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Hi All! Around 6:40, although my first LED was dead from the first capacitor experiment, the second LED was not dead! As some of you pointed out, I totally forgot about the fact that the LED, forcing the current one way through the capacitor only, charges the capacitor to the main voltage peak (hence the one quick blink) and after that because the capacitor is charged, the voltage across the LED doesn't go positive and so it won't turn on any more. The solution would be to discharge the capacitor, say by placing a reverse diode across the LED to discharge the capacitor in the negative cycle. The reverse diode could also be an LED, which means in both cycles you would have an LED on causing less flicker, which is nice!
Since I have to pin the other comment, I heart and like this one so it stays up! Otherwise I'm not one of those self loving people! If you like this comment, it helps keep it above pother comments so people can see.
Nope, the reason it's not lit is because of you exceeding the reverse voltage of the LED ;) But you would also need a reverse diode in case your led was 50x stronger than the datasheet Thanks for the video!
I am learning electronics for hobbyist purposes and rewatching your old videos has suddenly unlocked so much more stuff in my brain which i couldn’t get the first time around. Thank you!
I like Mehdi's style here. He demonstrates even with a university education and experience under his belt, an engineer still must build the circuit in real-life and see what happens.
I think you will find that electrical and electronic engineering students at university under take many laboratory experiments. It's not solely a theoretical education. It is quite practical. So I would fully expect any graduate electrical or electronic engineer to be constructing projects and testing them. That is, Mehdi's inclination to construct and test things is *NOT* unique to him. It's an attribute that can be ascribed to most engineers.
@@ChickenSDS you've never seen the one where he tried to hold in his pain and his child saw him? It was hilarious. I'm just joking and saying he's gonna fry himself if he keeps on. But he knows what he's doing.
@@reaganharder1480 That just means you need more current. Heat it up to a few thousand K and it'll glow for a while. Granted, it might be a puddle at that point, but the puddle will glow.
Thanks to you, Mehdi, I have finally reached a level where I can predict most of your BOOMs instead of being surprised by them. Thanks for all the teaching and entertainment that carries me through university!
@@sloppyprogrammer4373 yes indeed, and we'll call this program "THE BOOMER" LOL The only problem in our plan to take over the world and predict Mehdi's booms is... MEHDI IS UNPREDICTABLE even the google algorithm or you tube algorithm cannot predict his booms. PROOF : if they could they would insert an ad just before it happened so we would wait around for the boom On that note, Have you seen the movie HERE COMES THE BOOM :P instead of kevin in the movie i would have appreciate that Mehdi was the teacher and got into a cage match i would have appreciated if that cage was a Faraday Cage and that they might call it the Faraday Cage of Death but yeah Mehdi is just unpredictable although i'd love to see him in a movie
I'm so happy to have learned about the relationship between event horizons and LEDs. Now I will be able to say "I already know all about LEDs, come on..." in the next video!
This video is great. The fact that it goes through theoretically "correct" ways to drive an LED, and the reasons for why there are better ways, which follows the learning curve so well. Bravo
I think this is one of my favourite videos. I could not stop laughing every time Mehdi changed up the whiteboard overlay. First he was in front, then his head was overlayed, then he was behind the whiteboard, then he was in front and tiny. So good. Mehdi has such a great eye for comedy. Like the latity song. Gold Jerry, Gold.
Hey Electroboom. Could you do a video on what transistor is a good pick for various applications? (driving a motor, logic level shifting, HF radio, UHF radio, sound amplification, signal filtering, etc)? There are SO MANY different transistor technologies out there, and I don't know what to pick for which application!
He made electric toothbrush years ago (driving motor using PWM and MOSFET) Also used relays for logic gates And maybe also sound amplification in wire tapping telephone line
You should only know the difference between BJTs and FETs - the former will require that you supply some current to them and not just some voltage, while the latter can be finicky (as we also saw in the video) and are easier to mess up and burn. From there on it's just a matter of looking at the voltage, power and frequency ratings in the datasheets. (Wish I could elaborate more on BJTs vs. FETs but I want this comment to be readable after all.) Edit: I am also waiting for an Electroboom video on transistors!
Yes he should. He did covered semiconductor basics & diodes in his Electroboom 101 series (which is dead now) so next ideal device would be transistor.
Mostly depends on input, output current and frequency. All of the datasets cover these things. You need to know what your output current and voltage is, and what frequency you need it to be at. But it would be a good video explaining this.
I remember studing this stuff for my Amateur Extra Radio exam. Amazing how much I retained, but still love seeing your practical demonstrations. Thank you for posting these.
I honestly did not expect a video called "How to Turn an LED On" to finish up by actually teaching us how to make a full-on switching power supply (including the principles involved). That was really impressive (and cool).
