NSM wrote:

wrote in message
ups.com...

2 questions about a fully DC Sine Wave

One answer. Sine waves aren't DC.

N

I like Jack's terminology. The wave itself isn't DC, but I think "fully
DC" is an acceptable way of describing its location.

AC generators and transformers are usually designed to produce sine
waves with no DC, but sine waves were known long before those inventions.

A wave is a succession of curves. A sine wave is a wave whose
displacement follows the form of a sine. A pure acoustic tone is a sine
wave regardless of ambient pressure. A ripple on a pond is a sine wave
regardless of the water level.

As not all voltage variations are curves, our generic term was
"waveforms". If the plate voltage of an amplifier tube varied from 998
to 1000 volts in the form of a sawtooth, we'd call that two-volt
variation a sawtooth waveform. If it was sinusoidal we'd call it a sine wave.

To call a waveform an AC sine wave implies that there is no DC, but this
thread is the first time I've read the claim that all sine waves are AC
sine waves.