# Equivalent circuits and more signal flow diagrams

Discussion in 'Amp Tech Center' started by peteb, Jun 4, 2018.

1. ### petebFriend of Leo's

Apr 25, 2003
These are our target values.

2. ### petebFriend of Leo's

Apr 25, 2003
Let's try to map out the individual current bursts going thru the cathodyne PI using the premise that only one right ward current burst and one leftward moving current burst is on the load resistors at any one time.

They are intersecting, going right and left and we need both L and R to be on the cathode at zero and 360 degrees and both on the plate at 180 degrees and no bursts on either at 90 and 270 degrees.

It must look something like this:

3. ### petebFriend of Leo's

Apr 25, 2003
And this

See how there are no bursts on the plate or cathide at 90 and 270 degrees? But there is a burst at ground at both 90 and 270.

It seems to fit.

4. ### petebFriend of Leo's

Apr 25, 2003

The last point and the last diagram has to do with the sticking point that signal is traveling thru ground. How can that be? That is a legitimate question. Now we have found that AC signal is passing thru ground not only once but in two directions at once! How crazy is that?

The answer lies in the nature of AC and the operation of the tube.

5. ### petebFriend of Leo's

Apr 25, 2003
The diagram above, showing both load resistors connecting to ground is equivalent to these diagrams.

The key here is that it is impossible to send signal thru ground to a passive receiver. The signal will go to ground and that's it, it's done.

Neither The cathode or the plate are passive receivers. The are both AC sources. They are both (somewhat) indepependantly pumping AC into and out of the ground. Fortunately, when the plate is pushing electrons into the ground, the cathode is pulling electrons out of ground. And the other way around, the plate is pulling when the cathode is pushing.

Important concept about ground. It is neither negative or positive.

6. ### robrobPoster ExtraordinaireAd Free Member

Dec 29, 2012
United States
I love this comedy.

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7. ### LudwigvonBirkTele-Holic

Age:
116
Aug 26, 2017
deleted

Last edited: Jun 11, 2018

8. ### D'tarTele-Afflicted

Jan 11, 2013
WNY
.

Last edited: Jun 11, 2018

Mar 26, 2014
Northern Germany
How would this all (in the eventuality) interrelate with the frequency dependant phase angle shift in a global (negative) feedback ?

Last edited: Jun 11, 2018

Mar 26, 2014
Northern Germany
Of course all these ideas you have around the Class A Cathodyne phase inverter, might break down when applied to a Class B Cathodyne, which not only has unequal plate and load resistors, a gain of more like a common-cathode stage (depending how you design it), but still maintains an out-put that is (almost) equal in phase amplitude, yet contrary in wave form swing direction, as the plate and cathode are each only amplifying half the input wave-form.
Would this not be a ground to modify some of your theories?

Last edited: Jun 13, 2018
SSL9000J likes this.

Mar 26, 2014
Northern Germany
How do you think the wave form might dissipate if instead of plate and cathode resistors, one should use chokes of sufficiently large impedance to match the low frequency roll-off of the resistors that they would replace? And how do you think any reflective current from these chokes would effect the feedback factor, and therefore the overall amplification ratio of the stage?

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Mar 26, 2014
Northern Germany
If the cathode and plate resistors are replaced with chokes with a sufficiently high DC resistance, then they will react just like resistors in DC terms, but function as a constant-current sources in AC terms......interesting.

....well at least I think it is.

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13. ### clintjFriend of Leo's

Apr 4, 2015
Idaho
I presume you've seen the old Hammond chassis like the AO-43? Stock, they use a choke as the plate load on the reverb driver.

Mar 26, 2014
Northern Germany
Like this one:
I guess one would classify it as a SE parafeed.

There are output configurations where a single power tube has a choke on plate and cathode, driving a push-pull output transformer, self-splitting.

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15. ### petebFriend of Leo's

Apr 25, 2003

I assume that you are unable to find anything wrong with my analysis.

16. ### petebFriend of Leo's

Apr 25, 2003
Bendyha,

I read it, thanks, but I don't know where you are going with it.

this is meant to be simple analysis. I made it simple to make what is going on clear.

Last edited: Jun 14, 2018

17. ### petebFriend of Leo's

Apr 25, 2003
researching antenna's led to this image.

this is exactly how I see the voltages on the load resistors behaving except I see one major problem. What is it?

It could be linear, but I prefer the signal to be a real wave form.

the pink is the voltage, the blue is the current.

I don't agree with this diagram in one important way, and if I had to explain why, I would say this diagram is not of load resistors but of an antenna, that's why it is different.

I like the voltages, they are perfect, but not the current.

18. ### petebFriend of Leo's

Apr 25, 2003
This is why I say acceleration causes curves:

constant velocity-----------------acceleration

19. ### petebFriend of Leo's

Apr 25, 2003
Einstein's theory of special relativity involves constant velocity.

Einstein's train thought exercise involves a train traveling at a constant velocity past a platform. It can be extended to people on a train moving at constant speed and throwing an object at a constant velocity.

Finally he did and the result is Einstein's general theory of relativity.

Acceleration does some odd things.

when a 40 foot long train car accelerates, it is no longer 40 feet long.

mind blowing stuff like that. Don't under estimate the effects of acceleration.

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Mar 26, 2014
Northern Germany
You're the one "going with it"
What ever it is you have made simple, is not explained.....what is it you are trying to making clear in relevance to what ?

I posed questions hoping to find out what specific function this thread might be trying to offer, by relating it to "amp tech" matters.

What do you not understand in this simple question?

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