How To Drive A 7-segment Display - The Learning Circuit

Karen walks through how to use one type of decoder in a circuit, a BCD to 7-segment. While this circuit would typically use a microcontroller to provide the four necessary input signals, Karen’s circuit uses 4 switches to allow the user to manually input the BCD number. This circuit is helpful for practicing counting in binary as well as learning how to drive a 7-segment display.
This circuit uses a common-anode 7-segment LED display that is driven by an SN74LS47N decoder. If you would like to create a circuit using a common-cathode LED display, a 74LS48 decoder could be used and the power would need to be flipped
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[@klinkclang]

I'm taking a lab for a class I haven't taken in two years and this was a great review of all the concepts needed to understand this project. Fantastic job!

[@mircoblitz6780]

Not all of my electroniks skills are lectured by Karen, but now I understand al lot more. This is an awesome learning experience.

[@jeetenderkakkar7570]

Not all

[@raimondsandze2239]

Nice video. I would like to see more in depth videos related to 7segment displays, like for example when would you choose Common Anode and when Common Cathode?

[@adminwintrec2768]

Clear & to the point presentation. Can be recommended for academic

[@donaldklopper]

Perfect video for my needs to learn to create 7 segment visuals using arduino etc. Thanks.

[@burhanuddinbhiwaniwala618]

U know mam electronics simply goes above my head... But still your videos are so simple and understanding that I never ever have skipped your video...😊😊😊

[@vihaandixit6965]

Very well explained and exactly what I needed 👏😊

[@charlesbrown980]

Built the circuit and it works perfectly, nothing like " hands on " to reinforce the learning process.

[@maker_karen1785]

That's awesome!

[@jeopardy60611]

I searched this out because I was curious as to how a numerical display works. This explains it well. I suppose that if you added logic to the decoder, you could make it a hex display that would output the hex digits A-F, since we have 4 bits available that can count that high. Also, by adding additional LED segments and more input bits, you can do a display that does letters like a Speak & Spell.

[@bald_engineer]

3:07 Yay! Karen mentioned current limiting resistors!

[@DerRindenmulchficker]

@@electromagic3111 but he stayed silent

[@shvideo1]

Excellent video, very well explained. Thank you for sharing your knowledge.

[@kahnfatman]

Thank you! You've got a new sub!

[@MrCardeso]

Thanks, Karen!

[@jeetenderkakkar7570]

Thanks

[@gurjantsingh6647]

Good knowledge

[@rohanverma6058]

Great work Karren, thanks for the help.

[@masoudjvn355]

Wouldn't it be better to use resistors in the positive route?

[@renantejosesiguiente1442]

Wow, a lady like u is cool learning about electronics

[@sciencespectrum3855]

Amazing explanation 👏👏👏🎉🎉

[@jonathangainsford6811]

I like these videos a lot I am new to this but can thus not be done with a shift register, with less pins and putting them in serial you can add more segments

[@knifeninja200000]

Ive tried making this chip in a simulator with minimal experience in the field and after seeing what the diagram looks like I'm not surprised at how bad I failed.

[@iamthekittycat]

Ahh, snapping things off of snap circuits! Snappy!

[@GurinderSingh]

How can I use 7 segment ds for my four relay rf switch 433 module if I press 1 relay I see 1 on segment display then 2 ……

[@jeremyjohansson3445]

Thank you, exactly what i needed!

[@onurolce]

day by day you became more impressive Karen :)

[@shaoxiongduan]

5:26 I'm subbing.

[@scientifiko4246]

Very well explained. Do you have a video on 7448?

[@mrdarbab]

multisim logic decoder sure helps with truth tables i find.

[@jhunbanerjee3175]

Thanks Karen, it's hard to find actually helpful information from loads of other bullshit in here... Great video and thanks for it.

[@jeetenderkakkar7570]

Thanks

[@alibehrouz9833]

nice job that's useful

[@americanrebel413]

Cool, thanks!

