Thank you so match
Your answer is absolutely correct and professional. The interesting thing is that the multimeter and the simulator show the rms current value, right. While the current and voltage waveforms are similar.

Hi,

Yes, maybe that exemplifies the idea that some meters read differently than others when some are not used for the right measurements.

I guess we have this expectation that all meters should read alike, but when they are used for something they are not really made for, we could see issues come up. Maybe we can say the same thing for a measurement error that would be more obvious, such as trying to measure an AC voltage with a DC meter.
I think the problem originates from when AC meters were first made. Before we had digital meters or true RMS meters they all read an average value and then used a correction factor to be able to display the right value. The assumption was that you would be measuring an AC voltage that was a regular sine wave. A lot of digital meters still do it that way too, except for the true RMS ones. They all have a frequency limit though and most of the cheaper ones only work for 50, 60, and maybe 400Hz and maybe up to 1000Hz, but after that the response falls off and they are no longer reliable. An expensive meter can go up higher like 100kHz, but technology is always improving in this area so we may see better meters as time goes on.

 

V(out), AC part of V(out) and DC part of V(out) on diagram:

 

V(out), AC part of V(out) and DC part of V(out) on diagram:

Thank you, exactly what I was trying to say but could not make my case.

 

Hello,
Falstad is one of the worst simulators.
Better use LTspice as many other users here are using.

Bertus

Yes and no. Maybe he doesn't know it exist. Visualization of things happening helps a lot.
Not for serious design, yeah, but it's easier to see voltages and currents than rely on putting probes on nodes and keeping track of which node is which.

 

it's easier to see voltages and currents than rely on putting probes on nodes and keeping track of which node is which.

That's easy in LTspice if you give the nodes logical names.

I find the Falstad interface to draw circuits rather awkward and non-intuitive, but perhaps that's just because I'm used to using LTspice.

 

Hi,

Yes, maybe that exemplifies the idea that some meters read differently than others when some are not used for the right measurements.

I guess we have this expectation that all meters should read alike, but when they are used for something they are not really made for, we could see issues come up. Maybe we can say the same thing for a measurement error that would be more obvious, such as trying to measure an AC voltage with a DC meter.
I think the problem originates from when AC meters were first made. Before we had digital meters or true RMS meters they all read an average value and then used a correction factor to be able to display the right value. The assumption was that you would be measuring an AC voltage that was a regular sine wave. A lot of digital meters still do it that way too, except for the true RMS ones. They all have a frequency limit though and most of the cheaper ones only work for 50, 60, and maybe 400Hz and maybe up to 1000Hz, but after that the response falls off and they are no longer reliable. An expensive meter can go up higher like 100kHz, but technology is always improving in this area so we may see better meters as time goes on.

An "expensive meter" could be a cheap digital oscilloscope, which many simple ones calculate the RMS voltage of such high frequency waves. I'm not sure about they do with high frequency content on top of low frequency wave, eg., what a cheap oscilloscope would read of a 100 Hz sinusoid being amplitude modulated by the carrier of 100 kHz. But that's another topic of discussion. For pretty much all cases, it works.

 

That's easy in LTspice if you give the nodes logical names.

I find the Falstad interface to draw circuits rather awkward and non-intuitive, but perhaps that's just because I'm used to using LTspice.

I'm pretty sure you are used to LTspice. It's been a long time I don't need to test something there, so then I would find it awkawrd.

 

Falstadt is like training wheels on a kid’s bicycle. It helps the beginner to become comfortable on a bike, but eventually one has to go to the next level.

 

An "expensive meter" could be a cheap digital oscilloscope, which many simple ones calculate the RMS voltage of such high frequency waves. I'm not sure about they do with high frequency content on top of low frequency wave, eg., what a cheap oscilloscope would read of a 100 Hz sinusoid being amplitude modulated by the carrier of 100 kHz. But that's another topic of discussion. For pretty much all cases, it works.

Hi,

Yeah sure, you could use a scope, even a cheaper one. It's just that some people already have some test equipment that may include a more high-end digital meter. I happen to have a very high end meter myself I got several years ago that reads a lot of things my $30 USD meters or even my $100 USD meter can't read. I don't use it as much as I thought I would however because super accurate measurements are not very often needed