Caught this video before leaving for work. This is great info for a beginner. That presentation board w/ the Uno and BB is totally awesome, have a great Monday buddy!
This is also a good watch to understand the relationship between voltage and current. I had no idea it would take a whopping 16V to heartily light up 5 LEDs in series .... working with this stuff really helps to understand it better.
Great vid, I'm following each one of these basic electronic vids, building the circuits doing the math so as to reinforce what I've learned. If, as you say, you are going to do more of these great basic vids I'm signed up and ready to go. The Arduino ones sound really interesting, its an area that I've been keen to explore. Really great idea to do these and I cannot thank you enough for what you have taught me already. Thank you for sharing your skills.
Paul, perhaps an explanation of LED fundamentals is due, judging by some of the questions posted here and elsewhere. Like how the resistance of the LED increases as the LED light intensity increases, until an equilibrium between current and resistance is reached, therefore self limiting the current at Vf.
HAM radio, really expensive telephone. 😀 Serial LEDs = Christmas lights. Great basics and good math to remember. Thanks, Paul another really good basics video!
Good beginner video. One thing I think you missed was to calculate a "good resistor". This could be very important in a beginners understanding of why you picked a 330 ohm resistor as a good resistor.
Hi.I’m looking at a 12v vw t4 badge it has already a string of bulbs behind badge in vw shape.some bulbs been out a while.I’ve ordered some 3mm led bulbs to replace.if old bulbs were not led.do I need resistors for led bulbs need about 10 extra in total of 25 .it’s 12v supply from side light circuit just when engine running normally .thanks .Steve
I would have liked to know if there where two parallel lines of serial LED's. How the amps react if one LED in one line goes out. I guess that amps going through the remaining line of serial LED's does not change? The other thing I would like to know if for some reason one LED in serial is brighter than all the rest what can you do to lower the AMPs for that one LED so it dulls slightly.
Typical dumb question, but I'm putting some LED's in a circuit that also has a 555 chip. I want the LED to show that the circuit is on, not so much interact with the 555. How would I treat the 555 when it comes to calculating the circuits voltage so that the LED doesn't burn out. I'd be using a 9v battery.
I've wondered about the voltages on some LED's. Some say like 3 volts etc. But I've wondered if you can use them in a 10 - 20 volt circuit just as long as you don't go over the maximum 20 ma rating. It confuses me on that. And I've seen where they use LES's in AC circuits with no diode. I guess because they are diodes. But you can notice a slight flicker. Any words on the mater of the limit of voltage on an LED ?
Great vid for the beginner indeed, as which I also see myself, so thanks. Paul if you have a VCC voltage of 2.4V and you will connect a green LED than the voltage is enougth to light the LED. But the current is not limited by a resistor in this case, so I think the LED will not survive this? Is there any way to deal with this, or can the current be limited to less than 30 mA if the LED and the VCC can not be changed? Because if you have a light bulb of 120V and you connect it to 120V there is no problem, so with a VCC that matches the needed voltage of an LED you should be safe one would think.
Roland Berendonck perhaps you should think of the LED as resistor. At 2.4V, with zero resistance 2.4 amps will flow from positive to negative but the LED also limits current to what it requires, therefore it will not blow!
@@captainpugwash4100 At 2.4 Volt and with no resistance in the LED I should think that the current is infinitive. As I understand that is the thing with LED's that they have little to no resistance. So I think it will blow at 2.4 Volt, but as Omnipotent says there is a sort of safety range for the Voltage in which it will not blow. I will look for such a graph. And thanks for your answer :)
Roland Berendonck I didn’t say that the LED has zero resistance, it does indeed have one. Divide the Vf (forward voltage e.g. 2V for red or 3.3V for green) by the recommended current (say 0.02A) and you get the resistance. What I did say was that if you apply just the Vf across the anode - cathode, the LED reaches an equilibrium and draws no more current than it needs.
