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Author Topic: Transformer Induction  (Read 41541 times)
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Re: Transformer Induction « Reply #225 on: 2026-07-01, 16:59:27 »

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Further to the previous post the E field in the core window is not uniform.  It is maximum closest to the inside surface of the core and minimum at the center, but both pointing parallel to the core axis.   This is probably why we get induction within that interior closed circuit.  Maximum induction will occur wth the wire short touching the inner surface and the capacitor along the center.  If PM used a rectangular shorted wire circuit instead of his shorted capacitor he will lose the resonance but should still see a square wave current flow within that closed circuit.  It would then be interesting to observe whether the input sees that effect when the rectangular circuit is moved into the core or is switched from open to closed (but the switch has to be positioned there and controlled remotely).  Then place a load resistor as described previously and measure power into the load and power into the driving circuit.  Is it OU?  The voltage driving the load is the difference between the two induced voltages along the axis-parallel sides of the rectangular circuit.  We can''t measure this difference using two probes and a differential measurement because both probes will see the same flux change.  If the differential could be taken within a single probe (are there such probes?) then maybe we could.  I will produce a view showing the E field vector lengths using the FEMM axisymmetric simulation but deriving them for the H field within a current loop where the math is the same as the E field within a flux loop.

Smudge
   
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Re: Transformer Induction « Reply #226 on: 2026-07-01, 17:27:58 »
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Quote from: Smudge on 2026-07-01, 10:08:14
The significance of these measurements is the build up and decay of some kind of resonance shown in post #192 and continuous in post #206.  What is this resonance?  IMO it is due to the self inductance of the 8uF capacitor which appears to be about 0.114uH.  it demonstrates that applying an electric field of a certain type (E=-dA/dt) across the shorted capacitor gets inside that closed circuit, and we should be concentrating on how that occurs and can it be put to good use.  PM talks of charge separation and that is what the electric field does in the short passing through the core center.  It must also do something to the series LC of the capacitor and it is obvious from these results that for rapidly changing E field the short and the LC combination do not exhibit the same charge separation.  With the square wave applied E field PM gets this significant effect that AFAIK has not been seen before.  I think PM is wrong to ascribe it to an H field, in my opinion it is a feature of the particular type of E field here, and would not occur in an E field between two electrodes.  The pumped currents PM is measuring are quite significant, so I think he should put a small resistor in series with his short on the capacitor and determine the output power going into that R determined from the current measured by the current probe.  It should be possible to orientate R so that it is at right angles to the E field.  Will that give us OU?  PM has all the expertise and equipment to find out, and I get the feeling that he has done something like this before.  What is new is the realization that a magnetic vector potential derived E field can get inside a closed circuit within that E field, a circuit that does not enclose magnetic flux.

Smudge

Smudge,

You have no idea how thankful I am in regards to your response!  I hope to respond a little bit later but right now I'm experiencing a third round of C-Diff!  I think we have a solution now using pulsed antibiotics as I'm already feeling better.

In the meantime, you might wish to ponder the results when the LC network is rotated 90 degrees.

Regards,
Pm
   
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Re: Transformer Induction « Reply #227 on: 2026-07-01, 19:08:48 »

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Quote from: Smudge on 2026-07-01, 16:59:27
It is maximum closest to the inside surface of the core and minimum at the center, but both pointing parallel to the core axis.   This is probably why we get induction within that interior closed circuit. 
Like this, but without the gap:
   
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Re: Transformer Induction « Reply #228 on: 2026-07-01, 19:51:41 »

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Here is the FEMM result where FEMM current into the page models rate of change of flux so that the H field around the conductor models electric field E.  Yes there is a difference for a wire along the center where I get 0.3744V compared to one near the core which is 0.4897V.  But the tilted E vectors along the top and the bottom also induce voltage that makes the closed circuit voltage nill.  But PM gets a current in his closed circuit so maybe the fact that he has series L and C over part of the circuit creates the induction he witnesses.  Forget making a rectangular wire circuit with a resistor and concentrate on adding a resistor onto his LC circuit to look for power there.

Smudge
   
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Re: Transformer Induction « Reply #229 on: 2026-07-01, 19:55:15 »

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Quote from: Verpies on 2026-07-01, 19:08:48
Like this, but without the gap:
No, it is the E field external to the core from E=-dA/dt, not a magnetic field.
   
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Re: Transformer Induction « Reply #230 on: 2026-07-01, 20:15:53 »

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Quote from: Smudge on 2026-07-01, 19:55:15
No, it is the E field external to the core from E=-dA/dt, not a magnetic field.
Do you think that the magnetic field does not leak into the eye/window of the core when the primary/driving winding is narrow (does not span the entire circumference of the the core) ?
   
