# Questions tagged [multisim]

A SPICE simulation and schematic capture package distributed by National Instruments.

74 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
97 views

### How to determine LS, CS, RS, and CO of a piezo transducer for simulation?

I have a 24mm piezo transducer with the marking SSE2425TAL from overseas. There are no detailed specs nor graphs to get LS, CS, RS, and CO at various frequencies (but just 25 kHz is fine). I'd like to ...
• 259
317 views

### Multisim : Wrong Output for 1 way traffic light using 555 timers

I made a curcuit using the given diagram in Multisim but my output is of the order Green->Yellow->Green->(Yellow and Red) . Pls tell what should I do to get the output of the order Green->...
623 views

### Multisim, Simulation Error

As the picture describes, the Vout is the division's result, but we have an error. Because my experience with MultiSim is not at a high level, why does this happen? Is this my fault ? ]1
1 vote
209 views

### What is the function of frequency resolution in multisim

In this circuit, noticed if the frequency is set to be the same as source frequency, the display will show a constant peak. The modulation index is 0.6. However, if the resolution frequency is set to ...
• 609
1 vote
112 views

### how to calculate rx, ro given gx and go from XSPICE

I have a set of XSPICE data extracted from multisim as can be seen in the attached image. How do I calculate the ro and rx (base spreading resistance) given the parameters go and gx. Thanks
1 vote
131 views

### Improving input impedance at higher frequencies for multi-stage MOSFET amplifier

I am trying to design a three-stage amplifier and I currently have two common source amplifiers and a buffer, to help drive a small 8 ohm load. However, as my frequency increases, my input impedance ...
• 11
1 vote
92 views

### amperes too low on this circuit

I'm trying to get the voltage between phases, the line current and the apparent, real and reactive power of the next circuit: but there are a few things dazzling me, the most important is why the ...
• 530
1 vote
267 views

### Multisim (2008) - How do I provide a reset stimulus using a controlled one shot pulse, in order to properly initialize my design under simulation?

Apologies for the captured image quality but I have a circuit from a communications textbook Fundamentals of Electronic Communication Systems 3rd Edition, by Louis E. Frenzel Jr. The image below ...
• 171
1 vote
167 views

### How to generate a random signal in multisim 14.1

I'm trying to design a circuit which digitised a very noisy input. It is normally +/- 1mv but will randomly peak up to +/- 20mv, the frequency of interest is 0.1<hz<10 but the signal contains ...
• 111
1 vote
73 views

### Using an NMOS as a switch for a 10V DC source in a 555 timer circuit

I used NI multisim and created a circuit with a 555 timer that will allow a diode to flash at a frequency of about 4HZ. This is the circuit: As you can see in the above image, the oscilloscope graph ...
• 13
1 vote
47 views

### Trying to create a 555 timer but nothing shows up in my transient analysis

I'm trying to learn more about 555 timers but my transient analysis renders me this empty graph. Is there something wrong with the way I am setting up my MultiSim Circuit?
1 vote
497 views

### Why doesn't this 950 MHz to 2200 MHz Colpitts VCO circuit work in Multisim?

I found a 950 MHz to 2200 MHz Colpitts VCO circuit from this web page. I tried to design it in Multisim, but doesn't produce any signals. Why? I used BB130 diodes instead of SMV1232 because Multisim ...
1 vote
192 views

### Op-amp power supply driver problem (multisim), LM2679 simple switcher

The simulation works OK when I run with ideal op-amp but the problem comes whenever I change the op-amp to a real one (LMH6642MF) and that results in a converge error and a warning. I have tried to ...
1 vote
273 views

### Implementing a counter using multisim

There was an assignment as follows: implement a counter which gets as an input of 8 pulses, 5 volts each, with frequency of 40K Hz, without using counter block, or any IC components. In the output ...
• 197
1 vote
399 views

### Exponential circuit in Multisim

I have a circuit which has an exponential function as shown in the figure. I tried to put an anti-log op-amp with the diode and BJT transistor, but did not get what I wanted. I think the whole ...
• 17
1 vote
993 views

