I love how you show real world examples and all the sparks and fires. It makes it a lot more engaging especially so when you know the consequences of doing something wrong has very real potentially dangerous outcomes.
Sir... don't ever die, please! You are the best teacher I've ever had, and we're not even face-to-face! Your content hits the zen spot for understanding something that used to seem like an off-world language to me. With the deepest respect I can muster, I thank you. Leo.
it's videos like these that make me second guess why I'm in college learning this stuff when amazing people like you explain it so much more thoroughly than any of my professors ever could, and it 's their JOB.
we have a youtube channel that deals with Arduino,ATmega328P,Java,Serial programming ,robotics. So if you like these stuff do Subscribe. Sorry for annoying
62 and just now learning about electronics. I might have found interest years ago if somebody would have explained it the way you do. Subscribed and gonna check out some more videos. Thanks!
Your videos are Awesome! It took me 2 years to fully understand all of these things myself, if I would have found this channel beforehand it would have taken 2 days. I hope your videos get to as many enthusiasts as possible! Thank You!
Same here, i'm near retirement after spending 41 years in electronics trade. Why am i watching this video? Good video for youngsters to learn from. Please stick to battery power until you know what you are doing. Stay safe. @billigerfusel
Afrotechmods you are an amazing teacher, these videos always clear stuff in my head despite doing electronics for so long your understanding of the topic is very very impressive.
God bless you man. Please keep up this good work. I am from infosec. I wanted to learn about electricity. I always learn anything by visualizing and by imaginating it. So, your animated videos are very useful for visualization in mind. Thank you so much
Thanks for actually showing what happens when you run too much current thru an led, instead of just saying 'something bad will happen' or 'you don't want to do that' like the other videos!
Woah, you're actually here. Just to let you know, I love it when you explain a 'somewhat complex' circuit using your Keysight. And when you start taking notes and do calculations, that's when I feel somewhat advanced and professional. XD Love your vids, thanks.
"bad conductor, like this... er...dried out piece of carrot" has to be the most unusual choice of poor conductor to-hand I've seen, lol. Brilliant video. You have really helped my son learn the basics of electricity today, thanks for making these basic vids along with all your other awesome vids.
I've only watched this video and your LED video, and so far these two videos made by presumably one guy has taught me infinitely more about electronics than several lessons at school ever did. And this was a lot more fun than those lessons too.
Just found this channel. You must be a teacher because the clarity of your presentation is streets ahead of most people's. Unfortunately, I came upon this after two years of trial and error getting my grandchildren's train set and trains illuminated; at least I have ended up with roughly the same resistor values as the maths suggest. Next time, I'm armed with the correct information to bypass the trial and error. Many thanks.
Great video! The extra detail you put in describing how it works helps a lot. Examples both written and in performed in real world are excellent. More examples the better! I've watched multiple videos on resistors but I learned the most from yours. Looking forward to more videos.
I really appreciate all the detail in your videos and when theirs a lack of detail you refer us to an explanation in another one of your videos. Electronics is my biggest engineering weakness and so what better thing to do then to learn it, and with your help I can. Thanks -Jackson
explosion at 5:53 made me jump from my chair 😂 for some reason I was concentrated on something on the screen and when the explosion happened, it made me jump
in my teem years i attended an college electronics course but had a lot of trouble following the lecturers teaching. how i wish we then had ut where i could have learnt a lot more that what i was able to learn from the college lecturer. this presenter is many many time a better presenter than the then lecturer ever was.
I have an electronics shop in my basement. I have a Tenma 40 MHz oscilloscope with two inputs. I also have a Tenma Universal Test Center with a multimeter, a power supply with a 5 volt, a 13,8 volt and variable 0 to 30 volt, a signal generator up to 2 Mhz and selection of sine wave, square wave and triangle wave, and a frequency counter. I use the variable voltage to calculate the resistance of an LED when it gets bright enough and the current flow. This gives me what I need to know to add a resistor for the LED in a 12 volt circuit. I also design circuits for my model railroad signal system.
In your simple circuit with a 9V battery, LED, and resistor @5:58 I see the resistor on the anode side. I've seen this before and know it works but never understood why. Can you explain? If electrons flow from negative to positive I would think that this location is "too late" to save the LED. Wouldn't it be more appropriate to have the resistor on the cathode side?