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Re: Transformer Induction « Reply #231 on: 2026-07-02, 07:45:24 »

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Quote from: Verpies on 2026-07-01, 20:15:53
Do you think that the magnetic field does not leak into the eye/window of the core when the primary/driving winding is narrow (does not span the entire circumference of the the core) ?
I know it does but the leakage quantity reduces the greater the pemeability of the core.  For high perm cores I tend to think its value is negligible.

I can add more to this theme as we know the current probe clamps a magnetic core around the wire thus adding inductance.  This may be the inductance responsible for the resonance PM found, and not the self inductance of the capacitor.  If this is the case we have the cap in one side of the rectangular closed circuit and the inductance in a different side.  When this is modelled against the induced voltages in each side it opens the door to understanding where the induced current comes from.  The text books all tell us that the induced voltage in a closed circuit that does not enclose flux is zero, and simulations do show that.  We tend to think that the induced current must therefore be zero.  But that is only true if each part of the circuit has impedance that relates current directly to voltage.  If one part relates current to the time integral of the induced voltage and another part relates current to the time differential of voltage then clearly it is possible to have a voltage waveform that does induce current in the closed circuit.  PM has shown that.  The interesting point now is how does the presence of that current feed back to effect the drive into the ring core?  I am sure this will eventually be discovered.  More on this later as I have to dash off for routine living.

Smudge
   
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Re: Transformer Induction « Reply #232 on: 2026-07-02, 14:52:11 »

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Quote from: Verpies on 2026-07-01, 20:15:53
Do you think that the magnetic field does not leak into the eye/window of the core when the primary/driving winding is narrow (does not span the entire circumference of the the core) ?
Looking at the photo in reply#192 PM does have a narrow primary driving coil and the closed rectangular circuit in the core window is orientated to have the leakage flux flow through it so you could be correct here.  Easy enough to rotate the closed circuit 90 degrees to see if the effect goes away.  Maybe PM has done this and chosen the orientation that maximises the effect.  Still thinking about what I said in my previous post and is this really possible.

Smudge
   
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Re: Transformer Induction « Reply #233 on: 2026-07-02, 15:25:55 »
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Smudge and Verpies,

After reading your comments, I think it might be best if I were to ask if there is any specific type of test you would like me to perform with/or on this setup that may help answer any questions.

Edit:  One thing I might add that I haven't stated before, is the part of the test where the LC assembly is rotated 90 degrees in the core with the result of zero resonant current.  For example, if the LC assembly is rotated yet another 90 degrees, resonant current is again seen with positive current flowing from the cap when a positive voltage is applied to the primary.  IMO, the H_Field is inducing the foils in the cap.  The current  level is ~.5A peak and thus lower than the wire induction but this is due to the fact that C is two paralleled 4ufd caps place side by side.

The cancellation of current when the LC network is at 90 degree rotation is due to the induction via the H-Field into both the L and the C when properly positioned in the core.  This creates equal currents which cancel each other.

 

Regards,
Pm
   
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Re: Transformer Induction « Reply #234 on: 2026-07-02, 17:19:29 »

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Quote from: partzman on 2026-07-02, 15:25:55
After reading your comments, I think it might be best if I were to ask if there is any specific type of test you would like me to perform with/or on this setup that may help answer any questions.
Yes, axially rotate the following planar metal loop in the eye/window of the core when the narrow primary winding is being pulsed and measure the amplitude of the pulses across the rotating 10K resistor using your scope's voltage probe at various angles.


The loop does not have to be in motion when you make your amplitude measurements at various angles.
   
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Re: Transformer Induction « Reply #235 on: 2026-07-02, 19:37:05 »

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I have used FEMM to look into leakage flux.  This is for a ring core that is infinitely long (an infinite cylinder) but it demonstrates something useful.  The first image shows flux in the core from a small winding at the left.  The H field normal to the red line is shown and the B field there integrates along the like to 8.26x10-9 webers.  In the second image the core has been replaced with air so the H field is what emanates from just the coil.  The B field there integrates to 2.83x10-9 webers.  Thus the presence of the core has increased the flux from the coil by a factor of nearly 3.  There is no doubt that the coil alone would pump some energy into the closed LC circuit, and the core adds to that pumping.  Is that knowledge helpful?

