Scullcom Hobby Electronics #53 - DC Voltage Calibrator Part 1

Ғылым және технология

In this project we will design and build a DC Voltage Calibrator, providing a voltage range from 0 to 10 volts in 1 milli volt steps. The user interface will be a TFT display with touchscreen.
Below are links to version 1 of the software for the Arduino Nano. Also a zip file which contains the schematic, PCB artwork (Version 2) and component layout:
www.scullcom.com/DC_Voltage_Ca...
www.scullcom.com/DC_Voltage_Ca...
Parts List link below:
www.scullcom.com/DC_Voltage_Ca...
Below is a link to my KiCad files for this project:
www.scullcom.com/DC_Voltage_Ca...

Пікірлер: 283

  • @basildouglas855
    @basildouglas8555 жыл бұрын

    An exceptionally well presented project. Bundles of information and zero guess work required. Brilliant!

  • @williamna5800
    @williamna58006 жыл бұрын

    Welcome back! Great to see you're back in the saddle, and new projects coming along. This just made my day!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Hi William, Glad to hear it :-). Nice to be back. Regards, Louis

  • @isidoromaich7226
    @isidoromaich72266 жыл бұрын

    It great to have you again doing videos... I think you gave us some time to finish the past projects :)

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks. Its nice to get back to electronics and a new project. I need to get back in to the swing of things again. Regards, Louis

  • @guilldea
    @guilldea2 жыл бұрын

    Amazing, this is exactly what I used looking for to expand my electronics knoweledge, a thoroughly explained design process and process

  • @Moonbrony
    @Moonbrony6 жыл бұрын

    Glad to see you back again. Great little unit, worth the wait for this one.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks nice to be back. Regards Louis

  • @tonysfun
    @tonysfun5 жыл бұрын

    We all miss you! Hope you'll get more time for your hobby! God luck and wish you lots of health and no more problems!

  • @IanScottJohnston
    @IanScottJohnston6 жыл бұрын

    Love the calibrator project, I can see this one being built by lots of folks. Well done.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Ian. Its not quite up to the standard of your unit but it may prove adequate for the hobbyist. All the best Louis

  • @valakatz3967
    @valakatz39673 жыл бұрын

    Nice to see you back, great project and thank you.

  • @markj3851
    @markj38513 жыл бұрын

    Louis- We love your videos and hope you are well. Looking forward to some future updates and wish you the very best!

  • @techtalkmike4968
    @techtalkmike49686 жыл бұрын

    Good to see back in the lab Louis. This will be an outstanding project to build from start to finish. Thank you.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Mike. Hope to get Part 2 filmed soon. Regards, Louis

  • @TheKetsa
    @TheKetsa6 жыл бұрын

    Good to see you back. Thanks for the great projects !

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks for you kind comment. Regards, Louis

  • @recolaq
    @recolaq6 жыл бұрын

    Thanks again for another awesome opportunity to learn electronics. Opposed to all the other channels trying to explain how the components work, your channel shows what you can with it. This triggers me to dive deeper in to the nitty gritty of electronics. Thanks again

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks for your comments. Glad to hear you find it helpful. Regards, Louis

  • @tonybell1597
    @tonybell15976 жыл бұрын

    Welcome back! Nice project!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Tony. Regards Louis

  • @jameshauser1507
    @jameshauser15076 жыл бұрын

    WOW Louis, that was a long recess from Scullcom School of Electronics. But, family does come first. I think I can speak for all that we missed you so much. Yes we missed the projects and the videos---but the real truth is we missed YOU. It is so good to see you again. We love you buddy. Have a Merry Christmas and a Happy New Year. I am not sure how you come up with these ideas for projects but I like your way of thinking. Take care Louis. God bless you.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks James. Very nice of you to say. Have a great Christmas :-) Regards, Louis

  • @qsptecnologia
    @qsptecnologia6 жыл бұрын

    It's great to see you again. I will follow this other project. Thanks a lot to share your acknowledge

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks for your comment. Regards, Louis

  • @Gooberslot
    @Gooberslot6 жыл бұрын

    Woohoo! A Scullcom video in my subscriptions? Christmas has come early. Glad to see you haven't abandoned making videos.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks. Have a good Christmas. Regards, Louis

