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First attempt am I doing this right?

B

brownb56

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Dec 25, 2014
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Host case will be a stream light case, currently holds two cr123a batteries. Will use 18650 battery if diameter fits or two 16340s.

Diode
http://pages.ebay.com/link/?nav=item.view&id=281499276392&alt=web

Driver
http://pages.ebay.com/link/?nav=item.view&id=321623487075&alt=web

Diode housing
http://pages.ebay.com/link/?nav=item.view&id=331103444452&alt=web

Heatsink
http://pages.ebay.com/link/?nav=item.view&id=231109754174&alt=web

As long as I got the right parts, soldering and fabrication is the easy part lol.
 





The mechanical part seems good, but I'm probably not the best person to judge mechanics..
The driver should be ok, too, but you cannot use it with two batteries in series, because the maximum voltage is 5.5V!
 
Oh yea my bad lol, had about 3 hrs sleep in the last 24. Was thinkin the batteries where in parallel not series xD
 
brownb56 said:
Host case will be a stream light case, currently holds two cr123a batteries. Will use 18650 battery if diameter fits or two 16340s.

Diode
http://pages.ebay.com/link/?nav=item.view&id=281499276392&alt=web

Driver
http://pages.ebay.com/link/?nav=item.view&id=321623487075&alt=web

Diode housing
http://pages.ebay.com/link/?nav=item.view&id=331103444452&alt=web

Heatsink
http://pages.ebay.com/link/?nav=item.view&id=231109754174&alt=web

As long as I got the right parts, soldering and fabrication is the easy part lol.
Click to expand...

I don't mean to be rude but I can already tell that you are not even remotely close to being ready to build a laser. Streamlight makes many different flashlights, you should show us the one your using and maybe someone can comment on it. I have never seen anyone using one as a host though so there may be a reason for that. You can't use just any heat sink, you will have to have one machined to fit your non standard host, so you are better off going with a commonly used host or one that already comes with a matching heat sink. You are tremendously complicating things if you use that driver. Most hosts can't accommodate a driver of that type with a spring attached, only a host that wouldn't use a pill and battery contact board. If you could even use that driver you will need a test load and DMM and know how to use them to set the current on the driver. The diode module is also nonstandard although I think it would be fine. I could say more but I don't have time. You need to do much more research on building lasers. It's very easy to assemble a laser from off the shelf parts where some of the work is done for you, that's probably the best way to go for a first build, otherwise you need to do some reading here everyday for the next several months.

Welcome to LPF and have a Merry Christmas.

Alan
 
Ase certified automotive electrical and have done a lot of work with small electrical circuits. So the use of a dmm is definitely not an issue, currently have a decent fluke in my garage. And have seen a couple diagrams of load test circuits. Fairly simple stuff, another thought on that driver being variable is it maxes out at 250mw the same as the diode I was going to use. I assume there isn't much concern running the diode under power, and I won't be able to turn it up high enough to overload it? Like the idea of turning down the power if I choose. Will get a picture of my host case. Looking at it and doing the rough math in my head the diode housing will stick out a bit past the edge of the original light housing. May not look pretty but confident I can make it functional. Also the on off button is at the back of the case interrupting the negative side of the battery. So I do not want an on/off switch at the driver itself. Lastly if the diode houseing sticks out as far as i think it will the heat sink will be out in the open air away from the case. Will figure out how to center up the diode housing and secure to the case when I get that far. Hopefully it will be completely self contained and secure the spring will contact battery. And I can pull the top section off to replace battery as needed.

I have been lurking off and on for awhile now. I agree I need more knowledge but I am a hands on kind of guy. Reading only goes so far I need something to get my hands on. Right now all I am looking for is verification that it is functionally accurate and not accidentally using something technically incompatible. From there confident I can make it work.
 
brownb56 said:
Fairly simple stuff, another thought on that driver being variable is it maxes out at 250mw the same as the diode I was going to use.
Click to expand...

Just a small note: mW is not the same as mA... a 250mW diode produces 250mW of LIGHT, but it will use more than 250mW of power (efficiency...)

