I'm trying to build an LED light box for my filming rig. I have 108, 3.6v, LEDs connected in series. The resistance 22ohms, from a 9V 2.50 amp battery. What further resistor should i use to prevent making the battery hot?
Ohms law isnt V=IR, it is U=RI because the man who came with this law is named Uri Geller, and he did these U=RI by his first name, what i learnt in school anyway, but things could be different here in sweden....
Here is something doesn't make sense to me if I had a 9 volt battery at 1 amps & if I put in a 1 ohm resistor than I would have increased my amps to 9? 9v*1ohm = 9current.
Hey I'm currently majoring Automotive Technician and I was going through lessons of Ohm's Law and didn't understand this much but watching this completely made me understand alot more of Ohm's Laws thanks alot we could really use you as a teacher :D
as a newcomer to electronics, and i mean, im a complete noob, it would be handy if you explained to people how 30M/a translates into .03amps, and the reason why you need to convert it in the first place.
while i can follow your example much better than any of my lecturers, its a shame you qualified guys still assume that us wee students should automatically know how to convert these simple figures, and should automatically know the reason why to do so.
@DaveyLoosesWeight volts, amperes and ohms are the standard units for voltage, current and resistance respectively. He said that he wanted to produce 30 milliamps, by milli meaning 1/1000. So converting that he divided 30 by 1000 producing .03 amps. This is absolutely necessary to avoid confusion dividing 9 by 30, getting 0.3 but forgetting it has a different unit.
@DaveyLoosesWeight Of course you can use milliamps, giving you .3. Take note that its unit is not just ohms but kilo ohms so you'll have to multiply that by 1000 and you get 300 ohms
@Generalvaldez I think you're mistaking 'grammatically correct' with 'completely incorrect'. And what would you say apart from 'in hospital'? :p
I don't care if people add to the English language, quite the opposite. But when they make up new things for things we already have it's just completely pointless, and it creates a gap between English speakers all over the world. For example: "sidewalk"? What was wrong with "pavement"? Not painfully obvious enough for you? ;)
@SepradistPhantom The countries we come from have standardized the dialect of English spoken. Math in America is completely correct, In America we don't say in hospital, we say in THE hospital. Language would be boring if there was only one word for the same idea, sidewalk and pavement, two words, same idea. Knowledge is power, there is absolutely nothing wrong with the variations our language has all over the world, its fun to learn. btw, I like how we are talking English on a circuitry video.
@Generalvaldez The point of language isn't to be interesting, it's to facilitate communication. OF COURSE the world would be a better place if we all spoke the same language :p
@SepradistPhantom If the world were to speak one language, it would be culture-less. Everyone expresses their ideas differently, different languages is one basic example of that.
@Generalvaldez That's completely untrue, culture has little to do with language. If everybody were to speak one language then we would all be able to experience each culture in far more depth. Note i didn't say 'if everybody were to speak ONLY one language'.
@SepradistPhantom Language has the most impact on culture. Just look at chinese! Sometimes a word in a language cannot be accurately translated to another language simply because its not a part of the other language's culture, prime example, Ungeziefer in german, often translated to some type of bug or insect, however that is not its meaning.
@SepradistPhantom I speak English(natively), Spanish (natively), Chinese, and Japanese. In my studies of Chinese and Japanese, I've learned ( in america there's no such word as learnt btw) that English as expresive as it is, it cannot express the same cultural values of the Japanese and Chinese. Language is fundamental to culture.
i have a 18v battery with 200ma and i want to turn it into that same current into 12v but also increase the amps up to 9 amps (if possible) how can i acomplish such thing? my dad sugested me a transformer but i dont know how it works, if you have a better ideia please advise!