Omnipotent ! I am fully aware that there are LEDs with different data sheets showing different operating values. I have taken some up to 140 - 150% of the Vf before they burnt out. Certainly if you look at the graphs for normal or zener diodes there is a very steep gradient close to the y axis and especially near the breakdown voltage!
Please don’t be insulted as you are probably a decade or two younger than my 60 years, but you talk to me like the good teachers I knew at school and my criminal law lecturer (professor) at uni. Tell us what you’re going to teach, teach summarise. I respond best to good old fashioned teaching styles as the afore mentioned lecturer would testify. Please keep this style.
Im sorry but as beginner who would like to use leds this ok as a demo, but i need to know when and if i need a resistor. How do i find out what resistor works best . For me a better understanding would have been a wire from the uno to led and not a fancy power supply . Do i just adjust voltage or milliamps as well. How do i find the numbers to do the math ,and once i have the answer how do i apply that.If my transformer says 300 milliamps at 1.5 volts do i just wire any led without a resistor.
He does cover what you're asking in the video, but it's only mentioned in passing and he's also assuming that you understand the most rudimentary aspects of Ohm's Law. You know you need to drive the LED with ~20 mA (.02 A) because much more than that will kill the LEDs, or at least significantly decrease their lifespan. So that's your value for current. Then take your voltage (5V for arduino) and plug both values into the Ohm's Law equation, solved for Resistance. Here are the maths spelt out: R = V / I R = 5 V / .02 A R = 250 Ω
I am the complete novice to whom you refer and at 12 minutes I had to give up as I have no idea what your are doing or trying to demonstrate other than to show how many devices you can connect to one LED
The "4k7" bit should be considered as a unit and just means 4700 ohms. The "R" after that just means "Resistor" (or maybe "Resistance"?). I'm not sure why it's done that way - seems like putting an actual Ω symbol on there would make more sense.
@@largepimping Thanks for your reply. I kinda figured that myself, but I wasn't sure, being that they have some labeled "470K R 25PCS", without anything at the R. It's a bit confusing.:)
I'm sorry, I disliked this video as I have many of yours. I want to watch and follow along but you constantly disappoint in your methods. In this one you were driving the "LED at 15mA" then adjusting your power supply voltage until it lit. That wasn't doing what you said, which is why later on when you measured your current you got no reading. Your process is seriously flawed. You stated early on you had the power supply set to 15mA current, then later on you proved you couldn't do exactly that same thing. As part of that failed process you blew up an LED and just laughed it off as part of the process. This type of error in process has been in many of your videos and is not really helping beginners, learnelectronics. Start again. The way I suggest measuring the required voltage for the LED is to use a series resistor of maybe 470 Ohm and adjust the voltage while measuring the current and watching the LED. You'll need about 5-15v for most basic LED types. Choose a light level you are happy with by adjusting the voltage. Now you can measure the current through the circuit and measure the voltage on the LED. That will show you exactly the current and voltage you require for resistor calculation. Most general LED's will be very happy with 10mA and can often be driven at far less while maintaining good light output.
@@rolandberendonck3900 so you are accepting that someone is giving out terrible advice. Not even by accident. Paul was aware of the errors but didn't care to fix then. Your accepting of that?
"not really helping beginners" you are too far elevated along to path of EE to even remember what it is like for beginners. We need as many viewpoints and demonstrations as we can get and some people just resonate better with each of us. Between the time this video was upload and I posted this reply to you, some THIRTY FIVE videos about FLAT EARTH were uploaded to UA-cam. Three live streams as I type. Just saying ... wanna vent? Priorities! Take care and thank you for being a contributor of PROGRESS.
