1W 445nm Blue Laser Build

I built a >1W handheld laser using a diode from a Casio laser projector. These diodes cost about $50 each and can be found for sale online. My driver is a buck-boost topology using a TPS63020 IC from TI. This driver tested to be 82% efficient into my laser diode at 1.25A. At 1.25 A, my laser diode has a forward voltage of about 4.5V. My driver features reverse polarity potection, undervoltage protection for lithium batteries, and output overvoltage protection. Photos of my driver board unpopulated are here and here.

This housing was machined by laserpointerforums.com member Ehgemus. It is a combination of polished and sandblased aluminum.

I stuck the driver on a block of copper using some arctic silver for testing. It never got more than warm even at 2 A into my test load.

I used 26 AWG silicone insulated wire. This wire is very flexible and does not apply much force to the leads of the laser diode.

The driver was glued to a brass heatsink using thermal epoxy. This heatsink arrangement is very good at dissipating the heat that is produced in the driver. The heatsink is also a slight press fit into the housing so nothing can vibrate around.

Schematic of driver. Click to enlarge.

These batteries are 26650 size and rated at 4 AH. They are 3.6 V nominal LiMnNi batteries from batteryspace.com. I made a holder for charging them from a C size battery holder. I charge them with a bench power supply set at 4.2V with a current limit of 4 A.

Laser Safety

Laser safety glasses must be worn when opperating a laser of this power level. Direct and indirect exposure to the light produced by class IV lasers can cause permanant eye damage. Do not build anything on this page without proper safety equipment. This page is for informational purposes only. The author takes no responsibility for injuries caused by big scary lasers.

All text and images on this site are the property of the author.
If you wish to use my designs for profit or as part of your own work, please contact me to arrange something.

See other projects on my main page at rfhv.com