[sdiy] saw core JFET mystery

[jhaible at debitel.net]

For some reason, JFETs seem to *have* such a wide variance. Sometimes they are
sold in selected groups. 

I don't remember why that is (I think it was answered at one time on this list).

I'm using BJTs in my Living VCOs. I haven't explored the pro's and con's of BJTs
vs. FETs in VCOs. (Just saying that I don't feel like an expert in JFET
discharge circuits. Ian can certainly tell us more here.)

JH.


> Ah, OK. I was suprised because David mentioned he used a time 10x
> smaller than he normally saw in circuits.
> 
> Would another FET model be better with regards to the current it can work
> with?
> 
> D.
> 
> On Mon, Mar 1, 2010 at 13:21,  <jhaible at debitel.net> wrote:
> > No, larger time constants in the circuit than it would be necessary with
> an
> > optimal (high current) FET, to provide enough time for a FET with lower
> current
> > to fully discharge the integration cap.
> >
> > JH.
> >
> >> BTW, I think you mean smaller time constants :-)
> >>
> >> Thanks
> >> D.
> >>
> >> On Mon, Mar 1, 2010 at 10:55,  <jhaible at debitel.net> wrote:
> >> >
> >> >> Jürgen,
> >> >> Are you saying that it might be better to use something else instead
> >> >> of the jfet?
> >> >
> >> > No - just explaining why you might find larger time constants than
> >> "neccessary"
> >> > in the usual designs.
> >> >
> >> > JH.
> >> >
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> >> >
> >>
> >>
> >
> >
> >
> >
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> > debitel.net Webmail
> >
> 
> 




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