In this case it does not matter which side the resistor is located in the circuit, so long as it is present. The omitted part of the video does not detail the fact that the entire circuit is in so called "series," meaning that every component is tied end to end with each other. In this format, the current is determined by the circuit voltage divided by the entire circuit's total resistance. The cool part of this setup is that the resistor and LED will both experience the same constant current in amps while having different voltages, since the individual component voltage is current times resistance. The only concern of resistor placement would be if the circuit was so called "series-parallel" where a drop in voltage could cause power problems in other branches of the circuit. Another concern on resistor placement would be purely for safety concerns if you wanted to limit a particular side of the circuit's current that might be exposed to human interaction, say a light switch.
In this case (since the circuit is in series), the current at any point is the same as the current at another point. What dictates current is the overall resistance. Resistors don't "use up" current in order to save the LED, but instead limits it overall.
I've likewise been thinking about this issue recently and am still confused about it...Glad Harvey and Ryan chimed in with their answers. Not sure why that apparent aspect isn't proactively noted more often when explaining this subject. I.e., the fact that a resistor (at least in a series rather than parallel circuit) will effectively decrease the current of the entire circuit (rather than simply a locality of it proximal to their placement). Because it seems (I would think) an obvious question for curious electronics newbies like myself. So yeah, I can defintely see the overall decrease in flow of electrons meaning lower current level the LED will be exposed to...BUT, is the voltage level the LED will be exposed to identically effected by the resistor (or is it, on the other hand, comparatively more dependent on location in the circuit relative to the resistor - i.e., whether it precedes or follows the resistor in the direction of electron [not conventional] flow)?
best explanation about resistance i understod by seeing this video with experiment and by knowing about wich colour have what amount it i really a great video
Thank you for this video! I have a pretty basic question here-- I see you followed your conventional current flow diagram when wiring up the 9v/LED/resistor. Why did you not wire it up according to neg to pos electron flow? If the electrons flow from the anode and hit the LED before the resistor, how is the resistor doing its job? It seems as if the resistor would serve no purpose after the high current flow already the LED. What am I not understanding correctly?
Think about the current flow in a circuit as a whole - where does the current go OUT of the led in that case? If you connect one leg of the LED to a high current source like a 12v car battery, but leave the other leg disconnected, what happens?
If electrons actually flow from negative to positive, could you have placed the resistor in series with the cathode side of the LED and achieved the same function?
Very nice... I wish if I could have u in my Electronics Engineering time and in my Electronics Lab. Now I am an eng but still I watch ur videos.Your lectures are awesome.
My 5 year old daughter just watched the movie earth to echo. She wanted to have a toy echo doll. Echo has two blue eyes. Simple, when I go to wire up the 2 blue LED for the eyes to make her Echo toy, I now know how to wire it up safely. Great video! I took some notes for later project use!
One of the most important things about LEDs are that they are low power. You put the LED in series with a 300Ω resistor. This meant that the LED was getting only 33% of the power and 66% was wasted in the resistor. With the 140V you toasted the resistor with 2.74 W as it got 98% of the 2.8 W of power leaving the battery - only 2% was used in the LED. How do you actually use LEDs without wasting power into resistors? Even LED strips you buy on Amazon have resistors. How do we use energy-saving LEDs without wasting energy in resistors?
Which means I shouldn't be using LED strips if I want more than 30% of the energy to go into the LEDS. I don't see how I can connect a constant current buck converter to 16 feet of www.amazon.com/LEDwholesalers-Flexible-300xSMD3528-Adhesive-2026WH/dp/B002Q8V8DM
Why limit that question to resistors? Many discrete components have limits on how much current they can handle. So one simply uses the appropriate resistor. An LED is no different.
Basically, you have a chain of LEDs in series and a small sense resistor at the end, (0.1ohm or so). You know elements in series must have the same current going through them, as part of KCL. You also know that in a resistor, current is directly related to voltage, and more importantly, linearly. What you do is measure the corresponding voltage across a resistor to read the current through the LEDs, then use that as feedback in your buck/boost driver. It's more complicated that that, but that's the gist of it.
+Idjles Erle With LED strips you don't waste 66% in the resistor. Have you ever tried measuring the voltage drop in those resistors? It's typically 2 out of the 12V you run the strip at, so 16% loss in the resistor, which is actually a better efficiency than many of the cheap constant current drivers (for low currents). You can't use a constant current driver for a strip. Such a driver can only drive a single series connection of LEDs, parallel connected ones (exceptions if you know what you're doing), which for a long strip would mean dangerously high voltages.
question: so could I also place the resistor BEFORE the LED then, instead of after as you have here? seems if actual current is flowing from neg to pos, I'd want it to traverse the resistor first... or is the placement of the resistor unimportant because it affects the circuit as a whole?
