Ohm's Law - The Learning Circuit

[@andrascsirmaz3043]

Holy smokes I have NEVER understood Ohm's law in applied circuits - I now understand that we need it to know how much resistance we need to decrease the original voltage to a desired one, using the known current required. Thank you soooooo much!!!!

[@ericvanstrom3395]

This is perfect! Awesome job showing the way the circuit look on paper AND on a bread board

[@Maverick7r]

I think this was a great tutorial for basic concepts. Very nicely laid out and explained in a way that's easy to understand. Great job IMHO!! :)

[@jono0007]

I really like the way these videos are laid out, and Karen improves as a presenter with every video

[@LarixusSnydes]

I always connect my power rail as the last step in completing a circuit, rather than the first. This allows me to double check it before applying any power and potentially destroying a component in case of a mistake. Although making mistakes can be a learning experience ;-)

[@GameTechRefuge]

I hope you guys can get these videos into classrooms and schools. Their great, perfect for kids ( & noobs such as myself).

[@profgallaugher]

Your tutorials are great. You are a wonderful teacher!

[@hammer86_]

Great episode! I don't know why I had so much trouble in my Electronics 101 class. Seems so simple now. I'd like to see more examples of Ohms Law.

[@CarlJohanvonGegerfelt]

Dividing the resistance by two when placing resistors in parallel is only applicable when the resistors are equal to one and other. In any other case you ned to calculate 1/R1+1/R2=1/Rtotal

[@pyotrleflegin7255]

I wish I had had you as a college teacher 55 years ago!

[@scotttovey]

Good job Karen. I think I missed the parallel resistors reducing resistance part in the electronics class. That, or it was said in such a complected way that I disregarded it. Years ago after having taken the electronics class I happened upon a KZbin video put out by an 11 year old by the name fo Sylvia and she was teaching something about electronics that I didn't quite grasp in class (can't remember what), but after watching her video I thought: So that's how that works! Yep, sometimes it takes an 11 year old to explain things because the adults are to busy using non understandable verbiage in order to make themselves look smarter than all the rest.

[@Remy21289]

I get it now, for anyone else stumped on where she gets 4 volts from in her equation, she is taking the 4 EXTRA volts off the 6 volt battery pack, since only 2 volts are required for the LED (6-2=4) The 4 is then plugged into her equation.

[@livefrog2791]

thanks 👍😆

[@Zaekk]

Very good video, I learned a lot about the maths surrounding circuitry. I usually copy other's work rather than get down with the nitty gritty of doing my own maths. Baking a cake by the book vs assembling your own list of ingred-aminos.

[@tabliqatchi6696]

The reason its 4 ohms is the fact the resistor limits current based on the voltage across it, There is 2V across the LED so there can only be 4V across the resistor so 4/200 = 20mA (~DashApple)

[@ilankhatire8199]

next transistor concepts will be a good one to ponder about...

[@fisforfriendship6093]

for stranded wire just solder the tips after twisting so they are firm enough for the bread board

[@markmessie5427]

You’re a wonderful teacher. Thanks a lot.

[@BarefootBushcraft]

Amazing video Karen! I love learning new things! Were you a teacher by any chance? The way you carry yourself and explain things is unbelievably good. You make it so easy to understand what I thought at one point to be basically magic! Haha Thanks to you and your "wiggle bot" episode, I finally got to fulfill a childhood dream and build my own robot! :) Keep the great videos coming my friend!

[@RetroAmateur1989]

I just learned what a resistor does. But I think I will have to watch this a few more times.

[@anand_dudi]

I have never get things in my school college which have been discuss here thankyou so much i always wanted to be learn electronics with practicals

[@unbelievablevideos3557]

This should be the show!

[@erikcire7809]

Love your way of teaching !

[@kamalswami8374]

You are a great teacher

[@skygame5004]

Thank you.

[@snarkybu42]

Thank you for these video’s! I appreciate what you do!

[@flipsidezw]

It's not just a good idea, it's the law.

[@PAPICREW12]

Why you divide 4v with 0.02mA I thought power supply was 6v same for the 3v supply you use 1v. Where are you getting those values?

[@wedgebeard]

This wasn't really spelled out, but, to find the value to use for V in the formula (R=V/I) to calculate resistance needed, Karen took the total available voltage in the circuit (6V in the case of the 4 AA batteries), and subtract the target Voltage she wanted (2V requested from the LED), to get 6-2=4. I'm not sure why she didn't just use the total circuit Voltage divided by the target current like, 6v / .02A = 300 Ohms. I also wonder if we could get some clarity on that.

