I built my first laser in a project box last week. It worked but it was big, heavy and ugly. I wanted to be able to have the laser in a compact flashlight style case. I quickly realized that the task would be difficult not just because it was all home built, but because I am using a LM317 driver. Space was def. going to be an issue. I documented my project with pictures to show others that a compact project can be done still using the LM317 style driver.
Here is the host. Its a 2xC cell LED aluminum flashlight.
And Dissembled
I took apart the LED housing removing the LED and circuit guts. I was surprised to find that the LED heat sink was actually three different threaded pieces.
After I found the pieces I wanted to use, I bored out the top half of the aluminum LED housing to make room for the LD module. I secured it with hot glue. (strong but temporary if needed taken apart)
Next I cut a matching circle out of thin aluminum to fashion the front plate. This is the plate the LD will poke through at the front. It does provide some heat sinking but is mostly aesthetic.
After a little bit of solder work the LD housing is complete. The wire leads are ready for additional soldering to the driver.
Next I assembled the LM317 driver. Parts include a small breadboard, LM317 module, 5.6ohm resistor, and 35v 100uF capacitor.
The driver need to have the smallest profile possible. I mounted everything in a way that would make it flat in order to install it in the battery compartment of the flashlight.
I found this breadboard in a kit I bought at Radioshack. It was a perfect fit for the top part of the flashlight where the positive side of the batteries would make contact.
Easy to see how well it fits in the top part.
Using a filed down quarter, I soldered a wire to the backside then placed the quarter on the breadboard forming the positive contact for the batteries. The quarter was exactly the right size.
This is a pre-fab layout of how everything is supposed to go together.
I soldered up the final connections from the LD to the driver and from the battery contacts to the driver.
I chose to use 3 cr123 lithium batteries because they are almost the same height combined as 2 C batteries and they are 3.0 volts 1800mah each. The width of the batteries are smaller and should allow my driver to sit side by side while still allowing some movement to the batteries when the bottom piece is closed.
Batteries and driver installed into middle housing. You can see how tight the space is, but both the driver and 3 cr123 batteries fit.
The finished laser.
Some action shots with my cell phone. My camera doesn't pick it up, but he beam is clear as day in a dark room. The diode is from a 16x DVD burner driven at 255mA. Estimated power output is around 125-150mW. Easily pops balloons and lights matches.
Here is the host. Its a 2xC cell LED aluminum flashlight.
And Dissembled
I took apart the LED housing removing the LED and circuit guts. I was surprised to find that the LED heat sink was actually three different threaded pieces.
After I found the pieces I wanted to use, I bored out the top half of the aluminum LED housing to make room for the LD module. I secured it with hot glue. (strong but temporary if needed taken apart)
Next I cut a matching circle out of thin aluminum to fashion the front plate. This is the plate the LD will poke through at the front. It does provide some heat sinking but is mostly aesthetic.
After a little bit of solder work the LD housing is complete. The wire leads are ready for additional soldering to the driver.
Next I assembled the LM317 driver. Parts include a small breadboard, LM317 module, 5.6ohm resistor, and 35v 100uF capacitor.
The driver need to have the smallest profile possible. I mounted everything in a way that would make it flat in order to install it in the battery compartment of the flashlight.
I found this breadboard in a kit I bought at Radioshack. It was a perfect fit for the top part of the flashlight where the positive side of the batteries would make contact.
Easy to see how well it fits in the top part.
Using a filed down quarter, I soldered a wire to the backside then placed the quarter on the breadboard forming the positive contact for the batteries. The quarter was exactly the right size.
This is a pre-fab layout of how everything is supposed to go together.
I soldered up the final connections from the LD to the driver and from the battery contacts to the driver.
I chose to use 3 cr123 lithium batteries because they are almost the same height combined as 2 C batteries and they are 3.0 volts 1800mah each. The width of the batteries are smaller and should allow my driver to sit side by side while still allowing some movement to the batteries when the bottom piece is closed.
Batteries and driver installed into middle housing. You can see how tight the space is, but both the driver and 3 cr123 batteries fit.
The finished laser.
Some action shots with my cell phone. My camera doesn't pick it up, but he beam is clear as day in a dark room. The diode is from a 16x DVD burner driven at 255mA. Estimated power output is around 125-150mW. Easily pops balloons and lights matches.
