Voltage regulation question

[desolator144]

I'm doing a variation of a minimag maglite with a DVD diode with case in place of the bulb project. I'm using the recommended 12X30mm brass case from mfgcn.com. They have specs for basically every case BUT the 650nm 5mw one I ordered. Not that the specs really mention this either though lol. Does the case's circuit have a voltage regulator in it? And whether it does or not, can a voltage regulator smooth out surges and stuff from non-rechargeable batteries or should I definitely get some rechargeables? If it does have a voltage regulator, can it probably handle a 200+ mw DVD burner diode's current draw? I think they draw like 70 milliamps and most good regulators can handle half an amp but I wanted to make sure. Oh yeah and one kinda related question. DVD burner diodes are 650 nm too, right? Just wanna get the right protective glasses. Oh and speaking of that, do welding masks protect against lasers of most wavelengths?

 

[chido]

You can't use the driver that comes with the module, you need to build your own. Check this thread for instructions and this one for a video tutorial.
Yes DVD burner diodes are around 650nm.
You can't use welding goggles, you need to use 650nm protection goggles, I recommend these. (the only good product wicked lasers sales)

 

[BlueFusion]

It is NOT a voltage regulator. it is a CURRENT regulator and you need to do this:
A) choose a better host than a maglite, one with room for a driver.
B) build yourself a driver circuit, use the above links.
C) A welding mask doesn't protect against anything but a UV laser.

Some info about diode drivers:
You need to regulate current. The voltage will sort itself out. Don't worry about it.

 

[desolator144]

I'm no electrician but that doesn't make sense. If I'm powering a small light bulb off a car battery, it doesn't matter that it's capable of 900 or so amps. It's 12 volts so the current is determined by the resistance of the bulb. The only way more current would flow through it is if the resistance of the bulb changes or the voltage change. Aren't laser diodes the same? I figured a small increase in voltage would push too much current through the diode and fry it from severe overheating due to the increased energy output. Of course current limiters work cuz police tasers are like 10,000 volts but they're electronically limited to like 25 milliamps or something so they don't fry the person's nerves. But wouldn't a voltage regulator work too? I thought I saw someone build one with just one of those.

 

[chido]

You need to use a current regulator when working with diodes. The laser diode will take whatever voltage it needs to work but the important thing is the current.

 

[desolator144]

Well I guess regulating the voltage to regulate current is kinda indirect. You know that gives me an idea.  Would it run at peak power without risking damage and be really efficient with the most steady output if I got it up to like 600 volts but limited it to the correct current?  I think then it couldn't receive too much current and fry but there would always be enough voltage to affect every atom of gas or whatever.

 

[rkcstr]

Umm... I'd just stick with regulating current, unless you would like to sacrifice some diodes.  The diode has a voltage drop across it, giving it a higher source voltage won't do anything except potentially damage it.  I'm not real sure why you speak of gas??

 

[desolator144]

don't they have gas in them?  Military lasers and industrial lasers have gases in them.  I thought all lasers just put voltage to a gas and the current makes it emits photons.  But for all I know, they got ground up unicorn horns in em lol.  I'm more of an LED knowledgeable person myself actually

 

[rkcstr]

Laser diodes are very much like regular LEDs, but very high output.  In fact, you could literally classify a laser diode as a "light-emitting diode", lol.  Typical LEDs are just the same as laser diodes, they work best on a regulated current rather than voltage.  But, you can get away with a voltage source in series with a resistor, which acts to limit current and drop voltage.

The lasers you're thinking of are gas lasers, which are only similar to laser diodes in the respect that they produce a coherent light source.  They're typically driven with a high-voltage source, yes, but they're not what you'd find in most of the lasers we discuss here, such as those in a DVD burner  

 

[desolator144]

well anyway I think I could make a pretty nice driver that way but my goal was to make it all portable. I could put it in something with more room than a maglite but I still want it to be kinda small. Does anyone know where I can get a really compact (like half a credit card sized or smaller), premade driver that can handle this powerful of a diode and doesn't cost waaay too much?

 

[Spyderz20x6]

Hey, you can get small drivers from rckstr that fit the bottom half of the aixiz modle for 5 bucks each. Also, you could find a resistor calculator on google. If you take it from me, use a 10 ohm 1/4 watt resistor in series, you could do it in a dorcy because kenom has a tutorial on video. Or, you could fit the resistor in the maglite. I have experience with red lasers, it is just the IR diodes i hate....
BTW, don't use welder goggles, and no, laser diodes dont have gas in 'em. Good luck

 

[IgorT]

With some practice you can even make a 317 fit into an AixiZ module.

There are no advantages in using voltage regulation. Not even in size. Only drawbacks.
Unlike a light bulb, when a LD heats up, it drops in resistance, so a constant voltage source would push more current through it, which would result in more heat, more current and so on, sometimes ending in a thermal runaway.

A current regulator will constantly adjust the voltage, so that the current through the LD is always the same. A current regulator is actually a voltage regulator, but wired in a way, that it keeps the current constant. When a LD heats up, it will drop the voltage slightly, to compensate, and keep it safe.