WOLFRAM SYSTEM MODELER

SchmittTrigger

Schmitt trigger with hysteresis

Diagram

Wolfram Language

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SystemModel["Modelica.Electrical.Analog.Examples.OpAmps.SchmittTrigger"]
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Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

This is a (non-inverting) Schmitt trigger. Resistance R1 can be chosen, resistance R2 is defined by the desired hysteresis. The output gets Vp for input voltage > vHys and Vn for input voltage < vHys*Vns/Vps.

The example is taken from: U. Tietze and C. Schenk, Halbleiter-Schaltungstechnik (German), 11th edition, Springer 1999, Chapter 6.5.2

Parameters (8)

Vps

Value: +15

Type: Voltage (V)

Description: Positive supply

Vns

Value: -15

Type: Voltage (V)

Description: Negative supply

Vin

Value: 5

Type: Voltage (V)

Description: Amplitude of input voltage

f

Value: 10

Type: Frequency (Hz)

Description: Frequency of input voltage

vHys

Value: 1

Type: Voltage (V)

Description: (Positive) hysteresis voltage

k

Value: vHys / Vps

Type: Real

Description: Auxiliary calculated parameter to be used in R2 calculation

R1

Value: 1000

Type: Resistance (Ω)

Description: Arbitrary resistance

R2

Value: R1 / k

Type: Resistance (Ω)

Description: Calculated resistance to reach hysteresis voltage

Components (6)

opAmp

Type: IdealizedOpAmpLimited

Description: Idealized operational amplifier with limitation

ground

Type: Ground

Description: Ground node

vIn

Type: TrapezoidVoltage

Description: Trapezoidal voltage source

vOut

Type: VoltageSensor

Description: Sensor to measure the voltage between two pins

r1

Type: Resistor

Description: Ideal linear electrical resistor

r2

Type: Resistor

Description: Ideal linear electrical resistor