  • @frandavies944
    @frandavies9446 жыл бұрын

    Great return project! Looking forward to Part 2, including how to calibrate the calibrator and exploring future options.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks. I will be working on Part 2 in the next days. Regards, Louis

  • @paulcollins664
    @paulcollins6646 жыл бұрын

    I'm skipping a couple of past projects for the moment to get to this one, I'm having to build a much more compact workshop, where I'm building almost all home made equipment,because I enjoy the building, I've wanted one of these for sometime, thank you Louis you certainly have your finger on the pulse,I love these projects featuring TFT, screens, and the fact your using normal size parts, the nano and tft are quickly becoming the hobbyists and radio amateurs friend. 73 Paul M0BSW

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Hi Paul, Looks like you are going to be busy. This is the first time I have done a project using a TFT touchscreen so it is also a learning process for me to. All the best, regards Louis

  • @paulcollins664

    @paulcollins664

    6 жыл бұрын

    ~Hello Louis, I like to keep the grey matter busy,, plus I'm learning something everyday,TFT & Oled are very interesting devices although Oled screens of a decent usable size, are still a bit expensive in my view.

  • @vernonbosshard9317
    @vernonbosshard9317 Жыл бұрын

    I think your projects are the better ones to build, they seem to be very accurate and well designed. I had no idea all this stuff was available, I graduated tech school in 2000 and kind of dropped out of the scene for a while. No I wasn't in prison, worse, I lived with my ex. AKA wicked witch of the west

  • @esnam6557
    @esnam65576 жыл бұрын

    Very nice project. Thanks you very much for sharing all the details with us. Looking forward for part 2.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks for your comment. Regards, Louis

  • @PeterRidge
    @PeterRidge6 жыл бұрын

    Good to have you back with new vids, Louis. Looking forward to the next part.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Peter. Regards, Louis

  • @kaumohlamonyane272
    @kaumohlamonyane2726 жыл бұрын

    Amazing engineer, amazing indeed👌

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thank you :)

  • @renelefebvre53
    @renelefebvre536 жыл бұрын

    Great work and very good description . Bravo à vous monsieur !

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thank Rene, much appreciated. Regards, Louis

  • @timothysvec8568
    @timothysvec85686 жыл бұрын

    Sir, your voice was just made for explanation of projects. Thank you for explaining things, in a way that I totally understand.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Timothy for you nice comment. Regards, Louis

  • @mrtom64
    @mrtom646 жыл бұрын

    Excellent! Your projects just keep getting better. Thank-you for the time and effort you put into your videos, it must be heart-breaking to have to eventually wipe off those white-board diagrams....they are very much appreciated.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Tom, Yes it is a shame when I have to wipe off some of my drawings. But I hope they help with the explanations :) Regards, Louis

  • @psilin9473
    @psilin94736 жыл бұрын

    Very glad you’re back. Another great learning project! Good explaination also. Thumbs up!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thank you :-)

  • @MaddMart
    @MaddMart6 жыл бұрын

    Glad you're back with another great little project. Something to get my teeth into over the Christmas holidays :-)

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks for the comment. Hope to get Part 2 of this project done before Christmas. Regards, Louis

  • @rolanddietrich5776
    @rolanddietrich57766 жыл бұрын

    great to have you back

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Roland, nice to be back. Regards, Louis

  • @MarcoFranceschini1971
    @MarcoFranceschini19714 жыл бұрын

    Amazing design Louis...

  • @berniken6511
    @berniken65116 жыл бұрын

    Hi Louis, very nice project and good to see you back. its obvious to see the work that has gone into the project..............thank you.................................................Berni

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Hi Berni, Thought I would try something different. First project with a touchscreen. We learn as we progress :) Regards, Louis

  • @no1spod
    @no1spod6 жыл бұрын

    Glad to see you back! thanks for another great project.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Simon.

