AC power control without touching AC power

2015-11-04 10.49.30bIn this article I’ll show a simple 3D design for a servo mount to control a light switch for about $3, plus some electronics to drive it with a neat little interface. This article explains how I used it to regulate my air conditioner, but the basic bracket allows control of any U.S. standard wall switch.

I just moved into a new office and there’s a window-mounted air conditioner. There’s a remote control to set the target temperature, but the unit isn’t smart enough to turn off at night. Instead, there’s a physical wall switch so you can turn it off with your actual physical hands, like a barbarian.

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I’m not going to put up with a hot office in the morning, nor will I let the unit blow cold air all night and weekend when nobody’s around.  Instead, I will Build Some Crap.

Details after the break. Continue reading

How to make a ton of clear LEDs into diffuse LEDs

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Step 1: Make a rock tumbler out of some threaded rods, bearings, a motor, and a spaghetti jar:

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Step 2: Get sand. If you don’t live in a beach/desert, you can probably get some for free from a landscaping supply place. (They charge per ton, so when you ask for a cup, they will think you are a crazy person and just give it to you.)

Step 3: Chuck the LEDs and sand into the thing and run it overnight.

That’s all.

Here’s what not to do:

  • Use an orbital sander to wiggle the jar. It’s super load loud and doesn’t do much.
  • Add water. This just gives you corroded LEDs that arent even diffuse.
  • Run it with so much power that centrifugal force sticks everything to the sides and it vibrates itself off your desk overnight.
  • Run it with so little power that it stalls.
  • Fail to own a variable power supply so that your only choices are 12V and 9V (see above).
  • Make your first shaft coupler out of gaffer tape. I ended up designing and 3D printing a simple shaft coupler.
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Video: