Deux auteurs bien connus des initiés ont eu de courtes et nettes interventions relativement à validité de l'expression "contre-réaction en courant" (comme topologie) qui préoccupe certains électro-sémantologues.
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Ian Hegglun [1]
My analysis shows the resistor to ground on the inverting input 'Rg' (Rp in Ketje's circuit) is simply an emitter degeneration resistor for a common emitter input stage. This resistor needs to be small for useful gain (gm). And a small Rg means 'Rf' needs to pass a lot more current from the output via the feedback voltage divider than standard VFA opamps -- which makes it appear to us in the outside world as if current is fed back. But internally, a voltage difference to the input stage is still the feedback operational variable.
(En interne, c'est la différence de tension à l'étage d'entrée qui reste la variable opérationnelle de la contre-réaction.)
Source
http://www.diyaudio.com/forums/solid-sta...80222.html
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Dennis Feucht [2]
Comments D Feucht
Whether feedback is called "voltage" or "current" is misleading. Those names have more to do with how the circuit is analyzed rather than what it is.
(Que la contre-réaction soit appelée en tension ou en courant induit dans l'erreur. Ces termes ont plus relatifs à la façon dont le circuit est analysé que ce qu'il est.)
Source
http://www.edn.com/electronics-blogs/ana...medium=EDN
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[1] Ian Hegglun
https://linearaudio.net/authors/387
https://paklaunchsite.jimdo.com/
[2] Dennis Feucht
http://www.edn.com/user/D%20Feucht
https://www.amazon.com/Dennis-Feucht/e/B001HPLH4U
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Ian Hegglun [1]
My analysis shows the resistor to ground on the inverting input 'Rg' (Rp in Ketje's circuit) is simply an emitter degeneration resistor for a common emitter input stage. This resistor needs to be small for useful gain (gm). And a small Rg means 'Rf' needs to pass a lot more current from the output via the feedback voltage divider than standard VFA opamps -- which makes it appear to us in the outside world as if current is fed back. But internally, a voltage difference to the input stage is still the feedback operational variable.
(En interne, c'est la différence de tension à l'étage d'entrée qui reste la variable opérationnelle de la contre-réaction.)
Source
http://www.diyaudio.com/forums/solid-sta...80222.html
*
Dennis Feucht [2]
Comments D Feucht
Whether feedback is called "voltage" or "current" is misleading. Those names have more to do with how the circuit is analyzed rather than what it is.
(Que la contre-réaction soit appelée en tension ou en courant induit dans l'erreur. Ces termes ont plus relatifs à la façon dont le circuit est analysé que ce qu'il est.)
Source
http://www.edn.com/electronics-blogs/ana...medium=EDN
*
[1] Ian Hegglun
https://linearaudio.net/authors/387
https://paklaunchsite.jimdo.com/
[2] Dennis Feucht
http://www.edn.com/user/D%20Feucht
https://www.amazon.com/Dennis-Feucht/e/B001HPLH4U