DVDRW lasers

[Tomcat]

I am planning to make a laser with a DVDRW Diode I know they run at 2.4-3v but I was wondering how to make a control circuit because I am poor and only have 1 old (broken tray) DVDRW 16xwrite... also what can I do with a 52x CDread Diode (I am sure these are invisible infared) Advice / curcit diagrams would be nice

im planning to use the laser for "destructive" purposes so Infared filters not needed

[Jem]

I am planning to make a laser with a DVDRW Diode I know they run at 2.4-3v but I was wondering how to make a control circuit because I am poor and only have 1 old (broken tray) DVDRW 16xwrite... also what can I do with a 52x CDread Diode (I am sure these are invisible infared) Advice / curcit diagrams would be nice

im planning to use the laser for "destructive" purposes so Infared filters not needed

Hi Tomcat and welcome to the forum

The first thing we need to ask is... How much do you currently know about lasers and more importantly, how much do you currently know about about safety when working with lasers? I don't want to sound condescending but if you are a newbie to lasers there are certain things that you should be aware of. If you already know this stuff please forgive me for the following information...

I can (if I try very hard) appreciate why some people want to burn things with lasers, it is quite fascinating how light can burn things I suppose. BUT, that same light can also burn your eyes - Badly. You only have one pair of eyes to last you a lifetime, once these get damaged, that's it, no second chances. You can't see infrared light, but it's there. You may just see a faint glow from an IR diode and want to take a closer look - DON'T - It is most likely putting out invisible light that WILL damage your eyes.

I'm sorry, I don't mean to preach to you, but I just felt a moral obligation to warn you that mishandling of lasers can cause you and others around you a problem if not handled with care and respect. I work in Ophthalmic Optics and it would be remiss of me not to give this warning to you.

This forum is a vast font of knowledge with many (and I mean MANY) incredibly talented people frequenting it on a regular basis. There is a 'slight' bias towards building laser projectors here, however pretty much anyone with an interest in lasers is welcome. I fear you may find few on this forum who are really into burning stuff with their lasers. There are a couple of other forums that are more orientated to laser pointers and burning stuff. If you aren't aware of these and want to know which ones they are please ask.

Finally, It's nice to see someone else from the UK here. Enjoy your lasers and enjoy the hobby but above all please be safe!

Cheers

Jem

[Tomcat]

yes i am a omg laser can burn stuff guy... but a sensible one i already have some IR protection and everything protection for that point Welding goggles with opaque sides because a TIG/MIG spark puts out everything from microwave to xray at aorund 10w i think im sorted

this is my first venture into lasers i have a fair amount of small eletronics knowlage my budget is 20-30quid ( already have my 200-250mw DVDRW diode 640-650nm if im corect)

i already have my 16x Diode sittin front of me and i have polarity tested it with 3v ( led in the loop for voltage drop and indication)

question= what is the third pin for?? all the tutorials say to disregard but im curious is it a feedback to the DVD drive for data reading purposes?

i have experiance in dangerous "firearms" because i have made many small 1stage coilguns (fireing metal BBs)

also= what effect would the unfocused diode procuce and what sort of lens/cohesion would i need (instructables say a normal 5mw red laserpen lens does the trick)

all materails would most likley be from my eletrical store ( maplins) i have a freind that gets me cheap componants the case will be hand made ( most likley a small black case i have and MECHANO for structure

[carmangary]

One way to go is to buy the die4drive module. It is an adjustable supply.

www.die4laser.com

[platinum]

I saw a video online where a guy took a DVDRW Diode, modified it (soldered on pins) and installed it in a mini-Maglite in place of the bulb. That seemed pretty interesting, but I doubt I'll get around to that.

[andy_con]

One way to go is to buy the die4drive module. It is an adjustable supply.

www.die4laser.com

agree, worth every penny

http://www.laser-man.co.uk/2006/inde...id=20&Itemid=6

[buffo]

Hi Tomcat;

Welcome to PhotonLexicon! I see you've been seduced by the dark side already. (Burning things with lasers!) No worry, we're not going to gang up on you. Just be sure you're careful. Jem's post offers some excellent advice.