Smudge
   
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Re: Transformer Induction « Reply #236 on: 2026-07-02, 23:19:33 »
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Quote from: Verpies on 2026-07-02, 17:19:29
Yes, axially rotate the following planar metal loop in the eye/window of the core when the narrow primary winding is being pulsed and measure the amplitude of the pulses across the rotating 10K resistor using your scope's voltage probe at various angles.


The loop does not have to be in motion when you make your amplitude measurements at various angles.

OK, I hope this is what you are looking for!  The loop is built to just fit into the core window and has a 10K carbon film resistor centered in the top section.  I attached a ground wire to the center of the bottom section which is attached to ground.  CH2(blu) is then attached to the side of the resistor that is closest to the primary winding and CH3(pnk) is connected to the other side.  These are the probe positions for the first pix PR1A.

The assembly is then rotated 90 degrees in PR1B, 180 degrees in PD1C, and 270 degrees in PR1D.  It appears there is little to no change in the voltage differences.

I then did the exact same procedural measurements without the ground connected and the voltage differentials were basically the same but the voltage magnitudes changed with each different position as was expected.  I have those scope shots if you wish to see them.

I then took it upon myself to do a similar protocol using a shorted loop by replacing the resistor with a piece of wire.  Pix PR2A shows the results with the loop aligned with the primary winding and the current probe showing the current leaving the  loop lead closest to the primary winding.

The next three pix show the current in the loop after 90,180, and 270 degree rotation respectively.  IMO, this indicates H-Field induction into the loop.

Regards,
Pm
   
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Re: Transformer Induction « Reply #237 on: 2026-07-03, 01:18:24 »

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My 'guess' would be that the magnetic field traversing across the core window would be weakest in the center of the window, as there is more say stretching of the field there. 

Could just measure a wire that was just in different areas of the window. with a 10k voltage most likely be the same anywhere, if efield is what determines the voltage.  Maybe make say 20, 30 turns coil that was large in dia to be able to shift the coil portion that is in the window, but using a much lower resistance rather than 10k, to see if current is limited to placement in the window.

mags
   
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Re: Transformer Induction « Reply #238 on: 2026-07-03, 02:41:24 »

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Quote from: partzman on 2026-07-02, 23:19:33
I attached a ground wire to the center of the bottom section which is attached to ground. 
That is not exactly what I asked for.

I asked:
Quote from: Verpies on 2026-07-02, 17:19:29
...measure the amplitude of the pulses across the rotating 10K resistor using your scope's voltage probe at various angles.
Routing the probe's ground wire/clip randomly can lead to completely different outcomes in these types of experiments.

Quote from: partzman on 2026-07-02, 23:19:33
The assembly is then rotated 90 degrees in PR1B, 180 degrees in PD1C, and 270 degrees in PR1D.  It appears there is little to no change in the voltage differences.
These unfortunate choices of measurement angles do not allow to me make a cosine fit because cos(90°)=0 and cos(270°)=0 and cos(180°)=-1.
Making these measurements in 30° degree increments would have been more informative ...and you don't need to post scope shots for each of them (I know how much work that is) - a copy of numeric amplitude readouts is sufficient.

Quote from: partzman on 2026-07-02, 23:19:33
I then did the exact same procedural measurements without the ground connected and the voltage differentials were basically the same but the voltage magnitudes changed with each different position as was expected. 
So what were the ground wires/clips doing when they were not connected ?  What was scope's chassis ground connected to ?

Quote from: partzman on 2026-07-02, 23:19:33
I then took it upon myself to do a similar protocol using a shorted loop by replacing the resistor with a piece of wire. 
That's a different experiment yet because it is measuring current (not voltage).  Current is more informative wrt coils than the induced voltage but it is generally harder to measure.
However putting a contactless current sensor in place of the rotating resistor (now wire) is closer to the measurement point I had initially intended.
   
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Re: Transformer Induction « Reply #239 on: 2026-07-03, 08:01:33 »

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I have superimposed the two FEMM results showing both the flux in the core and the much smaller magnitude leakage flux.  I also show a closed electric circuit in the donut hole depicted as a copper ring to show that the leakage flux lines pass through that ring.  PM talks of H field induction and those leakage field lines depict both H field and B field.  So the closed loop gets some voltage induction from the rate of change of flux that passes through it just like in any transformer.  Flux is B*area and in this closed loop in air it is u0*H*area and d(u0*H*area}/dt is H field induction.  Does PM have a different view on what H field induction is?

PM has measured significant current (amps) in his LC loop and I don't know whether this leakage flux pumping is sufficient to do that.  It may be that the leakage flux starts the resonant build up process process and some other effect amplifies this, so IMO this still needs consideration to nail it.

