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ArcticMyst Security by Avery

Beginner needs some advice.

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Jan 25, 2011
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So heres the story. I'm about to embark on the construction of my first laser and I need a little bit of guidance with regards to the components I've decided I want to buy. Basically I want my first laser to be a 1 Watt 455nm laser. Furthermore, since I live in Australia, things are a little harder to get.

Now I understand it would be better for me to start off with something like a red laser from a DVD burner but quite frankly, with shipping, a red DVD burner diode comes out to be around 10 dollars less than an A-140 diode. So i figured why not pay the remaining few dollars and get something that will really make it worthwhile.

These are the components I've been considering and hopefully you guys can tell me if this will work and if theres anything I need know before proceeding.

1. A-140 455nm 1W diode.
2. 1W 445nm blue laser diode driver from O-like.
1W 445nm laser diode driver / 200mW 405nm laser diode driver [OL-445-D] - $14.99 : Welcome to O-Like.com, Your source for laser products

3. 405NM/445NM Laser module housing with glass lens. (From O-like)
4. Heat sink.
5. Battery: Either 18650, 14500 or 10440?

Will this setup be alright? And is there anything that I need to do to get the current right, or is that just handled by the driver.

Thanks in advance. :)
 





GBD

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Ive had a setup exactly like this, except I Have used an 18650 (2800mAh)

The o-like driver is under spec, and will probably only drive an A-140 around 600-800mW.
It really needs only about 1200mA of input current, so im guessing the other cells will work fine as long as they provide 3.7-4V.
If you want higher powers, either make your own linear or boost driver, or buy a flexdrive or microboost.

The o-like driver is a DC-DC converter thats current regulated, also it will take 3.7-4V and boost it to around 4.8V. That being said, do not run this driver without a load, doing so will cause the driver to kill itself.
The electrical connections on the o-like is setup for a case positive style build, so just keep that in mind if you plan to work this into a host.
(spring negative, B+ battery positive, R4+ diode +, - is diode negative)

So in short, yes, the parts you listed will work for a working build.

EDIT: Also, even though some people may yell at me for this, I think an a-140 is a good diode to start off with, not so much regarding its power, but just the robustness of the diode itself. These are very hard to kill unlike the diodes in DVD burners. That does not make the diode invincible, but it does have a less chance of accidentally wrecking the diode.
The diode's threshold varies around 200mA IIRC, so it needs some significant power just to make it lase, after that the power output VS input is non-linear, and can spike to near full output in the matter of a few mA

Lastly, you need one more item to your list:

SAFETY GOGGLES FOR 445nM!!!

If those diodes can almost instantly burn things and smoke wood, imagine what it will do to that fleshy thing you call your eyeball.
 
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SAFETY GOGGLES FOR 445nM!!!

If those diodes can almost instantly burn things and smoke wood, imagine what it will do to that fleshy thing you call your eyeball.

+1. Don't save a few bucks by gaining a blind spot. All it takes is one stray reflection.
 
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Of-course eye safety will be first on my list. :)

You said that the driver is case positive. What does this mean exactly? And what do I do if I don't want to use a host, just a heat sink kinda like a labby for now. Do I do anything with the case pin at all?

Apart from the case positive thing, does the following sound right?

The first 2 diode connections on the driver go to the diode. (obviously)

The spring touches the negative side of the battery, I then solder a wire to the positive connection on the driver and complete it by hoking up the battery.

Thanks.
 

GBD

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Of-course eye safety will be first on my list. :)

You said that the driver is case positive. What does this mean exactly? And what do I do if I don't want to use a host, just a heat sink kinda like a labby for now. Do I do anything with the case pin at all?

Apart from the case positive thing, does the following sound right?

The first 2 diode connections on the driver go to the diode. (obviously)

The spring touches the negative side of the battery, I then solder a wire to the positive connection on the driver and complete it by hoking up the battery.

Thanks.

Ill try to clarify.
The A-140 diode has 3 connections as you know, +, -, and case.
The A-140s are ALL case neutral, that means the laser die itself has no electrical contact to the brass can its sitting in, and is isolated from it. so how you connect the case to whatever polarity DOES NOT MATTER, what matters is the correct polarity on the + and - pins themselves.

A case positive/negative build, in hosts, uses the body of the laser itself (or your heatsink, w/e the diode is in) as a conductor to complete the circuit, in the case of the O-like board, it was designed to be used so that you insert your battery, touching the spring negative, then tie the B+ on the board to the laser host itself, to complete a circuit.

So when I said that the driver was case positive, I meant that the board itself was designed for the configuration I described above.
It doesnt have anything to do with the driving style, all it does is manipulate the inputs on the board to fit a certain host building style.

For your lab, you can leave the case pin alone, it serves no critical purpose other then again, as an extra electrical contact.
All you need to do for your power input, is have a negative input to the spring, and solder a wire to B+ for the positive contact.

As you described will work.

EDIT: Also, take a close look at the O-like driver's pads.
The top two, "-" and "R4+" are set up in a close distance, and directly under them on the other side of the board, you have B+.

This was designed this way to solder the - and + of the diode to the "-" and "R4+" respectivly
and the case to B+

This way once its fitted into a host, heatsink, lab, w/e, you use the spring as the negative power input and heatsink as the positive input.

DOUBLE EDIT: How could I forget,

WELCOME TO LPF!
 
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Oh I see, so it is more of a convenience thing that the B+ connection is there, and that's what makes it a case positive driver right? Because it would connect to the host which in turn is connected to the battery. But in my particular case I would simply connect it directly to the battery since I have no host. Did I understand correctly?

One more question and I will leave you in peace. :)

With this particular driver, is there anything that needs to be changed or adjusted (eg Current etc..) to work with the A-140 diode? Or is this particular driver already set up to work out of the box. Oh and just 1 battery right?

Anyways, thank you so much for all your help.
 

GBD

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Oh I see, so it is more of a convenience thing that the B+ connection is there, and that's what makes it a case positive driver right? Because it would connect to the host which in turn is connected to the battery. But in my particular case I would simply connect it directly to the battery since I have no host. Did I understand correctly?

One more question and I will leave you in peace. :)

With this particular driver, is there anything that needs to be changed or adjusted (eg Current etc..) to work with the A-140 diode? Or is this particular driver already set up to work out of the box. Oh and just 1 battery right?

Anyways, thank you so much for all your help.

Either way its set up, to have the case (host) as positive or negative, the goal will always be the same, to use the metal body of your laser (as you see in flashlights) as a conductor to complete the circuit of the battery to your driver. How hard do you think it will be to have the + and - connections running by wire throughout a host and all that mess? where you can just use the body of the host as the common point itself.

Your case, what I would just do is solder a wire to the spring (as negative) and a wire to B+ (as positive) and use that as my inputs, leaving the heatsink isolated. That is what you will effectivly do, except maybe not solder the spring, but general idea is that you will not be using the heatsink the diode is sitting in as your conductor.

This driver was made for the A-140, and has no adjustable pots or anything like that, it doesnt really heat up during use so you dont need to heatsink the driver itself. For 15$, IMO you are pretty much getting what you payed for, its a pre-set driver, and just needs you to connect it as is to your A-140.

You just wire the driver as you got it and your good to go.
It needs an input of 3.7V-4.2V, so one battery will work. (also, Id recomend to use at least a 2000mAh, just to give you some decent battery life).
 
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