Well, here's the thing. Voltage and current flow are about voltage differential. You have to imagine that there's someone pushing the electrons at the negative side, but there's also someone pulling them on the positive. No matter what side the resistor is on, the current will flow just the same through the led.
That's revolting! you never know watt to expect! Don't resist the temptation to laugh every now and then, that's the most current joke I know. Great video. Thanks for sharing with us dummies.....
Great job sir! Awesome work.. I think you should do all the videos on TH-cam period. Well done! I was just fooling around and wasting time watching videos and I was very happy. Do more vid's..
To calculate the resistance value, you need to group the values of the significant digits bands - i.e., the values of the first two or three bands from the left, depending on the total number of bands. Then you need to multiply that value by the multiplier to get the resistance value of the resistor. Let's take for example a four-band resistor with the following band colors: Violet Green Yellow Gold Since it is a four-band resistor, the first two bands (violet and green) will indicate the significant digits which are, according to the table above; 75. We then multiply that number by the multiplier indicated with the 3rd band (yellow) which has the value of; x104 = 10000. The result of the multiplication will be: 75 x 10000 = 750000Ω = 750kΩ. The fourth band (gold) will indicate the tolerance which in our example is: ±5% To calculate the minimum and maximum resistance values, we multiply the resistance value by the tolerance percentage to come up with the following values: Minimum = 750000 - (750000 x 5/100) = 750000 - 37500 = 712500 = 712.5kΩ Maximum = 750000 + (750000 x 5/100) = 750000 + 37500 = 787500 = 787.5kΩ
you are connecting them in parallel to a voltage source so it is the same thing as connecting one. If you connect them to a current source then also its not a good idea as leds don't do current sharing very well. One will take a lot of current first and blow up, then next will do the same and soon you will have 100 burnt leds on your hand.
+Qaz Wsx it depends on if u wanna use just one single resistor for the whole LEDs or a single resistor foe every LEDs. I think his question was if he would use just one single resistor!
No, you don't need one, you need one hundred. Unless the LEDs are matched (i. e. have the exact same electrical properties, which is improbable unless you measured them all) and thermally coupled (all stay at the same temperature by mounting them on the same heatsink for example), you must never connect LEDs in parallel without a resistor for each parallel string.
Back in my day, current flowed from negative to positive. Lightning didn't strike the ground, electrical fingers rose from the ground and drew the bolt down. I was recording clouds that looked like they were trying to form a tornado. Lightning was striking all around at times. Later when I reviewed my video, I recorded lighting striking the front of my truck while I was driving and I had no idea it had. You could actually see the finger reach up from the front end and the bolt come down to meet it.
Interested in learning about wireless power? Subscribers can get up to 80% off my course Wireless Power to the People - Wireless Charging 101 on udemy using the coupon code "TH-cam" www.udemy.com/wireless-power-to-the-people-wireless-charging-101/?couponCode=TH-cam
I used to have a Electronic project box from Radio Shack with 300 or more projects and I learned a lot about circuits, radios, etc, etc. But now that Radio Shack is closed, can you tell me how to get one? Thank you very much for these videos.
I remember experimenting to prove Ohm's law for 'O' level physics. Then we went on to 'A' level, and the teacher pointed out that the experiments were worthless, because the meters we used to prove Ohms law themselves relied on Ohm's law.. (Yes, you CAN prove Ohm's law, but you have to be careful what tools you use to do it.)
I am totally new to electric wiring. I found your videos very clear and informative. My question is power source. If I want to create plug for regular current, I assume I need to get different resistor. Could you recommend what to do? Thank you. These videos are very well done!
we have a youtube channel that deals with Arduino,ATmega328P,Java,Serial programming ,robotics. So if you like these stuff do Subscribe. Sorry for annoying
Man im jealous! you got some very nice equipment. Great videos too, really helped me to understand LEDs. Do you think you could do one about the LEDs like in a remote controler sometime?
hi afrotechmods i am priyanshu i have also a channel named as techy ideas i saw your 3 videos today i found them very very useful i thank u for making such great videos this video cleared almost every confusions i have in my mind about resistor. i am also a boy crazy about technology studying in standard 8 knows most things about robotics i love to see videos related to arduino and electrical parts.but i dont have any arduino till now hope my father will buy this for me soon. thankyou
The fucking fuse being handy for not burning your house down in the first vid made me laugh, the Minion squealing whaaaaaat in the second vid cracked me up, and now the dried out carrot for a resistor in this video made me lose my shit!
