The Science and Circuitry of DIY LEDs

[@YoungTheFish]

I love this whole "Filmmaker but also Physicist/Chemist/Engineer/Historian IQ" shebang

[@YoungTheFish]

Oh and Fashionista IQ apparently

[@FilmmakerIQ]

Don't forget about "Groom of the King's Close Stool".

[@schitlipz]

Two mins in and scratching my head about how this relates to film. Aw whatever, generally you have great vids. A couple quick notes though: reversd bias is employed too (zeners), and LEDs can also sense the freq they emit (shine a red laser on a red LED and measure). Have a great day. I decided to continue watching. Sorry, as a retired electronics engineer, and being practiced at failure mode analyses, I like watching people try to explain basic circuitry and get a kick outta all the little details that get screwed up one way or another. Like how it really doesn't matter if the resistor is in series with the diode at the cathode or anode - electrically it's the same thing. And you don't need the 1ohm resistor in a simple 9v alk battery cct because the battery has about that as an internal resistance. You're definitely right when you say that typical values aren't accurate (like the battery voltage). This is true for all non-precision components. Even "identical" transistors can be off just a bit from batch to batch, and is why some ccts are better when integrated on a chip, like phase discriminators for example. Temperature also has effects on values, which is why some components are kept in an oven to maintain exacting temps, like a crystal oscillator. You've likely experienced the temperature effect with automobile batteries (if you have winters where you are). The way you make vids is just top notch though. I've learned a helluva lot from you with regards to motion pictures. Thanks. And you're well-spoken, and you got nice graphics... very nice work.

[@FilmmakerIQ]

Everything is related to film. With basic LED knowledge you can add lights for your miniature shots. LEDs are now part of many lighting instruments. With a bit of knowledge you can add light anywhere you want.

[@3DSage]

You are so amazing at teaching.

[@THesK8LEmoN]

Damn you are one of the best channels out there! Unique, on-point, high production value, very detailed and for every level of experience. And all of it is free!! This is a gift from filmmaking heaven!

[@JoshuaCasper]

I figured this would be another led video.. but, you really got into the subject! Impressive, enlightening, informative. Thanks so much for quality over quantity on this channel!

[@FilmmakerIQ]

I've seen all those LED videos, they look so cool but I didn't understand why they were doing what they were doing. This course was a way to give someone like me (and everyone else) a base line understanding. LEDs have since become a sort of obsession of mine now.

[@OctoberLandon]

I'm so glad John is a visual teacher, for us "visual" learners! :-)

[@pdrg]

Glad to see you experimenting and almost all the information is technically spot on, although the M in PWM refers to Modulation (ie switching off and on). It's important because it means that PWM-controlled LED's are flashing off and on, and this can very much interfere with sensor frequencies. It might be something you wish to expand on, John, as it can mean a visually lovely scene can be ruined in camera, and you're technical enough to explain it well to your audience, I'm certain.

[@sparkybluefox]

Great work Mr Hess ! As an EE kind of guy it started out slow but the final third of your video blew me away! Very creative work ! Thank you so much for posting this for us all. Cheers. SBF

[@romankorseev3703]

Thank you for a great video! I just wanted to let you know that there is a slightly noticeable hiss around 15,8kHZ. It ends at 6:07 mark.

[@MarvinStroud3]

I love the squirt sound when the electron drops in energy.

[@fhajji]

Let's call that sound a "sonon". :)

[@mohkazmoh]

Thanks for the video. It's very useful even for engineers. PWM stands for Pulse Width Modulation and with an appropriate capacitor parallel at the end there would be no blinking.

[@b22ba]

Damn. If you'd make a five episode series about how to eat bread, I would watch the whole in one sitting, super excited from start to finish. I love your videos, and you always amaze me, when you tell something new about a topic which I thought I had known.

[@tenchimod]

Love the in-depth videos, John. Thank you for the hard work you put into these!

[@johneygd]

You made cool stuff with leds.

[@Refsiul222]

I really needed to watch this video, thanks a lot!