Love you dude! I was graduated as Electronic technician some 30 years ago. And it's nice that most of my knowledge is still valid today. Than I started an Electrical Engineering university course, but I feel in temptation with Computer Sciences, and I didn't mess up much with electronics all this time. You bring so much fun memories. Thank you very much for your work. 😂
First time catching a new upload after discovering your videos. I really appreciate your channel, and your incredible teaching. I ordered a Tesla coil kit yesterday (:
Just make sure you read the changes to the instructions very well first. They don't update the manual, they just list the changes at the beginning of the instructions. That's why I built the tiny tesla before attempting the ts. My first experience I had a 100 ohm resistor in place of 1000ohm and I evaporated all the copper off the tiny tesla board.
@@treybarnes7932 for sure, thanks! I didn’t want to get a boring one, so I spent a couple hundred. It looks decently legit, and instructions are in English. Will definitely be careful
Now that we have had LEDs taught Mehdi style, it would be cool to see a zener diode video. It would be funny to see you illustrate an over voltage protection system using a zener diode after you have already destroyed a bunch of LEDs.
For a simple LED its just a DC source like an I/O port, the LED, and a resistor. But in commercial designs, driving an LED efficiently as well as controlling the brightness actually takes a bit of work. There are two methods. The most common method is to use a current-controlled driver chip, usually set to near the LED's rated current (e.g. 20mA), and you then control the brightness with a PWM. The PWM is sometimes built-into the driver chip and controlled via I2C, but it is just as easy to use a little PIC microcontroller to handle the PWM. The PWM typically runs at 40KHz and has 256 brightness levels (base clock is thus around 10MHz). LED driver chips allow you to set a fixed current with a resistor and you use something like a PIC microcontroller to control it. However, there is a 'minimum' brightness when using this method because LED driver chips can't actually turn on and off quickly enough to handle PWM settings below around 100uS. The driver chips work best for LED strings. We don't use inductors... Actually, we try to avoid using inductors at all because they vibrate and they are expensive components compared to other components on the board. They are EXTREMELY efficient. We try to arrange the voltage drop across the string such that the voltage is close to zero at the bottom of the string. The driver chip then basically connects the bottom to ground (current controlled), so the losses through the driver chip are extremely low. e.g. if you have a 20V series string of LEDs you make your power supply something like 21V and thus the driver chip's internal FETs only has to dissipate 1V, yielding an efficiency of 95%. The second method is to servo the current with a FET/op-amp circuit for brightness and use a simple fixed PWM to limit power consumption. Again at around 40KHz. This is more difficult to get right because the FETs linear range is really sensitive to voltage (hence why it has to be a servo), but it works. It isn't as efficient because the FET eats the difference, but it allows the PWM to have a wide pulse width without being too bright, which is important for certain transmitter/detector applications. Then finally, one might ask why use a 40Khz PWM instead of, say, 60Hz from a half bridge? Well... because the human eye can easily see the flicker at 60Hz, but won't see any flickering at 40KHz.
10:14 You acually just described half a semesters worth of Electronics I (EE Major) in like 20 seconds, I wish this was there when I struggled with the class LOL
Never knew about that simple boost circuit for LED driving, high voltage spikes like that sketch me out. Always used a buck converter that has a sense resistor shunt for current control as opposed to voltage control. Always fun to learn new topologies. Great video as always.
5:25 In India, LED chains are available in local market where near about 80 LEDs are connected in series with some resistor (in series) also. Those chains are used for decoration and need to connect to 220v AC pwer outlet. After watching this video, I have decided not to use those chains anymore for their amount of power loss...
For that much price you will not get a smps voltage regulator and those decoration lights are used for sometime and not for prolong use, so it is fine.
The more LEDs in series, the less the voltage drop across the resistor will be so your efficiency goes up. In this video most of this vdrop was across the resistor so of course it was not efficient.
@@HodgePodgeProducts Then I have to do some calculations so that I can get the number of LEDs I should connect in series in order not to use a single piece of resistors, still I can lit it up with 220v AC...
At 12:02 One can add a small capacitor across the diodes to absorb a significant amount of the voltage spikes where it will discharge through LEDs over time untill the next inductor voltage spike. it's just takes the edge off the peek of the voltage spike across the diodes, and being small doesn't contribute much to lighting the diodes.
I love Medhi's unique way of getting me to watch his videos - asking me a question, then berating be for not knowing something else and telling me to listen. Thing is, it works, so you know I really can't fault him.
In a future episode it would be cool to see the interactions between dimmer switches and led lights, how dimmer switches work, and why only certain LEDs are dimmable.
I think in the seat heater video Mehdi already talked about LED lights that use resistors or capacitor/transistor drivers will work with dimmers since they're directly run from the input power but LED lights that have their own specific rectifier and voltage/current regulator would want a constant current and voltage. The dimmer switch simply does the PWM pattern thing by cutting off a portion of the wave.
If he explained why dimmers seem to go bad so easily in the process, I would be _very_ interested. As a guy in home repair, I'm frequently replacing the things (and returning ones I've purchased to the store when they don't work).
