SV: Re: [sdiy] integrator / capacitor leakage

[karl dalen]

I have been redaing that polycarbonate is
a stain better then a polyproylene, is there
anything into that if used as integrators?

And why swing 20V it would certainly put
constraints to the integrator in the high
freq range. I would personally put 10 euro
for keeping the integrator to a lot less
voltage swing.
 
KD 


--- harrybissell <harrybissell at prodigy.net> skrev:

> imho the weak link is the capacitor...
> 
> if the 'smaller' cap allows you to get into a high-quality type
> like a polystyrene, I'd go that direction.  Its hard to get large
> value, low leakage caps.
> 
> Good amplifiers are easier to find.
> 
> H^) harry
> 
> 
> 
> jhaible at debitel.net wrote:
> 
> > When I'm building an integrator for a triangle or sine wave oscillator with
> an
> > amplitude of 20Vpp, I have two options:
> >
> > a) run the integrator at 20Vpp, or
> > b) run the integrator at a lower voltage, and amplify the signal
> >    with an extra amp.
> >
> > Now, for a certain current into the integrator, the integration capacitor
> > in case (a) will be much smaller. (Larger voltage to pass in the same time
> > at th esame current.)
> >
> > What is better, in terms of precision / leakage?
> >
> > At first glance, I'd say leakage is mostly leakage _currents_, so
> > it will be the same in both cases.
> > At second glance, I'd say if the leakage currents are not entirely
> > independent with voltage, case (a) will be worse.
> >
> > Is this right? Are there other things to consider?
> >
> > Background: VCO which not only will run from 0.03 Hz to 20kHz,
> > but which will also produce very precise waveforms over that
> > whole range.
> >
> > Any ideas / hints welcome.
> >
> > JH.
> >
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