Talk:Ivor Catt/Archive 1

message: Should we move all those discussions about capacitors, TL, the meaning of life etc. here now?--Light current 14:00, 15 October 2005 (UTC)
thread_title:  Location of similar discussion material 

message: No idea why he thinks displacement current is not "needed" if you treat the TL as a transmission line.  The telegrapher's equations, and the behavior of a TEM wave, require the displacement current term of Ampere's law for their derivation.  A transmission line certainly has a changing electric field which is all that displacement current is, a quantity proportional to the derivative of the electric field.  It seems to me that he has just used transmission line equations to come up with a description of capacitor behavior that doesn't mention charge or displacement current, and then said viola, charge and displacement current don't exist.
:Well thats what he reckons! Have another look at his pages to see if you can find his reasoning.--Light current 20:53, 15 October 2005 (UTC)
thread_title:  Displacement current 

message: There, satisfied?  I've said it many times, but apparently you didn't hear me.  dD/dt is not a current.  Happy now?  Nobody says it is a current.  But the dD/dt term is needed.  Displacement current is simply what the dD/dt term is called.  I don't know why, but it is.  In a vacuum, this is proportional to dE/dt as you quoted.  It is needed to get waves.  Can we agree on that?
:Did you say displacement current is not a current? OKAY!
Sorry, but I couldn't resist a little theatrics.  Pfalstad 01:44, 18 October 2005 (UTC)
replies: text: No its not needed to get waves (see above).--Light current 01:07, 18 October 2005 (UTC)

text: dE/dt along with -dB/dt actually describes the wave when transformed into the cartesian coordinates and leads quite simply to the traveling wave equations with which we are all familiar. So rather than being needed to get the waves - it is the wave (well the electric part anyway)--Light current 01:18, 18 October 2005 (UTC)

text: I dont know at the moment. But I'll think about it  Time for bed! goodnight--Light current 01:32, 18 October 2005 (UTC)

text: Small localised currents flow in the surface of (see skin effect) conductors but do not involve any major movement of charge carriers along the line. Is this answer OK?--Light current 02:32, 18 October 2005 (UTC)

text: Low frequencies are not the problem- any theory (almost) works at LF--Light current 04:30, 18 October 2005 (UTC)

text: I dont understand the question here. Do we have to define resistance in terms of EM waves? In an imperfect conductor some current will be induced below the surface.--Light current 04:30, 18 October 2005 (UTC)

text: EM waves have trouble in semiconductors - thats why they are slow (unless you count the plasma devices where em waves can travel). Otherwise its the very small distances involved in semis that give the speed. What about tubes? Are photoelectric devices fast?--Light current 04:30, 18 October 2005 (UTC)

text: What we get is a more complete understanding of how things work and how to design fast circuits as Catt has demonstrated. Its certainly not a complete mess. Its far simpler and more coherent than conventional theory and answers questions conventional theory cant. However, no ones asking you to accept it. Were just writing an article-- remember? at least I am!--Light current 04:30, 18 October 2005 (UTC)
thread_title:  DISPLACEMENT CURRENT IS NOT A CURRENT 

message: Now that I have seen the excellent simulation for EM fields, Im thinking I may be able to simulate what I had thought I would have to do in hardware.
The experimental idea is this:
If the waves are counter-propaging adding to DC, there is no way of detecting them until they are disturbed. This is easily done in one way by connecting a load at either one end or the other and observing the pulse output. However, I think you AC and others could object to the validity of that expt becuase a TL charged with plain dc would exhibit the same effect.
Outline
My alternative expt involves the use of a parallel plate capacitor made from thin square plates (say 1m sq). The energy in the form of a travelling wave is introduced from a step generator along one edge of the square by means of an exponential matching transformer to go from the generator Z to the Zo of the plates. Interposed between the matching section and the plate edge are a number of electronic switches, all capable of being operated electronically at the same time. When the energy has been deposited in the TL/capacitor (or whatever you want to call it), the switches are opened. Also, at the adjacent edge (not the opposite edge) of the square, we have a similar arrangement of switches and a matching section terminated in a load and a detector of waves (O'Scope).
The output waves (if any) therefore must travel at right angles to the direction of the input wave.
Procedure
1.Charge the device with energy and isolate the source.
2.Connect the detector by operating the switch array and observe the delay and shape of the detected signal on the scope
Interpretation of results
A.If the detected signal is observed to have zero delay from switch closure and risetime only dependent on the switch performance, then it is likely that no counter propagating waves were present, becuase the system acts as tho' it was charged with plain dc.
B If, however, there is appreciable delay between switch closure and arrival of the signal at the detector (allowing for the delay in the matching section), this would tend to indicate that the counter-propagating waves did exist and they take a finite time to alter their direction of propagation. If no energy whatsoever is detected (unlikely) that would tend to prove the theory without doubt!!.
I would be very interested in Paul's (or any physicist's) comments as to the validity  of such an experiment/ simulation.
--Light current 18:44, 18 October 2005 (UTC)
replies: text: If the counter-propagating waves did exist, there would be one going in each direction, right?  So the one going in the right direction would be observed immediately.  How much delay would you expect to see, and why?  Pfalstad 02:41, 21 October 2005 (UTC)

text: Ok, so you have two parallel plates, with a generator attached to both plates at one edge, and a detector and load attached to both plates at the adjoining (not opposite) edge?  Ok, that is an interesting setup.  In standard physics, there will be no delay.  Even if you treat the incoming voltage as a wave, it will still diffract downwards instantly when the switches are closed.  Pfalstad 16:11, 21 October 2005 (UTC)
thread_title:  Proposed experiment or simulation to prove/disprove counter-propagating wave theory 

message: :If the counter-propagating waves did exist, there would be one going in each direction, right?  So the one going in the right direction would be observed immediately.  How much delay would you expect to see, and why?  Pfalstad 02:41, 21 October 2005 (UTC)
replies: text: Ok, so you have two parallel plates, with a generator attached to both plates at one edge, and a detector and load attached to both plates at the adjoining (not opposite) edge?  Ok, that is an interesting setup.  In standard physics, there will be no delay.  Even if you treat the incoming voltage as a wave, it will still diffract downwards instantly when the switches are closed.  Pfalstad 16:11, 21 October 2005 (UTC)
thread_title:  Comments on experiment proposal