Scullcom Hobby Electronics #40 - Design & Build a Low Current Reference

Ғылым және технология

In this project we will design and built a Low Current Reference Source which has four switched ranges, namely; 100μA, 200μA, 300μA and 400μA. No calibration is required and it will operate from a standard 9 volt battery with no on/off switch. The unit will have an accuracy of ±0.5% or better.
From the links below you can download the schematic, wiring diagram and front panel artwork for this project.
www.scullcom.com/Low_Current_R...
www.scullcom.com/Low_Current_R...
www.scullcom.com/Low_Current_R...

Пікірлер: 111

  • @oetken007
    @oetken0076 жыл бұрын

    You are a very good teacher Scullcom Hobby Electronics. Thumbs up.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thank you.

  • @ericgee6585
    @ericgee65858 жыл бұрын

    Another great project Lewis. Thanks

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Eric Gee Thanks Eric. I have a number of other projects and ideas in mind and just need time to do them all!!

  • @MrMonomonster
    @MrMonomonster8 жыл бұрын

    The funny thing is that I have the REF200 on the way because I want to build a variable current source / sink using the IC + a very good quality opamp and precision resistors! I have the wiring done exactly as you did, however I am using relays in order to automate the operation of the device. As always - very nice and clear video! A joy to watch!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +MrMonomonster Thanks for your comments.

  • @Roy_Tellason

    @Roy_Tellason

    4 жыл бұрын

    Relays was one of the things that occurred to me too, when I was looking at that switching...

  • @wim2874
    @wim28748 жыл бұрын

    Very nice. Puts a big smile on my face, so simple and yet very innovative. Love it

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Wim Huyghe Thanks.

  • @MarkGarth
    @MarkGarth8 жыл бұрын

    Another excellent build and very well described. Many thanks.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Mark Garth Thanks Mark.

  • @no1spod
    @no1spod8 жыл бұрын

    another great little project, Thanks!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Simon Donnellan Thank you.

  • @BreadboardingDe
    @BreadboardingDe8 жыл бұрын

    Great idea, quick and straightforward solution. I also like your way of presenting, keep it up!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Breadboarding Thank you.

  • @ACPCalin
    @ACPCalin8 жыл бұрын

    I just found this channel and I love it! Thank you for the educational videos! :)

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +ACPCalin You are welcome.

  • @fpvrcstuff
    @fpvrcstuff8 жыл бұрын

    Nice little project . Thanks for sharing .Cheers

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +fpvrcstuff Thanks.

  • @wither8
    @wither88 жыл бұрын

    As usual, good sir, your attention to detail is fantastic. You can tell by the attention to detail (say, in your resistor alignments uniformly positioned, so reading codes is easy) that you've been doing this quite a while and mastered the craft. Your explanations about your thought process is clear for us hobbyists to understand (teaching us in the process). The block diagrams are better on your white board than most computer laid out products. My only complaint is, gosh, I'd love more (but I understand that for each minute of content you make, it must take 10x more in planning, filming, editing, etc). Alan (W2AEW), Sharhiar (The Signal Path), Paul (Mr Carlsons Lab) and your channels make me want to do EE for a living ! I can't wait to see what you come up with next.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    Thanks for your kind comments. I hope to upload a new project shortly.

  • @BobMellor1954
    @BobMellor19548 жыл бұрын

    Once again, a great video. Kind Regards Bob

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Bob Mellor Thanks Bob.

  • @markusherrmann9681
    @markusherrmann96818 жыл бұрын

    Wow, your projects are so useful and very good explained. I learn so much from you and it makes a lot of fun to build the things. Thank´s for your hard work an sharing.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Markus Herrmann Glad to hear you find them helpful, thanks.

  • @yeeboi5545
    @yeeboi55458 жыл бұрын

    Your videos are great thanks very much, please keep making these.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Yee Boi Thanks.

  • @markbell9742
    @markbell97428 жыл бұрын

    GREAT 'thumbnail' project. I just ordered the parts from Digi-Key and will build it not so much that I need it, but to honor your thoughtful presentation and efforts. Cheers, Mark **************************************

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Mark Beeunas Thanks Mark.

  • @MarcoFranceschini1971
    @MarcoFranceschini19715 жыл бұрын

    Hi Louis...i've built my own one...many thanks...regards.

  • @ronniepirtlejr2606
    @ronniepirtlejr26064 жыл бұрын

    I'm happy I found your Channel! New subscriber!