@bazengao Current and amps are the same thing, so I was a bit confused by the question. Regardless, a transformer only works with AC power (like a wall socket), so that would be out of the question. You might want to look into a different source to provide that kind of current.
i think a narrowing in the pipe would be more like a transformer, because its reducing voltage, but increasing amperage. i would compare a resister in a circuit with a hole in a pipe.
so when doing the equiation i have to convert it to AMPS/Ohms/Voltage instead of mA/Kohms/mV ?? ex: 9 volts / 200mA is wrong i have to have them as AMPS
you scarred me as hell, i thought that i was messed up my psyhics test, but it appears to be that, we, in lithuania, mark voltage with letter U, not V, so everything is fine 8) :D
My native language is portuguese, I haven't studyied this at school yet and I could perfectly understand it! Why do explanations on youtube always seem to be 10x better than my teachers?
@muusicman1993 one example would be for something like and LED that can only handle a certain amount of current, by increasing resistance you limit the current that reaches the LED. Check out the Make explanation of a resistor on their Vimeo channel
*note, PLEASE don't even consider this if you are not a certified radiographer. You would end up in a legal mess( look into the NRC[nuclear regulatory commission], Madam Curie and Rad. Health for more general info.), and potentially dieing in the most painful way imaginable.
I <3 tech, and I want to do legitimate art w/x-rays, as well as general experimentation in the radiographic field. I just wish my certs were up. Oh well, too bad it takes ∞ $...
Use I=V/R. You have the initial voltage, yes? If so, then find the current for what ever you're trying to power and simply plug in the givens into your formula.
oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooohhhhhhhhhh now i get it
I thought resistors drop voltage not current?. I want to charge a shaver off USB instead of using up another of my plug sockets. The charger is rated at 3.8v pulling 80mA. How can I make 5v USB that pulls 500mA max suitable for charger the shaver?
I thought it would be easier to use an 3.3v Voltage Regulator with a resistor, But I don't know if 3.3v will charge it correctly and you always get a voltage drop out.
I had been having a little trouble getting my head around some of these rules of electricity, but your video really helped make things a little clearer for me, thank you :)
Ooops - I forgot to subtract the 3V LED voltage from the 9 V supply. When your circuit is running, there will be 3V across the LED leaving only 6V across the dropping resistor. Therefore, you need to divide 6V by the forward operating current of the LED to find the right resistor. Dividing 9V by the LED current would under power the LED by about one third.
You should be able to Google the part number of the LED to find the data sheet online.
The voltage to run the LED is 3V. So when the circuit is running properly, there will be 3 V across the LED leaving 6 V across the dropping resistor. Whatever current is required by the LED (found on the data sheet) is what will be flowing through the dropping resistor and LED. Therefore, to find the value of the dropping resistor (which will have 6 V across it, you then divide the 6 V by the current required by the LED.
So, 6 / LED current = value of the dropping resistor.
This is the fundamentals of electric flow, and conservation of energy across a closed path. However, it's not good enough to determine how transistor operates, electromagnetic field behaves on a PCB. You can build a simple circuit based on OHM's Law, but, not a complex circuit that requires further complex analysis such as signal processing, etc...When we introduce inductance and capicitance, AC, it's very complex.
But this law is used only for the part of a circuit. For the whole circuit the formula is : I=e/(R+r), where I is current, e is emf (electromotive force), R is resistance and r is resistance of the power supply. Emf=I*R+I*r where the I*R=V so emf=V+I*r. Wich means that I=V+I*r/R+r.
@makemagazine isn't I used instead of C, because C stands for Capacitance, unlike wat u said (Coulumbs)?. Because here I and C are symbols, whereas C for Coulumb is a unit.
You have to know the current requirements of the LED. You could look that up in the documentation (data sheet) for that LED. It will specify the maximum forward current, and then you would divide the voltage by that current to find the proper dropping resistor.
your video is good,I remember only a few instructors in the seventies and eighties that could teach with simplicity.the others should have stayed electronics engineers and nuclear physicists in the work force because they couldnt teach squat!
