Replacement microscope LED Light uses a few tricks

Mad scientist smellsofbikes decided to build a LED Microscope Light after picking up a faulty stereo microscope from eBay.

The LED is driven by a constant current buck regulator, powered by the original 17 volt transformer. A bridge rectifier and several filter capacitors result in a low ripple DC supply, for which he used the KiCad spice functionality to work out the values.

Even at 150 mA drive current, the LED lamp is mighty bright, and the over-kill driver will make sure he doesn’t have to worry about a burnt out lamp any time soon.