I don't think I know what I'm doing most of the time🤪

It's this one: github.com/c-lan/low-temf-scanner

Haha, thankfully this project is meant to be DC only, anything that involves AC is orders of magnitude more complicated to design and evaluate😄

For sure! He takes you by the hand and reveals all of his secrets so you can learn too😄

Also: subbed.

Could say the same when I destroyed an LM399 by connecting it the wrong way because I didn't pay attention to the pin number marking🤪 That was 2022, maybe I am more careful now...?

Thanks! When I started narrating my videos back in 2018, Marco Reps was my 'idol', so maybe I finally succeeded in my goal for this channel!?😵‍💫

Definitely Marco Reps inspired! :) but he also is original on his presentation format, some other channels try to be an exact copy of famous channels, mostly Great Scott's one.

@@tiagoferreira086 Somehow, even if you try to copy someone else's presentation style, you end up adding your own 'uniqueness' to it, so it ends up being somewhat original😄

I took a look at the amplifier...I daresay it's ever so slightly overpriced😅 I wasn't able to find a schematic for the power supply section after a quick googling though, do you think you could point me in the right direction? I'm quite curious to take a look. With that being said, I think a 78xx regulator is plenty good for my purposes.

@@NNNILabs Just use "Dartzeel" and look at images, keep scrolling down, maybe add "schematic" and try again, when i posted this comment i found it again in less than 4 minutes, otherwise change to other search engine. This amp is build on real 24 carat gold. This schematic shows how clean, filter before the rectifier, like EMC filter, i did some FFT in Ltspice. you can't do better.

@@NNNILabs Dartzeel + schematic under images, it will pop up somewhere.

Ironically it was Reps himself who helped me characterize the DAC😆

I have a similar aversion to plots generated by stuff like matplotlib, so I think I will stick to Excel🤪 Otherwise I'm glad you enjoyed the video!

Pyqtgraph is here for you. Or good old octave

@@NNNILabs Pyqtgraph and good old Octave will always have your back mate ;)

Thanks!

Thank you! Hope you enjoyed watching!

Thanks, glad you liked it!

That's a good idea! I guess you could get an idea of drift by getting a second opinion...kinda beats the point of having a standalone calibrator, but I guess when you get down to the sub-ppm level you really need the help🤔

