I have to admit, you read pretty many articles, but they don't replace formal education. Please keep your musings based on your misunderstanding of Wikipedia for yourself, your mentor tone confuses people. 😀
My opinion is, it is absolute useless to use gyrators in DC filters as drawn. Unlike real inductance, gyrator does not save an energy. It is an active unit that uses energy of power supply and loses it. I would use the same components for better filtering, using simple RC filters that supply filtered DC to gates of source followers. This topic was discussed many times here on the forum.
This time, you and I agree. Back in the tube era, engineers used filter inductors, because they couldn't get electrolytics big enough, so sufficient series resistance to don the job ruined regulation. You can still use inductors (chokes) - they will usually cost less and be a lot more reliable than any power MOSFET circuit. But you can get large capacity HV electrolytics now, so any series resistor, if needed at all, can be small enough that regulation and energy wastage is not significantly degraded.
Incidentally, no, reading does not replace a formal education, nor does a formal education replace reading or practical experience. All three complement each other. As some people may know from my postings on diyAudio and other forums, I have all three, as a professional electronics engineer, going back decades, right back to the tube era. I'm still involved as a consultant, even though I'm well over what the government thinks is retirement age.
Now, if I called a Ford Louieville a car, or a motorcycle, you'd think I was an idiot, wouldn't you? So why call a CCS a gyrator? A gyrator does a completely different job.
Incidentally, no, reading does not replace a formal education, nor does a formal education replace reading or practical experience. All three complement each other. As some people may know from my postings on diyAudio and other forums, I have all three, as a professional electronics engineer, going back decades, right back to the tube era. I'm still involved as a consultant, even though I'm well over what the government thinks is retirement age.
Now, if I called a Ford Louieville a car, or a motorcycle, you'd think I was an idiot, wouldn't you? So why call a CCS a gyrator? A gyrator does a completely different job.
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In cars wheels rotate physically. Rotating arrows on pictures in Wikipedia does not mean that something is rotating.
CCS is a function, not a component, it means a device with dynamic resistance much higher than it's static resistance. The same with inductive resistance, it increases with frequency. So, a unit that serves function of CCS if to add a DC servo, would act as having inductive resistance.
The same with tubes. If somebody wrote in Wikipedia that distortions increase with voltage swing, it does not mean that they do not increase with current swing, so we can get less distortions on the same swing increasing dynamic load resistance.
No. Reading you on this forum, I would say that you are a smart person who tries to construct the whole from distorted pieces you find.
The same way you call a unit with low static and high dynamic resistance CCS. Add there a servo feedback through RC network, and it turns into a gyrator, because has inductive resistance obtained without inductance. 🙂
CCS is a function, not a component, it means a device with dynamic resistance much higher than it's static resistance. The same with inductive resistance, it increases with frequency. So, a unit that serves function of CCS if to add a DC servo, would act as having inductive resistance.
The same with tubes. If somebody wrote in Wikipedia that distortions increase with voltage swing, it does not mean that they do not increase with current swing, so we can get less distortions on the same swing increasing dynamic load resistance.
No. Reading you on this forum, I would say that you are a smart person who tries to construct the whole from distorted pieces you find.
The same way you call a unit with low static and high dynamic resistance CCS. Add there a servo feedback through RC network, and it turns into a gyrator, because has inductive resistance obtained without inductance. 🙂
You are a very confused person, Wavebourn.
A practical CCS may well be designed to display a relative low, or even near zero, resistance at DC, as an additional feature in controlling DC operating conditions - that does not make it a gyrator.
Incidentally, you can have a resistance that changes with frequency that isn't inductive, that is, it continuously absorbs energy and never gives it back, and does not show a phase angle between V & I. Example: skin effect in a wire - no phase angle, but it increases with frequency.
So?
No. Look it up in any decent textbook. A Const Current Source is a circuit or device in which current does not change significantly with voltage. This IMPLIES a high slope resistance but DOES NOT imply the resistance changes with frequency. A true CCS can maintain its ability to keep current precisely constant at DC (zero frequency).
A practical CCS may well be designed to display a relative low, or even near zero, resistance at DC, as an additional feature in controlling DC operating conditions - that does not make it a gyrator.
No such thing. Inductance is inductance; resistance is resistance. One exchanges energy in and out over time, the other continually absorbs it and never gives it back. One imposes a phase shift of current wrt voltage, the other doesn't.
Incidentally, you can have a resistance that changes with frequency that isn't inductive, that is, it continuously absorbs energy and never gives it back, and does not show a phase angle between V & I. Example: skin effect in a wire - no phase angle, but it increases with frequency.
True, but its still the case that any distortion, whether arising in voltage swing or current swing, must inevitably reduce with reducing signal level, in proportion or faster. So, a CCS might be of benefit in reducing distortion in the voltage stage of a power amp, but any distortion benefit in a preamp is likely to be inaudible. But it may well give a clearly audible benefit is HT decoupling is inadequate. And the best way to fix it is better decoupling.
Clearly, that's what you've been doing. Metaphorically, you've been calling a cow a cat, (both have 4 legs, a mouth and a tail) and then trying to tell people a cat eats grass.
A gyrator is not a gyrator from displaying inductance without actually having a physical inductance. That's just one of the many things it can do. Gyrators can, and are, used for lots of things, including making a small or even negative resistance controlled by a normal high resistance pot. As I said, a gyrator is a device or circuit that exchanges energy between two places, working in both directions simultaneously. Two gyrators in cascade make a transformer. Look it up. Bernard Tellegen's paper is a good place to start (Tellegen was the first to describe it, and invented a symbol for it, 1948).
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Have to agree with this points made regarding the use of copious amounts of CCS the last decade. The advance of 'almost vertical' loadlines is not obvious as it is the constant in the v-a relation we are seeking, for low distortion.
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