  • @klcbsoft
    @klcbsoft6 жыл бұрын

    Most excellent presentation of a great project, especially the schematics - jawdroppingly awesome. Thanks for sharing your knowledge.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Glad you enjoyed it. Regards, Louis

  • @SpeccyMan
    @SpeccyMan6 жыл бұрын

    Nice to see yet another great project. I'll take quality over quantity with your videos every time, Louis.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Nick. I do spend a fare amount of time in preparing for my projects so it can take longer than doing reviews. I also spend time on editing my videos down to a maximum of about 45 minutes which also takes longer, especially deciding what to leave in and what to take out. Anyway just hope I get the balance right. Regards, Louis.

  • @MrOrangeman18
    @MrOrangeman186 жыл бұрын

    Can’t wait for part 2 of this. Keep up the good work 👍🏼

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks.

  • @engineeringadventures1229
    @engineeringadventures12296 жыл бұрын

    Great work man! I respect the time and effort you put in minute details like detailed schematic drawn on white board. I loved it all. I am also working on a similar project and would like to show you once completed. Thanks a lot, keep it up.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks for your comments, much appreciated. Regards, Louis

  • @cccyberfamilydk
    @cccyberfamilydk6 жыл бұрын

    Nice to have you back. And as usual a great video.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Christian. Regards, Louis

  • @jix177
    @jix1776 жыл бұрын

    Nice project, great to see you back.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks.

  • @looxylook825
    @looxylook8256 жыл бұрын

    Thank you verry much for all the effort put in your projects and videos. Learn a lot every time.

  • @looxylook825

    @looxylook825

    6 жыл бұрын

    Just one idea, in terms of signal to noise ratio - isn' it better to do the higher gain in the first stage (2x 1x instead of 1x 2x) ?

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks this may be an option which could be done in software. I will have a look at noise in Part 2 of this project. Regards, Louis

  • @akhurash
    @akhurash6 жыл бұрын

    Awesome project. You have great projects and such good details!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks. Regards, Louis

  • @kgsalvage6306
    @kgsalvage63063 жыл бұрын

    Very nice project. I like the touch screen with the audrino. I haven't got into using them. I have just been sticking to repairs. Might have to build some projects and utilize a touch screen interface. I liked your electronic load also. 👍

  • @kostasb8883
    @kostasb88836 жыл бұрын

    I love your videos. Learn a lot every time. Thank you!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Kostas.

  • @craxd1
    @craxd1 Жыл бұрын

    When calibrating a source, I was taught about using the first digit and decimal in lower digit numbered meters to gain a digit at the end. For example, when setting a 10 volt standard, you would adjust it to 9.9999 on a 4 1/2 digit DMM, so the digits shift between 9.9999 and 10.000, which will get you closer to a reading of a 5 1/2 digit DMM at 9.99999. This would apply to a 5 1/2 to 6 1/2 digit DMM as well, and even a 7 1/2 digit. Essentially, you're fishing for that last unseen nine and splitting hairs.

  • @FantaBH
    @FantaBH6 жыл бұрын

    Great video , well done explained . Thank you for your effort in making this project.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks, Your welcome. Regards, Louis

  • @TheFunkman
    @TheFunkman5 жыл бұрын

    I sure hope to see more great videos soon Louis. Hope you are well.

  • @bostedtap8399
    @bostedtap83996 жыл бұрын

    Excellent project and presentation.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks.

  • @MauroSedrani
    @MauroSedrani6 жыл бұрын

    Welcome back! Great work!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Mauro, Nice to be back in my electronics workshop working on a new project. Regards, Louis

  • @brucefox6580
    @brucefox65806 жыл бұрын

    Hi Louis, Thank you once again for a great project. Bruce.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Bruce.

  • @shaggygangst
    @shaggygangst6 жыл бұрын

    it's great to have you again doing videos. i was very excited when i saw the notification from youtube

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks. Managed to get back in my electronics work shed. Regards, Louis

  • @electro3976
    @electro39766 жыл бұрын

    As always extremely educational and expertly explained, wonderful stuff. Keep them coming.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks.