I recently purchased 3 - 300 watt/2 ohm resistors for the braking circuit for my wind turbine. I took a picture holding one of these monsters and posted it to a “nerd” FB group I’m in with the caption “Take that Borg!!”. Apparently I thought it was a lot funnier than most of them. I’m betting you’ll love it too. Also, I want a bench top power supply: is there any reason not to go for a 10A or will a 5 work just as well? I plan to test fans, motors and other randomness I might be able to turn into a toy or gadget. Thanks!
This reminds me of my electronics class at Jr. College in 1970. The class was taught by a retired Navy Chief Petty Officer. One day he was explaining in words and diagrams on the black board the resistor color code. At one point he said, "A BLACK color in the third band is a place holder it has no value, NONE !" The retired Chief then turns to me asking, "Do you know what a NUN is?" I thought ok I'll play straight guy as this has got to be good... "No Chief I don't. What is a Nun?" The Chief replies, "A NUN is a gal that ain't got none, don't want none, and doesn't want anyone else to GET none !" Needless to say the class was in an uproar of laughter... I hope this makes your day.
I love how you show real world examples and all the sparks and fires. It makes it a lot more engaging especially so when you know the consequences of doing something wrong has very real potentially dangerous outcomes.
Sir... don't ever die, please! You are the best teacher I've ever had, and we're not even face-to-face! Your content hits the zen spot for understanding something that used to seem like an off-world language to me. With the deepest respect I can muster, I thank you. Leo.
it's videos like these that make me second guess why I'm in college learning this stuff when amazing people like you explain it so much more thoroughly than any of my professors ever could, and it 's their JOB.
we have a youtube channel that deals with Arduino,ATmega328P,Java,Serial programming ,robotics. So if you like these stuff do Subscribe. Sorry for annoying
62 and just now learning about electronics. I might have found interest years ago if somebody would have explained it the way you do. Subscribed and gonna check out some more videos. Thanks!
Your videos are Awesome! It took me 2 years to fully understand all of these things myself, if I would have found this channel beforehand it would have taken 2 days. I hope your videos get to as many enthusiasts as possible!
Thank You!
That feel when you're an electrical engineer already and still watch Afrotechmods, because he makes good videos.
billigerfusel right in the feels 💛
Same
billigerfusel
I want to be an electical engineer too. ❤
Same here, i'm near retirement after spending 41 years in electronics trade. Why am i watching this video?
Good video for youngsters to learn from. Please stick to battery power until you know what you are doing. Stay safe.
@billigerfusel
Afrotechmods you are an amazing teacher, these videos always clear stuff in my head despite doing electronics for so long your understanding of the topic is very very impressive.
Nice videos, all of them. As a field service engineer for 30 years (retired now) I'll use your videos for examples to my kids. Well done.
God bless you man. Please keep up this good work. I am from infosec. I wanted to learn about electricity. I always learn anything by visualizing and by imaginating it. So, your animated videos are very useful for visualization in mind. Thank you so much
Ashok Dewan Waaaait a second. I am from infosec too and I want to learn about electricity😑
Thanks for actually showing what happens when you run too much current thru an led, instead of just saying 'something bad will happen' or 'you don't want to do that' like the other videos!
Great video!
Woah, you're actually here.
Just to let you know, I love it when you explain a 'somewhat complex' circuit using your Keysight.
And when you start taking notes and do calculations, that's when I feel somewhat advanced and professional. XD
Love your vids, thanks.
GreatScott! You too do great job
Hey scott! I love your videos!
wohooo. hiii
Great Scott!!
"bad conductor, like this... er...dried out piece of carrot" has to be the most unusual choice of poor conductor to-hand I've seen, lol.
Brilliant video. You have really helped my son learn the basics of electricity today, thanks for making these basic vids along with all your other awesome vids.
Wow! This is totally electronics for dummies. Thank You! This is what I need.
I've only watched this video and your LED video, and so far these two videos made by presumably one guy has taught me infinitely more about electronics than several lessons at school ever did. And this was a lot more fun than those lessons too.
At 0:22 - 0:23 you can watch the little LED's soul being lifted to LED heaven
this comment made me cry an LED tear..
0:24 "I'm not dead."
0:26 "You soon will be."
0:27 "He's died."
Poor LED was sentenced to the electric chair
Bwahahahahaha!!!
Idaho Made bmwahahah
I wish this guy still makes electronics videos. He's actually one of the best.
another great video from one of the best electronics channels on youtube. more please - happy to sit through adverts for your content!
