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



help for on diode

toked323

New member
Joined
Sep 1, 2007
Messages
1,591
Points
0
hey guys i built my DIY red i used a 2.7 ohm resistor and 3v input it wont burn or pop balloons can anyone help me?
 



Gazoo

Active member
Joined
Jun 9, 2007
Messages
3,199
Points
38
With 3 volts and a 2.2 ohm resistor the diode will draw appx. 160ma's. If you have it focused properly, it should burn and pop balloons even with a 2.7 ohm resistor, assuming you are using fresh alkaline batteries.
 

Greenie

New member
Joined
May 31, 2007
Messages
635
Points
0
Yes it should with no issues. My DIY pulls 180ma to 160 depending on the bats and it will incinerate just about anything. Like Gazoo said, if you do not have it focused properly then it wont do squat.
 

toked323

New member
Joined
Sep 1, 2007
Messages
1,591
Points
0
i measured the current with my multimeter it goes to 208ma and settles at 206ma's
 

Gazoo

Active member
Joined
Jun 9, 2007
Messages
3,199
Points
38
Then it should burn like crazy. Which diode are you using?
 

o_DEATH_ANG3L_o

New member
Joined
Sep 7, 2007
Messages
634
Points
0
Well then I believe you are not focusing it my friend. Try getting a little smoke in the room and then look at the beam. You will see where it is the thinnest. This is where it is best for burning and fun stuff. :)
 

izzy007

New member
Joined
Sep 28, 2007
Messages
60
Points
0
by the way, doesnt 3v/0.0022= 1363
or do you consider the voltage drop aswell, well how much is the drop anyway
 

Gazoo

Active member
Joined
Jun 9, 2007
Messages
3,199
Points
38
Yes, you must account for the voltage drop and this will be dependent on the voltage going to the diode.
 

izzy007

New member
Joined
Sep 28, 2007
Messages
60
Points
0
rhnx
so roughly how much would the vd be
just a sort of rough estimate with laser didoes
 

a_pyro_is

New member
Joined
Aug 15, 2007
Messages
790
Points
0
Yes Gazoo, it is roughly 2.6 Volts. But I think we should suggest always checking it to be sure. I've seen an 8x DVD harvest reach laseing threshold at 2.45 Volts and 27 mA. and one I'm-not-even-sure-the-speed DVD burner yielded a diode that had a forward Voltage drop of almost 3 Volts.
All that to say, it's never a bad idea to check first.
If you can afford a laser you should be able to scrounge enough for a DMM ;)
 

toked323

New member
Joined
Sep 1, 2007
Messages
1,591
Points
0
so then i should add mor voltage? by the way i measured wrong i forgot to switch to ma
 

Gazoo

Active member
Joined
Jun 9, 2007
Messages
3,199
Points
38
If you are using fresh alkaline batteries, you should be able to burn. Are you?

Is the diode lasing?

Do you see a beam?

Is the dot at whatever you are pointing at real bright?
 




Top