  • @electro3976

    @electro3976

    6 жыл бұрын

    Sharing your expert knowledge and encouraging the hobby engineer is wonderful. Without doubt the most educational and matter of fact electronics design engineer on here.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks for your kind comment, much appreciated. Regards, Louis

  • @irawarnaca8133
    @irawarnaca81336 жыл бұрын

    Great video! You did an amazing job on everything, thank you.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Glad you enjoyed. Regards, Louis

  • @iuri.castro
    @iuri.castro6 жыл бұрын

    Its nice to see you're back!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Nice to be back doing electronics. Cheers, Louis

  • @craigs5212
    @craigs52126 жыл бұрын

    Nice project, board looks really great. One thing to consider is the ~30 ohm Drain-Source ON resistance of the DG303, it's a little high to use in the output circuit without upset to the calibration for differing load conditions without feedback compensation. One also has to watch the switch's leakage current as well. The switches are most likely ok in in the gain stage however I didn't check the gain sensitivity for the ON resistance vs the 25K internal op-amp resistors. Consider running the entire DAC/Op-amp chain for a fixed 10V output then use the analog switch to make a .5X ref voltage for the DAC for the low voltage range. Any switch error can be calibrated out with an adjustment resistor on the the reference and the reference .5 divider. Thanks for the video, I need to make one of these some day.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Graig for your comments. With regards the 30 ohm on resistance of the analog switch at the output. This should only be an issue once you start drawing say the higher or maximum current of this unit at about 30mA. But if the unit is used for checking the calibration of test equipment than I think it should not cause any real problems. That said, we could improve the accuracy at the higher currents by replacing the DG303B (U6) with a MAX4622 (but twice as costly) which has an ON resistance of only 3 ohm, but I would also have to alter the print layout on the PCB to match the changes in IC pin connections (maybe an option for another version of this project). Another option could be to use the existing analog output switch to control a small reed relay. Your second point is also interesting but the current DAC (MCP4922) I am using has a maximum supply voltage is only 5.5V. Regards, Louis

  • @anjayv8347
    @anjayv83476 жыл бұрын

    can't wait for the second part ! great video ! i learned a lot , thank you !

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Anjay. Hope to start work on part 2 soon. Regards, Louis

  • @tubeDude48
    @tubeDude482 жыл бұрын

    Very nice project.

  • @Yuehanlad
    @Yuehanlad6 жыл бұрын

    glad to here you call it an electronics workshop, I don't get why so many people on youtube call it a Lab

  • @Jackdantte
    @Jackdantte6 жыл бұрын

    Fresh content , nice video .... Thanks for that pasion you are the man

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks.

  • @ernestb.2377
    @ernestb.2377 Жыл бұрын

    Interesting watch. Quick to part 2 as during the video I was curious what the overall accuracy and stability would be...

  • @samuellourenco1050
    @samuellourenco10506 жыл бұрын

    Nicely drawn schematic!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks.

  • @GADELHAS82
    @GADELHAS826 жыл бұрын

    The return of the master

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks :-)

  • @aleneme
    @aleneme6 жыл бұрын

    Thank you sir for your time and the great video.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Alexandre.

  • @sanosanbaby
    @sanosanbaby5 жыл бұрын

    Awesome as usual!

  • @jcddcjjcdnz
    @jcddcjjcdnz6 жыл бұрын

    Wonderful presentation.Thanks.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks John.

  • @tommyh4049
    @tommyh40496 жыл бұрын

    Thank goodness you have this info posted I have been racking my brain for days trying to build schematic for same project. Biggest difference in mine is substituting adc to 22bit mcp3551 which may be overkill but fun to think of resolution in 6 digit ranges.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Hi Tommy, Glad to hear you found it helpful. You mentioned the MCP3551 which is an ADC, but for this project you would need to use a DAC. Regards, Louis

  • @tommyh4049

    @tommyh4049

    6 жыл бұрын

    Scullcom Hobby Electronics my mistake, I'm trying to build more of a self calibrating type bench multimeter/power supply to clear up any confusion. It's a rabbit hole for sure. It seems that your circuit would make it easy to make an add-on board to make this work especially since you have 2 voltage references to compare against and extra unused pins. I will try to get some simulation data when I get a chance to try this. Thanks.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    OK I understand now. All the best with your project. Regards, Louis

  • @subigirlawd_7307
    @subigirlawd_73076 жыл бұрын

    This is so awesome ❤ Thank you so much for making this educational video...