⁷
Just found this channel. You must be a teacher because the clarity of your presentation is streets ahead of most people's. Unfortunately, I came upon this after two years of trial and error getting my grandchildren's train set and trains illuminated; at least I have ended up with roughly the same resistor values as the maths suggest. Next time, I'm armed with the correct information to bypass the trial and error. Many thanks.
Great video! The extra detail you put in describing how it works helps a lot. Examples both written and in performed in real world are excellent. More examples the better! I've watched multiple videos on resistors but I learned the most from yours. Looking forward to more videos.
The ratio 0f r.ms value the average value of an alternating quantiy is called frim factor .. Rms .value /average value 1m£2 /=€\21M2€m=1.11.
I really appreciate all the detail in your videos and when theirs a lack of detail you refer us to an explanation in another one of your videos. Electronics is my biggest engineering weakness and so what better thing to do then to learn it, and with your help I can.
Thanks
-Jackson
Why am I buying resistors when I can just use a dried out piece of carrot?
Sir, you've made my day.
I don't know about you, bu I always had problems tinning the ends of the carrot. That's why I started using resistors.
A new unit of resistance? The impedance of this circuit is 3 dried out pieces of carrot.
tablatronix 😂
ys, you can add it or slowly sandpaper it to desired resistance
3:50 has done a much better explanation than anything anyone else has ever told me.
The best tutorial about electronics on TH-cam Great Job👍👍👍👍👍👍
i see around 15+ video but i didn’t understand. this video clear all misconception.specialy mathematical part is very helpful. thanks a lot.❤❤
afrotechmods, your videos are superb, waiting for the next one!
man, i am an information technology student. I mainly work on softwares, but arduino got me into electrical engineering which is awesome
explosion at 5:53 made me jump from my chair 😂
for some reason I was concentrated on something on the screen and when the explosion happened, it made me jump
@Badr Ahmed headphones actually... yes
that poor Raspberry Pi...
in my teem years i attended an college electronics course but had a lot of trouble following the lecturers teaching. how i wish we then had ut where i could have learnt a lot more that what i was able to learn from the college lecturer. this presenter is many many time a better presenter than the then lecturer ever was.
Yup. That's why I made these videos!
came here because my physics teacher can't explain well- 👁👄👁
I have an electronics shop in my basement. I have a Tenma 40 MHz oscilloscope with two inputs. I also have a Tenma Universal Test Center with a multimeter, a power supply with a 5 volt, a 13,8 volt and variable 0 to 30 volt, a signal generator up to 2 Mhz and selection of sine wave, square wave and triangle wave, and a frequency counter. I use the variable voltage to calculate the resistance of an LED when it gets bright enough and the current flow. This gives me what I need to know to add a resistor for the LED in a 12 volt circuit. I also design circuits for my model railroad signal system.
V
----------
I x R
Cover the quantity that you want to calculate with your finger, and you see the expression you need.
Or you would, if the editor hadn't removed the spaces before the 'V'.
im 70 and I start doing Arduino following you videos
In your simple circuit with a 9V battery, LED, and resistor @5:58 I see the resistor on the anode side. I've seen this before and know it works but never understood why. Can you explain? If electrons flow from negative to positive I would think that this location is "too late" to save the LED. Wouldn't it be more appropriate to have the resistor on the cathode side?
In this case it does not matter which side the resistor is located in the circuit, so long as it is present. The omitted part of the video does not detail the fact that the entire circuit is in so called "series," meaning that every component is tied end to end with each other. In this format, the current is determined by the circuit voltage divided by the entire circuit's total resistance. The cool part of this setup is that the resistor and LED will both experience the same constant current in amps while having different voltages, since the individual component voltage is current times resistance. The only concern of resistor placement would be if the circuit was so called "series-parallel" where a drop in voltage could cause power problems in other branches of the circuit. Another concern on resistor placement would be purely for safety concerns if you wanted to limit a particular side of the circuit's current that might be exposed to human interaction, say a light switch.
Richard Forester Seriously don't do anything with electricity take up macrame .
You are correct in your thinking but it will resist the flow in the entire length of the circuit, from battery back to the battery.
In this case (since the circuit is in series), the current at any point is the same as the current at another point. What dictates current is the overall resistance. Resistors don't "use up" current in order to save the LED, but instead limits it overall.
I've likewise been thinking about this issue recently and am still confused about it...Glad Harvey and Ryan chimed in with their answers. Not sure why that apparent aspect isn't proactively noted more often when explaining this subject. I.e., the fact that a resistor (at least in a series rather than parallel circuit) will effectively decrease the current of the entire circuit (rather than simply a locality of it proximal to their placement). Because it seems (I would think) an obvious question for curious electronics newbies like myself.