Your diode is NOT rated for 250mA, although you can easily push it that far (look at the eBay description!)
 
RGB said:
Just a small note: mW is not the same as mA... a 250mW diode produces 250mW of LIGHT, but it will use more than 250mW of power (efficiency...)

Your diode is NOT rated for 250mA, although you can easily push it that far (look at the eBay description!)
Click to expand...

I see it recommends 190 mA for long life of the diode. Assume the adjustment is measured in mA then since mW isn't something easily measured with a meter lol.
 
Go into the sale and trade, or the pro shop
section and find the test load sold by
jufran. It comes with a PCB so doesn't
have everything all hanging out all over
the place.

Working with laser diodes is a bit
different from the average automotive
circuit. ESD protection and a very clean
work are are very important. Get a good
ESD strap and make sure you are grounded at
all times until the diode has been sealed up.

Also, pick up some laser safety glasses to
protect your eyes from the wavelengths you
will be working with.

Survival Laser USA Store - Safety
 
brownb56 said:
http://pages.ebay.com/link/?nav=item.view&id=260705531970&alt=web
Found this setup to adjust my power output on the driverge. Thank you everyone for the input, I have learned more trying to figure this out and having people point out my mistakes than simply reading forums or assembling a pre made kit.
Click to expand...

That seems terribly overpriced! If you go with such a simple solution (everything hanging around), then try to buy the components locally, after all they are selling you a few diodes + a resistor for 10$...
 
I like the looks of Jufran's setup for the load tester, nice clean little board will definitely have to get one. What do you guy's work areas look like? Have been building my own computers for the last 15 years or so and familiar with esd straps. Usually just ground to the computer case, so would have to find something big enough to ground out to.

Also automotive electrical isn't much different. Alot of 5v components in body control modules. I know the stereotype of a mechanic is all greasy and dirty. But trust me, working inside a $50k vehicle the last thing you want to do is get a smudge of grease anywhere lol.

Found a different driver, will go with one that operates from 5-10v so i can use two 16340 in series.
Adjustable Current Laser Diode Driver 80 500mA w TTL | eBay
My only question on that driver is it mentions case +ve, can't really find much info on that. Does it mean if the circuit runs off of positive ground the diode has to be isolated?

Also do have access to a mill and lathe, with the outside diameter of that heatsink being 26mm have plenty of material to work with to punch the inside of the light out to fit it properly.
 
The ESD strap will plug into a grounded
outlet.

That driver should be okay. The case
polarity won't matter since your diode is
isolated. That only matters with diodes
that have one of the connections to the case.

To get them to work, the TTL pad has to be
connected to +.

8676-cheap-ld-driver-board-again.jpg
8675-disabling-ttl-cheap-ld-driver-board.jpg
 
Can't find a picture at the moment. But could also solder the diode directly to the driver as well correct? If I understand it correctly if I did it that way would slide the diode on the driver line up and solder at all three contact points? Using LD + and both LD - points.
 
Here are some pictures of my host, streamlight scorpion case. Gutted the lens portion of the light today.

Lens housing dimensions
40mm overall length
13mm of threads
28mm inside diameter at widest part
9mm from front to first lip
25mm inside diameter at first lip
6mm from first to second lip
18mm inside diameter at second lip
10mm from second lip to threads.

Hopeful depending on fit I will be able to press fit the heatsink in to the second lip with just enough sticking out to allow access to the set screw. Inside diameter at second lip is 18mm. And it is approx 15 mm from the end of the housing. Heat sink is 18mm on narrow end 15mm long, 30mm overall. Biggest question will be length of driver, will have between 15mm-30mm from diode mount to batteries depending on how far I screw cap on.

Pics 2,3 and 4 are all the same not sure why they double loaded.

streamlight laser host - Imgur
 
Everything ordered now to sit around and wait impatiently. Something tells me with my luck should have ordered a spare diode a driver lol.

One question about eye protection. Oxy acetylene has emissions between 380nm and 750 nm. Seems to me if I have access to eye protection for cutting and welding they would be adequate for this type of application as well?
 
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