@andrewyaoauatauabaea You got it. Because your resistance (Ohms) is so small, the electricity's rate of flow (current) is very large, even though you only have one volt. In other words, there's almost nothing limiting how fast the electricity can flow.
if you really want to design circuits, you should already know this, this is just the very basic, cause you need to know about how circuits work in series and parallel
like in serie the current constant and in a parallel circuit it wil be divided bij how many resitors you have
the voltage and resistance are added per resistor in a serie, but if it is parallel they are in every point of the circuit the same.
I learned this stuf a long a go in school when is was 14,and this is a small bit of it
blew my mind with the pyramid
BMSreligion 2 days ago in playlist MAKE Presents
I've got a science exam on monday, this helped so much!
clarissaallford 3 days ago
Awesome explanation! Music is bad though. Won't let you relax.
capcaunuu 4 days ago
Thanks, I forgot what all of that meant till I saw your video
903QTR 5 days ago
very nice realy understand very easily 10x u
deennizam 1 week ago
I'm studying Electric Installation at college, wish I had found this sooner! subscribed!
GreenGaslight 2 weeks ago
V and U is DIFFERENT !!learn to write U
cagalova 3 weeks ago
@cagalova
Americans use V for voltage.
OriginalUsername9000 3 weeks ago in playlist MAKE Presents
This has been flagged as spam show
nepsol.blogspot.com
This guy is bringing up circuits solution guys!!!
1Channelable 4 weeks ago
Twinkle twinkle little star / Power = I^2 R / Up Above the world so high / Power = V x I
opl500 1 month ago
Subbed. Really helpful, entertaining, and easy to understand! Thanks
xig08B6 1 month ago
Actually yes... i didnt expect a black elf..
AnnoyingXboxer 1 month ago in playlist Collins's Lab
you should make your videos ore exciting it gets a bit boring after a while
parkfilms1 1 month ago
Could you describe thevenins and nortons theorem?
mikado387 1 month ago 2
Subscribed ;-)
blackmesa25 1 month ago
I love ya videos Collin. There very helpfull all of them! very easy to understand. And the stuff you do cracks me up lol
Thanx Collin for ya time to help. ;-)
BIG THUMBS UP*
blackmesa25 1 month ago
Its U=RI
m8rox 1 month ago
U=IR not V=IR
pacanas9999 1 month ago
I have a science exam on this tomorrow thanks man you cool!
CaciumKid99 1 month ago
@MrPowQ Ohms law was created by George ohm. Who was a school teacher prior to his studies on the matter
1996krt 1 month ago
I'm trying to build an LED light box for my filming rig. I have 108, 3.6v, LEDs connected in series. The resistance 22ohms, from a 9V 2.50 amp battery. What further resistor should i use to prevent making the battery hot?
lightads 1 month ago in playlist MAKE Presents
definitely something to remember about electronics. Then there's Kirchhoff's laws and their applications which get more complicated....
DannickFox 1 month ago in playlist MAKE Presents
ohm is my nick name
soranut111 1 month ago
Ohms law isnt V=IR, it is U=RI because the man who came with this law is named Uri Geller, and he did these U=RI by his first name, what i learnt in school anyway, but things could be different here in sweden....
MrPowQ 1 month ago
I'm about as math averse as they come and I thoroughly enjoyed this.
Calpolecon 1 month ago
very good
ramulaabbas 2 months ago
Here is something doesn't make sense to me if I had a 9 volt battery at 1 amps & if I put in a 1 ohm resistor than I would have increased my amps to 9? 9v*1ohm = 9current.
lineage13 2 months ago
@lineage13
9volts / 1amp = 9ohms
9ohms + 1ohm = 10ohms
9volts / 10ohms = 0.9amps
Hope this helps :)
frazzlemartini 1 month ago in playlist MAKE Presents
just look at this for a refresher good job
DKLGalactus5 2 months ago
if this is science y the hell is it on my math test
st8r1 2 months ago
Top one 10/10 on this. thanks loads.
manchesterremix 2 months ago
I know what each code means:
V: Voltage
R: Resistor
I: Current
Before I watched this.
ideainsanity12 3 months ago
This has been flagged as spam show
is this device based on the gerdien tube design?
