Any of you all have something just "hit" you with an "Ah-Hah" moment at an odd time? I've had this happen frequently. This time, it was in the shower tonite. Yep, I know...all good ideas come up in the shower!
This time, it was abou tthe New York subway system. Last year, I noticed in many of the oldest tunnels in the lower part of Manhattan, I noticed that the tunnels there were lit with 5 incandescent lights together in the fixture. It looked like some sort of architectural element, but the inside of the train tunnel is not really seen by anybody, why would they take the effort to design these interesting looking light fixtures.
BOOM! it hit me what's up with these lights...it's actually an old design by a rather smart electrical engineer! Instead of running a separate power line to operate the tunnel lights at a different voltage, they just run them right off the third rail. Okay, so where in the heck do you find 600 volt light bulbs?!?! You don't! 600 volts divided by 5 light bulbs equals 120 volts! So, instead of having to get unusual 600 volt light bulbs made, they can go right down to any old hardware store and buy regular 120 volt bulbs. I imagine with this setup that all the bulbs need to be the same wattage to make the voltage drop the same, and they would be like christmas lights, where if one bulb blew, all the bulbs would go out at the same time.
19 Sep 2007, 10:22 pm
