# Equivalent circuits and more signal flow diagrams

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

Apr 25, 2003

2. ### petebFriend of Leo's

Apr 25, 2003
fixed end reflections are like a rope tied to the pole and the reflected wave in inverted.

Free end reflections are like a rope loosely tied to the pole and it is free to move up and down. the reflected wave does not invert.

3. ### petebFriend of Leo's

Apr 25, 2003
what are the boundary conditions here? the pic is from post 11 and the tube stage has a bypassed cathode resistor, so no signal at the cathode.

looks like a fixed or closed boundary at the cathode and a free or open boundary at the plate.

4. ### petebFriend of Leo's

Apr 25, 2003
What are the boundary conditions here? pic is cathodyne PI with equal loads.

it looks like free or open boundaries at the plate and the cathode and either a fixed or closed boundary in the middle or is it a node?

5. ### petebFriend of Leo's

Apr 25, 2003
is it two of these placed back to back?

6. ### petebFriend of Leo's

Apr 25, 2003
What is a standing wave versus a traveling wave?

standing waves occur when a wave is confined and it bounces back and forth between two reflective boundaries. it is two waves traveling in opposite directions that give the appearance of not traveling. a node is shown at B.

7. ### petebFriend of Leo's

Apr 25, 2003
lets try out the open free fixed thing here.

a positive wave traveling right would reach the free end at the plate and reflect back as a positive wave. the positive wave traveling left would hit the fixed end at the cathode and reflect back as a negative wave.

+>
+<
->
-<

+>
+<
->
-<

it seems to work

8. ### petebFriend of Leo's

Apr 25, 2003
lets try out the open free fixed thing here.

a positive wave traveling right would reach the node and become negative, travel further to the right and hit the free end and return to the left as a negative wave. hit the node traveling left and become positive, then hit the cathode's open end and reflect to the right as positive.

this didn't work out so well, as only one of the two lines is covered. maybe there is the need for two opposite waves out of phase waves (like there is supposed to be.

this is not the main point or a concern.

9. ### petebFriend of Leo's

Apr 25, 2003
these wave drawings look a lot like wave diagrams for wind instruments

10. ### petebFriend of Leo's

Apr 25, 2003
open ended - open ended

11. ### petebFriend of Leo's

Apr 25, 2003
closed ended - open ended

12. ### petebFriend of Leo's

Apr 25, 2003
This is as far as my analysis has gotten.

what I notice is that in both cases the voltage diagram is the same as the first harmonic. that must mean something??

open - open

closed - open

13. ### petebFriend of Leo's

Apr 25, 2003
I change my view, I will favor this model for the signal traveling thru the amp.

It is a longitudinal wave, but when passed thru a resistor a transverse wave is formed.

14. ### petebFriend of Leo's

Apr 25, 2003
The tube has two output poles, the plate and the cathode, much like the wall socket.

We are familiar with the wall outlet. Two poles that are interchangeable but they are not the same. One is hot and the other is the neutral return.

Is this also how AC signal eminates from the tube?

I don't think so. I don't think either is neutral I think they are both capable of putting out their own AC signal, but out of phase, like the cathodyne PI.

15. ### petebFriend of Leo's

Apr 25, 2003
I think the AC current flowing thru the load resistors would look like this with both the plate and the cathode sending out signals that look like this, but in opposite directions.

Every time a cluster of electrons traveling right is at the same place as a cluster traveling left that is a max, and a min is where two empty spaces line up, and any time the two signals don't line up, it is somewhere inbetween max and min.

Time to start dr&*king

16. ### LudwigvonBirkTele-Holic

Age:
116
Aug 26, 2017

Let's not wreck it by continuing it.

Agreed?

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17. ### xafinityFriend of Leo'sSilver Supporter

Dec 24, 2015
my Mom's basement
Its pretty clear all these schematic short hands are porn pure and simple. Well disguised but clearly smut.

peteb and robrob like this.

18. ### robrobPoster ExtraordinaireAd Free Member

Dec 29, 2012
United States
deleted

Last edited: Jun 9, 2018
LudwigvonBirk likes this.

19. ### petebFriend of Leo's

Apr 25, 2003

Good idea!

I thought I had taken the wave theory approach as far as I could, but I wanted to map out the individual current bursts as they traveled thru the cathodyne PI. I felt I was on the cusp but it proved to be an elusive goal.

20. ### petebFriend of Leo's

Apr 25, 2003
Each 360 degree full cycle is going to have one current burst, as shown below, but there are intersecting bursts as the rightward traveling bursts meet the leftward traveling bursts.

The peak signal voltages occur on the plate and the cathode when a rightward current burst meets a leftward current burst, and this happens alternatingly on the cathode and the plate.

What does it look like?

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