Spice simulations as a non-phd - Page 1
Forum section: electronics / general

author: liquibyte
author_rank: Frequent Contributor
timestamp: March 21, 2014, 02:39:47 am
content: Can someone look at this TINA simulation I'm working on and tell me what the **** I'm doing wrong? I've been working on this for two days solid and I can't seem to get consistent outputs no matter what I do to the transformer or voltage generator. I have no idea how you guys deal with these POS programs on a daily basis, it's pissing me off. If I change anything such as rerouting the wiring, all of a sudden I get some weird assed error and have to cut and paste that particular component back in to make it work again. Sometimes I have to do this 4, 5, or 6 times on different components and it's always one of the op amps or diodes.

author: liquibyte
author_rank: Frequent Contributor
timestamp: March 21, 2014, 12:43:30 pm
content: I'm sure it's a POS program, at least from a user interface perspective. The circuit may or may not be a POS, regardless, my output on the transformer most certainly is not what I should be seeing, theoretical vs real electrons or not. Fine, the ground wasn't in the circuit before. It is now and I still can't get the transformer to output correct voltages because I'm not a transformer designer and don't have the impetus to try that for a living. Why are we picking turns ratios instead of output voltages here? The only way I've been able to get close on this is by specifying a turns ratio of 0.36 which to my mind isn't a turns ratio at all. The problem with 0.36 is that, while the output voltages come close, the -1.3V I'm supposed to be getting below ground is 1.8V or so. If I get close to the -1.3V then the outputs go to the mV range. POS interface.

author: liquibyte
author_rank: Frequent Contributor
timestamp: March 21, 2014, 03:09:46 pm
content: I'm trying to get any voltage over the mV range. Period. I don't understand how I can put a transformer in here for simulation and it outputs anything other than a real world value. Other than the transformer not doing anything useful, everything else works ok I suppose. I'm new to this program and don't understand how to make things work. I don't care if the thing outputs a volt, 9 volts, 28 volts as long as I can make it do something useful without having to understand transformer theory. I suppose what I'm saying is how do I get this program to give me a transformer that actually outputs a voltage that's akin to what I would get in the real world?

author: Bored@Work
author_rank: Super Contributor
timestamp: March 21, 2014, 05:33:44 pm
content: Quote from: liquibyte on March 21, 2014, 03:09:46 pmHere is your problem. You don't want to learn the basics, you want to get it served on a plate. I doubt your strategy will be successful with any kind of SPICE simulation. It is just not the way SPICE works. Oh, did you believe the vocal people here telling everyone that all you need is enthusiasm, not education? And all you have to do is to throw a problem into a simulator, no need for math?Well, I would recommend you drop any SPICE and look for some of the kindergarten simulators around. E.g. Falstad. Or QUCS, if you manage to get it running. However, QUCS contains a bit of SPICE compatibility, too. But what about New Wave Concepts' Livewire? Components explode on screen if their maximum rating is exceeded. Doesn't sound this like fun for the whole family?

author: liquibyte
author_rank: Frequent Contributor
timestamp: March 21, 2014, 06:01:32 pm
content: Quote from: Bored@Work on March 21, 2014, 05:33:44 pmI understand basics and the math. What I don't understand is the transformer model that has no bearing on what I've seen in reality. You explain to me where exactly I input my math at and I'll do that. It's not that I don't understand the math, the problem is that I don't understand where to input the math at. How does this equate to wanting my hand held? I've never used this program before and was asking what I'm doing wrong and I get two people answering me with how stupid I am. I'm sorry I don't have your levels of expertise regarding simulation software and that I must seem immensely stupid to you and that you are deigned to be a god amongst your peers, how nice for you.Oh, and you're an asshole.

author: Protoid
author_rank: Newbie
timestamp: March 24, 2014, 12:56:00 pm
content: HelloI am a user of Multisim since a while, and it is a very efficient software for electronic simulation, in the past it has been some annoying bugs, on actual versions i consider it to be one of the best ones in its category.Schematics are not too bad on it too, a bit similar to Cadsoft Eagle.Spice is too difficult to use as is, i am surely not clever, i could never really use it.