[@gsdtdeaux7]

Im wanting to make this but instead of the individual switches i want to use a 5 position switch and the display to read 1-5. Any help would be appreciated. Thanks for this video

[@PankajYadav-hr8tp]

Hi....awesome video....please try op amp in digital circuits next time

[@3dkenn]

If it's a common anode 7 segment display, to light a segment would require a '0' to its cathode. Is the invert done in the 74LS47 BCD decoder?

[@joeljuarez3789]

how would you hook it up to output certain minterms?

[@azenkwed]

Well done.

[@willi4242]

Great Job! Hope you get a lot of people into soldering their own projects =:-) Keep up!

[@MuhammadIkram-kk4hl]

Great video

[@HazeAnderson]

Awesome project!

[@yafetabera3106]

Please can you tell me the difference between SN74LS47P and SN74LS47N. Because the one I found says SN74LS47P in its package.

[@Sickindian5]

How can you make dot/decimal point disappear on two number display?

[@joescartino2216]

Please let me/know the name of that vise and where it can be purchased. Thanks in advance..

[@kohtuthuman7628]

please explain about tl494ic.

[@nikjberry]

That's a dope board vise... Where can I get one?

[@vlogisehat3188]

74LS47 is not perfect solution because the six character "6" become "b".... and "9" become "q", maybe do you have another IC that have a perfect character ? Because i have a problem with it..and need another one..

[@julian4035]

why you dont use one resister on the common anode?

[@arewasmartlightdecorations6029]

Hello I want help! i make my own counter it works but I want to set with Reed switch but it's count over what is problem?

[@dps9988]

is that a Heathkit oscilloscope in the background?

[@iqbalmd6603]

Hi there, I have a weight scale with 4 digit 7 segment display. I wish to send the weight to my arduino. Please help me.

[@Creedarn]

Sooo. i bought a leddisplay with 3 digits.. i have 18 pins/ 9 pins on one side. and it says it is "without common pin" what is that?

[@jpl9148]

What we want is a "How to drive a 16 - segment display "video

[@onurolce]

Not exactly what you want but maybe it gives an idea.

[@mohdashifkhan2858]

How can i use common anode sevaen segments display with cd4026be ic

[@yosa9463]

Can you make an Full adder only on switches

[@Davidjacobson2795]

How much more complicated would the setup be if instead of combining the switches to display larger numbers(i.e. switches 4, 2, and 1 to make 7), 6 switches were used to display numbers 1-6. Each switch would then have a specific number and wouldn't be used in combinations. I'm playing around with a 7 segment display and considering getting an Arduino if necessary. I've seen lots of projects used buttons to count up or down, but rarely can i find a project that uses individual buttons to display individual digits.

[@Incommensurabilities]

Not an expert, though I figure you could wire up each switch to pull high the specific BCD pins, so there would be wires running everywhere

[@DMES-wp2fj]

is there another IC that we can use?

[@aasandi]

My 74LS47N is is outputting the correct truth table. if all my inputs are low, 0000, I should get a 0 on the display, but I'm getting a 4. I tried two other 74LS47 and they are doing the same thing. To double check, I used a voltmeter to check the Vout on each ping of the IC (abcdefg) and I'm getting HLLHHLL (abcdefg), which is a 4. Am I using the wrong IC or are they defective?

[@LegoCreationsbyDagupa]

Are you sure all your inputs are low? In this schematic all input pins are floating, which usually causes unpredictable behavior. Something similar happened to me. Remove the connection from the switches and LEDs to the four inputs. Put 1K resistors from each input pin to ground, now you have four stable low inputs that should display “0”. If this works, floating inputs is your problem.

[@CABohol]

Nice

[@pankajseth09]

One request, Hello, I'm Pankaj.I need to u r help for make a automatically turn counting, and 2sides rotate motor with auto stop for automatic coil winding turn counter...❤️❤️❤️❤️❤️

[@rafikamin6617]

Hi pankaj you can get help from my professor, soumya Mukharji. He is electronic engineer in IIT kharagpur and loves to help aspirants and any self studying engineer student . Just let me know. Don't vote for Modi ji.

