Precautions for using potentiometers: ① Before use, check the quality of the potentiometer. The potentiometer's shaft should rotate freely, with appropriate tightness, and without mechanical noise. Check the nominal resistance value with a multimeter; it should meet the requirements. When measuring the resistance between the fixed and sliding terminals with a multimeter, the meter needle should rotate smoothly without jumping when the potentiometer shaft is slowly rotated.
② Because some parts of the potentiometer are made of synthetic resins such as polycarbonate, do not use it in environments containing high concentrations of chemicals such as ammonia, amines, alkaline solutions, aromatic hydrocarbons, ketones, and halogenated hydrocarbons to extend the potentiometer's lifespan.
③ For potentiometers with grounding contacts, the contacts must be grounded to prevent external interference.
④ Do not overload the potentiometer; use it within its rated value. When using the potentiometer as a rheostat to adjust current, the allowable power consumption should be reduced proportionally to the travel of the moving contact brush to ensure that the current flowing does not exceed the potentiometer's allowable rated value and prevent the potentiometer from failing due to localized overload. To prevent the current from exceeding the maximum allowable value when the potentiometer's resistance is adjusted close to zero, it is best to connect a current-limiting resistor in series to avoid damage from overcurrent.
⑤ The voltage drop generated when current flows through a high-resistance potentiometer must not exceed the potentiometer's maximum allowable operating voltage.
⑥ To prevent deterioration or burnout of the potentiometer's contacts and conductive layer, the operating current of a low-resistance potentiometer must not exceed the maximum allowable current of the contacts.
⑦ Potentiometers must be securely and reliably installed. Nuts that require tightening should be tightened to sufficient torque to prevent loosening or displacement during long-term use, which could lead to contact with other components and cause circuit malfunctions.
⑧ Various fine-tuning potentiometers can be directly mounted on printed circuit boards, but attention should be paid to the arrangement of adjacent components to ensure convenient potentiometer adjustment without affecting adjacent components.
⑨ Non-sealed potentiometers are most prone to excessive noise, mainly due to oil contamination and wear. In this case, never use lubricating oil to solve the problem; applying lubricating oil will only exacerbate the accumulation of internal dust and conductive particles. The correct procedure is to gently wipe the dirt off the resistor element with a cotton ball soaked in anhydrous alcohol, and remove any oil residue from the contact brushes and lead-out springs.
⑩ When a potentiometer is severely damaged, it needs to be replaced. It is best to choose a potentiometer with the same model and resistance value as the original. Also, ensure that the potentiometer's shaft length and end shape match the original knob. If the original model and resistance value cannot be found, a potentiometer with a similar resistance value and model can be used as a substitute. The resistance value of the replacement potentiometer is allowed to increase by 20%-30%, and the rated power of the replacement potentiometer should generally not be less than the rated power of the original potentiometer. In addition, the replacement potentiometer should meet the requirements of the circuit and its intended use.