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thank you. Regards, Louis

  • @konicekj1
    @konicekj16 жыл бұрын

    thank you for another great educative video

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Jaroslav much appreciated. Regards, Louis

  • @manelsoria2403
    @manelsoria24036 жыл бұрын

    Well done !!! Congratulations and thanks !!!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Manel.

  • @wolfgangschweiger9557
    @wolfgangschweiger95576 жыл бұрын

    At the moment, I'm working hard on your DCLoad project and some modifications of mine. And now, you push the next out - I'm on hurry, on christmas time I don't leave the lab...;-) Nice and many thx!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Wolfgang. Looks like you are going to be busy over Christmas :-) Regards, Louis

  • @wolfgangschweiger9557

    @wolfgangschweiger9557

    6 жыл бұрын

    Ohhh yeah!

  • @Flip-Flop-Rio
    @Flip-Flop-Rio6 жыл бұрын

    Great project, my friend! As always your channel is 10. I always follow your videos! I already gave my like! Michel Rio de Janeiro - Brazil

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Michel, Glad you enjoy. Regards, Louis

  • @EdwinFairchild
    @EdwinFairchild3 жыл бұрын

    this gentleman is a genius

  • @samhsavdr9647
    @samhsavdr96476 жыл бұрын

    Great master again perfect job

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks ;-)

  • @electronic7979
    @electronic79796 жыл бұрын

    Excellent project

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks.

  • @MeiklesAndDimes
    @MeiklesAndDimes6 жыл бұрын

    Great video!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Brandon.

  • @jerkovicbrate
    @jerkovicbrate6 жыл бұрын

    Thanks for free knowledge.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Miloš.

  • @johnconrad5487
    @johnconrad54876 жыл бұрын

    That's very very good. the whole design is great! thanks for sharing. u got it. thumbs up and subscribe.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks John.

  • @Atteluxy
    @Atteluxy6 жыл бұрын

    Really good Explanation with those Drawings! please keep your good work up;)

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks.

  • @jlegen
    @jlegen6 жыл бұрын

    thanks for sharing this great project! perhaps just a tiny simplification - if the touch controller is a xpt2046, no level shifting is needed at least for the touch connections. the xpt is rated for 2.7-5v according to data sheet...

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks. Yes the TFT uses does use the XPT2046 touch screen controller. Thanks for the information. Regards, Louis

  • @tsmupdatertsm7633
    @tsmupdatertsm76336 жыл бұрын

    24:44 I think you did a lot of work to draw this diagramm. Great Job!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks. Yes it did take me some time to draw. Regards, Louis

  • @avejst
    @avejst6 жыл бұрын

    Thanks for sharing 😀👍

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Your welcome.

  • @MarcoFranceschini1971
    @MarcoFranceschini19716 жыл бұрын

    Very very very brilliant...

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Marco.

  • @TheDefpom
    @TheDefpom6 жыл бұрын

    Very nice project, you could use the 2nd dac to trim the op amp divider voltage to give smaller than mV steps.... I think you could take it down to uV levels. I did a video of my repairs to a Fluke 343A DC calibrator on my channel earlier in the year, and am in the process of a video series repairing a Fluke 5200A AC calibrator, some might find it interesting.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks for your comments. I am some upgrades planned for later. Thanks for the tip on your Fluke 343A DC calibrator. Regards, Louis

  • @rustyrebar9647
    @rustyrebar96475 жыл бұрын

    A dual tracking regulator might be necessary to preserve the dc accuracy of the opamps!