[@wedgebeard]

The reason Karen uses 4V to calculate the resistance is because: the source is sending out 6 volts, which is too much for the LED. The LED only wants 2 volts. In order to to give the LED only 2 volts, we need to "resist" 4 of the 6 total volts in the circuit (at that point in the circuit) - in other words, we need to drop the voltage from 6 to 2, so as not to destroy the LED. That's why she calculated the resistance needed for 4 volts, instead of 6 volts. Here's a deep dive in Ohm's law: kzbin.info/www/bejne/opeTnYB6j7uqiqs

[@ThePhosee]

@@wedgebeard thank you for so detailed explanation and a link!

[@crackseller321]

I love your videos.

[@philsbbs]

i enjoyed this video. Thanks Karen

[@Ometepe1957]

thank you!!

[@nickayivor8432]

Thanks 👍

[@lizard.babytok5457]

Good. I hope make more video like this

[@alhadinon]

The only thing I would question is to connect power AT LAST, not right at first. Otherwise, great beginners guide for circuitry. :)

[@ridwanhusainishraq]

I have a question maam. Doesn't the resistance should remain constant and the current should vary with the voltage? Ohm's law is the replication of that. but that experiment showed only that if we vary resistance current decreases. I think it would be better if you show a video keeping resistance of same value connected on the breadboard circuit in series or parallel with led(whatever combination you prefer) then vary the emf by connecting batteries of different values and measure the current or it can be demonstrated using the intensity of light. as voltage decreases, current decreases so light intensity decreases. By the way the presentation overall was way better than what we were taught at schools and colleges. Our school and universities require a teacher like you so friendly charming and jolly minded open minded to questions. I sometimes question why we even pay thousands of taka or even lakhs to universities to hear the tedious monotonous lectures of our professors whereas much of the work is done by KZbin with a gifted teacher like you. just to earn a paper certificate for a job or to write a status of being graduated as so called engineer with zero understanding concept of fundamentals? Our professors are so lame rubbish and quarrelsome. Some are known to demean too

[@MrCardeso]

Well explained. Thanks!

[@muhammedhalava6591]

it is a great, thanks

[@gristlevonraben]

Very cool lesson, thank you.

[@xKatjaxPurrsx]

Note to learners: If you get most of your components by scavenging them off discarded electronics like I did, the "longer lead" of the LED means nothing because they've already been cut! You can generally identify the negative side of the LED by looking through the plastic lens. The negative side is the big chunk inside and the positive side is the smaller chunk. See this diagram: upload.wikimedia.org/wikipedia/commons/thumb/f/f9/LED%2C_5mm%2C_green_%28en%29.svg/220px-LED%2C_5mm%2C_green_%28en%29.svg.png

[@elp09bm]

Excellent Stuff!!!

[@emulgator2403]

Gr8 informative clip! Thank you!

[@samirfakoua]

Why is it in physics anode is + and cathode is - but for galvanic cells the anode is - and cathode is + as the electrons flow from anode to cathode?

[@SAPsundar5]

Way to go, Karen !

[@cringebunny5886]

can you make video about transistor. how to calculate and choose for project.

[@sohamhonrao5622]

please list some basic electronics material to buy, to start a such experiments.

[@FernandoMedeiros]

Hey, I just bought my starter kit, and had the same question. Turns out Karen has already made a shopping list available at their community portal: www.element14.com/community/thread/65003/l/electronics-newbie-starter-kit-what-should-be-in-it

[@userou-ig1ze]

text/spoken language is right, the blatant error at 2:48 hurts the eyes though, please correct

[@khansher5683]

Nice extion

[@sundaykevin4314]

wawo this tutorials are very good

[@lucasalland8796]

But what happens if you do not want to change the voltage, just regulate amplitude. Dividing the difference in voltage, 0, by the desired max amplitude just returns zero which is incorrect.

[@glowingone1774]

Lucas Alland go back to your redstone I was joking

[@nanobytez6881]

Hey, do you know where we can get our hands on those component posters in the back? They look like a great way to quickly identify parts!

[@ajrand5306]

Ya I want to know too

[@technologylover5976]

I didn't understand the parallel twisters concept. How it decreased its value 🤔

[@ValkGame]

I have defiantly hooked an LED up to 6v without a resistor before I knew any better.

[@erifkind]

2:46 When you say we want no more than 20 milliamps, why and how is that number being determined? I'm having trouble with that part of the concept...

[@userou-ig1ze]

this is a usual value for (and cheapest) LEDs. You get the value from the datasheet of the component (where usually max voltage and max current are indicated, especially at what point you will cause irreversible damage)

[@erifkind]

@@userou-ig1ze thank you

[@rustyshackleford5166]

this is good information for the project i am taking on. I do have one question though. Are all red LEDs 2 volts? or do larger ones require greater voltage?

