Switch potentiometer application field and performance parameters

Switch potentiometer application field

The switch potentiometer is classified as a straight-slide potentiometer, which has been widely used in our peripheral electrical products. The switch potentiometer relies on the sliding handle to make the brush move linearly to change the resistance value, and then obtain a certain connection with the brush displacement. The output voltage. The switch potentiometer has the characteristics of long life and low noise. It has a wide range of applications and is used in the following aspects:

1. Used for various controls of various speakers or residential equipment;

2. Used for volume adjustment, picture quality, and various controls;

3. Used for various controls of kerosene heaters and electric carpets;

4. Used in thermal control equipment of electronic musical instruments and car air conditioners; 5. Used for seat heating, dimmer, water chaos and other controls in the car interior.

The skeleton and matrix of the switch potentiometer are usually made of materials with excellent insulation function, which require heat resistance, moisture resistance, good electrical insulation, good chemical stability and thermal conductivity, and only a certain mechanical strength. Usually there are laminated paper rubber sheets, laminated cloth quilts, plastics, ceramics, glass, and copper, aluminum and aluminum alloys that have been insulated on the outside. i This kind of metal substrates that have been insulated on the outside should have satisfactory appearance insulation. , This kind of framework matrix has outstanding heat dissipation and is easy to form.

When the switch potentiometer is rotating, its corresponding resistance changes with the angle of rotation. According to the changing law, it can be divided into X, Z, and D types. X type is linear, and its resistance changes linearly according to the rotation angle. This kind of potentiometer is suitable for dividing voltage, adjusting current, adjusting the field frequency of TV, etc. Type Z is an exponential type, and its resistance changes in an exponential relationship according to the rotation angle. It is often used in the volume adjustment circuit. Because the human ear’s auditory characteristics of sound are close to the logarithmic relationship, when the volume gradually increases from zero, the human ear is most sensitive to volume changes. After reaching a certain level, the human hearing will gradually become dull. Therefore, the volume adjustment generally uses an exponential potentiometer to make the sound change sound smooth and comfortable. Type D is logarithmic, and its resistance changes in a logarithmic relationship according to the rotation angle. Suitable for circuits such as tone control.

Although the resistance of the trimming resistor can be adjusted like a potentiometer, it is inconvenient to adjust because there is no rotary handle. Therefore, the trimming resistor is used in circuits that need to be adjusted but do not need to be adjusted frequently.

In computers, precision gears, communication equipment, and household appliances, switch potentiometers of shapes such as leadless chip or cylindrical shapes are also used. It has small size, light weight, good high-frequency characteristics, and wide resistance adjustment range. Features such as low temperature coefficient and low rated power.

The main performance parameters of the switch potentiometer

1. The nominal resistance and allowable deviation of the switch potentiometer

Commonly used switch potentiometers include E6 and E12 series. The maximum allowable deviation between the actual total resistance of the potentiometer and the nominal resistance is the resistance accuracy of the potentiometer.

2. Rated power of switch potentiometer

The definition of the rated power of the switch potentiometer is similar to the definition of the rated power of the resistor. According to national standards, the nominal series of potentiometer rated power

In the selection of the switch potentiometer, in addition to paying attention to the two parameters of the nominal resistance and rated power of the switch potentiometer, the volume, shaft length, and shaft end form of the switch potentiometer should also be considered.