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Need help still a noob :p

Austrazilian

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Hi guys i got interested with playing with lasers after watching a laser flash light hack kipkay put on in youtube and have a few questions that im confused about

i want to make a successful mag lite laser flashlight from a dvd burnwe that will not burn the diode and will last a good while tho i dont understand much about capacitors and resistors and wouldnt know where to put them also besides the AixiZ 650nm 12mmx30mm would i need a heatsink or does that alone hold up the heat.

another thing i am curious about is can cd players, cd burners, dvd players be used as a laser pointer or are they all IR Diodes.

if anyone knows where there is a detailed video of how to make a laser flash light (from a simple maglite) that will last and can list the exact resister/capacitor i would need i would be really grateful, also what kind of safety eye protection would i need and where can i buy it cheap in australia i realli like my eyes :p dont wanna lose my sight  :p

thanks for hearing me out

Your Noob
MICHAEL


btw wheres the best place to buy AixiZ 650nm 12mm x 30mm in Australia and if i cant is postage alot more frm over seas
 



o_DEATH_ANG3L_o

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Welcome to the forum! Don't listen to Kipkay. :p You're diode will die in a short time period if not instantly. If you absolutely want a minimag laser then I suggest you at least put a resistor in series with the LD. But as far as any room in the minimag, forget it. I would suggest a Dorcy Metal Gear or Dorcy Mini. They have plenty of room. Also if this is your first attempt at building one of these, please do some reading on this forum. It has excellent information for all your laser building needs. Well have fun and most of all be safe.
 

dilmah

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hey austrazillian, :D

i was a humble noob from australia a few weeks ago, but i think im quite sure i have things worked out now... :cool:

first, as death angel said, this forum is excellent, it has ALL the information you need, i used NO other source. I too saw
kipkays video, and i somehow winded up here, there was a link on someone's youtube video for cheap LD's.



About your question about lasers from cd players etc, your right, they are all IR diodes, so aren’t visible. but im not sure about the DVD player, i haven’t seen anyone confirm that they are IR, although they probably are...


ok, so you want to build a dvd laser? ;)

first of all, you'll need a LD. might I recommend purchasing one from Senkat, his Group buy order just went through, but luckily he ordered some extra’s. PM him and get in quick! The thread for the GB is at: http://www.laserpointerforums.com/forums/YaBB.pl?num=1189708669

be sure to thank him!

You should probably buy at least two, the diode’s are very sensitive to static etc. But I’m just being hypocritical, I only bought one and I’m just planning to be very careful haha.


After this, you’ll need an axis laser housing. It has an adjustable lense with which you can focus your laser diode. I purchased mine from paypal, its about $5 and $3.50 for international shipping. Its only $1 for international (its $2.50 for domestic to US) so don’t worry haha. With our exchange rate at almost US$0.90, it cost me about 10 dollars altogether. It takes a while to arrive though, I only got mine yesterday, after about 2 or 3 weeks.


Now, your have one of three options.


1. You can chuck a kipkay and just hook it up to two AA. But don’t do this. Its a joke option. Seriously. Your diode will fry. Actually, apparently it would fry, I wouldn’t know. :-/


2. You can put the diode in a pre regulated flashlight. These flashlights already have some circuitry which will help protect the diode from too much voltage/current. Most of them will need slight modifications, such as adding a capacitor. You can check out Daedal’s thread on modding a Mini Dorcy (whatever the hell that is, never seen one in aus) here : http://www.laserpointerforums.com/forums/YaBB.pl?num=1186966870
This will probably look the coolest, but I think it is quite difficult and expensive, but that’s just me, I’m a poor and lazy bugger haha ;)


3. You can build your own DVD laser diode driver. Basically, its a circuit that regulates current and prevents voltage spikes from the batteries from frying your diode. Its not hard, I had NO prior knowledge in electronics and managed to build one. Its quite fun actually, you should try this. After you’ve built the driver circuit, you can put it in your own tin or whatever, I’m planning to put mine in the eveready torch (the two buck ones) which take two D cells. The instructions for building the driver are here: http://www.laserpointerforums.com/forums/YaBB.pl?num=1185701612


If you decide to build the driver, I have a few recommendations:


1. Read through the entire driver building thread. It will take a coupla hours. :)


2. The LM317T is being used as a current regulator, taking a fixed amount of current from the batteries and feeding it to the diode, so as the diode doesn’t fry randomly. It has three pins, Voltage in, voltage out and Adj. It works by always maintaining 1.25 V between the Vout and Adj pins. So we place a resistor and a Potentiometer (pot) between the V out and Adj pins, and through V=I x R we can set the amount of current being fed to the laser. V will always be 1.25 v, and you are choosing R. You probably want I to be about 250 mA, and the best way to get this is to take two 10 ohm resistors and attach the pins together, which will result in a 5 ohm resistor, which will feed 250 mA to the laser.