@@PIXscotland I see a lot of video's on the web and there are very very few which are flawless and perfect. To tell you the truth even I make mistakes, however that is only sometimes. The way Paul makes a video is just letting the camera roll and do his thing and sometimes he makes a mistake. And from such mistakes there are a lot of people who can even learn from that, and that is besides Paul's adorable and highly amusing character, what it's all about. Another thing is that if you are studying on a subject it's beneficial to watch more video's on the same subject. And if you discover an error in some video that just shows that you have learned something and have evolved in a subject. For me that is something to feel content and proud off, and I can forgive someone that made a mistake because he just forgets, is not paying enough attention, is just human or doesn't know any better. If I don't like it and it disturbs me than that is my own responsibility because I am the only one who has control what to watch and what not. Peace :)
I am sorry, I missed your channel name. Could you please post the name of the channel where you are making your videos and posting them so I can watch you do what you are writing. Because short of that, it is merely arm chair quarterbacking and any twit can do that - so I am sure that is not what you are doing.
Great video Paul, it never hurts to reinforce the basics so I always watch the videos you say are the basics.
Caught this video before leaving for work. This is great info for a beginner. That presentation board w/ the Uno and BB is totally awesome, have a great Monday buddy!
This is also a good watch to understand the relationship between voltage and current. I had no idea it would take a whopping 16V to heartily light up 5 LEDs in series .... working with this stuff really helps to understand it better.
Excellent presentation. Always good to get back to basics.
Excellent class!! I learn a lot from you and your videos. You're a very good teacher Mr. Paul.
Great vid, I'm following each one of these basic electronic vids, building the circuits doing the math so as to reinforce what I've learned. If, as you say, you are going to do more of these great basic vids I'm signed up and ready to go.
The Arduino ones sound really interesting, its an area that I've been keen to explore.
Really great idea to do these and I cannot thank you enough for what you have taught me already.
Thank you for sharing your skills.
Very good video again Paul. Continue the good work.
Good stuff. I'm a novice, and just kinda playing with electronics here and there. Love the vids.
Paul, perhaps an explanation of LED fundamentals is due, judging by some of the questions posted here and elsewhere. Like how the resistance of the LED increases as the LED light intensity increases, until an equilibrium between current and resistance is reached, therefore self limiting the current at Vf.
Your teaching is fantastic 👍
Well done .That was very helpful .
HAM radio, really expensive telephone. 😀 Serial LEDs = Christmas lights. Great basics and good math to remember. Thanks, Paul another really good basics video!
Good beginner video. One thing I think you missed was to calculate a "good resistor". This could be very important in a beginners understanding of why you picked a 330 ohm resistor as a good resistor.
Hi.I’m looking at a 12v vw t4 badge it has already a string of bulbs behind badge in vw shape.some bulbs been out a while.I’ve ordered some 3mm led bulbs to replace.if old bulbs were not led.do I need resistors for led bulbs need about 10 extra in total of 25 .it’s 12v supply from side light circuit just when engine running normally .thanks .Steve
I would have liked to know if there where two parallel lines of serial LED's. How the amps react if one LED in one line goes out. I guess that amps going through the remaining line of serial LED's does not change?
The other thing I would like to know if for some reason one LED in serial is brighter than all the rest what can you do to lower the AMPs for that one LED so it dulls slightly.
Typical dumb question, but I'm putting some LED's in a circuit that also has a 555 chip. I want the LED to show that the circuit is on, not so much interact with the 555. How would I treat the 555 when it comes to calculating the circuits voltage so that the LED doesn't burn out. I'd be using a 9v battery.
I've wondered about the voltages on some LED's. Some say like 3 volts etc. But I've wondered if you can use them in a 10 - 20 volt circuit just as long as you don't go over the maximum 20 ma rating. It confuses me on that. And I've seen where they use LES's in AC circuits with no diode. I guess because they are diodes. But you can notice a slight flicker. Any words on the mater of the limit of voltage on an LED ?
But what happens if the Source Voltage and the Voltage Drop are the same ?
