Modulated cascode and positive feedback?

[Circlomanen]

I have been thinking a lot about modulated cascode, and I wonder if you can simulate a triode curve by modulating a normal fet or bipolare cascode with some positive feedback???
Something like this?

An externally hosted image should be here but it was not working when we last tested it.

 

[Nelson Pass]

I don't see the nonlinearity of the triode there - just that of
the Mosfet.

 

[Circlomanen]

I don't see the nonlinearity of the triode there - just that of the Mosfet

My thinking was that modulating the cascode with positive feedback would create an exponential curve..
I was just wondering how to create a triod like curve but without J-fets or triods. Can it be done???

 

[kekso22]

Hi Circlomanen,

if you want to play try this idea. It makes nices Triode curves.

Bye
Emil

 

[Circlomanen]

Thank you!! Thats nice with Lovoltechs, but I would like to find a way to create triode like transfercurves with only HexFets. (IRFPXXX) I dont know if that is doable at all but at least its a nice problem to work on.

Johannes.🙂