[@palpytine]

PWM = Pulse Width Modulation, not Pulse Width Modifier ... Time for a spot of ADR :) You might also be interested to learn that the way tungsten works is quantum too, and has a fascinating history of its own. Black Body radiation - as in tungsten - is produced by the photoelectric effect. The discovery and explanation of this was deemed so important that the Nobel committee awarded Albert Einstein his first (and only) prize for his 1905 paper on the subject This paper was instrumental in laying the groundwork for quantum physics, so named because everything must be "quantised" and exist in distinct states, with no middle ground (these are the energy bands you spoke of). It's a curious kind of a science, based entirely around probabilities, yet having more predictive power than any science formerly devised. The real irony is that this branch of physics, a branch based on probabilities, was part-founded by a man more commonly remembered for general relativity... and widely quoted for his belief that god doesn't play dice!

[@wildbestia]

Everything is quantum.

[@FilmmakerIQ]

Yeah, that's true.

[@palpytine]

wildbestia Sing to the tune of "everything is awesome" from the Lego movie. I now feel that I need to make up some more lyrics :)

[@johnhmaw]

Excellent and fascinating as always.

[@energiewender143]

Wow, excellently explained! Thank you.

[@minuscolochao1557]

thumbs up for all your awsome vids and your efforts in making them

[@celo2043]

Awesome content as usual!

[@QuinnWaters]

thank you John Hess, this was great!!!!

[@AviRotstein]

Why do you recommend that people put the resistor on the negative side? In this simple case it may not matter, but when common grounding is important, you really want resistors on the positive (+) side. Also, PWM stands for Pulse Width Modulation

[@FilmmakerIQ]

I've seen the negative side as a convention so I just stuck to that.

[@palpytine]

Have you considered doing a video on batteries? Not just the underlying tech, but also the various systems and connectors in use, which batteries seem to be most popular for 3rd party accessories (e.g. light), etc.

[@1st_ProCactus]

The current limiting resistor can be anywhere in a serial circuit. And PWM = Pulse Width Modulation, not Modifier

[@LandNfan]

Thank you! No where else have I found the answer to why red laser LEDs consume less current than green. Both colors are popular for laser sights on firearms, but no one seemed able to explain why battery life for red lasers was nearly double that for the green. That is a significant trade off since most people claim the green is easier to see in daylight conditions.

[@misterhat5823]

If you're going to use an AC adapter, keep in mind that unregulated adapters will output more the 50% more than the rated voltage at low currents. This matters when choosing the dropping resistor. Which can be in either the anode or cathode lead.

[@CommentFrom]

Thanks Mr hat it's nice to see you're happy now garrison doesn't have his hand up your backside

[@jakeclontz9525]

You are a genius. Really loved this one.

[@SaturnCanuck]

Very cool. Thanks. I remember in 1976 when my uncle had a VERY expensive LED watch, cause that was the latest thing.

[@EaziGX]

Silly question, ... why did he say to put the resistor on the negative side, but both the 'online led calculator site' (9:38) and the led that had the resistor already installed (11:48) had it on the positive side? Thanks for the great videos.

[@FilmmakerIQ]

I've picked up somewhere that the proper way to wire them up is on the negative side. That might be a convention based on the notion that electrons flow from the negative side of the terminal to the positive side (we named them positive and negative before we understood what electrons were). Still you could put the resistor on the anode side it shouldn't matter, but I thought I would stick to convention.

[@palpytine]

I can confirm that! It makes exactly ZERO difference. Where a convention exists it's entirely for human benefit as it makes circuit diagrams, PCBs, etc. cleaner and more consistent.

[@DrDaab]

Great Stuff - beautifully explained. Thanks ! ! ! ! !

[@davecarleton2598]

I gotta be honest, I'm pretty glad you found yourself a model for those costumes.

[@mychalsimmons4177]

That was Deep Jon

[@nationalist818]

If you want to play with LED bulbs try COB or CREE/SMD (same thing but CREE is a brand name) less heat more light and 4000k color temp. We use them in shop drop lights. Almost a laser effect that you can shine them across the street in day light.

