The Misleading Laser Diode Display Project

I recently came across a project by the YouTube channel RoboticsKanti that promised to create a laser diode display using electromagnets and a 5V laser diode. I was intrigued by the idea, but after building the project myself and analyzing the creator's instructions, I found numerous mistakes and inaccuracies.

The main idea of the project sounds plausible: using a laser diode that shoots out a red beam and four coils around it as electromagnets to attract the laser diode and create an image. However, upon closer inspection, I realized that this approach would not work.

For instance, the creator recommended directly powering the laser diode by a digital pin of the Arduino, which is not feasible due to the high current requirements of the diode (around 70mA at 5V). Additionally, the MOSFETs used in the circuit are wired up incorrectly, leading to continuous power supply to the coil regardless of the control voltage applied.

Furthermore, I found three other significant mistakes in the project. Firstly, the laser diode is not properly isolated from the Arduino board, which would cause damage to the device due to voltage spikes across the MOSFETs. Secondly, the electromagnets do not have flyback diodes, which are essential for reducing electromagnetic field collapsing and preventing damage to the circuit. Lastly, the Arduino code provided by the creator does not even compile.

Despite these mistakes, I was determined to explore the idea of creating a functional laser display using electromagnets. I began by cutting a piece of iron rod to size as the ferromagnetic core for my electromagnet, which resulted in a resistance very close to that of the original project's electromagnet.

To test this new design, I created another electromagnet and secured it near the laser diode, adjusting the Arduino code slightly so that all four coils are powered one after the other. While the diode did move, the resulting image was not what we had hoped for – a reliable laser display system like these would require perfectly adjusted magnets and potentially even a feedback system.

In conclusion, such a laser display is possible to make, but it's certainly not as simple as shown by other creators on the internet. I hope this video has been informative and entertaining, and maybe even taught you something new along the way.

Support me through Patreon so that I can keep the show going.