No digital radios here. May have to try one. What is number 3128831? Is that your DMR id or repeaters? Can I access direct via Internet like echolink?
thanks for the video, If I have a 5v RGB Led strip 28 segments, how can I choose the right resistor?
Thank you for the great video!
Hey Paul, I’ve been listening for you on TAC310. What time are you usually on there?
Evenings 1800-2100 eastern
Make a larger diameter knob to go over yours. Your arc will be longer, depending on diameter which will give you finer adjustment.😋
Great vid for the beginner indeed, as which I also see myself, so thanks. Paul if you have a VCC voltage of 2.4V and you will connect a green LED than the voltage is enougth to light the LED. But the current is not limited by a resistor in this case, so I think the LED will not survive this? Is there any way to deal with this, or can the current be limited to less than 30 mA if the LED and the VCC can not be changed? Because if you have a light bulb of 120V and you connect it to 120V there is no problem, so with a VCC that matches the needed voltage of an LED you should be safe one would think.
Roland Berendonck perhaps you should think of the LED as resistor. At 2.4V, with zero resistance 2.4 amps will flow from positive to negative but the LED also limits current to what it requires, therefore it will not blow!
@@captainpugwash4100 At 2.4 Volt and with no resistance in the LED I should think that the current is infinitive. As I understand that is the thing with LED's that they have little to no resistance. So I think it will blow at 2.4 Volt, but as Omnipotent says there is a sort of safety range for the Voltage in which it will not blow. I will look for such a graph. And thanks for your answer :)
Roland Berendonck I didn’t say that the LED has zero resistance, it does indeed have one. Divide the Vf (forward voltage e.g. 2V for red or 3.3V for green) by the recommended current (say 0.02A) and you get the resistance. What I did say was that if you apply just the Vf across the anode - cathode, the LED reaches an equilibrium and draws no more current than it needs.
Omnipotent ! I am fully aware that there are LEDs with different data sheets showing different operating values. I have taken some up to 140 - 150% of the Vf before they burnt out. Certainly if you look at the graphs for normal or zener diodes there is a very steep gradient close to the y axis and especially near the breakdown voltage!
@@mdrew44628 Ok thanks, now I have the answer to my question. Great answer.
who is best user friendly Arduino supplier i went cheep out of china no drivers or pinouts ?
Love this channel
Me too!
excellent video :) fun experiments :)
Thanks.good videos tutorial
Please don’t be insulted as you are probably a decade or two younger than my 60 years, but you talk to me like the good teachers I knew at school and my criminal law lecturer (professor) at uni. Tell us what you’re going to teach, teach summarise. I respond best to good old fashioned teaching styles as the afore mentioned lecturer would testify. Please keep this style.
Thank you. I'm 52. I follow this: tell them what you're going to tell them, then tell them, and finally, tell them what you told them.
Im sorry but as beginner who would like to use leds this ok as a demo, but i need to know when and if i need a resistor. How do i find out what resistor works best . For me a better understanding would have been a wire from the uno to led and not a fancy power supply .
Do i just adjust voltage or milliamps as well. How do i find the numbers to do the math ,and once i have the answer how do i apply that.If my transformer says 300 milliamps at 1.5 volts do i just wire any led without a resistor.
Rule of thumb: always protect your LED with a 1K resistor until you better understand what must be done to accomplish your goal.
He does cover what you're asking in the video, but it's only mentioned in passing and he's also assuming that you understand the most rudimentary aspects of Ohm's Law. You know you need to drive the LED with ~20 mA (.02 A) because much more than that will kill the LEDs, or at least significantly decrease their lifespan. So that's your value for current. Then take your voltage (5V for arduino) and plug both values into the Ohm's Law equation, solved for Resistance. Here are the maths spelt out:
R = V / I
R = 5 V / .02 A
R = 250 Ω
can you help me get going with HAM
email me arduino0169@gmail.com
Amateur radio, down the rabbit hole you go. 😎
I wish the old electronics world would stop calling hole flow as current flow. Electrons flow from negative to positive.