530BigBen 3 months ago
WOOOO. Science work made easy
THANKS!
PeterT491 3 months ago
Hey I'm currently majoring Automotive Technician and I was going through lessons of Ohm's Law and didn't understand this much but watching this completely made me understand alot more of Ohm's Laws thanks alot we could really use you as a teacher :D
uptownaaron90 3 months ago
Current uses I because it's latin and the world in latin for current is the same that evolved in english to intensity.
rafaelalis 4 months ago
thanks
janu396 4 months ago in playlist MAKE Presents
i love math f(t)=sin(124*PI*t)
dass0137 4 months ago in playlist MAKE Presents
as a newcomer to electronics, and i mean, im a complete noob, it would be handy if you explained to people how 30M/a translates into .03amps, and the reason why you need to convert it in the first place.
while i can follow your example much better than any of my lecturers, its a shame you qualified guys still assume that us wee students should automatically know how to convert these simple figures, and should automatically know the reason why to do so.
but thanks anyways. u did help me.
DaveyLoosesWeight 4 months ago
@DaveyLoosesWeight volts, amperes and ohms are the standard units for voltage, current and resistance respectively. He said that he wanted to produce 30 milliamps, by milli meaning 1/1000. So converting that he divided 30 by 1000 producing .03 amps. This is absolutely necessary to avoid confusion dividing 9 by 30, getting 0.3 but forgetting it has a different unit.
jrac0582 4 months ago
Comment removed
jrac0582 4 months ago
Comment removed
jrac0582 4 months ago
This has been flagged as spam show
@DaveyLoosesWeight Of course you can use milliamps, giving you .3. Take note that its unit is not just ohms but kilo ohms so you'll have to multiply that by 1000 and you get 300 ohms
jrac0582 4 months ago
we invent a machine that makes you grow hair
Drakkar35 4 months ago in playlist MAKE Presents
i still dont get it.... why do u need a resistor or resistance?
2enmi 4 months ago
@2enmi 5:01
BoltAndPennyFan 4 months ago
@2enmi to prevent short circute
Shadowconsilver 4 months ago
@2enmi
to limit/control current or voltage
tHaH4x0r 3 months ago
common canadian circuitry 120 v 20 a 120/20=6ohms like if this is correct
whosplayingyou29 5 months ago
Wow, this is really helpfull! Thanks.
PopeSweetJesus95 5 months ago
MATHS! GOOD GOD IT'S MATHS! YOU CAN'T HAVE A SINGLE 'MATHEMATIC'!
That aside, great video :)
SepradistPhantom 6 months ago
@SepradistPhantom dude, calm down, math is gramatically correct. Just like its correct to say "In hospital" where you come from.
Generalvaldez 5 months ago
@Generalvaldez I think you're mistaking 'grammatically correct' with 'completely incorrect'. And what would you say apart from 'in hospital'? :p
I don't care if people add to the English language, quite the opposite. But when they make up new things for things we already have it's just completely pointless, and it creates a gap between English speakers all over the world. For example: "sidewalk"? What was wrong with "pavement"? Not painfully obvious enough for you? ;)
SepradistPhantom 5 months ago
@SepradistPhantom The countries we come from have standardized the dialect of English spoken. Math in America is completely correct, In America we don't say in hospital, we say in THE hospital. Language would be boring if there was only one word for the same idea, sidewalk and pavement, two words, same idea. Knowledge is power, there is absolutely nothing wrong with the variations our language has all over the world, its fun to learn. btw, I like how we are talking English on a circuitry video.
Generalvaldez 5 months ago
@Generalvaldez The point of language isn't to be interesting, it's to facilitate communication. OF COURSE the world would be a better place if we all spoke the same language :p
And why not? ;)
SepradistPhantom 5 months ago
@SepradistPhantom If the world were to speak one language, it would be culture-less. Everyone expresses their ideas differently, different languages is one basic example of that.