3. Voltage spikes are not as harmful as it is mainly the current that fries diodes, but to “regulate” this, the capacitor is used. It doesn’t set the voltage, loads take as much voltage as they need, but just in case there is a sudden spike in the voltage it will suck it up.


4. The diode can be a 1N4004, thats the lowest one you’ll be able to find in Australia...it makes no difference don’t worry.


5. If you get confused as to how this works, JUST ACCEPT IT. IT WORKS OK? Just build it as it looks in the circuit diagram, and it will work.


6. Buy a DMM, you can get one for 7 bucks at jaycar (they advertise it as the cheapest DMM in aus haha) and it is really helpful. And a necessity. Just get one, you will understand how useful it is. You can test your circuit, check for shorts, check the charge on your batteries etc.


7. When testing your circuit, use the DMM to measure the voltage across a dummy load. I recommend using an 8 ohm or so resistor as the load (put it where the LD would be). I learned the hard way that the LM317T doesn’t work properly if the v drop on the load is too high, such as with two LED’s in series. To measure current, place the pins of the DMM across your other resistor, the 5 Ohm one in the circuit, and measure the voltage drop (of course it should be 1.25v if your pot is set to 0 ohms) and then use V=I x R to work out the current. This is the easiest way.


8. Speaking of Jaycar, if your planning to buy the parts from dick smith, don’t bother. Just go to jaycar, they have everything. ;D


Once you’ve built this, all you need to do is disassemble the Axis module, remove the LD in the axis module and put in your DVD burner LD. To put the LD in, I recommend using Senkat’s method™, you can find it somewhere in this forum, it involves using a vice...If you don’t have a vice, scroll to about page 3 or something (the last page at the time of this writing), and someone recommended a similar method with heavy books and a hammer.


ALSO REMEMBER THAT AFTER YOU TEST THE DRIVER CIRCUIT, you have to DISCHARGE THE CAP before putting the LD in. This can be done by shorting the leads of the Capacitor for a few seconds. If you test the circuit and plug in the LD, it will discharge onto the LD and could fry it.


Also, when touching the LD, static neutralise yourself. Either install floorboards in place of carpet in your house and walk around naked, buy a static wriststrap, or touch an unpainted part of your computers case or the PSU of your computer when it is plugged in (so the ground wire is earthed).

In regards to goggles, that is a very wise decision to purchase goggles. The best value are the wicked laser lasershades (don’t get the sports goggles, apparently the OD is so high you cant even see the dot of the laser..which defeats the purpose as you will remove the goggles to aim the laser). Or get the NES shades, or some from optotronics. Personally, I purchased the Ebay ones from zonestealth, but Senkat does not like the looks of them, and I must obey the god of lasers, so I should be sending them off to pseudo who has kindly agreed to test them for me. But I wont do this for a few weeks, because I know that if I send them off, when I get my GB diode, im going to use it without the goggles if I don’t have any...so ill be sending them In a coupla weeks and will inform you of the results.



PS in goggles you are looking for two things. Firstly, what wavelengths they block. You need one that blocks 650 nm for the red laser diode. They should might (thanks marianne) be blue in colour . Note that by purchasing goggles rated for red lasers, it will do nothing to protect you from green lasers etc, which brings me to the second thing: a high VLT. VLT is visible light transmission, or something random like that, and is a measure of how much of the other light wavelengths the goggles let in. This is very important, and this is why you cannot use sunglasses, which block basically all visible wavelengths to a certain degree. When you don’t have a high VLT, like in sunglasses, your pupils will dilate to bring in more light to compensate to the dimness, and thus if a laser hits you, it can do MORE damage than without sunnies. With a high VLT, this means that apart from the wavelengths the goggles are blocking (i.e around 650nm), it should let the others through almost unhindered, so your pupils don’t dilate, as you will still be viewing the same brightness, but just without the red light. Its really cool to look through laser goggles, if there is a red light on the wall, you just put your goggles on, and WHAM, its gone, take them off – its back, put them on, its gone again. The rest of the scene remains the same, except for the blue tinge. Hours of entertainment.



P.S in the above instructions I’m assuming you were as much of a noob as me. But your probably not haha so ignore all the obvious stuff.

I’ve probably forgotten something, just post back any more questions, or PM me...(PLEASE ...no one has PM’d me before unless it has been a reply to one of my questions..I wait in anticipation)


*breathe*


Hope this helps

dil
 

marianne

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wow, big big post dilmah! i'll try remember this for when i get round to building my lasers from senkat's diodes :) i may be wrong, but i believe it is possible to have goggles for red that aren't blue, and goggles for green that aren't red, they just seem the common tints? and good luck Austrazilian, welcome to LPF!
 

rog8811

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What Dilmah said :) (nice informative post)

Search, read, ask then success will be yours, welcome to the forum. ;)

Regards rog8811
 

dilmah

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haha thanks marianne your probably right, im no expert

edit: ok i changed that statement
 







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