More light transmitter experimentation…

Today, I had to do some yardwork, so I dusted off the weed whacker, and climbed the back of the hill to chop down some high grass. At the end of an hour, I was about 40% done (I’ll do the rest next weekend) but sneezing and coughing from the liberated pollen and dust. So, I called it a day, made a mental note to get a dust mask for next week, and showered.

But while I was chopping grass, I located an old solar powered LED light that had been lost among the tall grass. It was probably three or four years old, and covered in dirt and dust. The solar cell in particular looked like some water had gotten in it.

The perfect organ donor for an improved receiver for my LED transmitter, thought I.

And it is. I disassembled the light, snipped the LED panel out, and soldered it in place of the LED that I was using in place of my receiver previously. And, not surprisingly, it works better. A lot better! A lot louder. Over a greater distance. There is no real contest.

I tried to shoot some video of it, but my hands are simply too shakey (muscles twitching from operating vibrating machinery for an hour) and it’s unwatchable. But here’s a little MP3 file that will perhaps hint at some of the improvement.

Demonstration of solar cell as light receiver (MP3)

Addendum: I decided to go ahead and post some video. It’s still pretty shaky, but it’s a reasonable demonstration of what’s possible with a scavenged solar cell. Pardon for the relatively poor lighting: my office is lit by compact flourescent bulbs, and when they were all on, the 60 hz whine (which you can still hear despite lowering the light levels) was pretty irritating.