Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Nice Beam and burning. Thanx to all !!!

Thread starter mehra
Start date Nov 21, 2010

Nov 21, 2010

#1

mehra

0

Hi Friends !

I am a new member here. I can see a lot of friends those are "highly qualified" in lasers. Inspired, I also tried to make one. Here in India I could not find even an Aixiz housing. Well I made a laser with :

1. DVD Writer Laser Diode(> 16x).
2. A lens from DVD writer.
3. Self made housing.
4. 7.2 V rechargeable battery.
5. Common driver built with LM 317, 4.7 Ohm, 100 Ohm, 1N4001, 10 mfd etc
6. Preset is fully closed (to minim res) to get a bright beam, otherwise almost no beam.

I could not measure the current but I saw the beam to be good enough to reach about 2 Kms. Focus is good with bright round dot at about 10 feet.

THE PROBLEM

Simple : No heat, No burning and it's = No Fun :-

gun::gun:

Friends what's wrong. Please guide. Waiting eagerly.

:wave::wave:

Last edited: Dec 6, 2010

Nov 22, 2010

#2

mehra

0

Re: Help Needed Please !!!

No help yet. Plz friends, someone help me.

Nov 22, 2010

#3

Eudaimonium

0

Re: Help Needed Please !!!

You are giving us too little information.

Please, post pictures of your set up, take measurements of currents at critical points (we need to work with facts here), also, Aixiz housings are not available anywhere "locally" , they have to be ordered.

Here:
dia 12mm housing /5.6mm diode houisng with lens /10 pack [OL1230H] - $20.00 : Welcome to O-Like.com, Your source for laser products

Same thing, cheaper.

Pick up some lasers while you're at the site there

Nov 23, 2010

#4

Bionic-Badger

0

Re: Nice Beam but no burning Help Needed Please !!!

If you put your hand in front of the beam, does it feel hot? Also these lasers often aren't good at burning anyway. People pop black balloons, light black-markered matches, or other lame things (melting black garbage bags?), but really, that's not all that impressive. Red also doesn't burn quite as well as violet or other colors. A bright dot on the wall doesn't indicate a burn-capable laser; it could be 20mW which is quite bright, but won't burn anything except your retina.

Try attaching some photos as well.

Nov 23, 2010

#5

mehra

0

Re: Nice Beam but no burning Help Needed Please !!!

Bionic-Badger said:
If you put your hand in front of the beam, does it feel hot? Also these lasers often aren't good at burning anyway. People pop black balloons, light black-markered matches, or other lame things (melting black garbage bags?), but really, that's not all that impressive. Red also doesn't burn quite as well as violet or other colors. A bright dot on the wall doesn't indicate a burn-capable laser; it could be 20mW which is quite bright, but won't burn anything except your retina.

Try attaching some photos as well.

Thanks for replies friends.

No, the beam is nothing like hot, neither on focus nor anywhere else. But I could not understand that I have seen a lot of videos that ppl rip a LD from DVD rtr and simply put it in Aixiz module and its ready 2 burn. Then whats wrong with me. Lets say I m missing Aixiz, but I have quite a good focus and that's what an Aixiz does. What's missing then ??? I am putting some pics. Plz help me.

Nov 23, 2010

#6

Eudaimonium

0

Re: Nice Beam but no burning Help Needed Please !!!

What is the current setting it's running at? Have you tried to measure it?

What's the total resistance between OUT and ADJ pins?

Perhaps you're underpowering your diode if your driver was not properly tested and set.

Nov 23, 2010

#7

mehra

0

Re: Nice Beam but no burning Help Needed Please !!!

Eudaimonium said:
What is the current setting it's running at? Have you tried to measure it?

What's the total resistance between OUT and ADJ pins?

Perhaps you're underpowering your diode if your driver was not properly tested and set.

yes i think something is wrong with driver. plz tell me few things that need to be checked, and i will do so.
however, can u give any idea about the beams shown in pics, is it normal ...?:yh::yh::yh:

Nov 23, 2010

#8

Eudaimonium

0

Re: Nice Beam but no burning Help Needed Please !!!

mehra said:
yes i think something is wrong with driver. plz tell me few things that need to be checked, and i will do so.
however, can u give any idea about the beams shown in pics, is it normal ...?:yh::yh::yh:

Do you have a multimeter?

You need to check the current flowing out of the batteries. If pins of your switch are exposed, just switch to 10A mode, (plug the probe into correct socket if neccessary), and touch each pin of switch with one probe, or lead, or however you want to call them, it should give you a current readout.

Careful though, laser will turn on while you measure it. Don't let it surprise you.

Nov 23, 2010

#9

mehra

0

Re: Nice Beam but no burning Help Needed Please !!!

Eudaimonium said:
Do you have a multimeter?

You need to check the current flowing out of the batteries. If pins of your switch are exposed, just switch to 10A mode, (plug the probe into correct socket if neccessary), and touch each pin of switch with one probe, or lead, or however you want to call them, it should give you a current readout.

Careful though, laser will turn on while you measure it. Don't let it surprise you.

Dear Eudaimonium

When laser is on :

Batteries are giving 0.280 mA (Multimeter at 10 A ) range.

LD is getting 2.98 Volts

Effective resistance between out and adj of LM 317 is 3 Ohms.

Any idea ??? :bowdown::bowdown:

Last edited: Dec 7, 2010

Nov 23, 2010

#10

Eudaimonium

0

Re: Nice Beam but no burning Help Needed Please !!!

mehra said:
Dear Eudaimonium

When laser is on :

Batteries are giving 2.8 Amps (Multimeter at 10 A ) range.