Generalvaldez 5 months ago
@Generalvaldez That's completely untrue, culture has little to do with language. If everybody were to speak one language then we would all be able to experience each culture in far more depth. Note i didn't say 'if everybody were to speak ONLY one language'.
SepradistPhantom 5 months ago
@SepradistPhantom Language has the most impact on culture. Just look at chinese! Sometimes a word in a language cannot be accurately translated to another language simply because its not a part of the other language's culture, prime example, Ungeziefer in german, often translated to some type of bug or insect, however that is not its meaning.
Generalvaldez 5 months ago
@SepradistPhantom I speak English(natively), Spanish (natively), Chinese, and Japanese. In my studies of Chinese and Japanese, I've learned ( in america there's no such word as learnt btw) that English as expresive as it is, it cannot express the same cultural values of the Japanese and Chinese. Language is fundamental to culture.
Generalvaldez 5 months ago
@Generalvaldez The problem with that ideology being the distinct lack of language teachers who are good enough to actually teach somebody a language.
SepradistPhantom 5 months ago
Comment removed
Generalvaldez 5 months ago
@SepradistPhantom you are your only teacher, it just depends on whether or not you have desire.
Generalvaldez 5 months ago
good ol' Horowitz and Hill
myguitardidyermom12 6 months ago
thank you MAKE and thank you again
survivalyacoub 6 months ago
Voltage is normally E or V you understand campo4321
Chamillionaire791 6 months ago
Voltage is normally E..
campo4321 6 months ago
6:20 'USE IT!' *hands up* ok i'll! plz don't shoot!
shaurya6seth 6 months ago
why do you use V instead of U? I'm used to U : /
itsmeafreak 6 months ago
@itsmeafreak - V for volts. What would U stand for?
technologyguy223 6 months ago
@technologyguy223 Okay, I googled a lil and found out: U stands for latin "urgere" .
itsmeafreak 6 months ago
I make speakers and amps like pa amps stuff like that they handle 8 ohms to 3 ohms 200wrms to 400wrms its just a hobbie.
sonicfan76 6 months ago
2:40 that's the potencial !
BenarAndres 6 months ago in playlist MAKE Presents
VOLTAGE is not V !! VOLTAGE is U ! the formel code is U not V :D
BenarAndres 6 months ago in playlist MAKE Presents
i have a 18v battery with 200ma and i want to turn it into that same current into 12v but also increase the amps up to 9 amps (if possible) how can i acomplish such thing? my dad sugested me a transformer but i dont know how it works, if you have a better ideia please advise!
bazengao 7 months ago
@bazengao Current and amps are the same thing, so I was a bit confused by the question. Regardless, a transformer only works with AC power (like a wall socket), so that would be out of the question. You might want to look into a different source to provide that kind of current.
SolMaster 7 months ago
More make presents! The best videos on make!
lucasmontec 7 months ago
usually people that are involved with circuits have a keen interest in math...
sciencefreak2402 7 months ago
i think a narrowing in the pipe would be more like a transformer, because its reducing voltage, but increasing amperage. i would compare a resister in a circuit with a hole in a pipe.
123456789robbie 7 months ago
so when doing the equiation i have to convert it to AMPS/Ohms/Voltage instead of mA/Kohms/mV ?? ex: 9 volts / 200mA is wrong i have to have them as AMPS
eddiea6987 7 months ago
@eddiea6987 9 volts / 200mA would be incorrect, you should convert the mA to A which i beleive is mA/1000. so your quation would be 9 V / 0.2 A
123456789robbie 7 months ago
@Master0fDeasater lol you stole my word :P
aaarubalaaa 7 months ago
Awesome tutorial! Thanks!