So yeah, I can defintely see the overall decrease in flow of electrons meaning lower current level the LED will be exposed to...BUT, is the voltage level the LED will be exposed to identically effected by the resistor (or is it, on the other hand, comparatively more dependent on location in the circuit relative to the resistor - i.e., whether it precedes or follows the resistor in the direction of electron [not conventional] flow)?
best explanation about resistance
i understod by seeing this video with experiment and by knowing about wich colour have what amount
it i really a great video
My friend told me how electricity is measured and I was like Watt!
What is seen cannot be unseen...
electricity is amportant
Ohmy God!
NERD JOKES!!
Those jokes make me Hertz!
I took notes & saved it to Microsoft Word, It was very helpful when I setup my LEDS for my R/C vehicles.
Thank you for this video! I have a pretty basic question here-- I see you followed your conventional current flow diagram when wiring up the 9v/LED/resistor. Why did you not wire it up according to neg to pos electron flow? If the electrons flow from the anode and hit the LED before the resistor, how is the resistor doing its job? It seems as if the resistor would serve no purpose after the high current flow already the LED. What am I not understanding correctly?
I have the same question! Someone please answer!
@@seanlikestoeat lost all hope, 4 years and still no answer
Think about the current flow in a circuit as a whole - where does the current go OUT of the led in that case? If you connect one leg of the LED to a high current source like a 12v car battery, but leave the other leg disconnected, what happens?
Dude you literally just saved me my IGCSEs are in a day and this came out today
Hope you passed
Oh my God! Thanks so much for that comic! Everything makes sense now.
Thank you! :)
My professor spend long time rambling out words that to me give no sense, but now I understand much better!
If electrons actually flow from negative to positive, could you have placed the resistor in series with the cathode side of the LED and achieved the same function?
Actually electrons flow opposite to the flow of negative charge....
Very nice... I wish if I could have u in my Electronics Engineering time and in my Electronics Lab. Now I am an eng but still I watch ur videos.Your lectures are awesome.
muy bueno el vídeo, me vino bien toda la información!! saludos de Argentina
My 5 year old daughter just watched the movie earth to echo. She wanted to have a toy echo doll. Echo has two blue eyes. Simple, when I go to wire up the 2 blue LED for the eyes to make her Echo toy, I now know how to wire it up safely. Great video! I took some notes for later project use!
Yay! Next step: Teach her how to do it!
One of the most important things about LEDs are that they are low power. You put the LED in series with a 300Ω resistor. This meant that the LED was getting only 33% of the power and 66% was wasted in the resistor. With the 140V you toasted the resistor with 2.74 W as it got 98% of the 2.8 W of power leaving the battery - only 2% was used in the LED.
How do you actually use LEDs without wasting power into resistors? Even LED strips you buy on Amazon have resistors. How do we use energy-saving LEDs without wasting energy in resistors?
Constant current buck converters
Which means I shouldn't be using LED strips if I want more than 30% of the energy to go into the LEDS.
I don't see how I can connect a constant current buck converter to 16 feet of
www.amazon.com/LEDwholesalers-Flexible-300xSMD3528-Adhesive-2026WH/dp/B002Q8V8DM
Why limit that question to resistors? Many discrete components have limits on how much current they can handle. So one simply uses the appropriate resistor. An LED is no different.
Basically, you have a chain of LEDs in series and a small sense resistor at the end, (0.1ohm or so).
You know elements in series must have the same current going through them, as part of KCL. You also know that in a resistor, current is directly related to voltage, and more importantly, linearly.
What you do is measure the corresponding voltage across a resistor to read the current through the LEDs, then use that as feedback in your buck/boost driver.
It's more complicated that that, but that's the gist of it.
+Idjles Erle
With LED strips you don't waste 66% in the resistor. Have you ever tried measuring the voltage drop in those resistors? It's typically 2 out of the 12V you run the strip at, so 16% loss in the resistor, which is actually a better efficiency than many of the cheap constant current drivers (for low currents).
You can't use a constant current driver for a strip. Such a driver can only drive a single series connection of LEDs, parallel connected ones (exceptions if you know what you're doing), which for a long strip would mean dangerously high voltages.
finally a video about LED's that I can understand. thanks bro
question: so could I also place the resistor BEFORE the LED then, instead of after as you have here? seems if actual current is flowing from neg to pos, I'd want it to traverse the resistor first... or is the placement of the resistor unimportant because it affects the circuit as a whole?
Well, here's the thing. Voltage and current flow are about voltage differential. You have to imagine that there's someone pushing the electrons at the negative side, but there's also someone pulling them on the positive.
