Potentiometer Symbol
Definition: The Potentiometer symbol represents a three-terminal variable resistor whose output voltage or resistance is set by rotating or sliding a wiper contact along a resistive element, defined in IEC 60617-04 and ANSI Y32.2 / IEEE 315-1975, drawn as a resistor body (IEC rectangle or ANSI zigzag) with an arrow indicating the movable wiper contact connected to a third terminal, producing an adjustable voltage divider or variable resistance; the component is designated by the letter R (or RV) in schematics and its resistance is measured in ohms (Ω).
Also known as: pot, variable resistor, rotary potentiometer, trim pot (trimmer), voltage divider pot, pot divider, rheostat (2-terminal use).
What the Potentiometer symbol means
The Potentiometer symbol represents a three-terminal adjustable resistor that divides a voltage proportionally according to the position of its wiper. Terminal A and terminal B are the two ends of the full resistive track; the Wiper terminal taps off a fraction of the resistance between A and the wiper position, allowing the circuit designer to set any voltage between the voltages at A and B or any resistance between zero and the maximum value.
In circuit diagrams the potentiometer symbol is used for user-adjustable controls (volume knobs, tone controls, sensor calibration), for trimming bias voltages in precision analogue circuits, and wherever a continuously variable resistance or voltage reference is required. When only two terminals are used — one end and the wiper — the potentiometer acts as a two-terminal variable resistor (rheostat). The Wiper pin (x=30, y=0) connects to the sliding contact; pins A (x=0, y=20) and B (x=60, y=20) connect to the resistive track ends.
How to identify the Potentiometer symbol
The potentiometer symbol consists of a resistor body — a rectangle in IEC 60617-04 or a zigzag line in ANSI Y32.2 — with an arrow drawn perpendicular to and pointing at the resistor body, representing the movable wiper. The arrow's tip indicates the wiper contact point, and its tail connects to the wiper terminal. The two ends of the resistive element connect to terminals A and B on either side. A trimmer potentiometer (preset) uses the same symbol but may add a 'T' or small adjustment screwhead indicator. The arrow-on-resistor motif is the universal identifier for this symbol in both IEC and ANSI schematics.
Function in a circuit
A potentiometer operates as a mechanically adjustable voltage divider. The full resistance between terminals A and B remains constant (the rated resistance value); moving the wiper along the track changes the resistance between A and the Wiper and between the Wiper and B in inverse proportions. Output voltage at the Wiper equals V_A + (V_B − V_A) × (wiper position ratio). In rheostat (two-terminal) mode the wiper is connected to one end terminal, and the effective resistance varies from zero to maximum. Audio potentiometers use a logarithmic taper; most general-purpose types use a linear taper.
Standards: IEC vs ANSI
| IEC 60617 | IEC 60617-04 (passive components) defines the potentiometer symbol as a filled rectangle (the resistive element) with a diagonal arrow pointing at it from a third terminal (the wiper). The IEC symbol for a preset (trimmer) may show a 'T' shape with a cross for adjustment. |
|---|---|
| ANSI/IEEE 315 | ANSI Y32.2 / IEEE 315-1975 defines the potentiometer as a zigzag line (the ANSI resistor body) with an arrow pointing at the zigzag from a third terminal (the wiper). The ANSI symbol is functionally identical to the IEC version but uses the zigzag resistor body instead of a rectangle. |
| Key difference | The only glyph difference between IEC 60617-04 and ANSI Y32.2 is the resistor body shape: IEC uses a filled rectangle; ANSI uses a zigzag line. The wiper arrow pointing at the body is identical in both standards. |
Terminals / pins
| Pin | Name |
|---|---|
| a | A |
| b | B |
| wiper | Wiper |
Typical values
Standard resistance values: 100 Ω, 500 Ω, 1 kΩ, 5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ, 500 kΩ, 1 MΩ; power rating: 0.1 W (trimmer) to 2 W (panel-mount rotary); resistance taper: linear (B) or logarithmic/audio (A); rotation: 270°–300° (single-turn), 3 to 25 turns (multi-turn cermet trimmer); tolerance: ±10–20% end-to-end, ±3% linearity.