Hidframe 7 months ago
Awesome video!
dan30cal 7 months ago
thank you very much
NubKiler87 8 months ago
Thanks for the lesson. I've been trying to understand this lately, but I needed somebody to show me. Cool channel.
cgrobe21 8 months ago
THANK YOU THANK YOU THANK YOU Yr9 science PASS thx to you THANKS THANKS THANKS
MrJimmy713 8 months ago
@MrJimmy713 yr9?? y the hell r u doin this in yr 9??
wakablue3 8 months ago
@wakablue3 I know its so retarded
MrJimmy713 7 months ago
@wakablue3 OH NO, so are we. It's not that bad though.
americaneagle791 7 months ago
beleive it or not but, you just helped me with my public speaking class! thank you!!!
xXGlobalWarfareXx 8 months ago
@2Fast4You1264 why u watching it them? :L
Charlsas2724 8 months ago
LOL i see the angry transformer in the background
TechBoywii 9 months ago
you scarred me as hell, i thought that i was messed up my psyhics test, but it appears to be that, we, in lithuania, mark voltage with letter U, not V, so everything is fine 8) :D
sasafeda 9 months ago
lol voltage is marked with U not with V
AntyVirus80 9 months ago
the original is actually the letter E..... if you dont believe me take it up with Georg Simon Ohm.
algitrath 9 months ago
now can you explain it to me like im a six year old... just kidding. loved the video.
jihadpizza 9 months ago
My native language is portuguese, I haven't studyied this at school yet and I could perfectly understand it! Why do explanations on youtube always seem to be 10x better than my teachers?
kynigh 9 months ago
Pretty straightforward. Fantastic video. Related question: When/Why would one want to increase/decrease resistance?
muusicman1993 9 months ago
@muusicman1993 one example would be for something like and LED that can only handle a certain amount of current, by increasing resistance you limit the current that reaches the LED. Check out the Make explanation of a resistor on their Vimeo channel
shawnmoore1 9 months ago
I cant wait to make my own X-ray tubehead...
*note, PLEASE don't even consider this if you are not a certified radiographer. You would end up in a legal mess( look into the NRC[nuclear regulatory commission], Madam Curie and Rad. Health for more general info.), and potentially dieing in the most painful way imaginable.
I <3 tech, and I want to do legitimate art w/x-rays, as well as general experimentation in the radiographic field. I just wish my certs were up. Oh well, too bad it takes ∞ $...
nazaxprime 9 months ago
Wow, these videos are fantastic! Great presentations, interesting subjects.
GoaTseTung 9 months ago
iv got my big electric test to see if i get into electrical engeneering, life time opurtunity and this has helped out allott THANKYOUU!!! ;D
1997connors 9 months ago
so cool
LegoBoy126 9 months ago
#p# #p# es desir pelado pelotudo que hace pelotudeses
gachu26 9 months ago
This Guy makes Kipkay look like a noob!
No offence Kipkay his vid's are the only reason i ever heard of Make!
good job guys making electronics a little clearer to us non-engineers!
Vonditto 9 months ago
You should show how to get these values for parallel and series circuits so people don't get confused. I learned this in 9th grade this year lol
ColinAndrewLaws 10 months ago
how do you know what size resistor to use if you are trying to drop the voltage
KdrummerK 10 months ago
Comment removed
PlasmaCode 9 months ago
@KdrummerK
Use I=V/R. You have the initial voltage, yes? If so, then find the current for what ever you're trying to power and simply plug in the givens into your formula.
PlasmaCode 9 months ago
oh my gosh thumbs up if your nose bleed when you saw this math!! my brain can't function it anymore T^T
talabastardo 10 months ago
Comment removed
Dolby3d 10 months ago
This has been flagged as spam show
hi ..how to measure laptop battery (dell laptop battery) thanks
reerhoo 10 months ago
hi ..how to measure laptop battery (dell laptop battery) thanks
reerhoo 10 months ago
I like your pen :D
Master0fDeasater 10 months ago 47
oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooohhhhhhhhhh now i get it
needfuckspeed 10 months ago
7:09 made me pass my physics exam that was today!
rolingpingu 10 months ago
nice way to learn.plz visit our channel and send comment to us.
