This tutorial will explain every little thing you need to know about how to build a burning laser, it's an interesting project, which is still quite easy to make.
The picture above shows how mine looks but you can make the design of yours look totally different if you want to.
It's going to become a burning laser with controllable current. (current-regulated with an LM317T).
You can choose between a 9V battery and an external power input (see first picture on the left side).
Other regulators then an LM317T are also possible to use here. If you have any questions about them, ask it here!
Warning
It might be fun to have a burning laser, but not when it burns that one thing you don't want it to burn.
Use safety glasses! This is really not a simple toy.
High power lasers might also not be allowed in your country, keep that in mind.
I am not responsible for any accidents with this device, however all dangers are well noted in this instructable.
A video of the laser in action:
A video of the laser in action with a spirograph:
The picture above shows how mine looks but you can make the design of yours look totally different if you want to.
It's going to become a burning laser with controllable current. (current-regulated with an LM317T).
You can choose between a 9V battery and an external power input (see first picture on the left side).
Other regulators then an LM317T are also possible to use here. If you have any questions about them, ask it here!
Warning
It might be fun to have a burning laser, but not when it burns that one thing you don't want it to burn.
Use safety glasses! This is really not a simple toy.
High power lasers might also not be allowed in your country, keep that in mind.
I am not responsible for any accidents with this device, however all dangers are well noted in this instructable.
A video of the laser in action:
A video of the laser in action with a spirograph:
Remove these ads by
Signing UpStep 1: Requirements
The set-up is really simple, there are just few components:
(* means Required)
- Hot glue or other glue.
* A soldering iron /w soldering wire.
* A laser diode.
* A 100ohm potentiometer. (250mW)
* A 3.3ohm resistor (or 3x 10ohm resistor in parallel). (3x 250mW or 1x 0.5W).
- A regular diode 1N4001-1N4007 (everything between is also good).
(or any other diode that can hold a reverse voltage of at least 40V)
- An On-Off switch/push-button/... as a main switch for the circuit.
- An On-On switch for switching between battery or external input.
* A 9V battery clip. (click here if you don't have one)
- A 9V battery. (not required if you use the external power input)
* An LM317T regulator (really cheap).
- An enclosure/box to put the whole project in -> I used an 8*5*3cm = 3.15*1.97*1.18inches black project box.
* A lens for adjusting the focal point of the laser beam.
- A connector for the external power input (if you want to use that).
* PDF reader for the datasheets.
* Your healthy brain and attention for safety measurements.
(* means Required)
- Hot glue or other glue.
* A soldering iron /w soldering wire.
* A laser diode.
* A 100ohm potentiometer. (250mW)
* A 3.3ohm resistor (or 3x 10ohm resistor in parallel). (3x 250mW or 1x 0.5W).
- A regular diode 1N4001-1N4007 (everything between is also good).
(or any other diode that can hold a reverse voltage of at least 40V)
- An On-Off switch/push-button/... as a main switch for the circuit.
- An On-On switch for switching between battery or external input.
* A 9V battery clip. (click here if you don't have one)
- A 9V battery. (not required if you use the external power input)
* An LM317T regulator (really cheap).
- An enclosure/box to put the whole project in -> I used an 8*5*3cm = 3.15*1.97*1.18inches black project box.
* A lens for adjusting the focal point of the laser beam.
- A connector for the external power input (if you want to use that).
* PDF reader for the datasheets.
* Your healthy brain and attention for safety measurements.
Visit Our Store »
Go Pro Today »
You can use it, but because the maximum current is only 200mA, if you will be using strong laser diodes, I suggest you put two 1n4148's in parallel, so that they can handle 400mA.
greetings, SpecieS
I still use the same value, 100ohm (but I think 50ohm would be a little better, not sure).
It is indeed connected exactly the same, and placed in series.
A 300ohm resistor in parallel to the regulating potentiometer would reduce its maximum resistance to 75ohm. Seems to be a good compromise :)
greetings, SpecieS
You say 'reduce' it's maximum resistance, but you say it goes from 50 to 75 then?
Indeed, a 50ohm trimmer would be nice.
When adding a resistor in parallel over it, you'll Decrease it's resistance, not increase to 75.
And also, when you added a resistor in parallel, the track resistance won't e linear anymore.
You don't need to add a parallel resistor, the 50ohm trimmer is perfect.
but I don't think you'll get "more precision" out of it by doing that because it will make the slider non linear.
At the lowest resistance values, it will change faster now.
btw, I've made some new schematics including the second potentiometer using Eagle: http://img845.imageshack.us/img845/3899/schematicslaser.jpg
You may attach it to the instructable if you want.
The schematic is also good but I think I'll just keep the one that I already have.
Fortunately I have another dvd-burner laying around...
ps: Happy new year :)
I hope you got some nice results before the diode got fried? :)
Oh, and it's normal that you fried your first diode. You'll do that 10 more times haha! :)
Happy newyear!
And I hope I don't need ten tries to build a working laser :D
How is your laser now?
did it work out? :D
Greetings,
Electorials
it works, but I don't have a collimator yet. I've already tried focusing the beam with a single lens, but it didn't burn anything. Maybe the diode is too weak. It's a bit smaller than usual, because it's from a laptop dvd-burner.
It's nice to see that other people are also making this ;)
Good to see a picture of it!
And yes, the diode is probably just too weak.
However, DVD burner diodes should do the trick
Maybe it can handle more current than you are giving it now?
How To Make a Simple Double Slit
It's either the heat from the soldering iron or static discharge that very quickly destroys the diode. It doesn't have to be a massive/powerful discharge that you feel...
The safest thing to do is when you desolder the diode, solder or wrap a piece of wire to both pins so that they are always at the same potential and remove this wire right when you are ready to solder something else to it.
Also, don't forget that it is a diode, so it is polarised, meaning, if it does not work, try reversing the +/- to it.
Also, if you don't use the LM317 method described here, have some series resistor as supplying too much voltage will kill it just as quickly as a static discharge...
Have a good one.
maybe the heat of your soldering iron kills the diodes :/
A laser running at very low current is no more than a LED. As you increase the current, light gets brighter and starts to transition to coherent radiation (LASing). The difference between the lasing threshold and overload where you destroy the diode out is rather small, hence the desire to use a closed loop optical feedback. This also compensates drive current for die temperature variations.
Typical diode datasheet http://media.digikey.com/pdf/Data%20Sheets/Sharp%20PDFs/GH06510B2A,B.pdf
Some good applicatoin information http://www.repairfaq.org/sam/laserdps.htm
And that last link is indeed very useful ;)
Laser diodes are also rather sensitive to heat, mechanical shock and static discharge.
Could you tell me something about what driver, what pins on the diode (and polarity), power supply, resistors (if LM317), ... you are using?
(if you want to, you could also send me some pictures of the setup. it'll be easier for me to understand then).
They all had 3 pins!
do u need a other regulator or other different parts?
It can be used as a voltage regulator and it can also be used as a current regulator (which is what we use it for here).
The current can be set by changing the resistance between the output and adjust pin.
There are also other voltage regulators around which indeed just have a fixed voltage. For example: an L7808 will have a fixed voltage of 8V.
E mail for arsalanmzz@gmail.com
can i ask question ? in your 1st video, you labeled a trimmer potentiometer.
but it is not in your list of materials and circuit diagram.
only large 100ohms 250mw potentiometer.
what is the purpose of that pot and where i'll connect it on circuit ?
and how can i extract laser diode on "tiny thing" that extremely glued or epoxy ?
can i grind it using small file ??
thanks ! :)