[sdiy] Re: Leapfrog

[jhaible at debitel.net]

All right, I've taken a closer look at the integrator
(still numerical, not analytical), and it's an integrating
function as it should.

It _is_ more sensitive to the open loop gain of the opamp
than the inverting integrator. But even with a TL071, it's
pretty much a perfect integrator for frequencies > 1Hz.

With higher DC gain of the opamp, you can get as close to an
ideal integrator as you want. (Always talking about ideal
resistor values, simulation).

So I would be surprised if the analytical description would
give a different result.

JH.

> > >
> http://www.oldcrows.net/~jhaible/scanner_vibrato/jh_leapfrog_untested.pdf
> >
> > Trouble is... L3 is not being represented by an integrator, that's still a
> > lag filter!
> 
> Really?
> I haven't written down the equations for that single stage (just used a
> combined
> Lag / NIC integrator from the textbook), but the overall frequency response
> is identical (within 0.5dB) to the RLC filter. (Always talking about
> simulation / theory, not about a real circuit.)
> 
> JH.
> 
> 
> 
> 




-------------------------------------------------
debitel.net Webmail