@@benjaminoechsli1941 i dont know much about electronics but since dimmers are some sort of PWM or PID waveform it might have to do something with that
15:05 Holy shit how many times that shit when the probes and all the cables drag the whole montage down the table happened to me during laboratories? God dammit I felt that one...
On the topic of waveforms, rectified sine waves have to be one of my favorites. When using them in a music context, they can be really neat sounding....though doing them with an actual hardware analog synth is pretty much impossible
His messups always look genuine but I wonder what percentage of his "accidents" are not scripted. I imagine most of them are. He is not only a great electron manipulator but also an amazing actor!
I have to appreciate how his "accidents" always happen with the purpose of drawing attention towards a misconception people might have so he can turn that into a good teaching opportunity.
@@El-Burrito I'm not sure about that. He made the ladder extremely topheavy. As an amateur, even I would be so far away from it that could't fall on me. Just like with cutting down a big three, with that you step away very far before it falls.
@@gert-janbonnema Nah he's said in an interview that the Jacob's ladder was real, but I don't think there's been any other accidents that weren't intentional.
@@gert-janbonnema the Jacob's ladder accident could have seriously electrocuted him. Of course there are safety systems in the house like GFCI or similar that should protect you, but whether these are going to be quick enough to prevent you from dying or suffering serious damage is debatable. Every other "accident" has a few sparks or some resistor burning etc all of which act in one way or another like a fuse and stop current flow. Jacob's ladder though was too dangerous to be intentional.
Hey Mehdi, can you pleeeease consider an explainer on the different methods of dimming (TRIAC, 0-10v, Electronic Low-Voltage, Magnetic Low-Voltage, Incandescent/Halogen, etc.) and how they work?
I have literally spent all of today writing a whole section of teaching LED/resistor/current values for the return to teaching next week. Sat back, beer, TH-cam to see what's new and BOOM this! Not quite at the level of 12yr olds BUT I think I might share this video in lessons, part to back up what I'm doing but to just show electronics is fun, brilliant and amazing. Kids switch off because you kind of need a level of knowledge to understand what is being discussed. So glad you did it because I was almost playing drinking bingo as I checked off on my power point what you were saying! Thanks!!!!
This episode was excellent from start to finish. The script, the effects, all of it made me chuckle. And yes, please discharge your capacitors when you're done with them. 💀⚡
You finally explained to me why a lot of the time I can see the flicker and see "tracers" behind moving objects. It's 10x worse on dimmable and coloured LED bulbs. It may be my nystagmus but that flickering affects my ability to use the light for anything useful, like reading, etc... I thought it might be cheap rectification, or none, but it makes sense for dimmables to change the frequency of the power cycle than try to make an LED less delicate.
One thing that you did not mention is that a LED normally has a very low reverse breakdown voltage, of the order of around 5 volts. Even if the LED is not destroyed straight away by an excessive reverse voltage the life of the LED is drastically reduced.
I tried to build an LED driver once. I was pretty sure it was going to end up exploding because I understood it a lot less than Mehdi and he manages to blow everything up when he does know what he's doing
Mehdi stages almost all of the “accidents” in videos. This serves two purposes: 1) People love explosions so it’s more entertaining. 2) It’s a really fast way of showing common mistakes and their potential consequences
His life expectancy is a thousand times past if he isn't ducking up on purpose with mains voltages. I think he should state in each video what precautions he takes, like an isolation transformer
[EDIT] Wrong, check comments 4:45 no it's not. It's Vrms/2 or Vpeak/2✓2 7:35 it's not working because the current going through the capacitor is half wave rectified, not true AC. You would need two LED strings with reverse polarity to make that work.
1st point: I don't think you're right. I even simulated a half bridge rectifier and measured it. Vrms = Vpeak/2 = 170/2 =85V 2nd point: You're right. In steady state the average current in the capacitor has to be zero so current needs to flow in the other direction too. Without a diode in the opposite direction it can't, and so the circuit behaves sort of as a peak detector where the capacitor charges in the 1st cycle and never let's the LED turn ON again. Alternatively, something that is widely used in real light bulbs (instead of a 2nd diode), is to put a resistor across the capacitor. Having said that, Medhi did actually lit up the LED string with the capacitor only. So that LED string either has 2 strings running in opposite direction or it's made to break down in a controlled fashion, w/o emitting light, but discharging the cap.
@@justpaulo yeah... With half wave, power is halved, not RMS voltage. If power is halved RMS voltage must be 1/✓2 of the full wave voltage, which is already 1/✓2 of Vpeak. So Vrms half wave = 1/2Vpeak
Hi dear mehdi , I love to watch your videos and know that you carefully calculate the risk of blowing capacitors or any of electronic components but it still can hurt your eyes although it will spoil the excitement but I think its safer to wear a pair of glasses maybe you can wear them through the entire video thanks for the tons of things you teach in your videos
7:29 This led string must have been made of 2 led strings connected in parallel but in reverse if it was just a normal led string then the capacatior would charge through that led's but then it would not be able to discharge because led passes current only in one direction, so it means that this circuit would not work properly, all it would proabably do would be that the led string would blink once and then stay turned off.
