POLYSHINEHK / TECHNICAL GUIDE
Rotary potentiometers: a practical technical guide
A rotary potentiometer is a three-terminal variable resistor adjusted by turning a shaft. This guide explains how the parts of a rotary potentiometer work together, which parameters matter when specifying one, and the exact values we manufacture on our 9 mm F09K series.
How a rotary potentiometer works
Two outer terminals connect the ends of a resistive track; the centre terminal connects to a wiper that slides along that track as the shaft rotates. Wired across the full track it works as a voltage divider; wired to one end and the wiper it works as a simple variable resistor.
The resistive track can be carbon film (cost-effective, the usual choice for audio and general control) or conductive plastic. The relationship between shaft angle and output is the taper: B is linear, A and C are logarithmic curves used where human perception is non-linear, such as volume control.
Rotary potentiometers are continuous analogue devices, unlike rotary encoders, which output digital pulses. If you need absolute position sensing with a simple ADC input, a potentiometer is normally the simpler and cheaper answer.
What to specify
- Total resistance and tolerance
- Pick the resistance from the standard range, then check the tolerance band, which widens at the extremes of the range.
- Taper (A, B or C)
- Linear for measurement and set-point control, logarithmic for audio level and anything judged by ear.
- Gang number
- A single gang for mono or single-axis control, dual gang for stereo channels or two tracks driven by one shaft. Rated power and detent availability differ between them.
- Terminal style and mounting
- Top adjust or side adjust, with or without a sleeve bushing. This decides how the part sits relative to the board and the panel.
- Shaft type and length
- Splined, slotted, knurled and flatted shafts each suit different knobs. Shaft length also constrains whether a bushing can be fitted.
- Detents and rotational life
- A centre detent or 21-step detent gives tactile feedback; a long-life build is available where the control is turned frequently.
Typical applications
- Audio volume, tone, balance and gain controls in amplifiers, mixers, guitar pedals and instrument panels
- Set-point and trim adjustment on industrial controllers, power supplies and test equipment
- Speed, brightness and temperature dials on appliances and professional equipment
- Position and angle reference for joysticks, robotics and motion control assemblies
- Front-panel user controls on medical, laboratory and automotive interior modules
General specifications — F09K series
Values below are the published specifications for our 9 mm square insulated shaft rotary potentiometer. Other sizes and custom builds are quoted case by case.
- 전체 저항
- 1KΩ ~ 1MΩ
- 전체 저항 허용 오차
- 500Ω < R < 1MΩ: ±20%; R ≤ 500Ω or R ≥ 1MΩ: ±30%
- 저항 곡선
- A, B, C
- 최대 사용 전압
- AC 50V / DC 20V
- 정격 전력
- 1련: 0.05W; 2련: 0.03W
- 회전 잡음
- 100mV 미만
- 절연 저항
- DC 250V에서 100MΩ 초과
- 내전압
- AC 250V에서 1분
- 잔류 저항
- 단자 1~2: 20Ω 미만; 단자 2~3: 20Ω 미만
- 련간 오차(2련)
- −40dB ~ 0dB ± 3dB
- 련 수
- 1련 (N) / 2련 (G)
- 클릭 옵션
- 클릭 없음 / 중앙 클릭(1련) / 21단 클릭(1련)
- 전체 회전 각도
- 280° ± 10°
- 회전 토크
- 10 ~ 90 gf·cm
- 스토퍼 강도
- 3.0 Kgf·cm 이상
- 밀고 당기는 힘
- 5.0 Kgf 이상
- 클릭 토크
- 30 ~ 120 gf·cm
- 회전 수명
- 표준: 15,000회 이상; 긴 수명: 100,000회 이상
- 작동 온도
- −10°C ~ +70°C
Dimensions and construction
- 본체 크기
- 9 mm 사각형
- 단자 및 부싱
- H 상단 조절, 부싱 없음 / V 측면 조절, 부싱 없음 / A 상단 조절, 부싱 있음 / B 측면 조절, 부싱 있음
- 높이 H
- 0 해당 없음(상단 조절) / 1 = 6.5 mm / 2 = 10.0 mm / 3 = 12.5 mm(측면 조절)
- 축 유형
- F / N / C / Y / T / D / P / Q / K 유형(슬롯, 널링 등)
- 축 길이
- 코드별 지정; 부싱은 축 길이 20 mm 초과 시에만 가능
- 반시계 방향 끝 위치
- 축 유형에 따른 C / A / D, 40° ± 10°
Build the exact part number
The F09K page includes a part-number builder that only allows valid option combinations, so the code you send us is one we can manufacture.