AHProduction1214 10 months ago
thank you, have a test tomorrow, this is great
bjarni1995 10 months ago
lolol I said "simple algebra" out loud EXACTLY when you said "thanks to algebra" in the video so we both said algebra at the same time! :D
accountmaniac 10 months ago
I thought resistors drop voltage not current?. I want to charge a shaver off USB instead of using up another of my plug sockets. The charger is rated at 3.8v pulling 80mA. How can I make 5v USB that pulls 500mA max suitable for charger the shaver?
I thought it would be easier to use an 3.3v Voltage Regulator with a resistor, But I don't know if 3.3v will charge it correctly and you always get a voltage drop out.
haz939 10 months ago
I had been having a little trouble getting my head around some of these rules of electricity, but your video really helped make things a little clearer for me, thank you :)
TheTranceSound 10 months ago
Great video helped me cram for the ole physics test, though if anything is turning me off of circuit making is those long ass fingernails
sky30394 11 months ago
fuck man ur amazing
kindle2468 11 months ago
can you be my math teacher? :D
321beth321 11 months ago 78
@321beth321 would you happen to mean physics?
BleachBlonde147 10 months ago
@BleachBlonde147 oh well yes, yes haha i feel stupid.
321beth321 10 months ago
@321beth321 LOL i know he's amazing :D
Charlsas2724 8 months ago
@DoingItYourself
Ooops - I forgot to subtract the 3V LED voltage from the 9 V supply. When your circuit is running, there will be 3V across the LED leaving only 6V across the dropping resistor. Therefore, you need to divide 6V by the forward operating current of the LED to find the right resistor. Dividing 9V by the LED current would under power the LED by about one third.
You should be able to Google the part number of the LED to find the data sheet online.
MandrewP 11 months ago
@MandrewP that will be the voltage that you are measuring running in the circuit not the voltage needed to run the led.
aayush10001 11 months ago
@aayush10001
The voltage to run the LED is 3V. So when the circuit is running properly, there will be 3 V across the LED leaving 6 V across the dropping resistor. Whatever current is required by the LED (found on the data sheet) is what will be flowing through the dropping resistor and LED. Therefore, to find the value of the dropping resistor (which will have 6 V across it, you then divide the 6 V by the current required by the LED.
So, 6 / LED current = value of the dropping resistor.
MandrewP 11 months ago
Same concept of density... Density = mass divided by volume.
MrRyanstutorials 11 months ago
love u
megasmart1337 11 months ago
very informative
DaMostEnigmatic 11 months ago
thanks its useful
laal1975 11 months ago
This has been flagged as spam show
you are the only solution for bbw naneedj.info
devi105 11 months ago
This comment has received too many negative votes show
this video SUCKS like ASS
101nerdychick247 11 months ago
This is the fundamentals of electric flow, and conservation of energy across a closed path. However, it's not good enough to determine how transistor operates, electromagnetic field behaves on a PCB. You can build a simple circuit based on OHM's Law, but, not a complex circuit that requires further complex analysis such as signal processing, etc...When we introduce inductance and capicitance, AC, it's very complex.
consolemaster 11 months ago
But this law is used only for the part of a circuit. For the whole circuit the formula is : I=e/(R+r), where I is current, e is emf (electromotive force), R is resistance and r is resistance of the power supply. Emf=I*R+I*r where the I*R=V so emf=V+I*r. Wich means that I=V+I*r/R+r.
Electricsrb 11 months ago
@makemagazine isn't I used instead of C, because C stands for Capacitance, unlike wat u said (Coulumbs)?. Because here I and C are symbols, whereas C for Coulumb is a unit.
khaledelmansoury 11 months ago
What I just don't get:
When I have a LED (3 volt) and a 9 volt battery, what resistor do I use ?, 'cause the only thing i know is the voltage of the battery and LED...