This may be in the top ten. Much I can use in teaching to my HVAC students. Yes, HVAC. The trade is getting heavy into electronics and technicians need to understand some of this.
You know, watching this as an electronics engineer turns this from an informative piece into probably the best component comedy I've ever seen. This is so good. Plus he is mostly on point on what he is teaching so its a great information well for most viewers. I love this channel.
Let Audible help you discover new ways to laugh, be inspired, or be entertained. New members can try it free for 30 days. Visit audible.com/electroboom or in US text electroboom to 500-500.
First
Also love your videos
تامبنیل خیلی گاد بود
Nice!
Super interesting video.
bro you really help me out with engineering♥
Hi All! Around 6:40, although my first LED was dead from the first capacitor experiment, the second LED was not dead! As some of you pointed out, I totally forgot about the fact that the LED, forcing the current one way through the capacitor only, charges the capacitor to the main voltage peak (hence the one quick blink) and after that because the capacitor is charged, the voltage across the LED doesn't go positive and so it won't turn on any more. The solution would be to discharge the capacitor, say by placing a reverse diode across the LED to discharge the capacitor in the negative cycle. The reverse diode could also be an LED, which means in both cycles you would have an LED on causing less flicker, which is nice!
Since I have to pin the other comment, I heart and like this one so it stays up! Otherwise I'm not one of those self loving people! If you like this comment, it helps keep it above pother comments so people can see.
Nope, the reason it's not lit is because of you exceeding the reverse voltage of the LED ;)
But you would also need a reverse diode in case your led was 50x stronger than the datasheet
Thanks for the video!
ur vids r so educational and informational
@@ElectroBOOM why not just edit the pinned comment to add this under it
Oh wait sponsor nevermind
th-cam.com/video/xc2V2BS_Fng/w-d-xo.html
As soon as he mentioned using a capacitor instead of a resistor, I knew there was going to be an explosion.
He doesn't disappoint!
Smart🍪
How can your comment be older than the video?
@@hesamkarandish yeah wonderful 😂
Oh corse, hahaha. I wanted to say the same!
Damn, when Mehdi is worried about his circuit's safety, you know it's serious shit
🤣
Charged capacitors are no joke
@@Henrix1998 especially flash capacitors
Unless it's a Jacob's Ladder
@@ethanpet113 🤣
I am learning electronics for hobbyist purposes and rewatching your old videos has suddenly unlocked so much more stuff in my brain which i couldn’t get the first time around. Thank you!
I like Mehdi's style here. He demonstrates even with a university education and experience under his belt, an engineer still must build the circuit in real-life and see what happens.
When all else fails, 120V AC.
I think you will find that electrical and electronic engineering students at university under take many laboratory experiments. It's not solely a theoretical education. It is quite practical.
So I would fully expect any graduate electrical or electronic engineer to be constructing projects and testing them.
That is, Mehdi's inclination to construct and test things is *NOT* unique to him. It's an attribute that can be ascribed to most engineers.
He's gonna keep on and leave his child fatherless. Dude and electricity don't mix!
But I agree
@@michaelclark2097 what?
@@ChickenSDS you've never seen the one where he tried to hold in his pain and his child saw him? It was hilarious. I'm just joking and saying he's gonna fry himself if he keeps on. But he knows what he's doing.
Given enough current, pretty much _every_ component is light emitting.
:D you sir won my internet today!
Though some only for a short time...
@@reaganharder1480 That just means you need more current. Heat it up to a few thousand K and it'll glow for a while.
Granted, it might be a puddle at that point, but the puddle will glow.
Plus, you will most likely create a smoke machine that way.
similarly every machine can be a smoke machine
Thanks to you, Mehdi, I have finally reached a level where I can predict most of your BOOMs instead of being surprised by them. Thanks for all the teaching and entertainment that carries me through university!
We need to develop a formula that predicts Mehdi's BOOM's :P
@@martinkuliza If you can analyze the components by imagerecognition, then we could invent an algorithm that predicts Mehdi's BOOMs.
@@sloppyprogrammer4373
yes indeed, and we'll call this program "THE BOOMER"
LOL
The only problem in our plan to take over the world and predict Mehdi's booms is... MEHDI IS UNPREDICTABLE
even the google algorithm or you tube algorithm cannot predict his booms.
PROOF : if they could they would insert an ad just before it happened so we would wait around for the boom
On that note, Have you seen the movie HERE COMES THE BOOM :P
instead of kevin in the movie i would have appreciate that Mehdi was the teacher and got into a cage match
i would have appreciated if that cage was a Faraday Cage and that they might call it the Faraday Cage of Death
but yeah Mehdi is just unpredictable
although i'd love to see him in a movie
@@martinkuliza just expect it when he plugs anything into 120VAC, especially when there are capacitors involved
@@uwuLegacy
I expect it when there is a continuity test
I'm so happy to have learned about the relationship between event horizons and LEDs. Now I will be able to say "I already know all about LEDs, come on..." in the next video!
