DIY Laser Light Show - The Learning Circuit

[@KJ7JHN]

Karen, I'm so proud of you for getting in to electronics. This project is a prime example of what many of the Ben viewers were looking for when watching, while watching. Thank you for keeping the spirit alive. Someday we'll all get to microcontrollers and fpga's. What you have done here is golden.

[@BrandonFreemanAwesome]

I remember using a LM317 before I found out that L293s were a thing. They are probably outside the scope of the channel, but they are one of the more useful ICs that I keep on hand. Although, I feel like keeping with lower tech and passives is more beneficial to the intended audience. For a "further reading" type opportunity, L293s are a good time.

[@MAYERMAKES]

resister boxes are saving tinkerers so much hazzle for ages, I have a 1920´s one still in operation..it is a behemoth compared to your box, but also very accurate.

[@sidharthcs2110]

Our physics lab has a ton of those

[@stupossibleify]

You explained everything so well, and then suddenly capacitors appear!

[@stupossibleify]

Also, why does a rotating mirror produce a circular laser pattern when the laser is perpendicular to the mirror. If I look into a mirror and rotate it, my image remains unaffected.

[@evilpandakillabzonattkoccu4879]

@@stupossibleify that laser makes a circular pattern on the wall because of imperfections. The mirrors dont have flawless surfaces that change the direction of the light ever so slightly...compound that with a wobbly motor moving a 'not 100% true' drive shaft and you have a situation more like light hitting a spinning car wheel than a spinning mirror. The angle of the laser exploits these imperfections and the second motor adds more.

[@robinday8200]

Yup, would have been nice to have a basic explanation included for each of the capacitors used and the reason for choice of capacitance rather than them just magically appearing. Also would have been nice to see the final circuit diagram.

[@SineEyed]

​@@stupossibleify the capacitors are most likely part of the necessary external components needed to use the LM317 as a voltage regulator. But with motors that small, I really don't think any of that was necessary. A potentiometer in series with the motor would be just fine - 100 ohm would probably be best for this application, though 500 or 1000 ohm would be fine too. Anything higher and you'll lose control sensitivity. Don't listen to that panda guy about the mirrors. He doesn't know wtf he's talking about. Getting a circle/patterns has not a damned thing to do with imperfections in the mirror. Your intuition was correct - a perfectly perpendicular mirror with respect to the shaft of the motor will not produce a circle (cone). You get a circle when the mirror deviates from the normal. 'The normal' in this case is an imaginary plane, being perpendicular to the rotating shaft. The laser's interaction with the mirror follows the Law of Reflection, which basically says that the angle at which the laser will be reflected off the mirror is the same as the angle it contacted the mirror, with respect to its normal. So, a slight deviation will result in an oscillation at the point of contact (laser hitting mirror). If the oscillations are regular (even) then you get a circle. And that's how that works..

[@syedraheelhussain3553]

Lovely Karen sister you're teaching awesome plz connection time teach slow slow everything good video knowledge too much I don't have words to appreciate...

[@conroyquammie4028]

wow its so amazing seeing a lady doing electronics.am impressed.great job.i am looking forward to more videos.i really enjoy your video content.am watching your vids from st vincent and the grenadines ..

[@AshKast]

I've always wondered how those work. Now I know. Thanks!

[@AnandKumar-ym9yw]

Mam is doing so much hard work.

[@johnwiggins547]

on another note; would PWM be better than using potentiometers?

[@MrCardeso]

Nice project! Thanks, Karen!

[@makingstuffoutofstufforyou2687]

I like your presentation. I gave made cheap ‘x,y scanners out of two small midrangespeakers. You can build aft using from a rubber band. Then you will attach a push rod from the speakers coil to the mirror. Usually I use a planstic bristle from a broom.then I can play stereo to each speaker. The speakers should bet turn 90 degr opposing each other and now your done. I am in no way trying to steal your thunder. It could be the next progression of this type of device. I started with motors my self I also added an additional motor with a wheel of several fan blade type configuration.this will give your patterns a dotted line that can be in phase or out and really moving. This look particulay good when projecting beams in smoke. Ok I'm done hogging your presentation. Sorry if I overstepped. Peace, love and ubderstsnding. Your rig is rocktastic.

[@dafpnp]

Besides the way you explain, I loved that swivel arm holding the protoboard. What do you call that?

[@carbon273]

Where do I pick up heat sinks for this project?

[@xKatjaxPurrsx]

Heh... I remember making these. One thing I found interesting was that attaching everything to a flimsy chassis like a shoebox or cheap tupperware lid actually made the show more interesting than attached to a rigid chassis (did one with a metal frame.) Too bad I can't do this one at school because the kiddos would just shine the lasers at each other's eyes.

[@KJ7JHN]

Thanks Karen! Watch out for Dr. Pi-Face, I sense his presence. I'll make a vid of my build, and post it in a few weeks.

[@RoryOConnor]

Awesome stuff Karen, they should send you to Japan to research diy/crafty Japanese Karaoke Discos etc.. a huge crossover market for stuff like that just waiting to kick off!

[@RoryOConnor]

+ Japanese VR market and you are really golden! 1=D

[@easyerthanyouthink]

Wow still doing this stuff. Anyway as another user said PWM is better way but adds a little more complexity. Plus stepper motor or voice coil .

[@kevinmbrooks]

If the mirrors are mounted perpendicular to the motor axes, how is the laser affected? Is it just that they aren't perfectly perpendicular?

[@maker_karen1785]

A slight wobble causes the mirror to distribute the laser in a circle.

[@AirborneSurfer]

IT'S LASER TIME!!! 🕺💃🕺💃

[@LanzaOnWeb]

Why are capacitors popping all over the place ?

[@makingstuffoutofstufforyou2687]

If you use a function generator app that you can download to your phone or laptop you can get way more complex patterns for free.

[@DAVIDGREGORYKERR]

Very interesting but very retro things have moved on and are now used in TV projectors usually via two 50 sided mirror rotors to generate a raster and we would need three lasers one red,one green and one blue each using a Kerr cell to modulate the intensity of the laser beams before going through the two rotors to generate a image on the screen, maybe you should have a power regulator to limit the voltage to the laser to 4.5V so as not to burn out the laser.

[@Narendrakumar-ch3zg]

God bless you what is your country

[@johnwiggins547]

shouldn't the motors have flywheel diodes?

[@mohamedisma3ili355]

جميل تكون المراء في هد المستوى العليم شكرا

[@radioguy19510]

You referred to your common ground as a ground plane. It is not. A ground plane is usually understood to mean a single piece of grounding material that provides a certain amount of shielding (isolation) either at radio or audio frequencies from the rest of the circuit.

[@qwaqwa1960]

1.25V is actually the *minimum* Vout of a 317. I don't think it's guaranteed able to output Vin-1.25V, but you may have got lucky.

[@StigDesign]

Nice :D

[@dfalconerio]

I like Karen :)

[@reccothomas1689]

I was able to follow you all the way up until you started soldering everything on the board. Can you PLEASE slow that process down for those of us who need more of a slower step by step demonstration? I really want to be able to build my very own working circuit.

[@TheBic4]

Now replace the diodes with Co2 lasers lol

[@SineEyed]

I have a feeling this gizmo didn't live very long..

[@jonnupe1645]

Can it do text?

[@maker_karen1785]

I believe you're thinking of a persistence of vision or POV device. No, that requires a more complicated circuit.

[@gnamp]

"penshiometer"? Wha'?!

[@SalimSalim-cs5ep]

😧💭DIY laser 26 ? 🔧🔪 100%100