  • @DavidWatts
    @DavidWatts8 жыл бұрын

    I am never going to be this good at electronics, I might as well just hang up my test probes now. Great video mate, really enjoyed it.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +David Watts Glad you enjoyed. I have been following your 3D printer projects with interest.

  • @asniexasniex3571

    @asniexasniex3571

    8 жыл бұрын

    +Scullcom Hobby Electronics Get a prusa i3 full metal kit. You wont regret it sir. Been printing for quite a few years with mine. I made the enclosure for your freq gen with lettering on the front :) it would greatly help you with your projects :)

  • @rubenuspv
    @rubenuspv8 жыл бұрын

    Nice project, thanks. Also it'll be nice to see your review on the uni-t. Thanks again.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +.rpv Thanks. The Uni-T meter could be a review but I see other people have already done some reviews on this meter.

  • @nutlock2857
    @nutlock28578 жыл бұрын

    double thumbs up!! Brilliant Thank you

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Nut Lock Thanks.

  • @WaveShapePlay
    @WaveShapePlay8 жыл бұрын

    A nice touch to your video is drawings on the white board. You are good with a straight edge! Overall high quality content thanks for this video.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +WaveShapePlay Thanks for your comments.

  • @karlfell3768
    @karlfell37687 жыл бұрын

    I have now watched nearly all of your many videos, what an education it has been. Very well presented and with just enough detail so as not to be daunting or confusing to the average builder. Have you ever thought about building a AC voltage reference to go along with all your other fantastic designs? Keep up the good work. Karl

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    7 жыл бұрын

    Hi Karl, Thanks for your kind comments. Good suggestion about an AC voltage reference which I will have a look at for a future project. Currently working on Part 3 of the Electronic DC Load Project. Regards, Louis

  • @DeeegerD
    @DeeegerD8 жыл бұрын

    Now I know what I'll do with that switch ;) Well done.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Digger D Thanks. Glad to hear !! :-)

  • @MarcoFranceschini1971
    @MarcoFranceschini19716 жыл бұрын

    Great... 1*10^Infinity thumbs up Louis...

  • @andyclark2331
    @andyclark23317 жыл бұрын

    Nice project. thanks.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    7 жыл бұрын

    Thanks.

  • @robertcalkjr.8325
    @robertcalkjr.83258 жыл бұрын

    Thanks Louis. Nice little project. I have one of the UT 139C DMM's myself. It's a nice little meter for the price. Mine outputs 1.005V on the continuity tester, which could probably be used for a quick little 1V reference source.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Robert Calk Jr. Thanks Robert. Yes the UT139C is a great little multimeter for the hobbyist and low cost to.

  • @phantom349uj

    @phantom349uj

    8 жыл бұрын

    I think brymen is the oem Uni-T(as well as greenlee, amprobe, and some others) . Their website is straight out of 1995, but they are in my opinion the best bang for the buck.

  • @robertcalkjr.8325

    @robertcalkjr.8325

    8 жыл бұрын

    +Terry Myers My Brymen 869s is my favorite DMM. Though I'll admit that I'm not sure how much I can trust it yet. So anytime I deal with mains power, I use my Fluke 87V.

  • @asniexasniex3571
    @asniexasniex35718 жыл бұрын

    Wow ! just wow ! So simple and elegant. Cant wrap my mind around how simple this was. Mind = Blown. Bunch of wires and an IC for an ultra precise reference lol . Really appreciate your videos. I have been following all of your projects closely. And I am gonna build every single one of them. I have completed the frequency generator which was the cheapest of the bunch. Sadly I live where I cant really get genuine parts for the right price and some project cost a lot than I could afford now, so i have been saving for the parts and its worth every bit of penny :) Really appreciate your content good sir. Keep it going. Next a power supply project please : 30.000v 5.000A would be awesome

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Asniex Asniex Thanks for your comments and suggestion.

  • @G0WZB
    @G0WZB8 жыл бұрын

    Something else usefull to build, and a great lesson to boot Well done and Thanks. Brian G0WZB

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Brian Burdis Thanks Brian.

  • @cccyberfamilydk
    @cccyberfamilydk8 жыл бұрын

    As always I am glad to give you a thumbs up. Great job. Keep up the nice work. :-)

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Christian Christiansen Thanks nice to hear.

  • @qamarkilani551
    @qamarkilani5518 жыл бұрын

    Thanks Sir .. very intersiting project

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Qamar Kilani Glad to hear, thanks.

  • @vehasmaa
    @vehasmaa8 жыл бұрын

    Very nice project for us tight budject builders...