DoingItYourself 11 months ago
@DoingItYourself
You have to know the current requirements of the LED. You could look that up in the documentation (data sheet) for that LED. It will specify the maximum forward current, and then you would divide the voltage by that current to find the proper dropping resistor.
MandrewP 11 months ago
@MandrewP Thank you !
DoingItYourself 11 months ago
I wish this guy was my teacher in my Electronics Computer Tech courses I took.
TheDookieMaster 11 months ago
@TheDookieMaster I wish also. We had only junk teachers that make electronics look sooo boring........ :(
bogdanrech 11 months ago
best educational video soundtrack
lxoxl 11 months ago
How do you find total power ?
wirelesscps 11 months ago
@wirelesscps Voltage * Current = Watts
DrD0000M 11 months ago
The relationship between voltage, current, and resistance is similar to the relationship between distance, rate, and time
MrBigTubs 11 months ago
Good job professor!
nadalricardo 11 months ago
Thanks this vid helped me out in school
ElectricMuffinDude 1 year ago
Shouldn't his answer have been in kilo ohms? I'm probably wrong, haven't taken an electronics class in years.
CountStrangulaX 1 year ago
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ghfjtyufghdfj 1 year ago
6:20 epic face
AresExodus 1 year ago
HOLY CRAP thank a lot
that will help me
babedibab 1 year ago
this might sound stupid. but if you have something interesting to say. leave the fucking music out of the background
bushkilledtowers 1 year ago
Awesome, dude.
Thank you!
rastarigate 1 year ago
at 6:20 his head looks like the symbol of ohms
humxa24 1 year ago
your video is good,I remember only a few instructors in the seventies and eighties that could teach with simplicity.the others should have stayed electronics engineers and nuclear physicists in the work force because they couldnt teach squat!
w3mq 1 year ago
Does this mean that if I have one volt and 0.0000001Ohms My current is huge?
andrewyaoauatauabaea 1 year ago
@andrewyaoauatauabaea yes, but that little resistance is probably impossible
vssnfrankiej 1 year ago
@andrewyaoauatauabaea You got it. Because your resistance (Ohms) is so small, the electricity's rate of flow (current) is very large, even though you only have one volt. In other words, there's almost nothing limiting how fast the electricity can flow.
gbmodern 1 year ago
@gbmodern Except the internal resistance of the voltage/current source which would be the limiting factor.
Booger6995 11 months ago 2
use it xD
sounds like yes we can :p
vsvHUNTER 1 year ago
I go to school and I have learned the most just from this video, thank you.
toxic3n3rgy 1 year ago
you think my hair will fell if I get too smart?
suuuuuperman 1 year ago
more explanation about series and parallel would be appretiated
aallaaaa1 1 year ago
555 videos! YES! :) And before this one, 800 comments! Whee numbers.
zinodikudu 1 year ago
So well done, thanks for the help.
crisbourn 1 year ago
you are very helpful..and a pleasure to watch
thanks
spiderbabyspider 1 year ago
Comment removed
mrjimmyos 1 year ago
if you really want to design circuits, you should already know this, this is just the very basic, cause you need to know about how circuits work in series and parallel
like in serie the current constant and in a parallel circuit it wil be divided bij how many resitors you have
the voltage and resistance are added per resistor in a serie, but if it is parallel they are in every point of the circuit the same.
I learned this stuf a long a go in school when is was 14,and this is a small bit of it
Maik4343 1 year ago
6:19 "use it" haha
suchaboringusername 1 year ago
6:19 "use it"
suchaboringusername 1 year ago
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TheMangyfall 1 year ago
Thanks man, Youre awesome, helped a lot really
dominaiv 1 year ago
For all those people asking about his pen (all 3 of you), it's a Uni-Ball Gel Impact. Writes pretty smoothly.
jaylin27 1 year ago
@jaylin27 yea i have 1 and they last a long time too
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