"Trevor Wilson" wrote in message
.. .

"Doki" wrote in message
...
Is it possible to make a Sine generator for a couple of quid DIY? I want
to produce a sine wave around 15khz to drive a piezo tweeter...

**Just use a 555 timer to generate an HF (square wave) waveform. Don't
forget: The 2nd harmonic of 10kHz is 20kHz and outside the hearing
abilities of most humans. No need to worry about a sine wave. A 15kHz
square wave will sound just like a 15kHz sine wave. Well, almost.

I've got no clue about harmonics. What does that mean in practice?