Questions about first laser build

[sjesper]

Hello.

I've been having the idéa of making a ~ 650nm laser for some time, and now i finally want to make it after seeing the thread where Fretwrecker94 made one for only 16 bucks :yh:

For the components i have been looking on this:

- Laser Module (3V Laser module) - $3.40
- Laser Diode (LPC-826) - $10.99
- Host (1 x AAA) $3.30

Total: $17,69

I was wondering if i need a driver board or if it's included in the host, but the one that is in the host only need 1.5V while this diode need <2.2V.

Anything else i might need to get this laser working ?

 

[Blord]

You can't really use the existing LED driver for this diode. Laserdiodes are very sensitive compared to the LED's.
And another problem arises for this diode. The LPC-826 is a case negative diode. If the driver isn't designed for this, you may blow up the diode.

 

[jander6442]

Use the ghost drive if he still sells them they are cheap and hardy.

 

[sjesper]

Thanks for the feedback to both of you.

What if i choose this host as it's case negative: Mini LED Keychain Flashlight (1*AAA) - Free Shipping - DealExtreme This is the same as Fretwrecker94 used, so i should be ok with using the driver on it like he did, right?

If not will this driver work:
50 250mW Red Green Laser Driver Circuit Board Constant Current Adjustable | eBay

 

[SciFacts4YOU]

I tried building that laser. It failed, due to the bad driver the host came with. It fried my diode. So if you want to build it, buy yourself a driver as well.

 

[sjesper]

I tried building that laser. It failed, due to the bad driver the host came with. It fried my diode. So if you want to build it, buy yourself a driver as well.

Aww sadly to hear that. I've decided to order this one: Super Bright 7-2 1W 30-Lumen LED Flashlight with Strap - Black (1 x AAA) - Free Shipping - DealExtreme

Should i also order one of these? 650 600nm 200 250mW Laser Diode Driver Constant Current | eBay

Please correct me if i'm wrong - if i need the driver then i would do it like this:

1. Replace the diode in the module with the LPC-826

2. Take the flashlight apart.

3. Wire the diode to the driver i linked from ebay.

4. This is where i'm not too sure :thinking:: Wire the driver to the LED driver

5. Put 1 3.7V 10440 battery in to the laser

6. Turn the pot up to about 450 mA.

6. Turn it on and hope for the best :bowdown:

Anything i'm doing wrong? Just wan't to make sure as i want to have succes with my first laser build

 

[sjesper]

Aww sadly to hear that. I've decided to order this one: Super Bright 7-2 1W 30-Lumen LED Flashlight with Strap - Black (1 x AAA) - Free Shipping - DealExtreme

Should i also order one of these? 650 600nm 200 250mW Laser Diode Driver Constant Current | eBay

Please correct me if i'm wrong - if i need the driver then i would do it like this:

1. Replace the diode in the module with the LPC-826

2. Take the flashlight apart.

3. Wire the diode to the driver i linked from ebay.

4. This is where i'm not too sure :thinking:: Wire the driver to the LED driver

5. Put 1 3.7V 10440 battery in to the laser

6. Turn the pot up to about 450 mA.

6. Turn it on and hope for the best :bowdown:

Anything i'm doing wrong? Just wan't to make sure as i want to have succes with my first laser build

Hmm can't seem to find the LP+ and LP- on that driver board. Is it the CND and VCC?

Or would it be better to buy this driver board?

1 Pcs 635nm 300mW 500mW Laser Diode Driver | eBay

 

[sjesper]

Ok so i bought this one:

Adjustable Current Laser Diode Driver 80 500mA w TTL | eBay

Please tell me if i made a bad deal 6.75 dollars isn't really a lot of money. But, in my eyes, this one looks just fine for my projekt

 

[Cube777]

The driver in that cheap $16 build is not that bad, I bought one and it ran my test dummy load at around 300mA at 3.6V (battery's voltage)

 

[sjesper]

The driver in that cheap $16 build is not that bad, I bought one and it ran my test dummy load at around 300mA at 3.6V (battery's voltage)

Hmm. Well better safe than sorry . Seems like u can be unlucky and fry ur diode.

Btw two questions. Should i wire the driver to the driver that came with the host so it would be like this:

Batteries -> Host driver -> Adjustable current driver -> Diode.

Second question: First a picture of the driver:
http://i.ebayimg.com/t/Adjustable-current-laser-diode-driver-80-500mA-w-TTL-/00/s/NzcwWDUzNA==/$T2eC16hHJF8E9nnC9c4hBQfYCsL,O!~~60_3.JPG

Should i connect the diode to the LD- and LD+ and the host driver to the power+ and power-? And then just cut of the third pin?

 

[ApexProxy]

With a variable current driver you will have to use a test load to set your current before you can hook up your diode the risk is very high that you will just blow your diode instantly.

You never run a driver to run a driver. Ditch the original driver and use only the one you just purchased.

Solder the diode correctly to LD+ and LD- and you can solder the unused pin to the null contact or cut it off. Do not use the host driver unless you unsolder all its components and make your own leads from its + and - (not the ones it used originally make your own since it has no components).

 

[Moistenator]

Your gonna need a dummy load to set your driver at 450mAh, That's why I just buy them with the current already set..

 

[sjesper]

With a variable current driver you will have to use a test load to set your current before you can hook up your diode the risk is very high that you will just blow your diode instantly.

You never run a driver to run a driver. Ditch the original driver and use only the one you just purchased.

Solder the diode correctly to LD+ and LD- and you can solder the unused pin to the null contact or cut it off. Do not use the host driver unless you unsolder all its components and make your own leads from its + and - (not the ones it used originally make your own since it has no components).

Hmm. The reason i would use the driver to the host driver is because i need the spring for postive and i don't really know about negative.

But if i only use the bought driver should i then solder a spring to the positive of it? and what do i do about negative?

Thanks in advance

 

[ApexProxy]

The flashlight casing itself(AKA the host) is the negative. Also, for the contact board do what I said about desoldering all the parts off the original driver and using it just as a contact board to get direct power to your new board. There is not really any other way since you purchased a square driver.

Remember, you cannot power your new driver using the old driver. You MUST direct connect power to the new driver so that is why you remove all the components from the old driver.

 

[sjesper]

The flashlight casing itself(AKA the host) is the negative. Also, for the contact board do what I said about desoldering all the parts off the original driver and using it just as a contact board to get direct power to your new board. There is not really any other way since you purchased a square driver.

Remember, you cannot power your new driver using the old driver. You MUST direct connect power to the new driver so that is why you remove all the components from the old driver.

Thank you so much for the help. This might gonna be a succes

To measure the current from the driver i'm just gonna use an old multimeter

 

[ApexProxy]

That will not work unless the driver is under a real load. You need to power something equivalent to your diode for you to test the real current it is driving.

One of these is designed to do exactly that:
http://www.cajunlasers.com/store/index.php?main_page=product_info&cPath=3&products_id=100