LD is getting 2.98 Volts

Effective resistance between out and adj of LM 317 is 3 Ohms.

Any idea ??? :bowdown::bowdown:

Ahh man, no ...

You have shorted out the battery by measuring them directly.
You do not measure current draw parralel to battery, that's shorting it out.

You need to have your DMM in series to component your are measuring to get the current readout.

You need to place your DMM instead of the switch that you use to power up your laser. The current will flow through DMM instead of the switch, and it'll get read there.

Voltage to laser diode is not an issue, current is.

Measure the current flow in the circuit, then report back.

With 3 ohms of resistance, you should be getting exactly 420 mA, so expect a readout of 0.41 - 0.43 when you measure the current flow through your circuit.

Nov 23, 2010

#11

mehra

0

Re: Nice Beam but no burning Help Needed Please !!!

Eudaimonium said:
Ahh man, no ...

You have shorted out the battery by measuring them directly.
You do not measure current draw parralel to battery, that's shorting it out.

You need to have your DMM in series to component your are measuring to get the current readout.

You need to place your DMM instead of the switch that you use to power up your laser. The current will flow through DMM instead of the switch, and it'll get read there.

Voltage to laser diode is not an issue, current is.

Measure the current flow in the circuit, then report back.

With 3 ohms of resistance, you should be getting exactly 420 mA, so expect a readout of 0.41 - 0.43 when you measure the current flow through your circuit.

Sorry I made a mistake. Finally 0.28 A is being drawn from battery. And be assured, I did as you told and as it should be. The MM was in series with circuit. Switch being off and with probes connected to exposed terminal of switch one each. Touching probes lit the LD as it should when switch will be "ON". Thanks for keeping ball rolling. I think with your help I'll soon be burning things around. Thanks and advice further.

Last edited: Nov 23, 2010

Nov 23, 2010

#12

Bionic-Badger

0

Re: Nice Beam but no burning Help Needed Please !!!

Hmm, I'd look into a bigger heatsink, but as far as what you're driving your laser with, those laser diodes can usually handle up to 350-420mA (properly heatsinked), to put out about 250mW. At your 280mA setting, your laser is probably putting out about 150-180mW I'd say.

It's hard to tell just how big your laser dot is, but when I was trying to burn some things with a Dilda, which is about 200mW output, I really had a focus down to a pin-point to get any kind of heating action on blackened paper and stuff. Yeah, it's pretty lame, but these lasers just really aren't that great for burning things.

Nov 23, 2010

#13

mehra

0

Re: Nice Beam but no burning Help Needed Please !!!

Bionic-Badger said:
Hmm, I'd look into a bigger heatsink, but as far as what you're driving your laser with, those laser diodes can usually handle up to 350-420mA (properly heatsinked), to put out about 250mW. At your 280mA setting, your laser is probably putting out about 150-180mW I'd say.

It's hard to tell just how big your laser dot is, but when I was trying to burn some things with a Dilda, which is about 200mW output, I really had a focus down to a pin-point to get any kind of heating action on blackened paper and stuff. Yeah, it's pretty lame, but these lasers just really aren't that great for burning things.

Ya maybe so. Focused dot is about 2 mm. As for heat sinking, I m not having any LD heating issues. The only problem is burning. I m just crazy to make a burning capable laser with my own hands. God knows I will do it or not.....:cryyy::cryyy::cryyy:

And yes, please note that I have measured the current between battery to driver and not between driver to LD. That means that switch is between battery to driver & and thats where I took reading...

Last edited: Nov 23, 2010

Nov 23, 2010

#14

Bionic-Badger

0

Re: Nice Beam but no burning Help Needed Please !!!

My focused dot was about 0.5-0.1mm, depending on my ability to hold the thing steady. 2mm might be a bit too big. That's okay with the current reading, and sometimes you can burn out your laser accidentally by having the multimeter inline with the laser (like when you connect it/disconnect it. You can also check the voltage across your resistor that is used for regulating the current from the LM317 and compute the current that way using Ohm's law. In fact, that's a bit safer since you can just measure the voltage, not actually have a meter in-line with the circuit.

Nov 23, 2010

#15

Eudaimonium

0

Re: Nice Beam but no burning Help Needed Please !!!

mehra said:
Ya maybe so. Focused dot is about 2 mm. As for heat sinking, I m not having any LD heating issues. The only problem is burning. I m just crazy to make a burning capable laser with my own hands. God knows I will do it or not.....:cryyy::cryyy::cryyy:

And yes, please note that I have measured the current between battery to driver and not between driver to LD. That means that switch is between battery to driver & and thats where I took reading...

Current going through the switch is the same current that going through your laser diode. Same current that's drawn out of the batteries.

LM317 is positive side only regulator, there are no components of it being connected to negative side of battery.

Different story with Boost drivers. There, input current is not the same as output current.

Nov 23, 2010

#16

mehra

0

Re: Nice Beam but no burning Help Needed Please !!!

Eudaimonium said:
Current going through the switch is the same current that going through your laser diode. Same current that's drawn out of the batteries.

LM317 is positive side only regulator, there are no components of it being connected to negative side of battery.

Different story with Boost drivers. There, input current is not the same as output current.

280 ma shud show some heat in beam

You must log in or register to reply here.

Share:

Facebook X (Twitter) Reddit Pinterest Tumblr WhatsApp Email Link

Top