  • @RonaldWijermars-rohmega
    @RonaldWijermars-rohmega6 жыл бұрын

    Fantastic video once again. Your videos really help to make circuit design more accessible for beginners like me. I did notice that your tft refresh rate is very low. Have you considered trying the STM32F103C8T6 boards? The difference in speed is quite big, there is a comparison video between the stm32 and the arduino nano using a ILI9341 display, it really is night and day. Not to mention they can be bought for as little as $1.72 and have some other upgraded features as well.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Ronald for your comment. Thanks for bringing my attention to the STM32 board. I have not used this type of board yet but it looks very interesting and as you say the cost is very low. There must be a way of adding that type of board to the Arduino IDE software which would make life easy when programming. Regards, Louis

  • @alx_256
    @alx_2566 жыл бұрын

    Very nice video. In Part 2 it would be interesting to see what happens at the switching borders (4.000V / 4.001V and 8.000V / 8.001V ). It might turn out that 4.000V will measure more than 4.001V.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Alex for your comment. I will have a closer look at those crossover points and try and remember to show it in Part 3. Regards, Louis

  • @ivolol
    @ivolol Жыл бұрын

    The MAX6(2/3)41 are actually a trade-off. The temperature coefficient isn't long term, reference drift is. the MAX63NN has roughly half the typical temperature coefficient - 0.5ppm, of the MAX62NN's - 1ppm typical. However the MAX62NN lists its long term drift spec at only 20ppm/1000 hours, beating the '63 at 30ppm/1000hours; I believe this is where their numbering scheme comes from but I could be wrong. So it's basically a trade off if you want the tightest short-term tempco, or the lowest possible long-term drift.

  • @amberchaboya9051
    @amberchaboya90516 жыл бұрын

    Very nice, ty.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks.

  • @BeetleJuice1980
    @BeetleJuice19806 жыл бұрын

    always happy to have you back with amazing projects !! sorry about the stupid question , but how can an arduino nano handle over 5volts?

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks. The Arduino does not handle over 5V it only operates from 5V or 3.3V supply. We use the software code programmed in the Arduino to do the calculations and output a digital representation of that information on the SPI bus to feed both the TFT display and the 12 Bit DAC. It is the DAC that generates the actual voltage output in our case up to 4.096V and it is the other two OP Amps (their gain controlled by the Arduino and the CMOS anaolg switch IC) which use a higher supply voltage of ±15V to generate an output voltage up to 10V. Regards, Louis

  • @TrickyNekro
    @TrickyNekro6 жыл бұрын

    Great video! Thank you very much! I would have gone with some things different but that would be more for effect :-P For example, I would have gone with a flyback for example for the -/+15V rails, can be implemented with something as easy to get as MC34063 maybe another more modern IC but still with trafo, it can take a wider input range, make it easy for battery conversion. Would have gone also probably for another implementation to get also negative voltages, cause why not. Could also have gone with a MOSFET reverse input protection and combine it with a soft power button. Still, the idea is pretty cool! Thanks for that!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Hi, Thanks for your comments. It is interesting you mentioned the MC34063 as I am using that IC on a new Function Generator project I am currently working on as my next You Tube video project. Regards, Louis

  • @RobB_VK6ES
    @RobB_VK6ES6 жыл бұрын

    Welcome back with another outstanding presentation and explanation Louis. What is the bottleneck with display refresh? the SPI bus or the AT Mega 328? Perhaps one of the STM 32 F1 "Blue Pill" kind of sort of Arduino compatible boards might be faster. Dirt cheap on Ebay

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Hi Rob, Thanks, The problem is the screen refresh rate for the TFT. I am currently using the Adafruit library which may not be the fastest. I believe someone may have modified this library for a faster screen refresh rate, so I will have a look for it. I have tried in the software to only write to the TFT if something changes, this helps. Hopefully this is something that we can improve as the project progresses. Regards, Louis

  • @leonerduk
    @leonerduk6 жыл бұрын

    One very easy thing you can do is link both DAC channels with, say, a 1000:1 divider on one of them giving it the ability to "nudge" the output a little way. Between them they then act as a coarse/fine adjustment pair, greatly increasing the set resolution and possibly allowing you a digit or two more on your setting, if you calibrate it well enough

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Paul for the comment. I did have in mind something similar but I am also looking at some other uses for the second DAC. I will try and cover it in Part 2 of this project. Regards, Louis

  • @qzorn4440
    @qzorn44402 жыл бұрын

    wow, what would be cool is to place the 6.5 digit multimeter and the calibrator both in the same instrument enclosure 🤔 like the Ronan X86 with 2 input & 2 output leads 🤩thanks 💒

