Homemade Laser Power Meter - Experiment

[@zentechnician]

Electroplating is super easy. You can even plate your 3dprints. So for that peltier I would spray it with clear glaze and while it's wet you put it in a sealed container with fine graphite powder and give it a shake. Don't open the container right away. Graphite is very messy, wear a mask and if you do it inside do it in the bathroom, run the hot water in the shower to raise the humidity and this will keep your particles from going all over but in this case since we aren't playing I would take it outside and make sure the coverage is good and then let it dry outside. Start with less powder and add as you need. Wipe your surfaces off with alcohol before application but give the part some good squirts of clear. It should be easy to get a uniform layer on something as flat as that peltier. Don't do the mix your wets and drys together. The 2 mixed together block each other's most valuable properties. One sticky layer and then one matte black conductive layer gives you all the sticky while retaining the high conductivity of the graphite. Plating 3d prints means submerging them in a solution of vinegar, salt , and whatever you want to plate with. Nickel is quite good and you get to find out if those cheap nickel strips you bought are just nickel plated steel or the real deal.

[@roberttco1]

Since the laser "target" is not 100% absorptive, there can be a significant amount of reflected laser light. Laser safety is quite important. Making sure you wear protective glasses or, along with other's suggestions for using insulation, maybe make an enclosure to prevent the reflected light form damaging your eyes.

[@chrismayer8990]

Very interesting project. I am afraid that the heat dissipation from the Peltier element is different at the edge than in the center. It might be useful to heat the Peltier element in the middle when creating the characteristic curves. I am also afraid that the heating emits an enormous amount of energy into the air. Insulation might be useful. Then only the reflecting laser light is undefined and can be compensated for in the code. I have another idea for a laser meter. Why don't you place a small heating element on the back instead of the heat sink? Then let the microcontroller regulate the heating via PID so that 0V comes out at the Peltie element. This gives you pretty much the exact heat output that the laser puts into the element.

[@Aitch-Two-Oh]

Use an enclosure with mirrored internal sides to return any reflected light back to the sensor. It should help the efficiency. Mirrored perspex is available and easy to machine.

[@igorslobodnik809]

Very nice project. Just one question - why not heat up the cold side of peltier with resistor, and simultaneously apply laser to hot side? the balance point in this case is zero voltage. At first, it is easy to detect, and second - you don't need 2 cycles of consequent measurement as you do it now (first with light, second with resistor)?

[@bokisan7624]

This is a very good suggestion.

[@TheLukemcdaniel]

Also .. companies lie. There's zero guarantee you'll actually get what the label says, even on big name brands.

[@klave8511]

Seems much simpler to Get a piece of black anodized aluminium heatsink. Add a thermocouple in a small hole. Weigh the aluminium. Optional, for better accuracy:- cover the back and sides of heatsink with some thermal insulator like expanded polystyrene, leave one face open. Blast the black open face with your laser and see how much it heats up in say 20 seconds (time can vary for better accuracy or different powered laser). Multiply the temperature change (in celsius) by 0.902 x (weight in g) and divide by (the time in seconds). 0.902 J/g ° C is the specific heat capacity of aluminium. This is the power absorbed by the heatsink as supplied by the laser in Watts. I have several of these, I use a cheap battery powered digital thermometer. Accuracy is affected by the heat conducted away into the air during heating and by how well the black anodised aluminium absorbs heat. I calibrated it with a commercial power meter and found this to be reasonably close. You can (sort of) calibrate it with a resistor or transistor clamped to the heatsink that heats it up and since you know the power doing the heating it means you don't have to weigh the heatsink piece. At least now I can see if my laser is losing power.

[@tiger12506]

You misunderstand the substances you are working with. Printer toner is a plastic (probably with candle-soot carbon black in it). You want it to adhere to the peltier cell, just melt it on. You didn't try the UV cure resin because you think that won't withstand the heat, and I think that is incorrect also. Graphite from the pencil is a shiny gray color. That's just what it is. You're probably thinking it should be carbon black, which you already exemplify with the candle soot. It's just black spray paint on those aluminum sheets, you could just spray black spray paint on the peltier module and you get rid of one lossy interface entirely.

[@azyfloof]

Very interesting! I wonder how comercial testers work. Perhaps a thermocouple junction? I wonder, could you shine the laser on one side of the peltier, have the heater resistor on the other side, and adjust the heater power until the peltier balances and outputs zero volts? Oh also try dusting the surface with the toner powder then heating it with a hot air gun to melt and fuse it to the peltier :D

[@kavinprakash7868]

May use reflow oven, not hot air gun because it is dust

[@kavinprakash7868]

Even small reflow oven will do the work

[@azyfloof]

@@kavinprakash7868 Yeah that's a good idea :D You can do it with the hot air, but you'd have to be careful that you didn't blow it everywhere lol

[@bokisan7624]

Toner powder for photocopiers and laser printers is basically plastic. It could be melted or burned by the laser beam.