Really? To me, the cause-and-effect between them is still as opaque as a black hole.
@@Kevin-jz9bg same but at this point i want to know more there's no comming back to the old self
its pretty easy relationship, if you throw the shrödinger Operator onto the singularity of a LED.
th-cam.com/video/xc2V2BS_Fng/w-d-xo.html
@@neutronenstern. You know, black holes are described by GR, not quantum mech. The Schrödinger equation is purely for quantum mech.
This video is great. The fact that it goes through theoretically "correct" ways to drive an LED, and the reasons for why there are better ways, which follows the learning curve so well. Bravo
I think this is one of my favourite videos. I could not stop laughing every time Mehdi changed up the whiteboard overlay. First he was in front, then his head was overlayed, then he was behind the whiteboard, then he was in front and tiny. So good. Mehdi has such a great eye for comedy. Like the latity song. Gold Jerry, Gold.
Hey Electroboom. Could you do a video on what transistor is a good pick for various applications? (driving a motor, logic level shifting, HF radio, UHF radio, sound amplification, signal filtering, etc)? There are SO MANY different transistor technologies out there, and I don't know what to pick for which application!
I think this would make for a quite fascinating video!
He made electric toothbrush years ago (driving motor using PWM and MOSFET)
Also used relays for logic gates
And maybe also sound amplification in wire tapping telephone line
You should only know the difference between BJTs and FETs - the former will require that you supply some current to them and not just some voltage, while the latter can be finicky (as we also saw in the video) and are easier to mess up and burn. From there on it's just a matter of looking at the voltage, power and frequency ratings in the datasheets.
(Wish I could elaborate more on BJTs vs. FETs but I want this comment to be readable after all.)
Edit: I am also waiting for an Electroboom video on transistors!
Yes he should. He did covered semiconductor basics & diodes in his Electroboom 101 series (which is dead now) so next ideal device would be transistor.
Mostly depends on input, output current and frequency. All of the datasets cover these things. You need to know what your output current and voltage is, and what frequency you need it to be at. But it would be a good video explaining this.
I remember studing this stuff for my Amateur Extra Radio exam. Amazing how much I retained, but still love seeing your practical demonstrations. Thank you for posting these.
I wish I was as funny as ElectroBoom. His combination of entertainment and learning together is genius. Love the videos.
I honestly did not expect a video called "How to Turn an LED On" to finish up by actually teaching us how to make a full-on switching power supply (including the principles involved). That was really impressive (and cool).
Love you dude! I was graduated as Electronic technician some 30 years ago. And it's nice that most of my knowledge is still valid today. Than I started an Electrical Engineering university course, but I feel in temptation with Computer Sciences, and I didn't mess up much with electronics all this time. You bring so much fun memories. Thank you very much for your work. 😂
First time catching a new upload after discovering your videos. I really appreciate your channel, and your incredible teaching. I ordered a Tesla coil kit yesterday (:
Welcome to the club bro...
Just make sure you read the changes to the instructions very well first. They don't update the manual, they just list the changes at the beginning of the instructions. That's why I built the tiny tesla before attempting the ts. My first experience I had a 100 ohm resistor in place of 1000ohm and I evaporated all the copper off the tiny tesla board.
i just discovered his channel too
@@treybarnes7932 for sure, thanks! I didn’t want to get a boring one, so I spent a couple hundred. It looks decently legit, and instructions are in English. Will definitely be careful
@@treybarnes7932 I'm sorry, but your mix-up wasn't a "novice" thing, you should've known better.
Now that we have had LEDs taught Mehdi style, it would be cool to see a zener diode video. It would be funny to see you illustrate an over voltage protection system using a zener diode after you have already destroyed a bunch of LEDs.
I second this!!!
Aaaah.. a ZEN er diode... Might be featured only on Mehditation channel..? 🤔 I'll see myself out... K... Thx... 😁
th-cam.com/video/xc2V2BS_Fng/w-d-xo.html
when you turn on an LED is pretty normal ,
but when the LED turns on you .... thats a different story.
Turning an LED on?
A little wine, some well-chosen music, candlelight...
and when an LED turns you on, that's gotta be some sexy lighting.
@@lanthan598 emitters are inherently erotic, some might call them ejaculators
İm gonna make t-shirt out of this LOL
average day in russia
For a simple LED its just a DC source like an I/O port, the LED, and a resistor. But in commercial designs, driving an LED efficiently as well as controlling the brightness actually takes a bit of work. There are two methods.
The most common method is to use a current-controlled driver chip, usually set to near the LED's rated current (e.g. 20mA), and you then control the brightness with a PWM. The PWM is sometimes built-into the driver chip and controlled via I2C, but it is just as easy to use a little PIC microcontroller to handle the PWM. The PWM typically runs at 40KHz and has 256 brightness levels (base clock is thus around 10MHz). LED driver chips allow you to set a fixed current with a resistor and you use something like a PIC microcontroller to control it. However, there is a 'minimum' brightness when using this method because LED driver chips can't actually turn on and off quickly enough to handle PWM settings below around 100uS.
