Output classes A and AB
 

John said:

A capacitor is analogous to a spring. Don't be fooled by
the
symbols. A resistor is analogous to a damper,
incidentally.

It depends on which dual you are using, an inductor can
also be
analogous to a spring and a capacitor to a mass.

And a mass to a spring and a spring to a mass?

It is more intuitive surely to consider voltage to be an
analogue of mechanical force.

Whichever way round you think, I suppose. The analogy is of
limited value unless you are better at analysing complex
mechanical networks than you are at electronics, or you're a
mechanical engineer into analogue computing. The equations
are the same in the end.

cheers, Ian

Output classes A and AB
 

"flipper" wrote in message
...

: On Wed, 31 Oct 2007 13:10:20 +0100, "Rudy" wrote:
:

: it seems the error made is in using the wrong mental model, that is
: seeing the transformer primary as a resistance.
: sure, PP operating on a pure R load would cease to
: cancel when one side would be cutoff, as it would no longer
: partake in the transfer curve for PP !
:
: Even harmonics also cancel in a transistor (or any other for that
: matter) Class AB PP amplifier with no transformer, as long as the two
: sides are 'equal'.

yep, my mistake;-)
the function is realized by the configuration, not the components.
although the components in each half have to be dynamically matched
to realize the theoretical total annihilation ;-)
:
: Might sound like holy hell from the odd order harmonics but all that
: matters for evens is equal but opposite regardless of how 'screwed up'
: the equal but opposite signals are.
:
: with a transformer, however, the transfer curve is a function
: of the tight coupling of the primary halves, so always PP ;-)
: (not the current, but the core flux is what matters)
:
:

Rudy

Output classes A and AB
 

"flipper" wrote in message
...
: On Sat, 3 Nov 2007 22:15:13 +0100, "Rudy" wrote:
:
:
: "flipper" wrote in message
: .. .
:
: : On Wed, 31 Oct 2007 13:10:20 +0100, "Rudy" wrote:
: :
:
: : it seems the error made is in using the wrong mental model, that is
: : seeing the transformer primary as a resistance.
: : sure, PP operating on a pure R load would cease to
: : cancel when one side would be cutoff, as it would no longer
: : partake in the transfer curve for PP !
: :
: : Even harmonics also cancel in a transistor (or any other for that
: : matter) Class AB PP amplifier with no transformer, as long as the two
: : sides are 'equal'.
:
: yep, my mistake;-)
:
: I think most people do, or did at one point in time, visualize it that
: way because it's intuitive from the name 'push pull' and the typical
: 'text book' simplified analogies 'like a see-saw', and such. which
: distinctly imply that the two sides are 'rigidly connected', so one
: 'affects' the other. A bit problematic finding a Class AB see-saw,
: though. hehe But that's really neither here nor there because in the
: typical PP output stage there's no fulcrum at all, so the analogy
: falls completely apart.
:
: However, the analogy works fairly well for the LTP, as long as it
: remains in Class A, because the common cathode connection is the
: fulcrum and they do 'see-saw' by pushing on each other's 'seat'
: (cathode).
:
: Btw, the analogy falls apart with a "PP output stage" because it,
: alone, isn't 'PP', per see. It's just two tubes connected to a
: transformer and it's the phase splitter that causes them to behave
: 'PP'. They're just a current gain device for the respective PS signal.
:
: the function is realized by the configuration, not the components.
: although the components in each half have to be dynamically matched
: to realize the theoretical total annihilation ;-)
:
: Yep
:
: :
: : Might sound like holy hell from the odd order harmonics but all that
: : matters for evens is equal but opposite regardless of how 'screwed up'
: : the equal but opposite signals are.
: :
: : with a transformer, however, the transfer curve is a function
: : of the tight coupling of the primary halves, so always PP ;-)
: : (not the current, but the core flux is what matters)
: :
: :
:
: Rudy

hmmm. so taken to the logical next step, maybe ;-),
what about a CCS feeding the center primary of a triode(d) PP
power stage? that must be ultra PP, eh ?

