[Prev][Next][Index][Thread]
Re: Ritchie Burnett's website
Terry Fritz wrote:
> At any given instant of time, All the energy is at one frequency (if you
> get technical it is actually a rate of change instead of a "point"
> frequency (like a location vs speed thing...). The two frequency spectrum
> is due to the fact that the spectrum analyzer displays the frequency over a
> time span much lower than the frequency being displayed. Thus, you see a
> spectrum of frequencies since the actual frequency wobbles around or is
> slightly Frequency Modulated (FM). That is totally an artifact of the way
> the analyzer displays the data. At a give time it is really just in one
> place but the analyzer "smears" that data over time (there is a knob to
> select the time span if I remember right). The same smearing is seen if
> you look at the output of an FM radio station on an analyzer. The Corums
> my disagree with me on this, but "I" think you can forget about the dual
> frequency energy storage thing... It does not exist other than in the
> spectrum analyzer's design tying to display events that are far to brief
> for us to see directly... Storage scopes (or simulations) show the real
> thing which looks pretty much like a sine wave (and is for practical
purposes).
The signals in a Tesla coil composed of (damped) sinusoids with two
different frequencies is very real, consequence of the behavior of a
system with four natural frequencies. What you observe in an
oscilloscope
looks as a single sinusoid at the common resonance frequency of the two
separate resonators, modulated in amplitude (double sideband), not in
frequency.
The relation between the single modulated sinusoid and the two
nonmodulated sinusoids at different frequencies is simple math
(damping ignored):
A*sin(wb*t)*cos(w0*t) = (A/2)*sin((wb-w0)*t) + (A/2)*sin((wb+w0)*t)
Antonio Carlos M. de Queiroz