ARTA/LIMP free software for LCR measurements with sound card - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: January 07, 2020, 03:09:26 pm
content: Hihttp://www.artalabs.hr/index.htmIs it ok?

author: JohnG
author_rank: Frequent Contributor
timestamp: January 07, 2020, 06:24:32 pm
content: I used this software quite a bit when I was more involved in audio and some related stuff (> 5 years ago). At the time, it had a lot more capability than I would ever use, but I still found it easy to use. I see it has been recently updated.I used it primarily for speaker measurements (characterization), some amplifier measurement, some signal source characterization, etc. Depending on what you are doing, you will need to have a good soundcard, microphone(s), and will probably need to build some test jigs if you want to do some speaker measurements.Excellent and thorough documentations with lots of theory and examples. If you are interested in acoustic measurements, I highly recommend downloading the documentation.Since I purchased this for my last job, I paid for the commercial license, and it was well worth it to me.John

author: 001
author_rank: Super Contributor
timestamp: January 07, 2020, 07:42:01 pm
content: I`m not audio man but I`m interested in coil measurments for SMPS. Is it good idea to use LIMP?

author: _Wim_
author_rank: Super Contributor
timestamp: January 07, 2020, 07:57:12 pm
content: Yes, you can use limp for that. It has an LCR function. You only need to wire in a series resistor from which you know the exact resistance. You can use the free download, only difference is the measurements cannot be stored.The same measurement principle is used by the Analog Discovery LCR module. It is not extremely accurate, but for sure good enough for your purpose.

author: JohnG
author_rank: Frequent Contributor
timestamp: January 08, 2020, 03:52:57 pm
content: The frequency range will be limited if you are looking at inductance for SMPS. Some of the more interesting stuff, e.g self-resonance, will probably occur out of the range of LIMP.John

author: DaJMasta
author_rank: Super Contributor
timestamp: January 08, 2020, 04:06:35 pm
content: Quote from: JohnG on January 08, 2020, 03:52:57 pmAnd if the software doesn't actually limit frequency range, the audio card hardware would. Switchers are commonly at frequencies above audio band, so anything filtering to keep high frequency noise out of audio equipment will remove measurement capability in that range. There are some sound cards that don't or which leave some ultrasonic range in, though, so it may be worth looking through the documentation for a frequency limit.

author: _Wim_
author_rank: Super Contributor
timestamp: January 08, 2020, 05:48:46 pm
content: Many modern sound cards support high sample rates (up to 192kHz), and limp does not limit the sample rate, so up to 96kHz is possible.But indeed an impedance analyser or something like the analog discovery can go much higher in frequency. But as a cheap alternative for an LCR meter which typically also stops at 100kHz, I think this is still an ok solution.For frequencies above 50kHz a NanoVNA could be used (up to 900Mhz)

author: 001
author_rank: Super Contributor
timestamp: January 08, 2020, 05:50:03 pm
content: Quote from: DaJMasta on January 08, 2020, 04:06:35 pmYea. It is dumb idea. Sorry

author: Frex
author_rank: Regular Contributor
timestamp: January 09, 2020, 05:35:00 am
content: Hello,Maybe the right intermediate between a soundcard and a VNA would be the AnalogDicovery.I allow to trace Bode diagram and Impedance analyser between DC to 10MHz.I used it to calibrate resonating inductive position sensor (~3MHz), i think it's an idela tool for SMPS design.RegardsFrex

author: 001
author_rank: Super Contributor
timestamp: January 10, 2020, 02:56:08 pm
content: Quote from: Frex on January 09, 2020, 05:35:00 amIt is about $300 so I`m going with my oldtimer bridge

author: SilverSolder
author_rank: Super Contributor
timestamp: January 10, 2020, 03:28:31 pm
content: Quote from: 001 on January 10, 2020, 02:56:08 pmThe Analog Discovery software actually works with a sound card... it is free to try.

author: 001
author_rank: Super Contributor
timestamp: January 10, 2020, 05:48:24 pm
content: Quote from: SilverSolder on January 10, 2020, 03:28:31 pmHow to do it?

author: SilverSolder
author_rank: Super Contributor
timestamp: January 10, 2020, 06:40:51 pm
content: Quote from: 001 on January 10, 2020, 05:48:24 pm1. Download the WaveForms software and install.2. Select "Sound Card" in the device manager in WaveForms (the one already in your PC will likely work fine)3. Strip down an audio cable to be able to connect the sound card input/output to your experiment4. Knock yourself out... most features work.The big limitation with using a sound card instead of the Analog Discovery hardware is that the sample rate is a lot lower with a sound card, so it is really only good for audio frequencies (perhaps a bit higher than that if you have a higher end sound card with high sample rates).Another thing is - make SURE you don't apply any external voltages into your sound card, that could be an expensive mistake. Passive component testing only!

author: _Wim_
author_rank: Super Contributor
timestamp: January 10, 2020, 08:44:29 pm
content: Quote from: 001 on January 10, 2020, 02:56:08 pmThe nano VNA can be had for only <40$, and together with the lastest Nano-saver app (https://github.com/mihtjel/nanovna-saver/releases/tag/v0.2.1) you can plot L an C curves untill 900Mhz. Only starts at from 50kHz however.

author: _Wim_
author_rank: Super Contributor
timestamp: January 10, 2020, 08:47:35 pm
content: Current features of the Nano-Saver software (seehttps://github.com/mihtjel/nanovna-saver):Reading data from a NanoVNASplitting a frequency range into multiple segments to increase resolution (tried up to >10k points)Averaging data for better results particularly at higher frequenciesDisplaying data on multiple chart types, such as Smith, LogMag, Phase and VSWR-charts, for both S11 and S21Displaying markers, and the impedance, VSWR, Q, equivalent capacitance/inductance etc. at these locationsDisplaying customizable frequency bands as reference, for example amateur radio bandsExporting and importing 1-port and 2-port Touchstone filesTDR function (measurement of cable length) - including impedance displayFilter analysis functions for low-pass, high-pass, band-pass and band-stop filtersDisplay of both an active and a reference traceLive updates of data from the NanoVNA, including for multi-segment sweepsIn-application calibration, including compensation for non-ideal calibration standardsCustomizable display options, including "dark mode"Exporting images of plotted values

author: _Wim_
author_rank: Super Contributor
timestamp: January 10, 2020, 08:53:24 pm
content: Or if you have any of these scopes (shameless plug)https://www.eevblog.com/forum/testgear/rlc-impedance-viewer-for-picoscope-bode-plot-data/msg2190516/#msg2190516

author: DaJMasta
author_rank: Super Contributor
timestamp: January 10, 2020, 11:57:43 pm
content: Quote from: 001 on January 08, 2020, 05:50:03 pmNot all of them do, I've heard the older Creative EMU series don't, and I think the QA401 is limited, but a bit above the audio band. It's not that the idea can't work, it's that it would be easy for some hardware to prevent it from working, so you have to choose carefully.