Potentiometer

Resistor with a wiper at the input position (0…1).

  • signal
  • electrical
  • Modelica Standard Library
  • 4 ports
  • 1 parameter
BlockPotentiometerKindpotentiometerLibraryElectrical

Description

A resistor of total resistance R with a sliding contact (wiper). The position input splits R into two parts: 0 puts the wiper at pin_n, 1 puts it at pin_p.

Example

Variable parts A resistor, an inductor, and a capacitor whose values follow signals, and a potentiometer.

R = 10 + 5 sin 2πtDC 10 VVariable resistori RGround RL = 2 + sin(πt/2)DC 1 VVariable inductori LGround LC₀ = 1 mF+1 mF at 0.5 sCDC 1 mAVariable capacitorv CGround CWiper positionDC 10 V (pot)PotentiometerWiper voltageGround P
In Gradara, select a Potentiometer block and press F1, then choose Open example. It opens as a new model in My models, ready to run.

Also in this example:DC voltageVoltage sensorCurrent sensorSumConstantStepGroundRampSine waveVariable resistorVariable capacitorVariable inductorDC current

Ports

Inputs 1

  • posrsignal

    Wiper position, from 0 to 1. Values outside that range are clamped.

Conserving terminals 3

  • +pin_pelectrical

    End pin at position 1.

  • −pin_nelectrical

    End pin at position 0.

  • wcontactelectrical

    Wiper pin.

Parameters

  • Total resistanceR1000 Ω

    ≥ 0

    Total resistance between pin_p and pin_n, in ohms. 0 or more.

Equations

Modelica
r′ = min(1, max(0, r))
pin_p.v − contact.v = R · (1 − r′) · pin_p.i
pin_n.v − contact.v = R · r′ · pin_n.i
pin_p.i + pin_n.i + contact.i = 0

Implementation

Modelica Standard Library 4.1.0Modelica.Electrical.Analog.Basic.Potentiometer
MSL documentation

Assumptions and limitations

  • No temperature dependence, contact resistance, or wiper travel limits beyond the clamp.

Tips

  • At either end of travel one section has zero resistance, which shorts the wiper to that end pin.

See also

Select a block in Gradara and press F1 to open its page offline.