What is the accuracy of the simulation?

[hauser]

Circuit simulators are rare, and ones that simulate them completely accurately even more so, because certain components like transistors and diodes require differential calculus. Differential calculus needs to be very accurate with many simulation steps each second, because otherwise the end result will be nonsensical, and the importance increases the more components you put in the equation.

This brings me to the title of this post: what is the accuracy of the simulation? For example, are transistors merely "no current passes through unless there is equal or greater than this specific amount" gates, or are the values actually curved and dissipate power as electricity passes through? What about capacitance of wires or traces between components?

[CEO of Big-game fishing]

I was thinking along the same lines.

Probably not going to be replacing spice simulation anytime soon haha

[em_t_hed]

idk what the accuracy of the sim is, BUT according to the circuit i made, while adjusting NOTHING with the circuit itself... ONLY changing the frequency of the simulation itself... the in game oscilloscope is literally telling me the sim is ONLY accurate at 300hz...

I'm supposed to be getting a clean sine wave on the scope and the only time i get a clean sine wave on the scope is when the simulation frequency is at 300hz...

[KuraT]

First thing I did was setup a simple negative and then a positive feedback amplifier with the lm741. It's not wrong, but it certainly isn't right (greater than 1% error). Even when doing a comparison with my own parts and breadboard in real life, measuring the actual values and inputting them in the sim, the values are just off more than I would like for genuine simulation.

That being said, it's still a nice little program for the money. As a tool to teach digital electronics that don't require so much accuracy it would be fine. Which I'm thinking is the point since there is no way, which I could find, to get a negative voltage source and the lm741 is the only truly analog IC in the kit so far. It does have inductors and caps I think so maybe you could build some passive filter circuits, but everything else seems to be there for the purpose of the digital computing. If someone had a book on digital ICs they could follow the path of flip-flops, basic clock circuits, down counters, etc. And for those purposes it's accurate enough.

As of this comment it's been out for a few days so maybe over time it will get better, but for the price it's pretty fair just understand, if my findings are correct, you wont be getting valuable output from oscillator circuits, active filters, or op-amps in general. It's also worth noting that I'm not an Electrical Engineer and my calculations could be off, or there may be something the sim accounts for that I didn't or that wasn't apparent in the circuits I built. I will say I haven't bunked it up in my linear circuits class that bad so there is some credibility backing my opinions and findings. In short: take this with a grain of salt.

[Squidbush]

If it is revealing in any way, I ran 7 amps of power through a quarter watt resister and it didn't destroy it. though there WAS a red outline and a warning, so I'd say it at least tells you when your components are going to burst into flames.
What little I've done with it though, it's generally accurate. I didn't see any tolerance variation in the parts though so I'm guessing the values are pretty rigid.

[em_t_hed]

Originally posted by KuraT:

First thing I did was setup a simple negative and then a positive feedback amplifier with the lm741. It's not wrong, but it certainly isn't right (greater than 1% error). Even when doing a comparison with my own parts and breadboard in real life, measuring the actual values and inputting them in the sim, the values are just off more than I would like for genuine simulation.

That being said, it's still a nice little program for the money. As a tool to teach digital electronics that don't require so much accuracy it would be fine. Which I'm thinking is the point since there is no way, which I could find, to get a negative voltage source and the lm741 is the only truly analog IC in the kit so far. It does have inductors and caps I think so maybe you could build some passive filter circuits, but everything else seems to be there for the purpose of the digital computing. If someone had a book on digital ICs they could follow the path of flip-flops, basic clock circuits, down counters, etc. And for those purposes it's accurate enough.

As of this comment it's been out for a few days so maybe over time it will get better, but for the price it's pretty fair just understand, if my findings are correct, you wont be getting valuable output from oscillator circuits, active filters, or op-amps in general. It's also worth noting that I'm not an Electrical Engineer and my calculations could be off, or there may be something the sim accounts for that I didn't or that wasn't apparent in the circuits I built. I will say I haven't bunked it up in my linear circuits class that bad so there is some credibility backing my opinions and findings. In short: take this with a grain of salt. :sotfood:

I got valuable enough data from the in game scope to know the sims frequency to be working for a simple RC Phase Shift Oscillator circuit. Any other frequency and the scope wasn't able to produce an 'expected' sine wave. IDK why you need an IC to check the sim accuracy.

[hauser]

Thanks for the input, guys. Sounds like the simulator is not exact. What a shame.

[KuraT]

Originally posted by em_t_hed:

Originally posted by KuraT:

First thing I did was setup a simple negative and then a positive feedback amplifier with the lm741. It's not wrong, but it certainly isn't right (greater than 1% error). Even when doing a comparison with my own parts and breadboard in real life, measuring the actual values and inputting them in the sim, the values are just off more than I would like for genuine simulation.

That being said, it's still a nice little program for the money. As a tool to teach digital electronics that don't require so much accuracy it would be fine. Which I'm thinking is the point since there is no way, which I could find, to get a negative voltage source and the lm741 is the only truly analog IC in the kit so far. It does have inductors and caps I think so maybe you could build some passive filter circuits, but everything else seems to be there for the purpose of the digital computing. If someone had a book on digital ICs they could follow the path of flip-flops, basic clock circuits, down counters, etc. And for those purposes it's accurate enough.

As of this comment it's been out for a few days so maybe over time it will get better, but for the price it's pretty fair just understand, if my findings are correct, you wont be getting valuable output from oscillator circuits, active filters, or op-amps in general. It's also worth noting that I'm not an Electrical Engineer and my calculations could be off, or there may be something the sim accounts for that I didn't or that wasn't apparent in the circuits I built. I will say I haven't bunked it up in my linear circuits class that bad so there is some credibility backing my opinions and findings. In short: take this with a grain of salt.

I got valuable enough data from the in game scope to know the sims frequency to be working for a simple RC Phase Shift Oscillator circuit. Any other frequency and the scope wasn't able to produce an 'expected' sine wave. IDK why you need an IC to check the sim accuracy.

Just explaining what I'd done based off of a lab I was doing in school at the time. So I just happened to have the exact same parts on my breadboard and the measured values written down. Made it fairly quick to check my results IRL against the simulation.

[KuraT]

Originally posted by hauser:

Thanks for the input, guys. Sounds like the simulator is not exact. What a shame.

For what it's worth, it's close enough. No simulator will be exact compared to built circuits due mostly to simulated components being "ideal" with no imperfections. Those components don't really exist in real life.