First Laser 650nm Lpc-815 LOC

Leodahsan said:

if you have not, use a resistor to limit current as I said..

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Sorry for the double post but I'm not sure how to edit my last post to include a quote. Wouldn't he be using a diode to limit the voltage. With the rckstr driver is now offered with pre-set currents. It would be a good idea to get a test load and test it when you receive it. You never know what happens in transit to your place, it could get bumped or something and the current could be off from what you ordered it as.

Thanks for the reply, i will probably order my rckstr preset or get a optiforce driver if i see a few good reviews on them, btw can you build your own testload?

also somebody whose used optiforce drivers can you please gimme some info on them

also +1 for kevlar and leodahsan and Blord.

@Kevlar
the lower the voltage, the lower the current into the diode. Look the vf/cf curve of the diode

Leodahsan said:

@Kevlar
the lower the voltage, the lower the current into the diode. Look the vf/cf curve of the diode

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Are you referring to the bench testing that has been done on these diodes?

@Kevlar
Yes..

The reason I asked is because I was under the impression that bench testing was done with a bench PSU only, not with a driver. So if thats the case then yes, your previous statement regarding the vf/cf curve of the diode is correct.

The laser drivers we use are constant current drivers. The current will be the same when using the recommended input voltage for any specific driver.

I assume you know this, so I must be just completely misunderstanding.

@Kevlar
No, they put a driver and a DMM on the load (diode) to test the voltage is going in at determinate currents. Bench PSUs can be set to constant current mode too.

The laser drivers we use are constant current drivers. The current is the same when you insert the right voltage (eg LM317 = Diode FV + 2.5V) until the driver max voltage. If you adjust the LM317 driver to 1A, he will output 1A in 7v, 10v, 20v until he blows up

No problem if you're misunderstanding. He are here to learn, this still sounds a little hard to me to learn (constant current constant voltage blah blah blah)

Oh just FYI.. eg 445s, if you put a constant VOLTAGE into the diode, he will suck different currents at different voltages; 4v he will be getting around 200mA, 4.2v 500mA, 4.5v 1.2A (this is an example, look for the diode curve for real values), so you can't supply the diode with 1A at 4v with a constant current source; the source will pump more voltage and less current to the diode, probably around 900mA..
I'm talking about 'wall adapters' and PSUs. I do not recommend testing what I said here. educational purpose only

edit, here it is:

U said it would be drawing 200mA from a 4V source, wasnt that it?? But thats only if there is something limiting the current...as this is a diode, everything beyond threshold voltage with no current limitations is asking for a dead diode...

its the other way around, when u pump a diode with 200mA for sure (ur power supply can give the thingie 200mA at whatever voltage) the voltage across the diode will be ~4V.

diodes have that steep current curve...if u just apply voltage over the gap value it will just be almost as a short-circuit aka amps and amps of current (again, if no limitations for it). At least thats what they teach us...those damn conspiracy theorists!!

But then, of course this isnt how things really work...there are impedances that will limit the current...

@LordKaramazov
you are contradicting yourself.
The impedance of the circuit, battery internal resistance and quality are the factors that allow the diode to live long. They will only die on a 'perfect environment' at 4v. However, accidents can happen and thats the reason DIRECT DRIVE is forbidden.

exactly! i wasnt contradicting...was just saying that if u just get 4V to a LD it will die, if u use for example a 18650 at 4V all the time...it wont die the time u turn it on, but it will die in a few hours of use...if u use a 18650 4V bat directly driving the LD im sure it wont be getting only 200mA out of the bats...and thats what i mean when i say its only a 4V forward voltage IF u give the LD 200mA of current.

Sorry to interupt but does anyone at all know about optiforce drivers? Im kinda getting desperate now that my parts are starting to arrive So please some1 help!!!!

I also would like some info on currents and how much heatsinking i would need and also any tips please!!!

Thanks!

Buy the LM317 and build the 'do-it-yourself' driver
if your parts are arriving, probably you will want a driver FAST too..

Here is my host that i will be using to place my heatsink into. Also the host is really cool for 6 dollars, its pretty much a chinese rip off of a Mxdl. Also the host has an extension tube which allows 2 aa batteries and with the tube off you can fit 1 aa into it. Also would 3.6 volts be enough to power a DIY driver running at 420ma???? and also how much heatsinking is needed at 420ma? ive got about 0.75 cm on both sides of my aixis module when its in the torch, so it wont be quite a Maglite 2D MONSTER of a heatsink.Also this thing is really bright and i mean it, it lights up my whole backyard perfectly at night and you can kinda see the beam coming off it and trust me, i have a big backyard

sorry couldnt upload my pics cause the resolution of my camera was like 3745x4523 or something bigger and the size of it was bout 7mb's so i cant show you the torch without the tube sorry. If you really want to see it i will photoshop it for you but Atm im tired and i cant be bothered,
Any way please any info on if a 3.6v rechargable battery would be enough to power a DIY laser driver.

Thanks !!!
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Hmm 420mA seems too much.. if it is a LOC, it will push 300mW at 400mA. Limit yourself to 350mA so your laser have a long and happy life.. just my two australian cents.

With 3.6v isn't possible to drive a LM317, not with a reddie.. you will need at least 5.5v. You can always use a resistor to limit current, LOC are cheap you know..

Leodahsan said:

Hmm 420mA seems too much.. if it is a LOC, it will push 300mW at 400mA. Limit yourself to 350mA so your laser have a long and happy life.. just my two australian cents.

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There have been many people here who have run their LOCs at 420mA and higher with good results. Personally, I had mine running at 434mA with an AixiZ glass for red and was getting ~260mW. I don't remember the exact mWs but Daguin LPM'd it for me.

I would say 380mA is safe, and as I said, many, many have run it higher ~420mA with much success.

BTW, there is no way you're going to get 300mW at 400mA unless you have a G-1 glass ($50 lens) for red AND a freak diode.

Lol, btw anyone know where to get a lens thats about equivalent to the g1 but cheaper cause i dont wanna spend 2 much