A
useful device found in most
electronics labs. At the very least, it can give you a
voltage source shaped like a
sine wave, a
square wave, or a
triangle wave as outputs, from .5
Hz upto about 1MHz. Better ones will give you more
bandwidth, and
sawtooth,
half-sine wave, and
noise waveforms, as well as allowing you to
modulate the
duty cycle of your waveform.
Best when used in conjunction with an oscilloscope.
If you hook a function generator up to a speaker, and twist the frequency dial to modulate, you can get a sound not unlike the high-pitched whine heard on certain songs by rap artists such as Snoop Doggy Dogg. This is the main reason I hate Snoop.