Returning to electronics after long absence - Page 1
Forum section: electronics / beginners

author: Kenmtb
author_rank: Newbie
timestamp: May 13, 2025, 02:21:22 pm
content: Hello all-I used to be a technician over a decade ago. After a career detour in software and optical device calibration/testing, I would like to return to being an electronics technician again.Is there a good (free?) simulator tool that lets you build analog and digital circuits and analyze the circuit with meters, scopes etc.?I need to refresh and get back into the swing. I have a AS/EET and a BC/CS.Thank you for any help!Ken

author: rstofer
author_rank: Super Contributor
timestamp: May 13, 2025, 11:04:12 pm
content: For analog, LTspice is very popular and it's free:https://www.nytimes.com/2025/05/13/opinion/ezra-klein-podcast-rebecca-winthrop.html?unlocked_article_code=1.G08.e4k7.cRZFqVJ3mH0n&smid=url-shareFor digital, the free version of Modelsim is popular for use with various HDL toolchains:https://www.intel.com/content/www/us/en/software-kit/750368/modelsim-intel-fpgas-standard-edition-software-version-18-1.htmlI use the free version of the Xilinx Vivado toolchain because I do most of my digital stuff on Digilent prototype boards which use Xilinx FPGAs:https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18842547/Install+Xilinx+Toolshttps://digilent.com/shop/fpga-boards/

author: SteveThackery
author_rank: Super Contributor
timestamp: May 13, 2025, 11:45:24 pm
content: Quote from: rstofer on May 13, 2025, 11:04:12 pm

author: Kenmtb
author_rank: Newbie
timestamp: May 14, 2025, 03:03:16 pm
content: Thank you for the help and links. Why is LTspice a bear trap??

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: May 14, 2025, 03:49:15 pm
content: In my opinion, the student version of Tina is fairly straightforward compared to LTSPICE. I use both, as LTSPICE has demo circuits of their Analog Devices ICs.https://www.tina.com/I have used Tina Student for several years, it has some minor limitations, but even if you want to model a more complex circuit, you can usually split it into smaller parts.SJ

author: xvr
author_rank: Frequent Contributor
timestamp: May 14, 2025, 07:31:37 pm
content: KiCAD has builtin Spice simulator. UI of KiCAD much better than both LTspice and Tina, but entry threshold is much higher also (because it is not only Spice, but a full featured Schematic/PCB design CAD)

author: SteveThackery
author_rank: Super Contributor
timestamp: May 14, 2025, 09:11:19 pm
content: Quote from: Kenmtb on May 14, 2025, 03:03:16 pmIt's the exceptionally crude and old-fashioned user interface, combined with the need to learn the deeply arcane command set, which looks more like a secret code than a set of instructions to be processed.A quick sniff around the Web and ChatGPT suggests some alternatives. If you are working at a hobby level thenFalstadis extremely easy and user friendly, and a great place to start. It lacks professional features, but that is only relevant when you want to move up the learning curve.SimulIDElooks like a promising next step. Also you can use the schematic and simulation features inKiCAD, which is pretty good and it starts you on your way to designing your own PCBs.Once you've worked your way up, starting with Falstad and then learning one or two others, you will find LTSpice a bit less intimidating and extremely powerful.

author: Gyro
author_rank: Super Contributor
timestamp: May 14, 2025, 09:25:39 pm
content: Don't forget Micro-Cap, which became freeware in its final revision. Still spice but more friendly than LTSpice...https://en.wikipedia.org/wiki/Micro-Cap

author: Terry Bites
author_rank: Super Contributor
timestamp: May 15, 2025, 03:07:38 pm
content: Qspice. Its free and it works really well.

author: bateau020
author_rank: Frequent Contributor
timestamp: May 21, 2025, 01:47:22 pm
content: The ones that I work with:ltspice: loads of users, multi platform (when using wine, the MacOS UI and CLI is crippled). Despite the crappy UI, the one I use most.ngspice: open source, multi platform, a bit rough around the edges, and I find the Kicad integration not to be a magic bullet. I still find myself doing my schemas in "PCB" and "simulation" versions.qspice: supposed to be the next big thing, but Windows only, not compatible (yet) with winexyce: open source, but seems even less used than the above

author: shapirus
author_rank: Super Contributor
timestamp: May 21, 2025, 02:54:35 pm
content: Quote from: xvr on May 14, 2025, 07:31:37 pm...but no builtin simulation models except for basic primitives.Many models can be found online and downloaded from semiconductor manufacturers directly. But it's an extra step and often models for specific ICs are simply not available or are encrypted and can't be read by ngspice (the simulator used in kicad). The unencrypted ones from TI and AD typically work fine.LTspice models are typically incompatible with ngspice (yes even in the "ltspice compatibility mode").In other words, finding working models for a specific element may be a pain. But usually it can be worked around.Quote from: xvr on May 14, 2025, 07:31:37 pmYes. LTspice UI is a non-funny joke, that's for sure. Can't speak about Tina.Kicad is actually very good, but requires a fair amount of getting used to. I do have experience of being able to manage to squeeze both simulation, schematic and PCB design into the same project. Of course not everything can be simulated, I needed to make shortcuts in some situations. But it's doable. I haven't designed anything complex though.p.s. kicad is well alive, it's FOSS and it's being developed at a steady rate. I think this makes it a good candidate to learn.

author: radiolistener
author_rank: Super Contributor
timestamp: May 21, 2025, 03:14:01 pm
content: Quote from: xvr on May 14, 2025, 07:31:37 pmyes, but it has a limited ability to customize simulator result graphs and no documentation about it. Also some things confusing after LTspice.

author: bateau020
author_rank: Frequent Contributor
timestamp: May 21, 2025, 03:42:13 pm
content: Quote from: radiolistener on May 21, 2025, 03:14:01 pmMemory is a bit fuzzy, but you should be able to intercept the RAW files and use external graphing tools. Intercepting the netlists from kicad and running them through an external ngspice simulation run (with or without the help of tools like spicelib) is a bit of a pain as far as I remember.

author: shapirus
author_rank: Super Contributor
timestamp: May 21, 2025, 03:49:43 pm
content: Quote from: bateau020 on May 21, 2025, 03:42:13 pmThere's an open feature request and (apparently) work is in progress that should make this more usable and convenient:https://gitlab.com/kicad/code/kicad/-/issues/16232

author: eugene
author_rank: Frequent Contributor
timestamp: May 21, 2025, 07:01:36 pm
content: LTSpice has been my go-to for years, maybe decades. A lot of people whine about the interface because it's not exactly what they think they deserve. But honestly, it's not that hard to figure out. I've taught hobbyists to use it successfully.For schematics and PCBs I switched from Altium to KiCad back around version 5 or 6, but I still don't use it for simulations because I don't think it's quite there yet, though I expect that it will be improved in the next version or two.I have installed on my computer a copy of Qucs-S which looks very interesting. It's a fork of Qucs that allows the use of different spice back-ends. It looks to me like it could replace LTSpice since it has the interface that everyone is crying for. I admit that I have not yet really dug into it, but I do recommend it to anyone starting out.https://ra3xdh.github.io/

author: djsb
author_rank: Super Contributor
timestamp: May 21, 2025, 08:39:22 pm
content: There is also QUCS-Shttps://ra3xdh.github.io/