No matter what side the resistor is on, the current will flow just the same through the led.
You need to be cloned……I’m an electrician……its so nice to listen to someone who can explain electricity so clearly
lol aww thanks
3:49 current abuse 😢
I have just found this video. Thanks. I will watch it again when I get ohm.
This video explained well than my electrical subject professor whom I paid a lot. life sucks
I love how you just made everything simple by using a dried out carrot 😋.
Who knew they were such good resistors?
th-cam.com/video/yP9KuasvrYM/w-d-xo.html
That's revolting! you never know watt to expect! Don't resist the temptation to laugh every now and then, that's the most current joke I know. Great video. Thanks for sharing with us dummies.....
I am really amped up when I hear/see puns
@@sushmaverma3562 no u
@@username0004 oh fuck
Ohm y
Great job sir! Awesome work.. I think you should do all the videos on TH-cam period. Well done! I was just fooling around and wasting time watching videos and I was very happy. Do more vid's..
Even my leds blowing up are less exciting than yours.
The fact that I 'm here just for my physics lesson...😂😅 I didn't expect i'll learn how to become an electric engineer
3:52 *crowd cheers*
3:57 *crowd boos*
Thank God I found this channel.
08:30 - 2.74W dissipated from a 0.25W resistor. Magic smoke released. Very hot electronics porn!
Porn?
LVB1B. You rather someone shit on your chest?
To calculate the resistance value, you need to group the values of the significant digits bands - i.e., the values of the first two or three bands from the left, depending on the total number of bands. Then you need to multiply that value by the multiplier to get the resistance value of the resistor.
Let's take for example a four-band resistor with the following band colors: Violet Green Yellow Gold
Since it is a four-band resistor, the first two bands (violet and green) will indicate the significant digits which are, according to the table above; 75.
We then multiply that number by the multiplier indicated with the 3rd band (yellow) which has the value of; x104 = 10000.
The result of the multiplication will be: 75 x 10000 = 750000Ω = 750kΩ.
The fourth band (gold) will indicate the tolerance which in our example is: ±5%
To calculate the minimum and maximum resistance values, we multiply the resistance value by the tolerance percentage to come up with the following values:
Minimum = 750000 - (750000 x 5/100) = 750000 - 37500 = 712500 = 712.5kΩ
Maximum = 750000 + (750000 x 5/100) = 750000 + 37500 = 787500 = 787.5kΩ
Uhhh that raspberry was a expensive test....
not really
That's the entire point of the PI, to learn, and breaking it is a form of learning.
Electricity engineering is very beautiful to study and imagined. Electricity is very smart and connected one.
Poor Raspberry Pi...
I thought the same
This topic never gets old. Subbed
I need a resistor for my head it's getting fryed
i calculated it for myself and it was 69,42 petaohms
this vedio cleared all my concepts feeling that i have acquired extreme knowledge
i m very thankful to you 👏👏👏👌👌👌
Reactor desind vedeo
Did anyone else almost jump at 5:47 - 5:55?
no
What great videos....makes the most confusing topics, easy to understand. Thanks.
in Germany we use U instead of V
Same in Finland.
Same in France
you guys just trying to be different hahahaha
???..a doubt from India
Every electronics beginner should watch your videos ... !!
Thank you Sir !!
Waiting for the next video ....
Everyone knows about resistance.
It’s futile.
I love elektrotechniek and elektronica. good video! resistor is warmth, fasecutting...
Resistor calculator? C'mon, son. Learn the mnemonic like the rest of us did back in the day. ;)
i r 2 stewpid 4 dat
electrodroid ftw xd
"I had to suffer and you should too!" :D
Hey, we can use those resistor things to make a machine to remember for us ;)
Bad Boys rape our young girls but Violet gives willingly. Get some now.
You are the best! You earn Millions of subscribers!
Children in africa could have ate that Raspberry Pi.
Raspi in Africa could've eaten that children.
Toto ate my raspberries.
+Afrotechmods It seems like Mr. Afro is in a good joking mood today XD
@2:40 , I like how out of everything in the world that could be used a dry carrot was chosen 😂 definitely had me LOLin
What if i put 100 leds in parallel do i need a resistor?
NE555 yes of course u need!
you are connecting them in parallel to a voltage source so it is the same thing as connecting one. If you connect them to a current source then also its not a good idea as leds don't do current sharing very well. One will take a lot of current first and blow up, then next will do the same and soon you will have 100 burnt leds on your hand.