[@filanfyretracker]

I would also say look into those Arduino boards. they are project/hobbyist micro-controllers but I have heard of people programming them to do things with LEDs they can also control switches to allow one to control a relay that is switching banks of LEDs. Raspberry Pi is another compact platform that one could use for LED control. On a set one could for example use these to setup the ubiquitous panel of flashy lights in the background of a computer room or science fiction stuff. these devices can also have sensors hooked up which would allow automation of LEDs for a scene. Say for example science fiction production and when the talent gets to a certain point a corridor the lighting goes red to give the image of power loss or red alert. Simple beam type setup could mean when the talent passes a certain point the micro-controller would flip from say white lighting LEDs to red ones. Or even just do sequenced illumination like is seen in some scenes in movies. neither of these have the power to drive large banks of LEDs solo but they can control relays that handle much higher power needs. www.arduino.cc/ www.raspberrypi.org/

[@FilmmakerIQ]

Thank you! Very cool info! I bought one of those Arduino board kits and read up about them. They seem to be a great first step solution to being able to translate computer code into the real world. I'll have to dig it back up and play with it (if I ever get some free time).

[@VicTilling]

Very good

[@brendanward2991]

Doubleplusgood. Why did it take me so long to find one of the best channels on KZbin? Nitpick: the SI symbol for volt is V, not v.

[@fhajji]

My favorite trick with LEDs is to point an IR remote to a camera, and see if the camera sensor picks up the IR light and makes it visible, which is very common with some IR wavelengths and sensors. Having such a sensor is a godsend sometimes. When patching fiber optics cables carrying IR light, I actually used my smartphone camera many times as an improvised detector to determine if a fiber is "hot" (connected at the other side). Of course, this only applies to regular IR LEDs used on multimode fibers. If it was IR laser light common on single mode fibers, I'd be much, MUCH more careful, obviously.

[@Forssa1]

LED master race.

[@zyzzy1944]

Take a look at individually- addressable RGB (NeoPixel) LEDs. They take the LED to the next level.

[@FilmmakerIQ]

Looks like some new toys I need to play with.

[@TheAnimeist]

The only thing missing is a demonstration of reverse bias with the watch-battery/LED circuit. Other than that, flawless in every way. Nice creativity with the dress, but the actress may have taken the show. Your videos are amongst the best!

[@ToastedSynapseGaming]

Can you talk a little about programming? Would love to know how easy or difficult it would be to do a DIY programmable dimmer like in superman.

[@FilmmakerIQ]

That's something I have yet to figure out but I think you would need to start with an Arduino.

[@ScottPinkhamMT]

Filmmaker IQ or use a Raspberry Pi! I'm a EE that works with programming LEDs everyday, would be happy to provide any assistance you might need. LOVE your channel! Episode on sensors was just superb.

[@palpytine]

If it's just "standard" pulsed sequences you're after, you can get dedicated controller ICs off the shelf for that kind of thing, they're generally rather nicely priced as they're made in bulk - for use in things like Christmas tree lights

[@Yelis3]

There is something that confuses me: The + and - convention. I am used to connect battery (+) then resistor, then LED, then battery (-). If you see the video in 10:05 the drawing shows first (+), then LED, then resistor and finally (-). I am pretty sure I would burn my LED if I do it that way ... But not sure, now I am confused!

[@FilmmakerIQ]

Either way is fine. There is a convention where the resister is placed on the cathode side (-) because electrons flow from negative to positive but you can place them on either and it doesn't affect the circuit.

[@lambdalambdalambda3250]

Hey, wouldn´t it be possible to make the crazy bar light with the angled aluminum and a LED strip? Also, thanks for the lessons, I have them as references by now!

[@FilmmakerIQ]

You could but you would want to layer a few roles of them - the strips themselves aren't terribly bright by themselves so you would need quite a few. Rosco is actually starting to sell a version of those LED strips for lighting small spaces - they'd be great for small spaces like cars. BTW - love the user name.

