Scullcom Hobby Electronics #40 - Design & Build a Low Current Reference
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- Опубліковано 22 лип 2024
- 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... - Наука та технологія
You are a very good teacher Scullcom Hobby Electronics. Thumbs up.
Thank you.
Another great project Lewis. Thanks
+Eric Gee Thanks Eric. I have a number of other projects and ideas in mind and just need time to do them all!!
another great little project, Thanks!
+Simon Donnellan Thank you.
Nice little project . Thanks for sharing .Cheers
+fpvrcstuff Thanks.
Another excellent build and very well described. Many thanks.
+Mark Garth Thanks Mark.
Once again, a great video. Kind Regards Bob
+Bob Mellor Thanks Bob.
I just found this channel and I love it!
Thank you for the educational videos! :)
+ACPCalin You are welcome.
Very nice. Puts a big smile on my face, so simple and yet very innovative. Love it
+Wim Huyghe Thanks.
Great idea, quick and straightforward solution. I also like your way of presenting, keep it up!
+Breadboarding Thank you.
Hi Louis...i've built my own one...many thanks...regards.
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!
+MrMonomonster Thanks for your comments.
Relays was one of the things that occurred to me too, when I was looking at that switching...
Your videos are great thanks very much, please keep making these.
+Yee Boi Thanks.
I'm happy I found your Channel!
New subscriber!
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.
+Markus Herrmann Glad to hear you find them helpful, thanks.
double thumbs up!!
Brilliant Thank you
+Nut Lock Thanks.
Nice project, thanks. Also it'll be nice to see your review on the uni-t. Thanks again.
+.rpv Thanks. The Uni-T meter could be a review but I see other people have already done some reviews on this meter.
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
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+Mark Beeunas Thanks Mark.
Great... 1*10^Infinity thumbs up Louis...
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.
Thanks for your kind comments. I hope to upload a new project shortly.
Now I know what I'll do with that switch ;) Well done.
+Digger D Thanks. Glad to hear !! :-)
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.
+David Watts Glad you enjoyed. I have been following your 3D printer projects with interest.
+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 :)
Nice project. thanks.
Thanks.
Thanks Sir .. very intersiting project
+Qamar Kilani Glad to hear, thanks.
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
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
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.
+WaveShapePlay Thanks for your comments.
As always I am glad to give you a thumbs up. Great job. Keep up the nice work. :-)
+Christian Christiansen Thanks nice to hear.
Very nice project for us tight budject builders...
+Jurva-Markus Vehasmaa Thanks and enjoy :-)
Great video, clearly explained! Subscribed :)
+Ben Adamson Many thanks.
+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/
+Ben Adamson Thanks Ben for the info and link.
Something else usefull to build, and a great lesson to boot Well done and Thanks.
Brian
G0WZB
+Brian Burdis Thanks Brian.
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
+Asniex Asniex Thanks for your comments and suggestion.
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.
+Robert Calk Jr. Thanks Robert. Yes the UT139C is a great little multimeter for the hobbyist and low cost to.
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.
+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.
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 ;)
+Isidoro Maich Thanks for your comments.
Very good!!
+Rob H Thank you.
Marsterful presenttation landing up with a handy little tool thanks
Thank you.
I wish to have this in the mA range.
I would like to see a video on the Uni T meter :) Great video btw
+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.
Another great project :) Would be great to hear your thoughts on the UNI-T meter.
+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.
I'm sure, most of us would definitely give you tens of thumbs-up for each of your video, only if UA-cam allowed it!
Great job, as usual!
You really need to start considering renaming your enterprise to Scullcom Precision Instruments :))
+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.
+Scullcom Hobby Electronics that's what I'm most interested in: small projects that I can. Learn from
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!
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
very interesting chip that ref200
+Eduardo J R Yes the IC is very versatile and I have played around with it in other circuits.
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.
+Weistek Engineering video blog i just actually saw your new site link in an old video..
+Weistek Engineering video blog Thanks. I will look at doing something on my website www.scullcom.uk This website is still work in progress.
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!
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?
+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.
@@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.
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.
+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
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.
+nikomo Yes nice little multimeter for the price.
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
+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:
ua-cam.com/video/EXTRKXhvBJU/v-deo.html
+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
If possible i would give you 10 tumbs up!!!!
+GADELHAS82 Thanks now I have a red face :-)
Brill
+Hans See Thanks.
Not seen any posts for a while, Hope you are ok
+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.
+Scullcom Hobby Electronics
Good to hear your just busy. Look forward to your next project. And Family/Work comes first.
Missing new videos! :-(
+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.
Family and Work First!!!! No problem!!! Post when is possible to you! Thanks
You should set up a Patreon account.
+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.
Hi: Can you 'gang' a couple together and make a 100, 200, . . . 700, 800 µA source?
Cheers, Mark
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+Mark Beeunas Yes you can.