[Peter] has finished up his fiber optic microscope light source. When we last visited [Peter] he created a dimmer circuit for a 10 watt LED. That LED driver has now found its final home in [Peter’s] “Franken-ebay scope”, a stereo microscope built from parts he acquired over several years. Stereo microscopes scopes like these are invaluable for working on surface mount parts, or inspecting PCB problems. [Peter] had the fiber optic ring and whip, but no light source. The original source would have been a 150W Halogen lamp. The 10 watt led and driver circuit was a great replacement, but he needed way to interface the LED to the fiber whip. Keeping the entire system cool would be a good idea too.
This was no problem for [Peter], as he has access to a milling machine. He used an old CPU heat sink from his junk box as the base of the light source. The heat sink was drilled and tapped for the LED. The next problem was the actual fiber whip interface. For this, [Peter] milled a custom block from aluminum bar stock. The finished assembly holds the LED, driver, and the fiber whip. A sheet metal bracket allows the entire assembly to be mounted on the microscope’s post. We have to admit, if we were in [Peter’s] place, we would have gone with a cheap LED ring light. However, the end result is a very clean setup that throws a ton of light onto whatever [Peter] needs magnified.
There is good hope that that discovery about LED that enables less loss will soon become commonplace in manufacturing, then heatsinking should be much easier.
Heat levels were really not too bad for the amount of light it puts out. More than likely I really did not need the fan. After an half hour or so running at full brightness the heat sink started to get warm. So just to be safe and maximize the LED life I went with the fan. No detectable warmth on the heat sink now with the fan running at 44% may even be able to go lower.