ANALOG ADVENTURES

One of the handiest widgets the dedicated “analogist” can have in his or her widget arsenal is a function generator. While I’ve had a number of high-end analog function generators over the years, this El Cheapo $35 DDS function generator I found at Daily Motion.com < www.dailymotion.com/video/x3ismd0> outperforms them all. No kidding.

The traditional function generator produces sine waves, square waves, and triangle waves in a rather efficient and clever manner. It starts out with a square wave generator (much easier to build than a sine wave generator, at least at lower frequencies), then uses a subsequent integrator to generate a triangle wave, and then another subsequent integrator to generate a sine wave. We’ll go into a bit more detail as to why this works later on, but suffice it to say that we can thank (or blame) Fourier analysis for the ability to do this.

But at this time, we’ll go into some of the more interesting applications of the function generator. [The DDS, or Direct Digital Synthesis, function generator creates these aforementioned particular waveforms