The driver chips work best for LED strings. We don't use inductors... Actually, we try to avoid using inductors at all because they vibrate and they are expensive components compared to other components on the board. They are EXTREMELY efficient. We try to arrange the voltage drop across the string such that the voltage is close to zero at the bottom of the string. The driver chip then basically connects the bottom to ground (current controlled), so the losses through the driver chip are extremely low. e.g. if you have a 20V series string of LEDs you make your power supply something like 21V and thus the driver chip's internal FETs only has to dissipate 1V, yielding an efficiency of 95%.
The second method is to servo the current with a FET/op-amp circuit for brightness and use a simple fixed PWM to limit power consumption. Again at around 40KHz. This is more difficult to get right because the FETs linear range is really sensitive to voltage (hence why it has to be a servo), but it works. It isn't as efficient because the FET eats the difference, but it allows the PWM to have a wide pulse width without being too bright, which is important for certain transmitter/detector applications.
Then finally, one might ask why use a 40Khz PWM instead of, say, 60Hz from a half bridge? Well... because the human eye can easily see the flicker at 60Hz, but won't see any flickering at 40KHz.
Fascinating insights. Much appreciated.
Chuck Norris once hired an electrician and taught him how to survive being shocked thousands of times.
Mehdi is the chuck Norris of electricity
10:14 You acually just described half a semesters worth of Electronics I (EE Major) in like 20 seconds, I wish this was there when I struggled with the class LOL
No, he really didn't.
ElectroBoom videos have more effective jumpscares than you regular horror film
Never knew about that simple boost circuit for LED driving, high voltage spikes like that sketch me out. Always used a buck converter that has a sense resistor shunt for current control as opposed to voltage control. Always fun to learn new topologies. Great video as always.
4:30 Use that LED diode to make a backlight for an LCD display!
You really baited me to watch the entire video with that event horizon. Well played.
I was hoping that part at 9:18 would go on for like 5 minutes. :)
7:02 That‘s something we don’t hear Mehdi say very often! :D :D
5:25 In India, LED chains are available in local market where near about 80 LEDs are connected in series with some resistor (in series) also. Those chains are used for decoration and need to connect to 220v AC pwer outlet. After watching this video, I have decided not to use those chains anymore for their amount of power loss...
For that much price you will not get a smps voltage regulator and those decoration lights are used for sometime and not for prolong use, so it is fine.
@@shashibhushansingh_ I'd like to invest single time and get the benefit afterward...
I think since the leds were in series then it would be much more efficient
The more LEDs in series, the less the voltage drop across the resistor will be so your efficiency goes up. In this video most of this vdrop was across the resistor so of course it was not efficient.
@@HodgePodgeProducts Then I have to do some calculations so that I can get the number of LEDs I should connect in series in order not to use a single piece of resistors, still I can lit it up with 220v AC...
14:57
He's invented the most stressful lightbulb ever
Real footage of gargamel doing magic
Oh my god now I can't unsee it
At 12:02 One can add a small capacitor across the diodes to absorb a significant amount of the voltage spikes where it will discharge through LEDs over time untill the next inductor voltage spike.
it's just takes the edge off the peek of the voltage spike across the diodes, and being small doesn't contribute much to lighting the diodes.
You make learning so fun. Thank you.
I love Medhi's unique way of getting me to watch his videos - asking me a question, then berating be for not knowing something else and telling me to listen. Thing is, it works, so you know I really can't fault him.
i love how you teach people by showing them what would happen if they make a mistake someone would actually make
I wanna thank you, I am learning to become Car Electrician and your videos are helping me understand electrical part of the job
1:42, oh man I enjoyed it so, much (yelling in pain) sorry 🤣🤣🤣🤣😂😂
00:32 Event Horizon is a great sci-fi horror movie with Sam Neill, and its relation to LEDs is that it's too scary to watch without the lights on.
I love your "retroactive precision" edits to fix the script flubs :P
0:27 You already gave an answer, whatever is in the event horizon or the LED, it can't go back
If you're not already, you should become a ham radio operator. You have the knack.
In a future episode it would be cool to see the interactions between dimmer switches and led lights, how dimmer switches work, and why only certain LEDs are dimmable.
I think in the seat heater video Mehdi already talked about LED lights that use resistors or capacitor/transistor drivers will work with dimmers since they're directly run from the input power but LED lights that have their own specific rectifier and voltage/current regulator would want a constant current and voltage. The dimmer switch simply does the PWM pattern thing by cutting off a portion of the wave.
If he explained why dimmers seem to go bad so easily in the process, I would be _very_ interested. As a guy in home repair, I'm frequently replacing the things (and returning ones I've purchased to the store when they don't work).