[@timbeaton5045]

Strictly speaking, the animation of electrons "flowing" round the circuit isn't actually happening. the CHARGE is transferred at the speed of the propagation in the conductor, the actual electrons only move a short distance before passing on their energy to other elections. The average speed of the electron movement is called the Drift Velocity and is counter-intuitively really slow! See www.scienceabc.com/nature/what-is-the-speed-of-electricity.html But this doesn't invalidate what you are saying, of course, it just means that, once again, the reality is more complicated, but not strictly necessary to explain the concepts. Great channel, BTW.

[@websitesthatneedanem]

18:05 - Is it April First?!

[@giuliofortunati8858]

grazie :)

[@no-lifenoah7861]

18:27 I *refuse* to believe this comment had anything to do with the woman. He is entirely entranced by the beauty of Ohm's Law.

[@topsykrett4439]

Who needs Ben Heck, if you can have John Hess :P

[@stephanberger3476]

Ben Heck is a hack.

[@kennynvake4hve584]

PMW is pulse width MODULATION....just picking...nice work here...

[@Holobrine]

You want LEDs, I suggest Neopixels and Arduinos, so you can code their performance!

[@BoomRoomFive]

Every time I see this intro I want to slap the character because he doesn't even try to save the camera!

[@supportlang6589]

Yow this is Good for Module LED best Explain

[@kennynvake4hve584]

They are also in the backlight in a laptop and TV...to light up the screen so you can see it..........

[@ronpetersen2317]

The minus green gel? What one did you use? Was it comparable to this? Thicker? Thinner? Rosco E-Colour #279 1/8 Minus Green

[@FilmmakerIQ]

That looks close enough.

[@CharlesBryan1]

PWM is actually "pulse width modulation", not "pulse width modifier". Sorry. Just the electronics engineer in me. :)

[@TurboHawkV6]

PWM is Pulse Width Modulation... Not "modifier". Also PWM is the best way to dim LEDs, because the voltage stays the same, it's just the amount of time that it is conducted that changes. Varying voltage both higher and lower than rated can shorten the life of LEDs

[@FilmmakerIQ]

+TurboHawkV6 I guess you didn't watch the video. PWM is murder on video cameras...

[@TurboHawkV6]

I did watch the video... but you said "The best way..." which in reality from an electrical standpoint is PWM, like I said using varied voltage reduces the life of LEDs, PWM does not. Using varied voltage may work better with certain types of cameras.

[@FilmmakerIQ]

+TurboHawkV6 PWM is very problematic on cameras. It really isn't even an option for anything video related.

[@kennynvake4hve584]

What if you dont know the MA hours in using the online calculator???

[@verdatum]

If anyone else happens to already be an electronics person and wants to skip to applications, you can jump to 13:06

[@Madness832]

"...a large can of baked beans..." So, I take it that you gave yourself serious gas, all in the name of science? :D

[@MartinBuzon]

I wanted to know how to conect a bunch of those strips of LEDs to my 220v home wall, I guess a phone charger will do?

[@FilmmakerIQ]

+Martin Clementz you need a driver to convert your home power to 12v. Most phone chargers are only 5v so you'll need something else that delivers 12v. Also keep in mind the power draw. I think 5m is one amp so there is a limit to how many your can string yup to one socket.

[@LazyScoutJace]

Reminds me of that little girl that had the LED Halloween costume...

[@rpervinking]

You used white LEDs to illuminate a green screen. Any reason you didn't use green LEDs?

[@FilmmakerIQ]

+Richard King well the main reason is there aren't green LEDs with light output that these white LEDs. But generally we don't illuminate a green screen with just green light

[@kennynvake4hve584]

Yes, current(MA) or (AMPS) absolutely has to be right..or the LED will smoke...and that means to get the current right you HAVE to have a resistor inline...or it(the LED) will burn up.....and there are limits to the current also...by this I mean...if a 3 volt diode will use say a 1k resistor...at 50ma....you cant run the diode at say 50 volts with a larger resistor...it will smoke...That always confused me...I would say "oh I have a higher voltage and want to use an LED...so I can use a larger resistor...and NOPE ....it will burn up the resistor.....

