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Adjustable resistance must pay attention to 6 matters!

Time：2023-07-25

Adjustable resistor is also called variable resistor. Its English is Rheostat. Adjustable resistor is a type of resistor. The resistance value of adjustable resistor can be adjusted artificially to meet the needs of the circuit. Adjustable resistors can be divided into many different models and types according to the size of the resistance value, the range of adjustment, the form of adjustment, the production process, the production material, the volume size, etc., which can be divided into: adjustable resistors for electronic components, adjustable resistors for porcelain plates, patch adjustable resistors, wire wound adjustable resistors, etc. The nominal value of the adjustable resistor can be adjusted to a large resistance value according to the standard. Theoretically, the resistance value of the adjustable resistor can be adjusted to any value within 0 and the nominal value. However, due to the actual structure and design accuracy requirements and other reasons, it is often not easy for 100 to meet the "arbitrary" requirement, but only "basically" to adjust within the allowable range to change the resistance value.

Let's talk about 6 things that must be paid attention to for adjustable resistance!

① The quality of the adjustable resistor should be checked before use. The shaft handle of adjustable resistance shall be flexible in rotation, with proper tightness and no mechanical noise. Check the nominal resistance value with multimeter, and it shall meet the requirements.

② Since some parts of the adjustable resistor are made of synthetic resins such as polycarbonic acid, do not use it in a high concentration of chemicals such as ammonia, amines, alkali solutions and aromatic hydrocarbons, ketones, halogenated hydrocarbons, etc. Use in an environment to extend the service life of the adjustable resistor.

③ For adjustable resistors with grounding solder pads, the solder pads must be grounded to prevent external interference.

④ The adjustable resistor should not be used under overload, but should be used within the rated value. When the adjustable resistor 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, so as to ensure that the current flowing through does not exceed the allowable rating of the adjustable resistor and prevent the adjustable resistor from failing due to local overload. ⑤ The voltage drop generated when the current flows through the high resistance adjustable resistor shall not exceed the large working voltage allowed by the adjustable resistor.

⑥ In order to prevent the contact and conductive layer of the adjustable resistor from deteriorating or burning, the working current of the small resistance adjustable resistor shall not exceed the allowable current of the contact.

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