Op Amps, Diodestom epplin: tje3@cec.wustl.edu

Intro to NI Multisim 10.1

Getting Started with Multisim (CEC)

> Engineering>

NationalInstrumentsMultisim 10.1

Getting Started with Multisim (CEC)

Adding Multisim Components

> PlaceComponent

Adding Multisim Components

> GroupBasic

Adding Multisim Components

> Capacitor300nF

Ok

(Objects may be rotated using Edit -> Orientation)

Adding Multisim Components

Adding Multisim Components

Adding Multisim Components

> PlaceWire

(or Ctrl+Q)

(Note that red dots appear where successful junctions have been established)

Adding Multisim Components

Don’t forget to place an appropriate reference ground:

> PlaceComponent

SourcesPower_Sources

o Ground

Example Problem 1: Op Amp

Input

Output

V2

V1

V3

Example Problem 1: Op AmpSolving manually:

V1 = (12V)(1kΩ/3kΩ)= 4V

V2 = V1= 4V

(12V – 4V)/3kΩ = (4V – V3)/6kΩV3 = -12V

Example Problem 1: Op AmpSolving using Multisim:

Compare voltages in circuit using an oscilloscope:> Simulate > Instruments > OscilloscopeAttach oscilloscope terminals across voltages to be

compared:

Example Problem 1: Op AmpSolving using Multisim:

Double-click on the oscilloscope to bring up its display, and hit the green play button in the Multisim toolbar

Example Problem 1: Op Amp

V3 = -12V

Example Problem 2: Diode

Input

Output

V1

Example Problem 2: DiodeSolving manually:

Try top diode conducting:Then, in ideal case (no loss through diode), V1 ≈ 3V

If V1 = 3V, then the middle and bottom diodes are not forwards-conducting

…No contradictory assumptions, and all voltages complicit

V1 ≈ 3V

Example Problem 2: DiodeSolving using Multisim:

Example Problem 2: Diode

V1 = 2.7V(real diode properties used)