One thing that was not mentioned, however, is the danger of static electricity to the diode itself. Laser diodes are particularly vulnerable to instant death from either over voltage (static shock) or over current (bad power supply design). Always take appropriate static precautions when handling your diode. And if you decide to build your own driver from scratch, be sure the curent regulation stage is stable and fast acting. Also, you want to minimize any capacitance after the final current regulation stage. See Sam's Laser FAQ for several circuit designs that should allow you to drive your diode safely. (Though admittedly, the die4laser driver is a *good* circuit at a *good* price.)

Remember to always keep the pins on the laser diode shorted together with some fine wire while you are handling it. If you don't, you stand a good chance of killing the diode with static electricity. Remember to never connect the diode to a driver circuit while the driver is powered up; this, too, can kill the diode. Also, make sure your driver has a soft-start feature so you don't kill the diode on power-up from a voltage spike.

I've already killed a few DVD diodes just with static. Some folks here have killed a few dozen diodes, both with static and with over-current. They'll tell you that if you play with laser diodes, it's not a matter of IF you'll kill one, but WHEN. So be very careful, especially since you're on a budget. You don't want to destroy your first laser before you get a chance to pop a balloon with it!

Otherwise, keep us informed of your progress!

Adam

[Tomcat]

fried the first one got a nice big red 1msq patch on my wall when i put half drainded AAs ( about 2.6v) raw but i think i fried it because i put new aas on the wrong way a few times and handled it lots it then just emitted a dull red glow when i hooked it up to AAs ( raw) like the lower power reader diode
BUT iv got 2 more i work at a computer recycling site so iv got easy acess to old dvdRWs just said to boss that there broken ( snapped the trays) and ripped em apart at work and put em back together without diodes ( we throw most away anyway)

THX for the driver board!!! gona get one soon and im gona power it with
EDIT4x to 6x) 6x1.2-1.3v rechargeable battries and a auto 6-12v--> 5v 1A-200mA( depends on imput voltage higher input = lower ampage will work)--> 500mA voltage regualtor (from my mains > old 9v phone charger > USB 5v charger) used for ipod chargin but i got another so ima gona rip that for parts

im plannin to make a handheld laser with control pack on the hip (containing the driver and batries) hooked to a handheld unit with the laser module and push switch with a umbilcal cord USB2 wire with the power wires as diode power ( datawires will be ignored and bridged)

i have a small fan from a laptop ( 1inchsq by 1/5inchdepth) it input from the top and exits the side (centrifugal) that would be hooked stright to the main power switch(in between the bataries and 5v voltage control) for the control pack and the handheld laser module will be passive cooled by the maglight case

the umbilical cord will come out of a drilled hole in the base of the maglight


im not started atall because i acess internet from work and ebay is blocked (forgot my paypal pw too) i would like to get the driver first before i start and i need to get cases and tools and the laser diode module (+lens) because im trying to get the best coherance as possible ( for long range small point burning laser)
i will make a small full curcit diagram for you to view (made in... PAINT :P)

and will that driver board allow me to put a pushswitch between it and the diode without damage (basic push on sprung off metal contact)

i know i cant spell just bear with me



EDIT: 6 AA nimh or NIcad


Also What Jumper Setting would i want for a CDRW ( running 200-240mw) output on the board

[buffo]

Sounds like static killed that diode. Make sure you short the pins together before you handle the next one. (Wrap them in very fine, bare wire and leave it in place until you've got the diode mounted and the wires from your driver soldered to the pins.) The wire should be the first thing you put on and the last thing you take off.

Re: you airsoft mod... Sounds cool, but remember that the output of that thing will be dangerous. Be careful where you point that gun.

Adam

[Laser Ben]

already have my 200-250mw DVDRW diode 640-650nm if im corect

Not exactly... The diodes are usually run at about 160mW pulsed with a 80mW CW rating. You might be able to push it and get 200mW but it would be for a short time without expensive cooling devices(TEC, large heatsink). As for the wavelength, I have measured the spectra of many of these diodes. I almost always get a peak of around 670-680nm. On top of that, they are multimode.