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Jurva-Markus Vehasmaa Thanks and enjoy :-)

  • @IceQubed
    @IceQubed8 жыл бұрын

    Great video, clearly explained! Subscribed :)

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Ben Adamson Many thanks.

  • @IceQubed

    @IceQubed

    8 жыл бұрын

    +Scullcom Hobby Electronics By the way, this video has been mentioned on reddit.com - here's the comments www.reddit.com/r/electronics/comments/4cq3gd/scullcom_hobby_electronics_40_design_build_a_low/

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Ben Adamson Thanks Ben for the info and link.

  • @PY4SR
    @PY4SR8 жыл бұрын

    Very good!!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Rob H Thank you.

  • @isidoromaich7226
    @isidoromaich72268 жыл бұрын

    Well done! I'm building all your devices because are very helpful and cheap, including if we compare with well known second hand units from eBay, yours are cheaper and probably have similar if not better specs. I will build this one also and saving some money just in case you come with an electronic load ;)

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Isidoro Maich Thanks for your comments.

  • @greenman2262
    @greenman22626 жыл бұрын

    Marsterful presenttation landing up with a handy little tool thanks

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    6 жыл бұрын

    Thank you.

  • @valordk
    @valordk8 жыл бұрын

    I'm sure, most of us would definitely give you tens of thumbs-up for each of your video, only if KZread allowed it! Great job, as usual! You really need to start considering renaming your enterprise to Scullcom Precision Instruments :))

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +valordk Thanks. Not sure about the "Precision" bit, but I do my best. My aim is to come up with useful and low cost projects for the hobbyist.

  • @phantom349uj

    @phantom349uj

    8 жыл бұрын

    +Scullcom Hobby Electronics that's what I'm most interested in: small projects that I can. Learn from

  • @NearFarMedia
    @NearFarMedia8 жыл бұрын

    Another great project :) Would be great to hear your thoughts on the UNI-T meter.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +NearFarMedia Thanks. I have looked at a few multimeters with the hobbyist in mind and I might do a short video on the ones I have tested.

  • @Blaff3tuur
    @Blaff3tuur8 жыл бұрын

    I would like to see a video on the Uni T meter :) Great video btw

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Blaff3tuur Thanks for your comment. I might just do that. I have been looking at a number of multimeters which are suitable for the hobbyist that are low cost but good value for the money. May be an idea to do a video show what I tested and my recommendation.

  • @pulesjet
    @pulesjet5 жыл бұрын

    I wish to have this in the mA range.

  • @Edu_RJR
    @Edu_RJR8 жыл бұрын

    very interesting chip that ref200

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Eduardo J R Yes the IC is very versatile and I have played around with it in other circuits.

  • @OCybress
    @OCybress8 жыл бұрын

    looking forward to this one, Is there any chance to get maybe a dedicated page for your project files? might make it easier to find stuff from your previous projects.

  • @OCybress

    @OCybress

    8 жыл бұрын

    +Weistek Engineering video blog i just actually saw your new site link in an old video..

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Weistek Engineering video blog Thanks. I will look at doing something on my website www.scullcom.uk This website is still work in progress.

  • @wither8

    @wither8

    8 жыл бұрын

    Tip: Read www.wordtracker.com/academy/content/wordpress/seo-wordpress-mistakes to get more traffic. A few plugins (Yoast is GREAT) and you can increase your traffic drastically! I don't like "social media" but "share" widgets + posting to will help increase traffic if you'd like. PM me if you want some help with a few tips!

  • @FlyingShotsman
    @FlyingShotsman8 жыл бұрын

    Nice little project, Louis. I like the construction method; it reminds me of an old Heathkit analog multimeter that I built in my youth. It had dozens of components soldered between lugs on a big multi-pole rotary switch. Will we see the reason you needed to build this?

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +FlyingShotsman Thanks for your comments. I had a number of reasons for building this project. One was to do with matching a group of low value resistors. Another was as a source for a circuit which can give Nano Amps and Pico Amps reference source. It is also useful for checking multimeter current range calibration. I have a number of other uses which I may cover later.

  • @Roy_Tellason

    @Roy_Tellason

    4 жыл бұрын

    @@scullcomhobbyelectronics1702 I too would be interested in hearing more about this. My reaction on seeing what it was and what it did was along the lines of "Neat gadget, but what's it good for?" Especially when your specifications at the beginning of the video are that precise.

