Questions before a build

[thatguy69]

Before I go out and buy any parts for a build, I'd like to make sure that I understand everything correctly, decreasing my chances of messing something up.

I'm interested in making a 405nm laser with 100mw of power.

So, I've gathered that while you can power a diode with simply a power source, this will usually result in a dead diode because there's a good chance you'll be delivering more current to it than it can handle. This is where a driver comes in, as it will deliver a constant current (of a specific magnitude) to your diode, correct?

As a beginner would it be better to buy a driver that will deliver the desired amount of current (In this case, I think it should be 100mA), or to build it from scratch?

So what I need would be:
Diode of proper power (100mW)
Diode housing and lens
Corresponding driver (built or bought, at 100mA)
Wire (any specific size?)
Power Source

As far as the power source is concerned, is that also dependent on the driver? It's unclear how one would go about using batteries as a power source. Batteries supply DC current (which I'm assuming any simple driver would use), and batteries connected in series (most everyday objects have batteries connected in series) would supply the proper voltage?

One last question concerning heatsinks, which are probably what I understand the least . I understand that these get hot and I know they need to be cooled, but how do you do that? Would the housing provide enough material to disperse the heat for a laser of this power, or would I need additional heatsinks? I would assume the driver would get hot aswell, how do I cool that?

 

[Kookapeli]

The diode housing will need to be heatsinked with the driver running the diode at 100mW it is unlikely that you will need to heatsink that too. What host are you going to put this into ??? is this going to be a lab build i.e a Box type build or a portable torch type build ?

As far as batteries go all depends on which driver you use a DDL driver a low drop out you will need around 7/8V to run the driver and diode.

If you use a booster river then only 3/4V will be needed as the driver boosts the power of the battery

 

[thatguy69]

I want it to be a portable torch type, and I have yet to actually select any specific parts. Do you suggest a booster driver, since that would allow me to use AA/AAA batteries? Also, all of the commercial laser pointers I own run on AAA's. Other than size, is there any advantage to using AAA's as opposed to AA's?

 

[Kookapeli]

Not realy, it all depends on the host. Have a look on the BST section there are a few sellers that have hosts for sale at reasonable prices then you can decide by what batteries they to see what driver to use

 

[WLHostage]

Unless your an electronics expert, use someone else's driver. No need to worry about that variable when someone else has already handled it for you .

If this is a first build you could take a look at Jayrob's kits. With his hot option you literally need to press the diode into the module, and solder two wires, and that's about it.

Also just FYI, the kits do not include batteries or a charger, that's seperate and you would still need to pick those up.

If you wanted to do it yourself you need the following items...

Host - you can build one yourself, just use a heatsink, or rework a flashlight host to fit the laser components.
Aixiz Module - Some of jayrobs kits have custom modules, this is what actually holds the diode.
Driver - You will need to pick this up unless you get one of jayrobs kits with the hot option.
Diode - These can be picked up many places or you could harvest one yourself.
Battery/Charger - depends on the host you use.

Some other things you may need that are not part of the laser...

Wire - used to connect the diode, driver and battery.
Solder - You'll need this either way
Soldering Gun - You'll need this either way
Shrink Wrap - Not necessary, but it's nice to have. At minimum you will need some electrical tape.
Clamp - often used to press the diode into place, you can use a C-Clamp, or even better would be a Vice.
Toothbrush - I found this useful to clean the threads on my kit as they were dirty and appeared to have some metal shavings stuck in them causing problems screwing it all together.

 

[thatguy69]

Awesome, thank you.