It seems like tinkerers are always being tapped to build or
repair exhibit hardware. This time around it’s [Dino's] turn.
He’s been asked to alter a light bulb efficiency demo so that it
includes an LED option. The idea here is that you crank a
generator to power different types of light bulbs. There’s an
ammeter built in, but possibly the best feedback is knowing how
hard you have to crank to illuminate the most inefficient
choice. As it stands there is a toggle switch to choose between
incandescent and CFL bulbs. [Dino's] solution is to use a three-
position rotary switch. He removes the toggle switch and
replaces it with a socket for the LED bulb. A new location for
the rotary switch is chosen and he does a bit of work to get it
mounted securely. If you haven’t worked with this type of switch
before he takes the time in the video after the break to explain
how they work.