[sdiy] Negistor Oscillators and web cleanups

[jhaible at debitel.net]

I'm not familiar with this negistor stuff, so I cannot
say if there is any connection to the Korg circuit
or not.

But just to avoid confusion: What Korg was using is
not a side effect of a single BJT. It's a 4-layer
structure (pnpn): An actual thyristor component
in some instruments (PE-1000, and VC-10 if memory serves),
and a composite thyristor built from two BJTs, thus
formin the pnpn structure. (Ok, there's also a diode
and a 3rd transistor, but it's basically just a 
thyristor nevertheless.)

Gate voltage exceeding a certain level -> the thing
will conduct

Positive feedback -> the thing will stay turned on

Current goes below some level -> feedback loop is
broken, the thing goes off.

Works over a wide range of current, too. (MS-20 ...)

JH.




> Hi, I don't know if my previous message went through, therefore this
> is another post in which you will find the URL where to get :
> Jurgen Haible's recreation of Korg PS3200 VCOs
> http://www.oldcrows.net/~jhaible/polykorg/sg_1sch.pdf
> and the shematics of the Korg MS50
> http://www.hylander.com/moogschematics.html
> 
> Cheers
> 
> > Hi Yves,
> >
> > Many thanks for this input -- could you possibly direct me to the 
> > schematics
> > somewhere? I did a quick search, and could not easily find the VCO 
> > schematics.
> >
> > Many thanks!
> >
> > Best,
> > Michael
> ----------------------------------------------------------
> Yves Usson
> 
> Lab. TIMC UMR5525 CNRS
> Institut d'Ingéniérie et de l'Information de Santé (IN3S)
> Faculté de Médecine
> Domaine de la Merci
> 38706 La Tronche cedex
> 
> email : yves.usson at imag.fr, yves.usson at ujf-grenoble.fr
> 
> tel.  (+33) (0)456 520 074
> fax.  (+33) (0)456 520 022
> 
> 
> 
> 




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