@@benjaminoechsli1941 i dont know much about electronics but since dimmers are some sort of PWM or PID waveform it might have to do something with that
Instructions unclear, accidentally caused a massive black out in my local town because I accidentally blew the entire local power station itself
💀
You are the fucking engineer from tf2. You built lots of stuff. How the fuck did you caused an blackout by pluging an LED in the power outlet. 💀
Hey Mehdi! Could you tell us more about transistors and in particular the difference between using them as amplifier vs. using them as switch?
Excellent presentation! I almost spit coffee when I saw the scorched project board. It is so ElectroBOOM!
I never learnt so much in my 4 year bachelor's, as i do from your videos. I wish all teachers were like you :)
Me:oh nothing blows up
Also electroboom: 6:19
15:05 Holy shit how many times that shit when the probes and all the cables drag the whole montage down the table happened to me during laboratories? God dammit I felt that one...
5:46
America be like: don't mind if i do
Not something that has ever happened
Also Israel
Im subscribed to you when you had 700k subscribers and I’ve watched all your videos I literally love your explanations
youre my new engineer teacher. i love your teaching style.
On the topic of waveforms, rectified sine waves have to be one of my favorites. When using them in a music context, they can be really neat sounding....though doing them with an actual hardware analog synth is pretty much impossible
His messups always look genuine but I wonder what percentage of his "accidents" are not scripted. I imagine most of them are. He is not only a great electron manipulator but also an amazing actor!
I have to appreciate how his "accidents" always happen with the purpose of drawing attention towards a misconception people might have so he can turn that into a good teaching opportunity.
The Jacobs ladder mishap I'm certain is one of the only real mess ups
@@El-Burrito I'm not sure about that. He made the ladder extremely topheavy. As an amateur, even I would be so far away from it that could't fall on me. Just like with cutting down a big three, with that you step away very far before it falls.
@@gert-janbonnema Nah he's said in an interview that the Jacob's ladder was real, but I don't think there's been any other accidents that weren't intentional.
@@gert-janbonnema the Jacob's ladder accident could have seriously electrocuted him. Of course there are safety systems in the house like GFCI or similar that should protect you, but whether these are going to be quick enough to prevent you from dying or suffering serious damage is debatable. Every other "accident" has a few sparks or some resistor burning etc all of which act in one way or another like a fuse and stop current flow. Jacob's ladder though was too dangerous to be intentional.
5:18 ... lmao 🤣
Potato-ish face 🥔
I love how the breadboard at 8:40 has a brown smudge on it. Makes me wonder what Mehdi blew up on there ages ago. :)
That part about LED color and then those toilet lamps got me. Love you sense of humor
5:55... In games i do
Hey Mehdi, can you pleeeease consider an explainer on the different methods of dimming (TRIAC, 0-10v, Electronic Low-Voltage, Magnetic Low-Voltage, Incandescent/Halogen, etc.) and how they work?
I have literally spent all of today writing a whole section of teaching LED/resistor/current values for the return to teaching next week. Sat back, beer, TH-cam to see what's new and BOOM this! Not quite at the level of 12yr olds BUT I think I might share this video in lessons, part to back up what I'm doing but to just show electronics is fun, brilliant and amazing. Kids switch off because you kind of need a level of knowledge to understand what is being discussed. So glad you did it because I was almost playing drinking bingo as I checked off on my power point what you were saying! Thanks!!!!
This episode was excellent from start to finish. The script, the effects, all of it made me chuckle. And yes, please discharge your capacitors when you're done with them.
💀⚡
You finally explained to me why a lot of the time I can see the flicker and see "tracers" behind moving objects. It's 10x worse on dimmable and coloured LED bulbs.
It may be my nystagmus but that flickering affects my ability to use the light for anything useful, like reading, etc...
I thought it might be cheap rectification, or none, but it makes sense for dimmables to change the frequency of the power cycle than try to make an LED less delicate.
One thing that you did not mention is that a LED normally has a very low reverse breakdown voltage, of the order of around 5 volts. Even if the LED is not destroyed straight away by an excessive reverse voltage the life of the LED is drastically reduced.
at 1:35 I started to feel that something wrong will happen
I tried to build an LED driver once. I was pretty sure it was going to end up exploding because I understood it a lot less than Mehdi and he manages to blow everything up when he does know what he's doing
Mehdi stages almost all of the “accidents” in videos. This serves two purposes:
1) People love explosions so it’s more entertaining.
2) It’s a really fast way of showing common mistakes and their potential consequences
Did you really think his mistakes were real?
mate he does that on purpose. He really knows his shit. The silliness and shenanigans are just part of the presentation.
He does it on purpose
His life expectancy is a thousand times past if he isn't ducking up on purpose with mains voltages. I think he should state in each video what precautions he takes, like an isolation transformer
my favoriute colors on led, red, blue, white, warmwhite like you is my favoruite too
This man is legitimately one of my favorite channels and my king.