☠

Am I cutting into your profit margins too much? ⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⡿⠟⠛⠛⠛⠋⠉⠉⠉⠉⠉⠉⠉⠉⠉⠉⠉⠉⠉⠙⠛⠛⠛⠿⠻⠿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣿⣿⡿⠋⠀⠀⠀⠀⠀⡀⠠⠤⠒⢂⣉⣉⣉⣑⣒⣒⠒⠒⠒⠒⠒⠒⠒⠀⠀⠐⠒⠚⠻⠿⠿⣿⣿⣿⣿⣿⣿⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣿⠏⠀⠀⠀⠀⡠⠔⠉⣀⠔⠒⠉⣀⣀⠀⠀⠀⣀⡀⠈⠉⠑⠒⠒⠒⠒⠒⠈⠉⠉⠉⠁⠂⠀⠈⠙⢿⣿⣿⣿⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⠇⠀⠀⠀⠔⠁⠠⠖⠡⠔⠊⠀⠀⠀⠀⠀⠀⠀⠐⡄⠀⠀⠀⠀⠀⠀⡄⠀⠀⠀⠀⠉⠲⢄⠀⠀⠀⠈⣿⣿⣿⣿⣿ ⣿⣿⣿⣿⣿⣿⠋⠀⠀⠀⠀⠀⠀⠀⠊⠀⢀⣀⣤⣤⣤⣤⣀⠀⠀⠀⢸⠀⠀⠀⠀⠀⠜⠀⠀⠀⠀⣀⡀⠀⠈⠃⠀⠀⠀⠸⣿⣿⣿⣿ ⣿⣿⣿⣿⡿⠥⠐⠂⠀⠀⠀⠀⡄⠀⠰⢺⣿⣿⣿⣿⣿⣟⠀⠈⠐⢤⠀⠀⠀⠀⠀⠀⢀⣠⣶⣾⣯⠀⠀⠉⠂⠀⠠⠤⢄⣀⠙⢿⣿⣿ ⣿⡿⠋⠡⠐⠈⣉⠭⠤⠤⢄⡀⠈⠀⠈⠁⠉⠁⡠⠀⠀⠀⠉⠐⠠⠔⠀⠀⠀⠀⠀⠲⣿⠿⠛⠛⠓⠒⠂⠀⠀⠀⠀⠀⠀⠠⡉⢢⠙⣿ ⣿⠀⢀⠁⠀⠊⠀⠀⠀⠀⠀⠈⠁⠒⠂⠀⠒⠊⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡇⠀⠀⠀⠀⠀⢀⣀⡠⠔⠒⠒⠂⠀⠈⠀⡇⣿ ⣿⠀⢸⠀⠀⠀⢀⣀⡠⠋⠓⠤⣀⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠄⠀⠀⠀⠀⠀⠀⠈⠢⠤⡀⠀⠀⠀⠀⠀⠀⢠⠀⠀⠀⡠⠀⡇⣿ ⣿⡀⠘⠀⠀⠀⠀⠀⠘⡄⠀⠀⠀⠈⠑⡦⢄⣀⠀⠀⠐⠒⠁⢸⠀⠀⠠⠒⠄⠀⠀⠀⠀⠀⢀⠇⠀⣀⡀⠀⠀⢀⢾⡆⠀⠈⡀⠎⣸⣿ ⣿⣿⣄⡈⠢⠀⠀⠀⠀⠘⣶⣄⡀⠀⠀⡇⠀⠀⠈⠉⠒⠢⡤⣀⡀⠀⠀⠀⠀⠀⠐⠦⠤⠒⠁⠀⠀⠀⠀⣀⢴⠁⠀⢷⠀⠀⠀⢰⣿⣿ ⣿⣿⣿⣿⣇⠂⠀⠀⠀⠀⠈⢂⠀⠈⠹⡧⣀⠀⠀⠀⠀⠀⡇⠀⠀⠉⠉⠉⢱⠒⠒⠒⠒⢖⠒⠒⠂⠙⠏⠀⠘⡀⠀⢸⠀⠀⠀⣿⣿⣿ ⣿⣿⣿⣿⣿⣧⠀⠀⠀⠀⠀⠀⠑⠄⠰⠀⠀⠁⠐⠲⣤⣴⣄⡀⠀⠀⠀⠀⢸⠀⠀⠀⠀⢸⠀⠀⠀⠀⢠⠀⣠⣷⣶⣿⠀⠀⢰⣿⣿⣿ ⣿⣿⣿⣿⣿⣿⣧⠀⠀⠀⠀⠀⠀⠀⠁⢀⠀⠀⠀⠀⠀⡙⠋⠙⠓⠲⢤⣤⣷⣤⣤⣤⣤⣾⣦⣤⣤⣶⣿⣿⣿⣿⡟⢹⠀⠀⢸⣿⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣧⡀⠀⠀⠀⠀⠀⠀⠀⠑⠀⢄⠀⡰⠁⠀⠀⠀⠀⠀⠈⠉⠁⠈⠉⠻⠋⠉⠛⢛⠉⠉⢹⠁⢀⢇⠎⠀⠀⢸⣿⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣿⣿⣦⣀⠈⠢⢄⡉⠂⠄⡀⠀⠈⠒⠢⠄⠀⢀⣀⣀⣰⠀⠀⠀⠀⠀⠀⠀⠀⡀⠀⢀⣎⠀⠼⠊⠀⠀⠀⠘⣿⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷⣄⡀⠉⠢⢄⡈⠑⠢⢄⡀⠀⠀⠀⠀⠀⠀⠉⠉⠉⠉⠉⠉⠉⠉⠉⠉⠁⠀⠀⢀⠀⠀⠀⠀⠀⢻⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷⣦⣀⡈⠑⠢⢄⡀⠈⠑⠒⠤⠄⣀⣀⠀⠉⠉⠉⠉⠀⠀⠀⣀⡀⠤⠂⠁⠀⢀⠆⠀⠀⢸⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷⣦⣄⡀⠁⠉⠒⠂⠤⠤⣀⣀⣉⡉⠉⠉⠉⠉⢀⣀⣀⡠⠤⠒⠈⠀⠀⠀⠀⣸⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷⣶⣤⣄⣀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣰⣿⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣶⣶⣶⣶⣤⣤⣤⣤⣀⣀⣤⣤⣤⣶⣾⣿⣿⣿⣿⣿

You'll have to thank ADI for doing all the hard work on the DAC, I just followed the instructions in the datasheet😅 PWM DACs are actually used in all the highest-end calibrators, and a friend of mine recently designed one that achieved ±0.1ppm INL...I hope I'll get a chance to feature it in a later DAC video. Regarding the RP2040 PWM - I've put some thought into this as well, it's not just PWM resolution, but there are other factors like jitter that can influence INL. Combining two 16-bit PWM channels to get 32 bits is also something I've considered, but of course, there's some nuance to that, for example the resistors you use to combine the PWM channels need to be very well matched. Of course, the workaround to that is having a few bits overlap so you can do some kind of gain calibration to line up the two channels (misalignment might influence INL again!). Jim Williams did something similar in AN-86 by combining two 16-bit DACs with 4 bit overlap to get a 24-bit DAC. Yet another thing to consider is ripple, you'd need a very good filter that is also DC accurate to achieve sub-LSB ripple. So many things to think about...enough yapping! The Jim Williams ADC is definitely something I'm looking forward to showcase. Spoiler alert - I was able to achieve single-digit ppm INL (±10V range)!

how about: pro pico

There was a certain Pro Pico video that I collaborated on recently 😉

Indeed, I wish I could get the focus right, plus I need to take it apart and fix some of the crusty switches...not that much of a repair person 😅

@@NNNILabs Ah, yeah, especially if it's the drum switches. I haven't found the focus on these to be super super sharp; some kind of trade-off for bandwidth I guess. I might have to steal that technique for improving INL ;)

@@fletcherreder6091 Feel free to do so! Just make sure that whatever you are calibrating can hold that INL😅

You can get in touch on Discord, same tag

It's been a while since I made this video (and I have to say, in retrospect, I'm not particularly proud of it) 😅 I don't remember exactly what I did, but I think the device had a third terminal you could attach to your body which reduced noise noticeably.