[@AlexCesare]

Different "sizes" and colors of LEDs will also have different Voltage and Currents they'll operate at best. If you buy LEDs somewhere, they should tell you what Voltage and Current it's rated for.

[@TheSliderW]

Check the datasheet provided by the manufacturer to get all that information. It should be mentioned on the packaging as well if you have it. It's under the section "forward voltage". In any case, always stay below the maximum voltage it can support. To be safe, don't go above 2V. Going above means, brighter lights but lower lifetime. More info : Typical red leds require between 1.7V and 2.4V maximum (as in, it will die faster if you try higher than 2.4V) while colder wavelengths ( green, blue ) can go as high as 3.5V and even more for some of them. Here is an example datasheet for a large red LED where you can see that information : sparkfun.com/datasheets/Components/LED/Red-10mm.pdf Look for the row "Forward voltage" in the second table. There are three columns "min", "typ" (as in typical) and "max". You"ll want to aim for a value strictly between the min and max. To calculate the resistance for your power supply, you'll also need the Current value that you'll find on the very first row called : "Forward Current" which is 80mA. The datasheet also has a row "Suggestion Using Current". It's not well translated but it means the manufacturer recommends aiming for that Current to be safe (Just like for resistors with their gold/silver rings, LED's are not perfect and their ratings might vary by 5-10% depending on the manufacturer and the process involved ). I hope this helps : )

[@maker_karen1785]

What Alex said. Best to check the specs of whatever you buy. They vary. Even different 5mm Red LEDs have different ratings depending on which ones you get.

[@rustyshackleford5166]

well, the thing is, i bought "gumdrop LEDs" some time ago and lost the package that tells that information. Is there any rule of thumb to go by on these types? The green one is 3v, that much i know.

[@zahmbiend6575]

You can always find the voltage of the LED by simply placing it in a resistor circuit like the one shown, and measuring the voltage between the two leads of the LED. If you're worried about burning it out by using too small of a resistance, just start with a really high resistance, and the voltage across the LED should measure as what the LED operates at, even if the current is too low to light up correctly.

[@garyprice3757]

2 min 51 secs. Mistake. Should be 20ma not 2ma...

[@maker_karen1785]

Danggummit! Well, I guess we don't catch every typo. ¯\_(ツ)_/¯ Thanks for the comment so others know!

[@presstmoded]

1 mm = 0,001 m, 1 mA = 0,001 A

[@Restlessfingers1]

Mam I want some help

[@ramumangali7034]

I want only values

[@konstmannlange]

2mA = 0.002A :)

[@durgeshbaviskar9014]

There is text 2mA But she says 20mA By texting she was wrong But , bye saying she is right

[@VideoGamer945]

7:20 boop

[@ezamora2113163]

We are going to miss Been Heck

[@jeanyveskaliva815]

Isn’t 2mA = 0.002A. Not 0.02A

[@DummyAccount]

Didn't know bread was electrically conductive

[@DaveMcAnulty]

With enough voltage it is!

[@BrandonGracyalny]

I was always taught that I stands for impedance.

[@RipperTips]

Vape naysh

[@liborchmelik8712]

Maybe it's an american thing, but in Europe voltage is U. As in U=R*I

[@davidkgame]

UK we use V.

[@microwar]

Pleace stop using the offset camera angles. Looks stupid.

[@stevesm2010]

Jan-Robert Nergård Agreed - So annoying!

[@adamfalldorf1581]

Agreed, I don't understand why so many shows do this. It's distracting and looks dumb when the subject isn't looking at the camera.

[@MC-hx6nk]

Why the gloves? a) They provide protection from electricity b) It's cold where we are filming this c) I'm just so damn emo

[@CimandeTube]

Go Karen!

[@victorprosa]

Please, be more careful. The way you explained some of the basic concepts is great for people with some knowledge of electronics. The problem is for the beginners (which i believe is your target audience with this segment), it leaves them open to interpret some cause-effect relationships and concepts in the wrong way and this may create some difficulties for them when they try to learn more complex concepts in their future. Regards, Victor

[@Plumbings]

Hii mam

[@Liamsoldvideos]

I don't understand a thing

[@harbselectronicslab3551]

those side shots are soooooo annoying and look stupid

[@tinkmarshino]

you electronics folks are as bad as scientist.. make things as complicated as you can I, R it should just be A, O call it what it is.. I am not even going to go into joules and oh the the other words you use for the same thing.. and is that input voltage or output voltage.. I am just to old to learn new tricks I guess.

[@nogarage]

omg those cringey-ass gloves

[@icecoldbeard5316]

Third

[@CollinstheClown]

Almost first lol

[@samuellopez6736]

First