Intro to NI Multisim 10.1
Op Amps, Diodes
tom epplin: [email protected]
Getting Started with Multisim (CEC)
 > Engineering
 > NationalInstruments
 Multisim 10.1
Getting Started with Multisim (CEC)
Adding Multisim Components
 > Place
 Component
Adding Multisim Components
 > Group
 Basic
Adding Multisim Components
 > Capacitor
 300nF
 Ok
(Objects may be rotated
using Edit ->
Orientation)
Adding Multisim Components
Adding Multisim Components
Adding Multisim Components
 > Place
 Wire
(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:
 > Place
 Component
 Sources
 Power_Sources
o Ground
Example Problem 1: Op Amp
V2
V3
Output
Input
V1
Example Problem 1: Op Amp
 Solving manually:
V1 = (12V)(1kΩ/3kΩ)
= 4V
V2 = V1
= 4V
(12V – 4V)/3kΩ = (4V – V3)/6kΩ
V3 = -12V
Example Problem 1: Op Amp
 Solving using Multisim:
 Compare voltages in circuit using an oscilloscope:
 > Simulate > Instruments > Oscilloscope
 Attach oscilloscope terminals across voltages to be compared:
Example Problem 1: Op Amp
 Solving 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
V1
Output
Input
Example Problem 2: Diode
 Solving 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 forwardsconducting
 …No contradictory assumptions, and all voltages complicit
V1 ≈ 3V
Example Problem 2: Diode
 Solving using Multisim:
Example Problem 2: Diode
V1 = 2.7V
(real diode
properties used)