The User's Manual is your best friend: download.tek.com/manual/2000-900_J-Aug2010_User.pdf Section 5-3 has everything you need

Thanks! I'm glad you like what I'm doing!

@@NNNILabs I came across your video when researching the Multislope II technique used in the HP3456A multimeter Im trying to troubleshoot. Do you know of any good resources to understamd at least the multislope technique? The service manual has a helpful explanation but it's not meant to be a textbook, just help along the troubleshooting. Many thanks :)

@@guilldea I am not very familiar with Multislope II, but if you want some general reading about Multislope III (which should be somewhat similar?), then the go-to resource would be the April 1989 edition of HP Journal: xdevs.com/doc/HP_Agilent_Keysight/journals/1989-04_HP3458A.pdf Alternatively, you can try simulating the circuit in Falstad, I spent hours playing around with it, which helped me develop some kind of intuition as to how it works: tinyurl.com/2a656hby

@@NNNILabs Very good advice man, thank you so much!

💀

Oops! Will try to fix it next time.

Sounds like an interesting experience! And yes, I can understand the feeling of leaving your lab behind...

Thanks! Looks like channeling my frustration with the customs into a funny intro worked!

Thanks! Glad to see someone is still interested in these things in 2023! This project is not dead, it's just that I've faced a lot of difficulties with it and have been bogged down with a million other things, but I do have a lot of updates here: hackaday.io/project/190528/logs?sort=oldest Hopefully after I finish the other stuff I will get back to this project.

You can build the same circuit, but instead of using a know capacitance, you can replace it with a known inductance. A display will require some kind of programmable device, if not a huge bunch of logic.

Thanks! Sadly couldn't use it with my computer

I've actually found that the exact behaviour is somewhat different for different parts, so it's always worth testing.

@@NNNILabs Ok, thanks! I will build a test circuit and give it a try.

Nice idea with the copper braid, I have a bunch laying around that I don't know what to do with and now I know! Thanks!

I mention in one of my more recent videos about why the flyback topology is more suited to capacitor charging.

Thanks for the comment, this video is five years old now but I appreciate the feedback 😅

@@NNNILabs came across it yesterday

try replacing the batteries or check for a broken connection

true that

Hello, 1. Most ICs do have some headroom above and below the max. supply range since datasheets are very conservative, but I still wouldn't recommend running it at the limit since any noise or spikes on the switching supply might damage the chip. And yeah, using an SMPS is perfectly fine. Most large-sized SMPS-es come with a trim potentiometer, so maybe you can trim the output voltage down to a reasonable value like 22V if possible. 2. The datasheet value for RDCM looks to be fixed based on internal biasing considerations, so 43K should work just fine. I would recommend Coilcraft transformers since they have a decent catalog and you can also get free samples by contacting their sales rep in India. Also, another recommendation would be to download the LTspice simulation of the LT3750 circuit available on the AD website and playing around with transformer values till you figure out something that works for you. And yet another recommendation would be to check out the LT3751, a fancier version of the LT3750 that's designed to take a little more power, one useful feature being differential shunt sensing. If you want any more help I'll be glad to do so, you can contact me on Twitter or Discord.

@NNNI Thanks for the very useful information, friend. I want to use MEANWELL SMPS, which definitely has a trim pot. I appreciate your advice 😊, I will simulate the circuit in Spice, and after successful results, I will proceed. I think it will be useful to take a look at LT3751, thanks again, and if I got confused I will contact you again 🙏🙏🌹

​@@miladchalipa2002 I'm glad I was able to help you! For some reason this chip gets so little attention that I always enjoy discussions with someone else wanting to apply it.

Yeah it should work.

Hello again, I built your design and it worked very well for my laser, thank you, unfortunately for my project I decided that I needed 8 high brightness LED diodes instead of the laser, each one has a working current of 20 mA and a voltage requirement of 3.5-4V. Can I still use your circuit design to power them? I tried it in parallel and they all worked but with a very diminished brightness. As I understand, if I connect them in series the current would be the same flowing through all of them but would I need a bigger voltage source or the 9v are still good? Would you recommend any other changes to the components or design in order for this to work? Sorry to bother you, I hope you can guide me a bit. Thanks for your knowledge.

​@@NNNILabs I tried to power the LEDs in series but it only worked for two of the eight. As soon as I put three they wouldn't power on at all.

@@mauiztic The driver as it is has a fixed output current and limited compliance voltage. Connecting all the diodes in parallel will divide the output current between the diodes, so that explains why they are so dim. And as for connecting them in series, the limited compliance voltage could only handle the forward voltage drop of two diodes. I would recommend making one driver for each diode.