Burnt Diode?

[danefex]

First off, I have been researching this, but nothing on the threads look like my scenario. I bought a Survival Lasers host kit. I followed the tutorial (this being my first laser build) and did every step.

Details: I ordered a 2 (ish) watt diode and sent a special request to Gary (head of Survival Lasers) to put a nice driver in. So, I soldered the connections, making sure not to overheat the diode. Put the Aixiz module lens in and turned it on. It did a really bring flash of blue (the diode is blue) and then went dim. The beam itself is way to big, being 3 inches at about 2-3 feet. What is going on here? Also, the heatsink gets way too hot.

There's a good chance one of your connections isn't complete. Put it together & turn it on again to get that dim light. When it's on and dim, carefully tighten and/or untighten the head of the laser (holds the heatsink) and the tailcap and see if you get any full power flicker. DO NOT overtighten these parts, if you dont get any bright flickering you dont need to force these too tightly and the problem is something else. This is just a test to see if your soldering is completely intact but you can ruin the threading if you use all your stregth to overtighten this - it's not necessary.

This just sounds like a focusing issue, you can correct this by turning the focusing lens to widen or tighten the beam once you get normal output from the unit

After how long? It's hitting 2 watts so yes it will get warm - but getting hot right away is another sign your driver is shorting within the aluminum in the host

 

[Eudaimonium]

There's a good chance one of your connections isn't complete. Put it together & turn it on again to get that dim light. When it's on and dim, carefully tighten and/or untighten the head of the laser (holds the heatsink) and the tailcap and see if you get any full power flicker. DO NOT overtighten these parts, if you dont get any bright flickering you dont need to force these too tightly and the problem is something else. This is just a test to see if your soldering is completely intact but you can ruin the threading if you use all your stregth to overtighten this - it's not necessary.

Nope!

This just sounds like a focusing issue, you can correct this by turning the focusing lens to widen or tighten the beam once you get normal output from the unit

Maybe!

After how long? It's hitting 2 watts so yes it will get warm - but getting hot right away is another sign your driver is shorting within the aluminum in the host

Yes!

Dude, the thread

My money's on batteries.

 

[ApexProxy]

Maybe if he was able to remove the driver from the pill he could verify if something was shorting out or not.

 

[danefex]

Nope!

Very possible, I've had this same thing happen several times before & the cause was a broken or 'barely soldered' connection with the driver. Also any contact point with the driver and the pill will short the circuit, I only offer this because its happened to me before but I can only speculate

Maybe!

Definitely!

Yes!

Dude, the thread

My money's on batteries.

I read through it for the most part, did I miss him mentioning how long it was on before it got hot? You are free to smack me one. The batteries are a common cause here, no doubt - but that's not the only possibility

EDIT: ahh I see now Eud, I was responding to the OP & a few comments down - I did not read down as far as you'd gotten with his testing the BRIGHT part each time before my reply... Batteries is def the case now I agree, sorry about going offcourse there

 

[Bristol]

Guys, today I picked brand-new CR123a batteries up.. sorry to disappoint. Another thing is, it gets really hot within 8 seconds. I can't even hold it cause it gets so hot. Also, I retried the solder-connection, it turned out the same. Really bright, then dim. Also, it is natural to have the beam look like a rectangle/blob with a couple lines, without the lens, right?

 

[Bristol]

I'm probably going to go with driver damage on this one. Should I attempt to re-heat the solder that attaches the driver to the host?

 

[danefex]

Guys, today I picked brand-new CR123a batteries up.. sorry to disappoint. Another thing is, it gets really hot within 8 seconds. I can't even hold it cause it gets so hot. Also, I retried the solder-connection, it turned out the same. Really bright, then dim. Also, it is natural to have the beam look like a rectangle/blob with a couple lines, without the lens, right?

Most likely your driver is shorting within the pill since its heating up this quickly. You shoud make sure all 4 edges of the driver are insulated & not touching any part of the aluminum pill as well as your soldering points, maybe wrap a layer of electrical tape around it to prevent the shorting. If you're certain this shorting isn't the case OR you've done this & the driver still gets hot - then I believe your driver is damaged & you need a new one.

Definitely the driver is failing, it allows full current to pass when its turned on but after a short time one of its components fails and the driver stops passing current (dimming) and all the current turns into heat fast

That is what I think

 

[Eudaimonium]

I have not yet seen a driver heating up THAT quickly.

What sort of driver is this?

To the best of my knowledge, the drivers supplied by Survival are switching ones, which means it should be able to hold out at least for a minute before going too hot.

Even if it's a linear driver, dropping down from 2x lithium ion voltage to 445nm voltage should produce that amount of heat.

And it's nowhere near the power needed to heat up any specific part of the laser assembly to the point of "not being able to hold it", that would mean that whatever faulty component would need to be getting to solder-iron temperature levels. I don't think the batteries can output that much.

When you bought the laser, did the driver already came pressed into the pill, or did you install it yourself?

 

[Bristol]

Okay, the driver is within a round metel container, soldered too tight for me to access, most likely just get ahold of Gary from Survival Lasers and see if I can return it, or what he would advise. Now, if the laser is in fact working full power, what up with the lenses not working? It is a huge dot measuring around 3" at 2 feet away... plus, even when it IS full power, it still seems no where close to 1.5-2.5 watts. :/

 

[danefex]

I have not yet seen a driver heating up THAT quickly.

That's because you're much better with electronics than I am & probably dont make this mistake. I've done this more than a couple of time before which is why I'm leaning so heavily on it being a driver short

What sort of driver is this?

To the best of my knowledge, the drivers supplied by Survival are switching ones, which means it should be able to hold out at least for a minute before going too hot.

Even if it's a linear driver, dropping down from 2x lithium ion voltage to 445nm voltage should produce that amount of heat.

And it's nowhere near the power needed to heat up any specific part of the laser assembly to the point of "not being able to hold it", that would mean that whatever faulty component would need to be getting to solder-iron temperature levels. I don't think the batteries can output that much.

Absolutely true but you'd be surprised how hot a shorted driver can get. His explanation is not unusual to me when this idea is a possible cause.

When you bought the laser, did the driver already came pressed into the pill, or did you install it yourself?

 

[Bristol]

I pressed it in myself, flush, with a vice. Using the other end of the Aixiz module drilled out so it would fit around the plastic red thing that keeps the pins from touching each-other.

 

[Eudaimonium]

That's because you're much better with electronics than I am & probably dont make this mistake. I've done this more than a couple of time before which is why I'm leaning so heavily on it being a driver short

Yep...

I pressed it in myself, flush, with a vice. Using the other end of the Aixiz module drilled out so it would fit around the plastic red thing that keeps the pins from touching each-other.

No no man, the driver, not the diode.

Did you isntall it yourself in the driver pill, or did it come already installed and current already set?

 

[Bristol]

Already installed, already set. All I did was solder the + - pins to the + - wires, after pressing the diode into the aixiz lens part.

 

[Eudaimonium]

Hmm weird, chance that you got a defective driver is exeptionally small, coming from Survival laser, but at this point, I guess it's our only suspect.

Do you think you can measure the current draw from the batteries? If we can eliminate that, it'd be great.

 

[Bristol]

Remember, this is my first laser build, although I am definitely hoping to get way more into this... How do I measure my current draw?

 

[Eudaimonium]

Well, let's start off with basics,

Do you have a Digital Multi-Meter (DMM)?

If so, you need to switch it to 10A measuring mode, re-socket the leads appropriately, and then place it in-line with batteries' negative pole and the body of the host, essentially replacing the tailcap with DMM (so the current goes through DMM where it gets measured).