[@zerozirozyroxcross4726]

Talking about LED superheroes : Kamen Rider Faiz : kzbin.info/www/bejne/l6KrfaWaeZySnLc Please keep in mind that this show came out in 2003 also that clip shows a powered up form but the first suit is the Rider's base form.

[@octap79]

You should have mentioned "CRI" in this video. Using any kind of led to light a video scene is not a brilliant idea

[@FilmmakerIQ]

+octap79 CRI is kind of an outdated concept. And I've been lighting with LED for a long time now. It's not as bad as it used to be

[@warhammer2162]

Great video and quite inspiring. My 2 part question is (1) I am using a DC12V - 2.0A - 5 Meter/ 16.4 feet LED colour changing strip light cut in the middle, when rejoining strip light, is it ok to use 240V 13A section of cable in-between, cuz in the UK I have lots of this cable around, I'm making the assumption that a higher Amp and Voltage rated cable is ok to use, though I'd like to know for sure? (2) , What is the maximum length cable joining the two I should not go beyond, I'm wanting to bridge a gap of 1.5M / 5 Feet, should I bin 1.5M of the LED strip to keep strip and joining cable a total length of 5 Meters, or preferably can I keep the whole strip? Thank u for any advice. I've recently joined filmmakeriq.com/courses/ and really like it

[@FilmmakerIQ]

+War Hammer if you are running the power from the cut lighting strip to the following cut lighting strip the power flowing through there is only 12 volts. So your 240 volt cable is way overkill for the job but it _should_ work. The only thing to be concerned about when bridging two pieces of strip lighting is possible voltage drop in the bridge. If you're bridging 5m it probably shouldn't be enough to be a problem. As far as the length of LED strip, that's a question of your power source. They're 2 amps per 5m so to drive more than 5 meters you'll need more than two amps. Now this is regardless of having a bridge Connection in the middle or not because remember the bridge doesn't actually do any work in terms of electricity

[@warhammer2162]

thank you for your very helpful answer.

[@DarrenNoFun]

But wait, there's more,

[@PEISHTV]

Why do cameras react so bad to pure Red and Pure blues LED lights?

[@FilmmakerIQ]

Just as we talked about in the video - the color LEDs put out a very specific wavelength of light. Cameras Sensors are used to seeing a wider spectrum and therefore weird things start happening when you feed them light from some LEDs.

[@PEISHTV]

I knew it was a wavelength issue.. But is there anyway to solve to problem except get rid of the pure forms?

[@FilmmakerIQ]

I'm not entirely sure - I think more modern sensors handle them better than older systems.

[@PEISHTV]

I recorded a dance recital and the dance company insists on using just RED or Blue LEDs to light certain dances and it comes out horrible with my JVC GY-HM200. And I have noticed that even big production events have trouble with that kinda lighting as well. Talking about a concert that was broadcast on TV and used pure red and blues for the back ground effect and it was did the same thing to even the most expensive systems! Oh well, Thanks for you response and keep up the great videos!

[@FilmmakerIQ]

Yeah - I have the same issue when shooting theater productions with my Sony EX1 - I don't see it so much on the BMCC which I sometimes use as a second camera angle. Theater lighting is sometimes so difficult to deal with...

[@devendrapatel197]

Let's make 100th comment

[@MarkKoolen]

PWM: M: modulation

[@ronpetersen2317]

I don't care how cool that Superman Lives LED suit looked. I am just damn glad that crazy film never happened!!!!!!!!!!! So stupid!

[@FilmmakerIQ]

Check out the film The Death of Superman Lives: What Happened amzn.to/2uUM7ul It's actually quite interesting.

[@ronpetersen2317]

Yah John Schnepp's film. I will watch it eventually. I still have to think it was just a train wreck avoided. The stills of Nick Cage were terrifying.

[@KowboyUSA]

That picture on your desk was extremely sexist. Subbed.