistance and model. The resistance value of the replaced potentiometer is allowed to increase by 20[[%]]-30[[%]]. Generally, the rated power of the replaced potentiometer shall not be less than the rated power of the original potentiometer. In addition, the replaced potentiometer should also meet the requirements of the circuit and in use.