There goes that hole theory again. LOL
E = Voltage. What is E?
Electromotive potential.
That should help out the newbies.
I am running currents thru my lead and it's not lighting up. 🤔
Haze Anderson Google it.
Next..How to build a simple power supply..because I can't afford one of those.. :P
Great
Oh no! I’m a beginner, again? Help!... 😱 💡 🐍
I am the complete novice to whom you refer and at 12 minutes I had to give up as I have no idea what your are doing or trying to demonstrate other than to show how many devices you can connect to one LED
Does anyone know what the "R" stands for on a "4k 7R 25PCS" resistor label?
The "4k7" bit should be considered as a unit and just means 4700 ohms. The "R" after that just means "Resistor" (or maybe "Resistance"?). I'm not sure why it's done that way - seems like putting an actual Ω symbol on there would make more sense.
@@largepimping Thanks for your reply. I kinda figured that myself, but I wasn't sure, being that they have some labeled "470K R 25PCS", without anything at the R. It's a bit confusing.:)
☆☆☆cool☆☆☆
I'm sorry, I disliked this video as I have many of yours. I want to watch and follow along but you constantly disappoint in your methods.
In this one you were driving the "LED at 15mA" then adjusting your power supply voltage until it lit.
That wasn't doing what you said, which is why later on when you measured your current you got no reading.
Your process is seriously flawed.
You stated early on you had the power supply set to 15mA current, then later on you proved you couldn't do exactly that same thing.
As part of that failed process you blew up an LED and just laughed it off as part of the process.
This type of error in process has been in many of your videos and is not really helping beginners, learnelectronics.
Start again.
The way I suggest measuring the required voltage for the LED is to use a series resistor of maybe 470 Ohm and adjust the voltage while measuring the current and watching the LED. You'll need about 5-15v for most basic LED types. Choose a light level you are happy with by adjusting the voltage. Now you can measure the current through the circuit and measure the voltage on the LED. That will show you exactly the current and voltage you require for resistor calculation. Most general LED's will be very happy with 10mA and can often be driven at far less while maintaining good light output.
Don't like it? Start your own channel :) One less happy LED, sacrificed for education; RIP
@@rolandberendonck3900 so you are accepting that someone is giving out terrible advice. Not even by accident. Paul was aware of the errors but didn't care to fix then.
Your accepting of that?
"not really helping beginners" you are too far elevated along to path of EE to even remember what it is like for beginners. We need as many viewpoints and demonstrations as we can get and some people just resonate better with each of us. Between the time this video was upload and I posted this reply to you, some THIRTY FIVE videos about FLAT EARTH were uploaded to UA-cam. Three live streams as I type. Just saying ... wanna vent? Priorities! Take care and thank you for being a contributor of PROGRESS.
@@PIXscotland I see a lot of video's on the web and there are very very few which are flawless and perfect. To tell you the truth even I make mistakes, however that is only sometimes. The way Paul makes a video is just letting the camera roll and do his thing and sometimes he makes a mistake. And from such mistakes there are a lot of people who can even learn from that, and that is besides Paul's adorable and highly amusing character, what it's all about.
Another thing is that if you are studying on a subject it's beneficial to watch more video's on the same subject. And if you discover an error in some video that just shows that you have learned something and have evolved in a subject. For me that is something to feel content and proud off, and I can forgive someone that made a mistake because he just forgets, is not paying enough attention, is just human or doesn't know any better. If I don't like it and it disturbs me than that is my own responsibility because I am the only one who has control what to watch and what not. Peace :)
I am sorry, I missed your channel name. Could you please post the name of the channel where you are making your videos and posting them so I can watch you do what you are writing. Because short of that, it is merely arm chair quarterbacking and any twit can do that - so I am sure that is not what you are doing.
Thanks for the great video! I'm fairly new to electronics and it was very helpful! 73! KJ7YSD