Leadlight green laser current draw survey

[The_LED_Museum]

I just checked the website for my local Radio Shack, and they say it can be ordered - don't know if it's in stock or not.
I'll go there later today (probably within the next hour or two) and see if they have it, and order it if they don't.

(Edit, a moment later)
I just got off the telphone with the downtown Radio Shack, and I had them check. Looks like I'm SOL.
They say they've had several orders for this LED (other CPF members?) and each time they come back with nothing.
So I'll *TRY* to order one and see what happens. In the worst case I'll be out less than $2.00. In the best case I'll have one of these LEDs in about ten days.

(Edit again, a while later)
As of 11:32am PDT, I have ordered a pack of these LEDs. They come two to a pack, so if I somehow manage to ruin one, I won't be SOL. Total cost was $1.40.

 

[sbk]

I based myself on the formula of greenlaserforum (mW = uA/2.8), and it appears to work, because without mod I obtain 12uA ==> 12/2.8 = 4.3mW.
I can take 4.5 but I only obtain 2.6mW for my laser, it is too low for a <5mW no?

So a thing is certain : I have measured 280uA from my laser, so it is 23 times more powerful than before, and in all facts it is /ubbthreads/images/graemlins/happy14.gif !

 

[moshen]

With the radio shack LED I referred, I get uA / 4.5 = mw power.

 

[sbk]

Did you verify it with a calibrated laser power meter?

 

[Uisgdlyast]

yes, this is very interesting because i just purchased the LED but i dont have a laser meter. What we need is someone with a laser meter, some different lasers, and time to try this. Or we need someone who bought from atlas nova who knows their power to try this.

Also i forgot, is the longer LED lead the anode? and which do i hook up to the black on the meter?

 

[The_LED_Museum]

[ QUOTE ]
Uisgdlyast said:
Also i forgot, is the longer LED lead the anode? and which do i hook up to the black on the meter?

[/ QUOTE ]
On most LEDs, the longer of the two leads is the anode (+) connection.

Connect the black lead on your meter to the shorter lead (the cathode or (-)) on the LED, and the red lead to the anode.

 

[moshen]

I did verify with a laser meter with the specific radio shack LED .... I posted the stock # in a previous message.

 

[TTaz]

An amperemeter is symetric.. so the polarity is not a problem... all you'll have is possibly a minus sign /ubbthreads/images/graemlins/smile.gif

 

[sbk]

Good remark TTaz /ubbthreads/images/graemlins/smile.gif
Et je suis ravi de voir que je ne suis pas le seul européen francophone sur ce forum lol!

 

[The_LED_Museum]

[ QUOTE ]
TTaz said:
An amperemeter is symetric.. so the polarity is not a problem... all you'll have is possibly a minus sign /ubbthreads/images/graemlins/smile.gif

[/ QUOTE ]
If you're using a DMM or a digital ammeter, this is probably the case.
But if you're using an analogue meter (with a marked meter face and a needle), then polarity will matter.

 

[Uisgdlyast]

Well i tried the method today, it jumped around A LOT and i would get flashes of 100-130 for a second or two. I averaged it to about 25mW with 4.5, the only mod i did was turn the pot so i'm not sure if this is accurate, plus my meter is cheap(4$).

This is my multimeter and i put it on the 2000u option, is this the right one? if i use 20m i get .03 or similar.
I also use the 20m to measure my current and get about .32 which i assume is 320mA?

Well anyways i think if anyhtign 4.5 would work, if i use 2.8 i get WAY more mW that i shoudl get for just turning the pot.

 

[sbk]

Could you measure the value you obtain with the stock current? You should obtain about 4-5mW.

With just the pot turned I obtain 82uA with the LED, so 29mW with 2.8, or 18mW with 4.5.

So I really think that 2.8 is good for my LED, having seen the big difference of brightness between 200 and 320mA of current consumption!

Here is my multimeter (a 400$ Fluke /ubbthreads/images/graemlins/grin.gif)

Note : the LEd is bad connected to the multimeter (normally in the uA/mA hole, but I had not seen it for the photo)

 

[Uisgdlyast]

Well i just switched the 102 resistor with a 100ohm resistor, it was very difficult consider all i had was a 30watt radio shack iron, pliars, tweezers, and small wire. The alligator clip at the end really helped though, it was my first time with something so small.

Before i was pulling about 320 mA(about, my cheap meter fluctuated) Now i'm pulling about 390-400, hard to tell because it shows it as .39.
Anyways i got about 540mA when i shorted the pot with the case(or just stuck my metal scredriver in it). I think i'm going to leave it at 400mA though because i didnt notice a huge difference and i'd rather keep my diode... but i'm sure in 2 weeks i'll either be shorting the case or buying more resistors.

My next project will be to realign the diode if i ever loosen the brass ring.

 

[sbk]

well, so it is the change of the 102 resistor which allow >500mA on the diode?
You can do a assembly like me, with a commutator which in one position short the pot with the case, and in the other position don't short the pot. So you have the max power only when you want and for a short time.
But if it isn't a significantly increase in power it is not worth to do that.

Have you measured the power with the LED test with 540mA?
I wonder if you obtain as much as my laser /ubbthreads/images/graemlins/smile.gif (peak of 290uA)

 

[Uisgdlyast]

it would be interesting, i however cannot easily short the pot and measure with an LED.
What is your current without shorting the pot? I could probably test that

Edit:!!! I finaly loosened the brass ring! i thought thought i would just edit this. TO sbk and all who want to do it, dont twist. What i did was i took a nail type thing(just use a nail that fits) had the diode in the vice grip, put the nail in one of the holes and tapped it with a metal object. Lightly tap it and then just increase, works a lot better than trying to twist.
I'm off to test this now, also sbk check your pms