### How can I use the component CD4538 or a 555 timer on Multisim?

How can I use the component CD4538 or a 555 timer on Multisim for a delay of 1 second ? I want both of the nor gates to be 1 for roughly 1 second when the output of the op-amps is either 01 or 10.
1 vote
3k views

### Verilog SRAM controller

I am trying to implement a SRAM controller module. It's structured as follows External connections: extA[18:0] -- address extIO[7:0] -- bidirectional input/output OE,WE,CE -- control signals ...
1 vote
854 views

### Load cell circuit does not work on circuit simulator

I want to simulate a load cell interfacing with AD620 for amplification. - My load cell is 40 Kg max with 2mV/V sensitivity and 10 V excitation voltage with input resistance of 405 ohm and output ...
• 11
1 vote
6k views

### Why do simulated results differ to calculated results?

Why, when using a program such as multisim, do the simulated results within the program differ slightly to those calculated analytically. Would there be any reasons other than rounding errors in ...
• 117
1 vote
643 views

### Multiple (independent) circuits on the same PCB in Multisim/Ultiboard

I have designed and simulated a few circuits on Multisim. Usually, I order a PCB for the layout of each circuit independently. However, it is cost-effective to put multiple circuits on the same board (...
• 151
1 vote
2k views

### Series diode voltage clipper, on Multisim clipping and shifting on positive and negative voltage

This is my circuit: I’m testing a Series diode clipper circuit, and the end result should be this: (I've used 5V in my circuit, not 10V like in this plot, but this is not the issue) Instead what I ...
• 135
1 vote
306 views

### How to model Texas Instruments UCC28700?

I'm using Multisim in an attempt to simulate a flyback supply design reference by Texas Instruments that makes use of a voltage controller - the UCC28700. Multisim has no SPICE model natively nor does ...
• 165
1 vote
500 views

### Op-amp: Floating input (Multisim)

I found this circuit from Encyclopedia of Electronic Circuits Volumes 1 by RUDOLF F. GRAF I used Multisim to simulate. When switches S1 and S2 are open (U1A@3 and U1B@6 are floating) and I measured ...
• 11
1 vote
4k views

### Zero Crossing Optoisolator in Multisim

I'm an electronics hobbist with relatively little experience and I'm playing around with Multisim to try to understand how to manipulate AC waveforms. Specifically, I would like to control the wave ...
• 1,957
41 views

### Multisim is not giving any voltage value for this simple capacitor circuit

This is the circuit: Even though I gave 12V it is showing 6V. Maybe it is peak voltage. Why are the voltages across each capacitor so weird?
• 95
47 views

### How can I apply this Vs(t) = 5cos(2000t) into the multisim circuit?

I found the rms = 3.53 it has 2000t whereas omega,w = 2000 so how can I use it to the AC source
• 95
45 views

### SIMetrix simulation

Determine the true power dissipated in the load of a single-phase half-wave rectifier fed from a 220 V 50 Hz supply. The load resistor is 37 ohm. I'm getting an error during simulation on simetrix:-***...
91 views

### Designing an ADC circuit incorporated into an 8-bit SAR that can convert an analog signal (such as sound from an electret microphone)

My task is to design a ADC incorporated into a system that converts an analog signal such as a sound picked up by a microphone into a digital signal. I have chosen an electret microphone. I know the ...
25 views

### Multisim Component Separation

This is how I created a circuit. How can I remove the R1 resistor from this circuit without breaking the wires as follows. Shortcut or otherwise.
45 views

### Why is this happening using Multisim?

I'm using the website https://www.multisim.com/create/ Why does Multisim show the current as negative above the Zener diode? Both probes are going the same way, yet the current is shown as a negative -...
• 2,008
53 views

### Liquid level control using AD620

I am making a liquid level control circuit as follows: I want to replace AD624 with AD620 is there any way to do so?
110 views