[@azyfloof]

@@bokisan7624 If it got too hot certainly, but testing lower powered lasers, especially given the beam divergence, it'd probably be ok :)

[@renequintana8921]

Thanks, Your project is very interesting, I think that regarding the black paint you need, toner is not a good idea, because it has plastic particles, black glass fusion powder would be better. a big greeting from Argentina

[@scr1ptery642]

You can create a map with voltage value and easy determine power. Of course need clibrate procedure at start.

[@jeremiahbullfrog9288]

Wow very thorough explanation, you anticipated all my questions. I wonder about some of the new "super dark" black coatings like Action Lab explored... vanta black, I forget the other ones

[@JohnDuthie]

such an awesome channel! Very creative use of electronics knowledge.

[@hichemhlS]

Consider to measure the speed of the increasing value instead of waiting for equilibrium, this ll give instant value without waiting for it to reach the maximum. To do this you have to plot the speed instead of the max as reference for your calculation

[@antrax3430]

muchas gracias Master saludos desde Cali-Colombia

[@davidwitten2746]

Great video, excellent presentation!

[@alessandrovichi761]

interesting experiment. I'm sure that you finish the project very very welllll

[@paulroberto2286]

That's really cool!! Awesome project and great editing!

[@harunkokten3691]

I'm skeptical that the system shown in the video will suffice for measuring my optical power, which won't exceed 5 mW. What alternatives should I explore?

[@lasersbee]

Google J.BAUER Electronics. They have affordable LPMs

[@kavinprakash7868]

Very interesting and new project nobody have thought off I like it bro ❤❤

[@fzigunov]

13:23 "The Celtier Pell" 🤣🤣🤣

[@lasersbee]

Yeah... I heard that as well..

[@ELECTRONOOBS]

I'm dyslexic 😅

[@Electroneer0]

@@ELECTRONOOBS for real?

[@ELECTRONOOBS]

@@Electroneer0 hahaha yes, but in that case was just a mistake

[@kavinprakash7868]

Use reflow oven and the plastic dust or that some dust you have Similar to powder coating There are lot of videos available about how to do powder coating

[@vladi_g]

The hole in the heater should be rectangular in shape.

[@lucianbetke]

Interesting post..

[@ELECTRONOOBS]

Glad you enjoyed it

[@adhil8918]

Yes amazing 👏

[@taham6757]

Nice video as always

[@daisizhou]

very good plan❤

[@DanBader]

You should probably leave the laser right where it is when you switch to electric heating. The presence of the laser changes the air flow around the heat sink in the random air currents of the room. Or perhaps switch to forced air flow

[@ELECTRONOOBS]

True. The idea of the final device is to have it inside of a controlled enclosure and also monitor the room temperature and compensate...

[@tomast9987]

Great idea, i am curious ;-)

[@Betterstartnow]

Nice project

[@DanBader]

How come you didn't get a little sample of vanta black?

[@ELECTRONOOBS]

would that withstand the heat? I know is like super dark, but can it withstand the laser power?

[@DanBader]

My bad, apparently that's got some export control issues and isn't sold to individuals

[@DanBader]

The real stuff would as it's basically a bunch of carbon nanotubes. I tried to cut through a multiwalled carbon nanotube with a focused ion beam tool, in an attempt to fix one of the defective AFM tips we had purchased. I could not trim the bugger off the end of the carbon nanotube regardless of beam power.

[@aleksszukovskis2074]

thats a 30 minute thank you

[@omsingharjit]

Why not using solar cell

[@ELECTRONOOBS]

It would get burned or saturated very fast. Only 1% of the laser power would already saturate the solar cell output for sure...

[@erdum]

❤

[@sharadvaishnav85]

nice one bro but we need an exciting project like a cannon or a tank.(AI included)

[@manarhaiedar5837]

Why don't you use LDR - light-dependent resistor ? You can claculate the luminosity instade of watt because light is measured in lumen

[@kavinprakash7868]

It may burn the LDR

[@manarhaiedar5837]

@@kavinprakash7868 you can put a filter infront of it

[@kavinprakash7868]

@@manarhaiedar5837 to reduce the power , I can't understand what type of filter you are talking about

[@manarhaiedar5837]

@@kavinprakash7868 something like aperture filters They are commonly made from glass or a polymer material, such as Mylar ,There are different degrees , Or any other material that absorbs light and allows a certain part of it to pass through The amount of change, even if it is small, can be processed to show the results, and the difference here is the instantaneous speed of reading

[@kavinprakash7868]

@@manarhaiedar5837 i think that is more useful

[@CesarAnton]

Thank you!

[@lasersbee]

Get a Calibrated Laser Power Meter...

[@Fjyclydjgu]

Пельтье нельзя использовать для охлаждения из-за его физического принципа работы, гораздо проще поставить алюминиевый радиатор или водяное охлаждение.

[@bokisan7624]

Peltier is used as a cooling element for small refrigerators, for example, used in cars on a 12V battery or for cooling in office devices for drinking water (one-gallon tanks).