[EDIT] Wrong, check comments
4:45 no it's not. It's Vrms/2 or Vpeak/2✓2
7:35 it's not working because the current going through the capacitor is half wave rectified, not true AC. You would need two LED strings with reverse polarity to make that work.
came here to say this; glad i checked the comments
I think Mehdi is trolling us.
1st point: I don't think you're right. I even simulated a half bridge rectifier and measured it. Vrms = Vpeak/2 = 170/2 =85V
2nd point: You're right. In steady state the average current in the capacitor has to be zero so current needs to flow in the other direction too. Without a diode in the opposite direction it can't, and so the circuit behaves sort of as a peak detector where the capacitor charges in the 1st cycle and never let's the LED turn ON again.
Alternatively, something that is widely used in real light bulbs (instead of a 2nd diode), is to put a resistor across the capacitor.
Having said that, Medhi did actually lit up the LED string with the capacitor only. So that LED string either has 2 strings running in opposite direction or it's made to break down in a controlled fashion, w/o emitting light, but discharging the cap.
@@justpaulo yeah... With half wave, power is halved, not RMS voltage. If power is halved RMS voltage must be 1/✓2 of the full wave voltage, which is already 1/✓2 of Vpeak. So Vrms half wave = 1/2Vpeak
@@justpaulo I thought the resistor was to discharge the capacitor when power is off for safety reasons. Otherwise agree.
@@BullCheatFR It's a resistor with double duty I guess.
While your use of a resistor in series with the AC line did light the LED, I expected it to fail because of reverse voltage exceeding the spec.
Maybe it is breaking down but the limited reverse current hasn't fried it yet?
5:19 That face after burning the resistor🙂
We need to meme that... make it last for centuries
I strongly believe that this man is immune to electricity, he just flinch because it's a primal instinct
The burn marks on the breadboard has me dying 😂 keep up the great work brother. Much love and appreciation.
13:19 Finally, the one you've all been waiting for!
FOOOL BRIDJ RECTIFIAAAAH
12:21 the intrusive thoughts winning
lick
I still don't know how to drive an LED. You didn't even get in your car!
Oh hello mr verified
7:33 That was the most spectacular LED death.
Hi
dear mehdi , I love to watch your videos and know that you carefully calculate the risk of blowing capacitors or any of electronic components but it still can hurt your eyes
although it will spoil the excitement but I think its safer to wear a pair of glasses
maybe you can wear them through the entire video
thanks for the tons of things you teach in your videos
As a mechanical engineer with a little bit of knowledge of electronics.
I forgot what I knew after watching this video😂😂
"How many engineers does it take to light an LED?"
One mechanical to plug it in, while 13 electricals are in the corner circle jerking…
7:29 This led string must have been made of 2 led strings connected in parallel but in reverse if it was just a normal led string then the capacatior would charge through that led's but then it would not be able to discharge because led passes current only in one direction, so it means that this circuit would not work properly, all it would proabably do would be that the led string would blink once and then stay turned off.
At this point, I instinctively flinch and squint whenever Mehdi plugs something in.
i was hoping for a dad joke of driving around in a car with an led in the back seat
Did you know that you can also turn on a diode ? With 50A the usual become pretty bright for a brief moment
With enough current, everything will glow
It's not hard to make a lightbulb
Not to mention becoming a cheap smoke generator :0)
I understand all the technical words while watching along! Learning with a smile :)
good job professor. and I'm glad to see your head stopped floating around all weird while using the white board 😆
6:20 I love how the bleep has reverb as if he doesn't actually swear he just makes bleep sounds
8:13 #toastBoard
5:48 Ahh I see Mehdi is aware of US foreign policy. xD
.14:05 I throwed my phone
I'm not even sure if there's such a word as throwed
Great comedic acting, should go to Hollywood,very funny.
Watching ElectroBOOM - all the fun, all the knowledge, none of the risk.
Hey, the red capacitor on 6:35 is NOT ceramic. It is a film capacitor, and in particular, most likely a polypropylene capacitor.
At 5:13... a light emitting resistor!
Aka an incandescent light
😂
Heat*
Or SER (smoke emitting resistor)
I love his face lol
I love how he green screened himself over himself
This may be in the top ten. Much I can use in teaching to my HVAC students. Yes, HVAC. The trade is getting heavy into electronics and technicians need to understand some of this.
Your sense of humor is unique, though every time I watch you get shocked, I wonder if this will be the end.
You know, watching this as an electronics engineer turns this from an informative piece into probably the best component comedy I've ever seen. This is so good. Plus he is mostly on point on what he is teaching so its a great information well for most viewers. I love this channel.
Likewise, Yet the way he appears to encourage playing with mains by people that do not know what they are doing is potentially very dangerous.
@@favesongslistuuuwuuuu5uunuau5uuuuùuyuuwunu5auuuauayyyh
9:28 thats how a dimmer switch works
What a thumbnail 😂
This one is a masterpiece! In school we just learned the resistor way. But of course there are more (power) efficient way. Thanks!
This video was absolute Electroboom brilliance.