### Using potentiometer to light three different LEDs (Multisim)

I want to make a circuit that connects a potentiometer to three different LEDs (green, blue, red.) This circuit would simulate the wind speed sensor. If the potentiometer is high (V is high, ...
• 1
80 views

### Low voltage to drive LED flash (not successful in simulation, but works on breadboard)

I first did this circuit on a breadboard, except I originally used a light-sensitive resistor, which is around 1 kΩ at daytime and above 160 kΩ in darkness. It oscillates with LED as capacitor adds up ...
182 views

### Combine two circuits in Multisim

I have two circuits, two separate simulations in Multisim, which work fine until I try to combine them. I tried a common ground, on-page connectors, added the voltage follower, but that didn't help. ...
87 views

### Why is this circuit not triggered (astable multivibrator) although it can be triggered on a breadboard?

Why is this astable multivibrator circuit getting balanced in a flash and not oscillating? It works on a breadboard. It once worked fine in simulation, but one day it stopped oscillating in simulation....
68 views

### Multisim schematic to other CAD

Does anyone knows a way to convert my schematic file in MS14 to any other CAD system? I want to open it with Altium.
169 views

### Why do I get the wrong phase shift?

I am trying to compare theory vs simulation values and it seems to be that there are differences. I am using Multisim to simulate a RLC circuit, the LC are in parallel and in series to the resistor. ...
• 97
49 views

### Issue with a circuit in Multisim V14.0

I have a part of this circuit on a PCB working with a frequency of 1 Hz (I tested it with an oscilloscope; it works perfectly). I have to change it to 2 Hz, so I tried to do that in Multisim V14.0, ...
176 views

### Slow slew-rate compared to the datasheet

I'm trying to create a 10 kHz PWM signal through use of op amps. In the output I'm using a TLV272IP op-amp working as a comparator: Since it has as slew rate of at least 1.8 V/us this should give a ...
85 views

### Trying to Construct Phase Shift Circuit in Multisim

I'm attempting to construct the variable phase shift circuit from this video (link takes you to the circuit diagram of it) within Multisim. As far as I can tell the circuits are identical, and yet my ...
113 views

### Secondary Coil Malfunction in an SSTC Circuit

I’ve designed an SSTC circuit which is based on a different topology and I wanted to accomplish it in real life. The circuit is operating at approximately 1.5 MHz during resonance and inherently, the ...
• 109
529 views

### How can I measure phase shift in Multisim using a Tektronix oscilloscope?

I have to measure the phase shift between input and output of amplifiers. Below is an example circuit with voltage charts (yellow is input, blue is output.) How do I measure phase shift between them? ...
70 views

### Troubleshooting 74LS136D in Multisim

Hello. I couldn't seem to get my U1A to work. I understand the open collector logic gates, like 74LS136, require a pull-up resister in its output terminal. An open collector needs to be powered-on. I ...
• 307
114 views

### integrator outputing velocity

I'm trying to make a integrator output the velocity receiving an accelerometer signal based on the next design But the output seems to be fixed on a certain level as showed here I'm thinking the ...
• 530
309 views

### How to do high frequency simulations in simulation softwares (proteus, multisim, etc)

So i am trying to build a buck converter which requires switching at high frequencies. Before making the whole circuit however, i decided to use a circuit simulation software so that i can experiment ...
313 views

### Simulation in Multisim is taking a lot of time. Probably due to the signal multiplier(Modulator)

In this AM modulator/demodulator circuit, I am trying to see the variations of output signal due to changes of frequency and phase of the carrier signal at the demodulator. All is working fine until ...
• 13
726 views

### Is it possible to convert/copy/transfer my MULTISIM circuit into LTspice file?

Hello, By any chance, if is there a way to convert/copy/transfer my MULTISIM circuit into LTspice. Would appreciate a lot your responses Thank you
139 views

### Trnsient simulation in multisim is a flat line, osciloscope shows good results

I'm trying to plot results of simulation of a simple Phase shift Oscillator. The plot looks ok in oscilloscope with an interactive simulation, but when I'm running Transient or AC Sweep, I'm just ...