Notes on installation and use of adjustable resistors

Adjustable resistors are a very common electronic component on instrumentation, security equipment, and home appliance control boards. The use of adjustable resistors is mainly considered from the perspective of voltage dividers. The resistance R on both sides of the resistor can be relatively stable and accurate. , the power specific efficiency of the adjustable resistor is small, and the absolute accuracy can be ignored, mainly from the perspective of the current controller. The following is a list of things to pay attention to when using adjustable resistors:

1. The power of the adjustable resistor can withstand the surrounding temperature of 70°C. When the operating temperature is higher than 70°C, its function may be lost.

2. The surface of the adjustable resistor should avoid condensation or water droplets, and avoid use in humid places.

3. The rotation operating force of the adjustable resistor will become lighter as the temperature increases and become tighter as the temperature decreases. If the potentiometer is used in a low-temperature environment, please note that special low-temperature resistant grease should be used.

4. When installing a rotary adjustable resistor and fixing the nut, the strength should not be too tight to avoid damaging the threads or causing poor rotation.

5. When installing the iron-cased adjustable resistor, do not use screws that are too long, otherwise it may hinder the movement of the slide handle or even directly damage the potentiometer itself.

6. Adjustable resistors are best used in voltage-adjusted structures. Current-adjusted structures should be avoided because the contact resistance between the resistor and the contact piece is not conducive to the passage of large currents.

7. If the welding temperature is too high or the welding time is too long when welding the adjustable resistor, it may cause damage to the potentiometer.

8. The terminals of the plug-in adjustable resistor should be welded at 235℃±5℃ and completed within 3 seconds. The welding should be more than 1.5MM away from the potentiometer body. Do not use solder to flow through the circuit board during welding.

9. The resistor body of the adjustable resistor is mostly made of polycarbonate synthetic resin. Contact with ammonia and other amines should be avoided, otherwise its performance will be affected.

10. The shaft or sliding handle of the adjustable resistor should be as short as possible when used and designed. The shorter the length of the shaft or slide handle, the better and more stable the feel. On the contrary, the longer it is, the greater the shaking will be, and the feel will easily change.

11. Avoid using water-capacitive flux when welding the terminals of chip adjustable resistors, otherwise it will promote metal oxidation and material mold.

12. Avoid using inferior solder when using it. Poor soldering may cause difficulty in tin application, resulting in poor contact or open circuit.