Recommedation on a circuit simulator?

Thread Starter

ScrubOak

Joined May 1, 2022
12
Hello, I am new to the circuit simulator world, and I happened upon this website:

https://www.falstad.com/circuit/

Is this a good resource, or is there a lot more out there I am not aware of? If anyone could help educate me on the simulation space, I would certainly appreciate it.
 

crutschow

Joined Mar 14, 2008
34,680
Falstad is a simple to use beginner's simulator, but is not Spice based and is limited in its capabilities.

Several of us on these electronic websites use the free LTspice from Analog Devices which is one of the best free ones available.
It has a somewhat steep learning curve, but there are good tutorials and sample circuits to help you with that process.
Also we can help you with any questions here.

Another one you might consider is the free Tina Spice simulator from TI, but I'm not that familiar with it.
 

Thread Starter

ScrubOak

Joined May 1, 2022
12
Thank you both.

Falstad is a simple to use beginner's simulator, but is not Spice based and is limited in its capabilities.

Several of us on these electronic websites use the free LTspice from Analog Devices which is one of the best free ones available.
It has a somewhat steep learning curve, but there are good tutorials and sample circuits to help you with that process.
Also we can help you with any questions here.

Another one you might consider is the free Tina Spice simulator from TI, but I'm not that familiar with it.
Would you say this is the one that is most commonly used?


You will find a lot of folks here using LTspice Simulator | Analog Devices which is free and with lots of support. Falstad looks pretty but isn't really much of a true simulator.
Can you elaborate on that distinction?
 

Alextrical

Joined May 5, 2022
18
If your are looking to simulate basic circuits with Transistors resistors caps and a few basic semiconductors (without needing specific branded component specs) I have used everycircuit.com in the past, and has a nice web and android app to simulate on the go. (its $15 for a lifetime licence after the trial)

however as others have said LTspice is a really good bit of software (I've only used it the last 2 days, but will be sticking with it), that runs on windows or mac (and linux under Wine)
 

BobTPH

Joined Jun 5, 2013
9,130
Manufacturers publish spice models for their parts. For anyone other than students, this is quite important.

Bob
 

kubeek

Joined Sep 20, 2005
5,796
I would say the biggest difference is that in falstad you start the simulation and watch in real time things unfold.
Compare this to a simulation in LTspice, where you define for how long the simulation should run and it saves all the datapoints in a file and then you can go and investigate all voltages and currents etc throughout that time frame.
I have had detailed simulations of switched power supplies including full models and parasitics, where the simulation would run for five or ten minutes on an i5-8600k six core cpu just to get a few tens of miliseconds worth of startup and transient behavior, and would produce a few GB of simulation data in a file. I cant imagine pulling that of in falstad, or how long it would take to simulate inside a web browser.
 

eetech00

Joined Jun 8, 2013
4,004
On one being more of a true simulator. In layman's terms, what is one doing that the other cannot, because viewed from space they looks quite similar unless someone differentiates them for us.
What is meant by "True" is that the simulation engine produces results that closely reflect the electrical behaivor of a real physical circuit. Many "engines" make adjustments "behind the scene" as an attempt to make the tool fast and more "user friendly". Some even prevent the user from making low level circuit adjustments that can provide realistic simulation results, or perform "what if" type analysis scenarios. The result of these "user friendly" engine adjustments is usually a sacrifice of realistic circuit behavior.

LTspice is an excellent engine, and, while the user interface is not the most "polished", or used friendly, the quality of simulation will be largely dependant on the quality of the spice library parts. If you want realistic circuit behavior, and low cost, LTspice will be tough to beat.

There are many discussions regrading the comparison of "Brand A" vs "Brand B" spice simulators.

Google can help you search...
 

ElectricSpidey

Joined Dec 2, 2017
2,829
One obvious difference to the lay user is Falstad provides an animated display of the circuit in action and LTSpice is strictly a waveform graphic view.
 

Thread Starter

ScrubOak

Joined May 1, 2022
12
What is meant by "True" is that the simulation engine produces results that closely reflect the electrical behaivor of a real physical circuit. Many "engines" make adjustments "behind the scene" as an attempt to make the tool fast and more "user friendly". Some even prevent the user from making low level circuit adjustments that can provide realistic simulation results, or perform "what if" type analysis scenarios. The result of these "user friendly" engine adjustments is usually a sacrifice of realistic circuit behavior.

LTspice is an excellent engine, and, while the user interface is not the most "polished", or used friendly, the quality of simulation will be largely dependant on the quality of the spice library parts. If you want realistic circuit behavior, and low cost, LTspice will be tough to beat.
Thanks, I appreciate the insight. This certainly helps me understand.


One obvious difference to the lay user is Falstad provides an animated display of the circuit in action and LTSpice is strictly a waveform graphic view.
To many it may not mean much, but often times the animation helps describe something about the circuit behavior that is not otherwise obvious.

Would Falstad be the kind of tool you use to show someone something about a circuit in a visual way?
 
Last edited:

eetech00

Joined Jun 8, 2013
4,004
To many it may not mean much, but often times the animation helps describe something about the circuit behavior that is not otherwise obvious.

Would Falstad be the kind of tool you use to show someone something about a circuit in a visual way?
That is a good point. Sometime multiple tools are required, but it depends on the audience.
I would still be careful about using a tool that might mislead, or fool, the user/audience.
 
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