Sorry for the delay, but the holidays have gotten in the wayOriginally Posted by rjr
I attached a jpg of the schematic as well as a snapshot of my initial light source. This can be easily adapted to digital control if desired. I'm going to use this one to build the mixing box, then adjust the number and power of LED's to get the light output where it needs to be for reasonable printing times, and a more power efficient source - all work to do...
A quick note or two. for M1 I used an IRLIZ14G, but any MOSFET with the proper voltage and current rating should work. Your friend should not have much problem finding something suitable. It will get hot - a good heat sink is necessary. The LEDs also need one. Their light output drops as their temperture increases, so for consistant light output during a printing session, a heat sink is needed here too.
Hope this helps,