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Perceptual illusions of brightness in 28 minutes
That which melts your retina might not be that bright The perceived brightness of a light source might mislead you to think that a light that doesn't put out that much light is brighter than it is. Allow me to illuminate this for you. Consider a laser, which is a very focused columated beam. A…

An introduction to switching DC/DC converters in 28 minutes
AC circuitry has been able to use transformers for a long long time to magically go from one voltage to another. But that gives you these giant hunks of metal and wire. The transformer is smaller and more compact if it's passing a higher frequency. Regular old mains power uses 50 or 60 Hz because…

Using multiple power supplies, maybe some of them USB in 28 minutes
A lot of times, it really helps to have multiple power supplies. Pretty much, unless you are making something that's small enough to be powered from the same USB port your microcontroller is programmed from, you already have multiple power rails. I hope to get you all... well... trained up, on the…

How to make it easier to prototype and complete projects in 28 minutes
It's real easy to get going on a project right up until you hit a barrier. Then you find yourself with a burnt out part and no replacement and the wires are a mess and you end up so frustrated that you toss the works. Here's some pointers to make the process a little more electrifying and a little…

PWM Speeds and why you should care in 28 minutes
Incandescent bulbs make things easy. Because they work by making a material hot, even if you feed them with 50 Hz AC power, they'll stay mostly lit. The first set of LED Christmas lights, however, were massive eyesores for a lot of people. Flicker fusion There's a few important things to…