[@fullbridgerecrifier]

3:11 name of the software?

[@Hektabyte]

What do you use for breadboard/circuit visualization?

[@HazeAnderson]

DaveCAD 😏📝

[@maker_karen1785]

I started using Fritzing, but it didn't give me a perfect aerial view of each part. I started making my own parts in Illustrator and use them for planning out spacing on perfboard now.

[@mdzarifnoor3101]

can you give me diagram please

[@driss25]

Cd4026 and ne 555

[@Unnikuttan___here54]

Ic number

[@lesics61Tiktok]

Please can you show as robat brain diagram ☺

[@osamaabbas6746]

I need code pic

[@urugulu1656]

using sil-resistor packages would be so much simpler...

[@maker_karen1785]

True. But if you learn how to do it with individual resistors, it's easy to switch to a SIL. Plus more people tend to have a collection of individual resistors lying around rather than a large variety of values in SIL packaging, so I went with the more accessible method.

[@oldisgoldsongsdigital]

😉😉😉👌👌👌👌

[@planker]

Like

[@clusternate]

Isn't that a 8 segment display? I remember that the point on the bottom was counted too.

[@clusternate]

@@kennmossman8701 OK, but COULD you adress it to do something?

[@clusternate]

@@kennmossman8701 OK let's fight. A decimal is in my book not trivial at all. IF you can adress the decimal point, than that's a segment for me. Hence my confusion. I would call a display with 7 stripes and 1 point a 8 segment display. At least thats what I learned in my studies. Did I win?

[@clusternate]

@@kennmossman8701 english is not my first so pls stay nice.

[@clusternate]

@@kennmossman8701 no, but I would count the thumb. Which is technically not a finger.

[@TomStorey96]

When you say you shouldn't leave pins floating, I don't think it'll matter for an LED display... It's a bigger issue for CMOS where a floating pin could sit in the nonlinear region where it may not really be high or low, this can cause higher power consumption, generate more heat, and produce unpredictable/undesirable results or behaviour.

[@Yotanido]

In this particular case, we actually want the pins high, since they are low-active, so they definitely need to be connected. But even if they were high-active, leaving them unconnected is a bad idea. Stray capacitance could induce a voltage on the pins which can be read as a high signal by the chip. I've had it happen before when I left a pin floating. Unless a pin is labelled NC, I think you should always have it connected to something. If nothing else, it is good practice.

[@TomStorey96]

@@Yotanido I know. I'm taking about the 7 segment display, not the driver chip. She said she would connect the dot point pin of the display because you shouldn't leave pins floating...

[@Yotanido]

@@TomStorey96 Fair enough, it doesn't make a difference there. But keep in mind that not all viewers will be able to tell the difference. Teaching them to always connect all pins is a good idea in my opinion.

[@TomStorey96]

@@Yotanido you would be better off teaching them those particular reasons in my opinion. It's all well and good to say "connect all of the pins to something", but maybe e14 viewers are the kind that could really benefit from knowing the reasons why, and the cases when it matters the most.

[@jeetenderkakkar7570]

Drive rajma

[@naderhumood1199]

Deligintly great vedio. And deligint and sweet lady..

[@DerRindenmulchficker]

Thats not what DP stands for!

[@ishanpatel8788]

speak slowly, very slowly so that a viewer can learn.

[@athanasiosgeorgopoulos5020]

Langsam langsam .

[@katsuyukihamamoto]

Arduinoならもっと簡単にできちゃいますね！

[@jkobain]

Burn.

[@zdenkokovac4557]

🤗💞💞💞💞🇭🇷

[@michaelromefelt762]

Why use an C Andode ever god*mn time...everytime on these "learning videos"

[@lojaloja3574]

its hard to learn from you because you look very attractive i cant focus on :)

[@briangriffin5701]

Thanks, Karen!

[@alirehman1529]

Cool, thanks!