[sdiy] why 10V

[René Schmitz]

Hi Jürgen and Don,

>>The Hilbert tranform is a 90-degree phase shift that's constant over
>>frequency.  If you apply a square wave to a Hilbert tranform, the
>>result is a waveform with huge spikes.
>>
>>So if the all pass filter aproximates a constant 90 degree phase
>>shift, the output peaks could be maybe ten times the input square wave
>>voltage.
> 
> 
> Thanks for adressing this, Don!
> 10 times is more than I expected. How did you calculate this?

Seems like the essentially linear systems theory isn't adressing this 
because its a nonlinear problem. So I wouldn't expect to find a formula 
for it.

I think the worst case would be if all peaks of the individual partials 
come out all at the same time after the delay network. It should be 
possible to see what the input signal has to look like so that this is 
the case. (I think this is the reverse thing to the impulse answer. 
Anyone?!)
Then one would adjust the partials so that the limitation of the 
amplitude at the input is met, and this again applied to the impulse 
answer function.

Does this sound reasonable?

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159