  • @zx8401ztv
    @zx8401ztv8 жыл бұрын

    Im supprised how good that is, so the chip has two constant current generators, accurate ones at that :-D Im not sure that i would ever need a uA range on a basic multimeter, mA is more my cup of tea, most of the things i repair are so crude that the uA range would be redundant. Is there such a chip that can provide constant current at higher levels? Nice little project though :-D :-D

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +zx8401ztv Sorry for delay in answering but for some reason google put your message in the spam folder - strange !! I have been using this Low Current Reference to precisely match some resistors. The LT3092 provides higher currents - I did an earlier video with the LT3092 and had two switched outputs or 1mA and 10mA - the link to this video is below: kzread.info/dash/bejne/d4yItK2RmNmoerg.html

  • @zx8401ztv

    @zx8401ztv

    8 жыл бұрын

    +Scullcom Hobby Electronics Oh im sorry, it seems my memory is playing up, i saw my comment on that video nearly a year ago, i need a new brain lol :-D Its possible that someone dislikes me and marks my comment as spam, dont worry :-D

  • @GADELHAS82
    @GADELHAS828 жыл бұрын

    If possible i would give you 10 tumbs up!!!!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +GADELHAS82 Thanks now I have a red face :-)

  • @peterfielden-weston7560
    @peterfielden-weston75608 жыл бұрын

    Very nice & simple project. Just the sort I like. :) Please could you include a Bill of Materials, and sources, with your project. I've just spent more time hunting down a pointer knob for the rotary switch, than I did watching the video. I tried to go to www.scullcom.com, but keep geting some comic & artwork site.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Peter Fielden-Weston Thanks. The comic and artwork is the work of my youngest son David. You can check out my other electronics website which is still work in progress at the following link www.scullcom.uk

  • @GeorgeGraves
    @GeorgeGraves8 жыл бұрын

    Does anyone have a part number for a switch they like? I could only really find one on mouser, and didn't see any part numbers in the documentation. Thanks!

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    Hi George, I used a Lorlin CK rotary switches (Mfr. Part No. CK1031). I purchased it from Radio Spares. Checkout the link below for full details: uk.rs-online.com/web/p/rotary-switches/0320691/ Also it is available from Mouser: www.mouser.co.uk/ProductDetail/Lorlin/CK1031/?qs=%2fha2pyFaduhnUOhbpoX3ZtFQoy%2fpFNukhOt8iLr3t54%3d Also from Farnells (Element14) uk.farnell.com/lorlin/ck1031/switch-3pole-4pos-0-15a-250v-solder/dp/1123707?ost=CK1031&selectedCategoryId=&categoryNameResp=All%2BCategories&searchView=table&iscrfnonsku=false Regards, Louis

  • @nikomo
    @nikomo8 жыл бұрын

    Same multimeter as I have! The NCV functionality really speeds up finding out what breaker got triggered by the idiots next to you, this time.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +nikomo Yes nice little multimeter for the price.

  • @G0WZB
    @G0WZB8 жыл бұрын

    Not seen any posts for a while, Hope you are ok

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Brian Burdis Hi Brian, Thanks for your message. Over the last few weeks I have been very busy with other work and family commitments, so had no spare time to spend on electronics and You Tube. I should be able to post a new video soon.

  • @G0WZB

    @G0WZB

    8 жыл бұрын

    +Scullcom Hobby Electronics Good to hear your just busy. Look forward to your next project. And Family/Work comes first.

  • @hanssee3677
    @hanssee36778 жыл бұрын

    Brill

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Hans See Thanks.

  • @GADELHAS82
    @GADELHAS828 жыл бұрын

    Missing new videos! :-(

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +GADELHAS82 Sorry for the delay in posting new videos. This has been due to other work and family commitments over the last few weeks. I hope to post a new video project soon.

  • @GADELHAS82

    @GADELHAS82

    8 жыл бұрын

    Family and Work First!!!! No problem!!! Post when is possible to you! Thanks

  • @Gooberslot
    @Gooberslot8 жыл бұрын

    You should set up a Patreon account.

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Gooberslot Thanks for the info Interesting suggestion was not aware of this. But I have not been doing this to make any money. I like to share the fun of electronics with others.

  • @markbell9742
    @markbell97428 жыл бұрын

    Hi: Can you 'gang' a couple together and make a 100, 200, . . . 700, 800 µA source? Cheers, Mark *****************************

  • @scullcomhobbyelectronics1702

    @scullcomhobbyelectronics1702

    8 жыл бұрын

    +Mark Beeunas Yes you can.

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