+Qaz Wsx it depends on if u wanna use just one single resistor for the whole LEDs or a single resistor foe every LEDs. I think his question was if he would use just one single resistor!
You need a Power MOSFET first to control big loads with microcontroller
No, you don't need one, you need one hundred. Unless the LEDs are matched (i. e. have the exact same electrical properties, which is improbable unless you measured them all) and thermally coupled (all stay at the same temperature by mounting them on the same heatsink for example), you must never connect LEDs in parallel without a resistor for each parallel string.
Back in my day, current flowed from negative to positive. Lightning didn't strike the ground, electrical fingers rose from the ground and drew the bolt down. I was recording clouds that looked like they were trying to form a tornado. Lightning was striking all around at times. Later when I reviewed my video, I recorded lighting striking the front of my truck while I was driving and I had no idea it had. You could actually see the finger reach up from the front end and the bolt come down to meet it.
Interested in learning about wireless power? Subscribers can get up to 80% off my course Wireless Power to the People - Wireless Charging 101 on udemy using the coupon code "TH-cam"
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I used to have a Electronic project box from Radio Shack with 300 or more projects and I learned a lot about circuits, radios, etc, etc. But now that
Radio Shack is closed, can you tell me how to get one?
Thank you very much for these videos.
Sir I must say you are a real Master, I always wanted to understand all of these things but I could not! Even in my own language (Spanish)
I remember experimenting to prove Ohm's law for 'O' level physics.
Then we went on to 'A' level, and the teacher pointed out that the experiments were worthless, because the meters we used to prove Ohms law themselves relied on Ohm's law..
(Yes, you CAN prove Ohm's law, but you have to be careful what tools you use to do it.)
Two thumbs up from the retired teacher of electronics.
Complete newb here actually taking notes like this is a school lecture. 🤣 So helpful!
This video is a gems and is really well explained about the eletricity current. Thank you so much!
Well done. Thank you for your concise explanations.
I am totally new to electric wiring. I found your videos very clear and informative. My question is power source. If I want to create plug for regular current, I assume I need to get different resistor. Could you recommend what to do? Thank you. These videos are very well done!
Very informative....how I wish you were my prof in Electronics before.
hey ! just found this awesome video , was finding a video that could thoroughly explain electronics to me, and i think i would stick to this channel !
we have a youtube channel that deals with Arduino,ATmega328P,Java,Serial programming ,robotics. So if you like these stuff do Subscribe. Sorry for annoying
Man im jealous! you got some very nice equipment. Great videos too, really helped me to understand LEDs. Do you think you could do one about the LEDs like in a remote controler sometime?
Great video
hi afrotechmods i am priyanshu i have also a channel named as techy ideas i saw your 3 videos today i found them very very useful i thank u for making such great videos this video cleared almost every confusions i have in my mind about resistor.
i am also a boy crazy about technology studying in standard 8 knows most things about robotics i love to see videos related to arduino and electrical parts.but i dont have any arduino till now hope my father will buy this for me soon.
thankyou
The fucking fuse being handy for not burning your house down in the first vid made me laugh, the Minion squealing whaaaaaat in the second vid cracked me up, and now the dried out carrot for a resistor in this video made me lose my shit!
I recently purchased 3 - 300 watt/2 ohm resistors for the braking circuit for my wind turbine. I took a picture holding one of these monsters and posted it to a “nerd” FB group I’m in with the caption “Take that Borg!!”. Apparently I thought it was a lot funnier than most of them. I’m betting you’ll love it too. Also, I want a bench top power supply: is there any reason not to go for a 10A or will a 5 work just as well? I plan to test fans, motors and other randomness I might be able to turn into a toy or gadget. Thanks!
Wonderful illustration
I can not stop watching videos to learn about the world
This reminds me of my electronics class at Jr. College in 1970. The class was taught by a retired Navy Chief Petty Officer. One day he was explaining in words and diagrams on the black board the resistor color code. At one point he said, "A BLACK color in the third band is a place holder it has no value, NONE !" The retired Chief then turns to me asking, "Do you know what a NUN is?" I thought ok I'll play straight guy as this has got to be good... "No Chief I don't. What is a Nun?" The Chief replies, "A NUN is a gal that ain't got none, don't want none, and doesn't want anyone else to GET none !" Needless to say the class was in an uproar of laughter...
I hope this makes your day.
Great explanations. Thank you taking the time to make these tutorials 👍😊
My pleasure!
If you are looking to remember resistor values, it's basically just ROY G BIV with a couple extra colors.
For viewer's information: In the text books, the symbol for voltage is likely to be "E". E=IR