alt.sci.physics.acoustics

"Dave Platt" wrote ...
> There are some ways of getting fairly close, I think, with the use of
> some circuits which are available off-the-shelf. Whether the result
> would be sufficiently accurate, or sufficiently analog, or would cover
> a sufficiently wide range of frequencies in any single implementation
> to be considered to be an acceptable answer to the problem would be up
> to our radioactive friend.
>
> If the incoming waveforms are sufficiently close to being sinusoidal,
> one could use analog comparator/latch/oneshot circuits to implement a
> frequency-to-voltage converter (or, perhaps more directly, a
> frequency-to-delivered-charge converter). The amount of charge
> flowing into/out of each such converter would be linearly proportional
> to the frequency of the signal. Feed each input signal to one such
> converter, and sum up the 4 charge-pulse chains into an accumulator (a
> capacitor).

Brilliant! I hadn't thought of that kind of solution. :-)
Since our radioactive friend just throws out these wild
arbitrary questions (unconnected to reality, anyway)
we can decide between ourselves to proclaim it solved.