Infrared Pulse Sensor

IR pulse sensor and oscilloscopeLast week, I bought something I’ve wanted for quite some time: an oscilloscope. I’ve been doing more projects where a scope would be useful, such as audio amplifiers, PWM, and AC-DC rectification. And besides that, oscilloscopes are just plain cool. Of course, a scope by itself isn’t much fun, it needs something to measure. Something like an AC sine-wave, or an audio signal, or maybe… a person’s pulse rate? It’s possible, with the right sensor. Sean Michael Regan shows us how in the latest MAKE Weekend Project. I knew right away that it was perfect for trying out my scope. It was a bit of work, primarily because I modified the circuit, but the finished sensor is a lot of fun, and there is a lot of potential for doing more with it.

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Japanese Toolbox header

Japanese Toolbox

Japanese Toolbox completeOftentimes, I find myself going to my parents’ house or a friend’s place to build or repair something, and I have nothing to put my larger tools in.  As a result, my drill, saw, clamps and other large items end up either laying on the floor of my truck or stuffed into whatever cardboard box I found laying around.  If I had a large, sturdy box to throw this stuff in, it would make these trips much more convenient and I would spend less time loading and unloading my tools and more time working.  So when I saw Len Cullum’s Japanese Toolbox project in MAKE 34, I knew I had found my solution.

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