PWM – Koraks tinkers

The Big Ugly, part 3: proper SMD LEDs, but no cigar (?)

In the previous part of this series, I told about the lessons I learned by trying to use a single RGB COB LED as a light source for both RA4 and B&W enlarging. I took those lessons and gave it another go, this time using a fundamentally different approach. As the title suggests, no cigar yet – although this isn’t really accurate. The second generation device I built was actually used for a year or two before I was sufficiently annoyed by its shortcomings to replace it. So the second generation actually did work – albeit with some caveats.

The Big Ugly, part 2: the RGB COB LED approach to color enlarging

Previously, I explained why I thought I needed a color light source and in general terms what it should be capable of. I also highlighted that it’s not so much a project with a clearly defined end (or at least, that hasn’t materialized yet), but more of a journey that continues into the present, and probably future as well. In this part, I’ll go through the phases this project has gone through. That is to say, there are really three distinct generations of the device I’ve built, and each has taught me different lessons. Before going into some details of the current (and 3rd) rendition, I’ll try to go through each generation and explain what it was/is and what its main caveats were (especially generations 1 & 2). Let’s start with the first generation I built.