Where the Potentiometer symbol is used
- Volume and tone controls in audio amplifiers and mixing consoles (logarithmic taper)
- Analogue sensor signal calibration and zero/span trimming in instrumentation amplifiers
- Brightness and contrast controls in displays and LED driver circuits
- Speed and position control reference inputs in motor drive circuits
- Bias voltage setting in transistor amplifier and oscillator circuits
- User-adjustable threshold setting for comparator and Schmitt trigger circuits
- Resistance substitution during prototyping and circuit development on breadboards
Example
In a classic non-inverting amplifier circuit, a 10 kΩ potentiometer is wired with terminal A to +5 V, terminal B to GND, and the Wiper to the non-inverting input of an op-amp. Rotating the knob moves the wiper from 0 V to 5 V, setting the reference voltage that controls the amplifier's output level — a standard voltage divider application.
Key facts
- The potentiometer symbol is a resistor body (IEC rectangle or ANSI zigzag) with an arrow perpendicular to it indicating the movable wiper, which connects to a third terminal; it is defined in IEC 60617-04 and ANSI Y32.2 / IEEE 315-1975.
- A potentiometer has three terminals: A and B (the resistive track ends) and Wiper (the adjustable tap); the resistance from A to B is constant while the wiper divides it proportionally.
- The component designator is R or RV in schematics; resistance is measured in ohms (Ω) and ranges from 100 Ω to 1 MΩ for common types.
- When only one end terminal and the wiper are used (two terminals active), the potentiometer functions as a variable resistor (rheostat) with resistance adjustable from 0 Ω to the rated maximum.
- Audio (logarithmic) taper potentiometers track loudness perception; linear taper types are used for voltage division and calibration; multi-turn cermet trimmers provide fine adjustment in instrumentation.
- IEC 60617-04 uses a rectangle for the resistor body; ANSI Y32.2 / IEEE 315 uses a zigzag — the wiper arrow is identical in both standards.
- Power rating for panel-mount rotary potentiometers is typically 0.5–2 W; exceeding this causes resistance drift and mechanical wear.
Diagrams that use this symbol
- throttle position sensor diagram
- guitar wiring diagrams
- 6 pin throttle position sensor wiring diagram
- potentiometer wiring diagram
- humbucker wiring diagram
- electric guitar diagram
- guitar pickup wiring diagram
- pickup wiring diagrams
Frequently asked questions
What does the potentiometer symbol look like?
The potentiometer symbol is a resistor (rectangle in IEC, zigzag in ANSI) with an arrow pointing at it from outside, representing the adjustable wiper contact. The arrow's tail connects to the wiper terminal; the two ends of the resistor body connect to the A and B terminals. The arrow-on-resistor motif is the universal identifier for a potentiometer in any standard.
What does the potentiometer symbol mean in a circuit diagram?
The potentiometer symbol means the component provides an adjustable division of the voltage across its A and B terminals. By moving the wiper, the designer or user sets an output voltage anywhere between V_A and V_B, or a resistance between 0 Ω and the maximum rated value.
What is the difference between IEC and ANSI potentiometer symbols?
In IEC 60617-04, the potentiometer body is a filled rectangle; in ANSI Y32.2 / IEEE 315-1975, the body is a zigzag line. Both standards use the same perpendicular wiper arrow pointing at the resistor body. The functional meaning is identical.
What is the designator letter for a potentiometer on a schematic?
The designator is R or RV. Fixed resistors use 'R'; adjustable resistors and potentiometers often use 'RV' to distinguish them (e.g. RV1, RV2). On older drawings 'VR' (variable resistor) is sometimes used.
What is the difference between a potentiometer and a rheostat?
A potentiometer uses all three terminals (A, Wiper, B) as a voltage divider. A rheostat uses only two terminals — one end and the wiper — to provide a variable resistance in series with a circuit. The same physical component can function as either depending on how it is wired.
What does a trimmer potentiometer symbol look like?
A trimmer (preset) potentiometer uses the same arrow-on-resistor symbol as a standard potentiometer but is sometimes marked with a 'T' shape or a cross symbol indicating screwdriver adjustment. It represents a small, PCB-mounted potentiometer intended for one-time calibration rather than user adjustment.
What resistance values are common for potentiometers?
Common standard values are 100 Ω, 1 kΩ, 5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ, 500 kΩ, and 1 MΩ. Audio volume controls typically use 10 kΩ or 100 kΩ logarithmic taper; precision trimmer circuits often use 1 kΩ or 10 kΩ cermet multi-turn types.
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