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WEBVTTKind: captionsLanguage: en(Yes, this really works!)NO; it doesn't because this project is fakeand it is also not mine.It is a project by the YouTube channel RoboticsKanti and a viewer of mine actually send methe link to check it out and I recommend youto watch it as well because what I saw andwhat I found out about it is just crazy.Now first off, the main idea of the projectsounds plausible.You got a laser diode that shoots out a redbeam and then you got 4 coils around it thatalternately get powered to act as electromagnetsin order to attract the laser diode and thuslet it move in a specific way to create animage with the beam.Like I said, sounds plausible; but after buildingthe project myself and having a look at allthe information the creator provided, I haveto say that there are so many mistakes andthings that just don't make any sense; itis kind of embarrassing.And worst of all he makes extra money throughwrong component affiliate links in case someonewants to recreate this thing.So to stop this spread of misinformation Iwill proof why this thing will never work,show you what huge mistakes were includedand at the end try to create my own real laserdiode display to show you what is actuallypossible.Let's get started!This video is sponsored by JLCPCB, who nowoffer flexible PCBs and of course that comeswith a super special offer meaning pricesstart at only $25.Their flexible PCBs are made with excellentquality raw materials, allow for great flexibilityand are ultra lightweight and best of all,of course, they easily bent for your uniquedesign.Check them out today and while you are atit, maybe visit their new 3D Model sharingplatform and get yourself a 7$ coupons fortheir 3D model service.Let's start off creating the original projectby grabbing ourselves one of those 5V LaserDiodes of which there is really only one kindpopular on the internet.And the first good news is that its enclosuretruly gets a bit attracted by magnets, sodragging it around with magnetic forces ispossible.And that brings us to the projects main structureonto which the diode gets secured in the middleand the coils all around it.Now my final version of this required objectlooked like this but it was not my first versionof it and I actually had to try out a fewdifferent sizes and whatnot; all because theoriginal creator didn't provide any informationabout the dimensions of this thing.So what I did was figuring out how big thediode was and then estimating how big therest has to be so that it fits in comparison.Another helpful clue I got though was thewire size he used which is linked in the videodescription through an affiliate link.It is apparently a 0.1mm enamelled copperwire and luckily for me I got that layingaround.But I immediately noticed that the 0.1mm wireis super thin in comparison to the wire shownin the video meaning this is not 0.1mm wireand the creator basically leads interestedmakers to the wrong product while making aprofit, lovely.So after doing my own research it seems likehe was using something like 0.45mm wire whichI of course also had plenty of laying around.And according to wire size and laser diodesize, I finally came up with my own fittingmodel for this project which I then 3D printed.Next I of course had to wind the first electromagnetcoil and let's just say that according tothe given information I had no idea how manywindings were used.But I made sure that my coil was thicker inthe end because that means I could make itmore powerful and thus be on the safe side.So with the first coil complete, I removedthe varnish from it ends and measured itsresistance which seems to be around 3Ω .And that actually fits great because accordingto the schematic given by the original creator,we should use 9 to 12V for the coils and witha 3ohm resistance, that would equal a currentflow of 3 to 4A which my power supply shouldbe able to handle.But before hooking up the coil; let's createthe back piece for the laser diode, attachtwo longer wires to it as well as a pieceof silvered copper wire to later give it somestability in the middle and push that allthrough the back piece and glue it all inplace.And with the diode being in position it wasfinally time to power the electromagnet whichas you can see the laser diode does not caretoo much about.Because yes, the created electromagnet fieldof this coil construction is way too smallto attract the diode in any way significantly.I mean even normal magnets are not very attractedto this magnetic field, even though we aredefinitely at the power limit of this electromagnetbecause it was heating up very quickly.OK, at this point I think it is pretty clearthat this diode electromagnet constructiondoes not work the way it got advertised bythe creator; but worst of all this is justone big mistake of many in this project.For example let's have a closer look at theschematic where you can easily find 3 otherbig mistakes.First off, the laser diode gets directly powerby a digital pin of the Arduino which soundsplausible.But once you realize that the diode drawsaround 70mA at 5V and an Arduino pin can notprovide that amount of current continuously,you know that this will not work.Next you see such N-Channel MOSFETs that getused to control the current and thus powergoing to the coils which once again soundsplausible because as you can see MOSFETs cando such a thing.But in this case the MOSFETs are simply wiredup incorrectly, meaning the supply voltageconnects to source and the Coil goes to drain.If we look at the datasheet of the MOSFETswe can easily figure out that if we woulddo such a thing, current would flow continuouslythrough the body diode and thus we would permanentlypower the coil no matter what control voltagewe apply to the gate.And even if we would wire up the MOSFETs correctlyand control them, there would still be theproblem of huge voltages spikes appearingacross them which eventually would also destroythem.The reason for those voltage spikes is thecollapsing electromagnetic field of the coilswhich we can easily decrease significantlyby adding flyback diodes across them whichare of course missing in the schematic though.And these were only 3 problems I found immediately;I bet there are tons more when you take sometime to think about this project and as afinal nail in this coffin, let me say thatthe Arduino code the creator provided forthis project does not even compile.So all in all the presented project neverworked and will never work.But honestly speaking I thought that the initialidea for this was rather intriguing and thusI wondered whether I could create somethingfunctional along those lines.To do that I of course firstly had to cuta piece of iron rod to size because everygood electromagnet needs a ferromagnetic core.And after winding tons of wire around it,I actually ended up with a resistance veryclose to the electromagnet from before.Thus it also drew around the same power asbefore, but this time our laser diode didget attracted to it and other magnets of coursenoticed it way faster.So this kind of electromagnet could be thesolution to creating a functional laser displaywhich meant I made one more of it for testing,designed a custom structure to place it allin, 3D printed that, mounted the diode andtwo magnets onto it, build a custom controlPCB with Arduino and MOSFETs, connected everythingand ultimately wrote a bit of code that turnson the two electromagnets alternately.And after then powering everything, it wasclear to me that this idea does hold somepotential.Meaning next, I created two more magnets,secured them close to the diode and adjustedthe Arduino code a bit so that it power all4 coils one after the other meaning our resultingimage should look something like a squareor circle, right?Well, first off, the diode did move; but theresulting image was not really what we werehoping for.But that is OK because for a reliable laserdisplay system like these we would need perfectlyadjusted magnets and maybe even a feedbacksystem to draw proper images and that is somethingI am not interested in making because thatwould be way too much effort for somethingthat is not really useful.So all in all such a laser display is possibleto make, but certainly not as simple to doas shown by other creators on the internet.With that being said I hope you enjoyed thisvideo and maybe learned something new alongthe way.If so, consider supporting me through Patreonso that I can keep the show going.As always don't forget to like, share, subscribeand hit the notification bell.Stay creative and I will see you next time.