Bright Light Circuit
These are good resources for creating wiki pages. Very Messy Example and Columbus --Sebastien Bailard 07:23, 10 September 2010 (UTC)
|FILE ID#||TYPE||DESCRIPTION||AVAILABLE FORMATS||CREATED/RESERVED BY|
|Your-File-Name||SOLID MODEL ASSEMBLY||These are CAD files for the Solid Model Assembly||.xml.zip, .stl.zip||--Example User 12:00, Today's Date 20xx (UTC)|
|Your-File-Name||CAD FILES FOR PARTS||These are CAD files for each part.||.xml.zip, .stl.zip||--Example User 12:00, Today's Date 20xx (UTC)|
|Your-File-Name||EVEN MORE FILES||These are are even more files.||.xml.zip, .stl.zip||--Example User 12:00, Today's Date 20xx (UTC)|-|
|Your-File-Name||SOLID MODEL ASSEMBLY||This is the final finished machine||N/A||--Example User 12:00, Tomorrow's Date, 20xx (UTC)|
Please edit this and click the links to put in your own files! --Sebastien Bailard 08:34, 10 September 2010 (UTC)
Just to put the gist of it in writing: OPA569 as a high-current unity-gain buffer, driven by a DAC7571, with an ADS1113 to monitor the current-feedback from the OPA569. It'd provide sub-millivolt control with power feedback and PWM(via the current monitor and enable pin on the buffer, respectively.)
The whole toolhead would be directly controllable via a single I2C bus, or, with an added ATMEGA, via the same CAN bus as all other toolheads.
It's better to control laser diode current more-or-less directly, rather than indirectly through voltage control.
20 W and 40 W laser diode modules are becoming available at surprisingly low prices. A typical 40 W laser diode requires 2 V at 100 A (!). Merely 2.1 V will kill the module; so it seems a bit tricky to get enough power to the laser diode: 100 A * 2 V gives 200 W of input electrical power. Even more tricky is getting rid of the 160 W of waste heat that remains after 40 W of optical power comes out. A heatsink that can handle 160 W of heat energy seems like it will be far too heavy to mount on a moving RepRap tool head -- is there a better way?
Are there any real advantages to spending time and energy designing and building a new custom "laser diode driver" electronics rather than buying one off-the-shelf? 
Bill of Materials/Parts List
- Laser Cutter Notes
- SLS Printer: might be able make a single machine and a single tool head both (a) do laser sintering when aimed at a powder bed, and (b) do laser cutting when aimed at a sheet of acrylic, etc.
- Protospace wiki: OpenSource Laser Cutter driver project 
- The Lasersaur Project, an open-source laser cutter
- RepRap: Builders blog: "selective laser sintering part 8: reciprocating laser cutter" uses a 1 Watt IR laser diode, and successfully cut some flat black plastic about 1mm thick at around one inch per minute, and 3mm mdf at the rate of about 1cm / 3 minutes.
- Is it possible to get *visible* (and hence safer and easier to align than IR) laser diodes at high power (at least 250 mW, preferably closer to 20 W) and reasonable cost?