A switch potentiometer (also known as a rotary switch potentiometer or a potentiometer with a switch) is an electronic component that combines the functions of a potentiometer and a switch. It is typically used to adjust circuit parameters (such as volume, brightness, etc.) while controlling the on and off of the circuit. The following is its detailed description:

1. Basic structure

Potentiometer section

It is composed of a resistor body (made of carbon film, metal film or conductive plastic), sliding contacts (brushes) and a rotating shaft, and the resistance value is changed through the rotating shaft.

Switch section

It is usually a single-pole single-throw (SPST) or single-pole double-throw (SPDT) mechanical switch, integrated at the bottom or side of the potentiometer, and triggered to turn on or off by axial pressing or rotation to a specific position.

2. Main types

Push-type switch potentiometer

The switch is triggered by pressing the knob (commonly used for volume adjustment in audio devices).

Rotary switch potentiometer

The switch is automatically triggered when rotating to the endpoint (such as the minimum/maximum position).

Push-pull type switch potentiometer

Control the switch by pulling out or pushing in the knob to avoid accidental touch.

3. Key parameters

Resistance value

Common ones include 10kΩ, 50kΩ, 100kΩ, etc., with resistance values varying linearly (Type B) or logarithmically (Type A).

Rated power

It is usually 0.1W to 0.5W, and overloading should be avoided.

Rated current/voltage of the switch

If the DC is 12V/50mA, it needs to match the circuit requirements.

Mechanical life

The rotational life is approximately 10,000 to 50,000 times, and the switch life is approximately 1,000 to 10,000 times.

4. Application scenarios

Audio equipment

Volume adjustment (rotation) + power switch (press).

Power supply circuit

Adjust the output voltage and control the on-off state.

Lighting control

The dimming knob is integrated with the light switch.

5. Precautions for Selection

Dimensions and installation

Confirm the shaft diameter (e.g. 6mm), shaft type (D-type/smooth shaft), and panel installation method.

Resistance value characteristic

Linear (Type B) is used for voltage division, and logarithmic (type A) is used for volume adjustment.

Environmental adaptability

When water and dust resistance are required, choose the sealing model (such as IP67).

6. Faults and Maintenance

Common Questions

Poor contact (clean the brush), switch failure (check for oxidation of the contacts).

Replacement suggestion

Match the resistance value, shaft length and switch type of the original model.