Rudy

Output classes A and AB
 

On Nov 5, 3:14 am, flipper wrote:
On Mon, 5 Nov 2007 01:38:25 +0100, "Rudy" wrote:

"flipper" wrote in message
.. .
: On Sat, 3 Nov 2007 22:15:13 +0100, "Rudy" wrote:
:
:
: "flipper" wrote in message
: .. .
:
: : On Wed, 31 Oct 2007 13:10:20 +0100, "Rudy" wrote:
: :
:
: : it seems the error made is in using the wrong mental model, that is
: : seeing the transformer primary as a resistance.
: : sure, PP operating on a pure R load would cease to
: : cancel when one side would be cutoff, as it would no longer
: : partake in the transfer curve for PP !
: :
: : Even harmonics also cancel in a transistor (or any other for that
: : matter) Class AB PP amplifier with no transformer, as long as the two
: : sides are 'equal'.
:
: yep, my mistake;-)
:
: I think most people do, or did at one point in time, visualize it that
: way because it's intuitive from the name 'push pull' and the typical
: 'text book' simplified analogies 'like a see-saw', and such. which
: distinctly imply that the two sides are 'rigidly connected', so one
: 'affects' the other. A bit problematic finding a Class AB see-saw,
: though. hehe But that's really neither here nor there because in the
: typical PP output stage there's no fulcrum at all, so the analogy
: falls completely apart.
:
: However, the analogy works fairly well for the LTP, as long as it
: remains in Class A, because the common cathode connection is the
: fulcrum and they do 'see-saw' by pushing on each other's 'seat'
: (cathode).
:
: Btw, the analogy falls apart with a "PP output stage" because it,
: alone, isn't 'PP', per see. It's just two tubes connected to a
: transformer and it's the phase splitter that causes them to behave
: 'PP'. They're just a current gain device for the respective PS signal.
:
: the function is realized by the configuration, not the components.
: although the components in each half have to be dynamically matched
: to realize the theoretical total annihilation ;-)
:
: Yep
:
: :
: : Might sound like holy hell from the odd order harmonics but all that
: : matters for evens is equal but opposite regardless of how 'screwed up'
: : the equal but opposite signals are.
: :
: : with a transformer, however, the transfer curve is a function
: : of the tight coupling of the primary halves, so always PP ;-)
: : (not the current, but the core flux is what matters)
: :
: :
:
: Rudy

hmmm. so taken to the logical next step, maybe ;-),
what about a CCS feeding the center primary of a triode(d) PP
power stage? that must be ultra PP, eh ?

I'm not sure what you'd call it but I doubt it would behave as I think
you're implying.

How would you keep the CCS working as a CCS when inductive kick
reverses polarity across it?





Rudy- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

So how much does the CT voltage to ground vary? I think not much, and
it would be fairly easy( though an exercise in heat management
perhaps) to keep from ever having it polarity reversed.

It is easy to call up 'inductive kick' when looking at voltage on an
OPT, but in this case I just don't see a mechanism. Both phases
conducting a little bit, CT voltage may try to move, but this is where
the last stage of the PS comes into play...and at twice the frequency
of the fundamental too.
cheers,
Douglas

Output classes A and AB
 

On Nov 5, 3:37 pm, flipper wrote:
On Sun, 04 Nov 2007 17:49:33 -0800, Multi-grid
wrote:

How would you keep the CCS working as a CCS when inductive kick
reverses polarity across it?

Rudy- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

So how much does the CT voltage to ground vary? I think not much, and
it would be fairly easy( though an exercise in heat management
perhaps) to keep from ever having it polarity reversed.

It is easy to call up 'inductive kick' when looking at voltage on an
OPT, but in this case I just don't see a mechanism. Both phases
conducting a little bit, CT voltage may try to move, but this is where
the last stage of the PS comes into play...and at twice the frequency
of the fundamental too.

If you interpose a CCS then there's nothing to keep it from moving.
Or, let's put it this way, If the CCS *does* anything then it's, by
definition, changing the voltage, and the induced voltage will swing
equally the opposite, but if the voltage is constant then it's not
doing anything so why have it there?



cheers,
Douglas- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

hey-Hey!!!,
You described an inductive kick that would reverse polarity across
this proposed current regulator. I took issue with that and said it
could easily be avoided.

So the CT voltage moves, that is proof the CCS is working. What's this
inductive kick comming from?
cheers,
Douglas