  • @johndavis1465
    @johndavis14656 жыл бұрын

    you need to put a series resistor on the ouput to limit the current in case of a s/cregards john

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks John for your comment. I believe the INA105 OP Amp I use already has Output Short Circuit protection built-in, like many OP Amps these days. According to the datasheet it states that the "Output Short Circuit to Common is Continuous". Regards, Louis

  • @ufohunter3688
    @ufohunter36886 жыл бұрын

    Another superb project by the master... One must be able to adjust the 4096 volt-ref with a meter like yours. Otherwise, it might not have the accuracy of 1mV, but it will surely have 1mV resolution. That'd reason alone to send it off for calibration, if you don't have the means to calibrate to 1mV. Figure-1 on page 3 of the DG303B shows how clever the switch is! I wonder how much noise these other ICs introduce into the static generated voltage by the voltage reference IC? Would one be able to connect a 1:1 push-pull audio amp to use as an output driver for a programmable power supply capable of 1Amp output?

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks for the comments. I will look at some easy ways for the hobbyist to calibrate this unit in Part 2. I will also be looking at overall performance and noise. We could use some of the techniques I use in this project with a programmable power supply, may be another project later. Regards, Louis

  • @ufohunter3688

    @ufohunter3688

    6 жыл бұрын

    The circuit is flexible and accurate enough to have both in one! With the right output driver that won't load the ref part, but could deliver 0-12V at 1Amp. Maybe a JFET OP amp as a voltage follower + a current driver. Or even use the second DAC. One thing though, what will happen in a case of a sweep say from 2V to 10V? Since it switches between 2 ranges, will it not cut power (brake before make) for a few uS, where the interruption is small enough that the inline caps would pickup the slack?

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Interesting idea. The break before make should not cause any issues as the time involved is only 50 nano seconds.

  • @rjordans

    @rjordans

    6 жыл бұрын

    You could add an LT3080 to drive larger loads, up to 1.1A and the voltage can be set by applying the right output voltage level directly to the control pin

  • @Graham1904
    @Graham19044 жыл бұрын

    Surely the 7912 is a negative 12Vdc regulator not a negative 15Vdc one?

  • @tonyperry6702
    @tonyperry67026 жыл бұрын

    Amazing

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks.

  • @karlD1963
    @karlD19635 жыл бұрын

    Given you can only multiply by 2 or 4, how do you get, say, 9.7V?

  • @mikaras
    @mikaras6 жыл бұрын

    Nice project.. I'm really impressed with the whiteboard schematics, It must have taken a bit of effort? :-)

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Mikael. Regards, Louis

  • @cmuller1441
    @cmuller14416 жыл бұрын

    Nice to see new videos. I would power the dcdc from 18v to avoid polluting the 15v with some switching noise. Also do the 2x first and the 1x next for 4V to 8v. Also why stopping at 4V? Why don't you go to 4.095v before the x2?

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks for your comment. Yes I agree about feeding the negative DC to DC converter IC direct to the 18V input supply. I did hint at that in my video and will have a look at that in part 2. With regards the 2x first and 1x next for the 4V to 8V range, I did try that originally in my testing with the software but found for some reason it worked better the other way - I will have a further look at that. Regards, Louis

  • @freda5344
    @freda53446 жыл бұрын

    what a great project. lots of expensive components tho. Just thinking if you get a single more expensive component - DAC, say 18bit, and less precise other components, analog switches already introduce a problem anyway. Then use software to calibrate away the errors. Major drawback, you need access to something to calibrate against, $$

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thanks Fred. Yes agree some of the parts are a little costly. In Part 3, I may make some changes to help with calibration. Regards, Louis

  • @thecombatengineer7069
    @thecombatengineer70696 жыл бұрын

    Christmas came early!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Merry Christmas, have a good one :) Regards, Louis

  • @thecombatengineer7069

    @thecombatengineer7069

    6 жыл бұрын

    You as well. Many thank you's!

  • @stoptheirlies
    @stoptheirlies9 ай бұрын

    So you have minus 15 from the charge pump feeding a minus 15 volt regulator? so how can it regulate with no voltage to work with? you need about 3 volts across it for it to regulate

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