Smudge
   
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Re: Transformer Induction « Reply #240 on: 2026-07-03, 21:02:04 »
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Quote from: Verpies on 2026-07-02, 17:19:29
Yes, axially rotate the following planar metal loop in the eye/window of the core when the narrow primary winding is being pulsed and measure the amplitude of the pulses across the rotating 10K resistor using your scope's voltage probe at various angles.


The loop does not have to be in motion when you make your amplitude measurements at various angles.

Let's try this a different manner so we're on the same page!  Specifically state how you wish the voltage probes and grounds to be connected or not connected to the loop plus any other details I may be missing.  State what it is you expect to see or what you are looking for.  Each sample angle will be taken in 30 degree increments for the reason you've described earlier unless specified otherwise.

On the floating measurements I made, there were no direct ground lead connections from each probe but rather the common scope ground was connected at the CH1(yel) probe which was connected to the power supply ground.  IMO, this test showed null results IOW, no appreciable voltage differential across the 1K resistor except for the quiescent channel offset voltage.

Regards,
Pm
   
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Re: Transformer Induction « Reply #241 on: 2026-07-04, 15:02:20 »

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The first image below shows the E field inside a ring core across its centre.  This is due to a rising flux in the core from a rising current in a coil wound on the ring core (not shown).  For the purposes of this lecture, we will assume the E field is uniform.

The next image shows a lump of dielectric material in the E field.  The magnetic vector potential derived (MVPD) field penetrates the dielectric to displace the orbital electrons so the dielectric gets charged just as it would if we had voltage applied to electrodes on its upper and lower surfaces.  Alongside the dielectric we show a copper wire.  The MVPD E field penetrates the copper to drive the mobile conduction electrons to one end.  Thus, the wire is also electrically “charged”, the potential across the dielectric being the same as the potential across the wire.

The third image shows electrodes on the dielectric connected to the wire, forming a shorted parallel plate capacitor.  The MVPD E field has the seemingly impossible property of charging the shorted capacitor.  The dielectric stores both charge and energy.

The final image shows the E field suddenly removed by holding the driving coil current (hence also the flux) constant.  The energy in the capacitor discharges through the shorting wire.  If we measure that current by clipping a current probe onto the top wire we add inductance, so the discharge will be sinusoidal.  This is exactly what PM has done.  To fully analyse his scheme, we would need to know the inner construction of his capacitor but suffice to say that this little lecture tells us that the E field inside the donut ring core can get a shorted capacitor to both charge and discharge if we drive the input coil in an appropriate manner.

Here endeth the lesson.

Smudge
   
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Re: Transformer Induction « Reply #242 on: 2026-07-04, 20:38:14 »
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Smudge,

The caps used to form the 8uf total capacitance in my resonance test are wound foil types.  With the foils placed vertically in the core window, both are charged separated equally with no energy being generated in the cap.  This makes your lesson above different as you appear to have horizontal plates in your capacitor which allows for energy to be developed during charge separation.

Therefore, in my experiment as shown in post #192, when the very first positive pulse is applied, the H-Field from the primary induces the amount of current shown in the bare wire connected to the cap at resonance.  As seen with each successive pulse to the primary, the resonant current builds to a continuous peak level as determined by the overall circuit losses.  The cap receives a small amount of energy during the positive half cycles to the primary with this energy being discharged during the negative half cycles.  The average is therefore zero when running in resonance continuously and stabilized.

I do adhere to the notion that the H-Field can also be called leakage flux but I prefer the former.

Now, I will make a statement that will get me classified as a heretic I'm sure!  When Faraday did his original induction tests using an iron toroid with a primary and secondary, he created his induction formula from his readings taken with his equipment at the time.  His resultant induction law we know is accurate and not in question.  However, he had no means at the time to measure the overall voltage differential around the perimeter of the core.  IMO therefore, one can apply his induction law to a solenoid coil and the E-Field will be linearly distributed around the perimeter of the coil.  However, when we have a folded or closed flux loop as in a toroid core, "U" core, or "E" core, the E-Field is not distributed linearly so we have to be careful if we apply his induction law to such.

My experimentation seems to show that the E-Field (in a rectangular cross sectioned toroid) is nearly all contained between the top and bottom surfaces of the core.  I know this is a real point of contention so I am attempting to devise experiments to prove or dispel this apparent anomaly.  I already have some to show but I have another test to try before disclosing anything at this time.

Regards,
Pm 
   
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Re: Transformer Induction « Reply #243 on: 2026-07-04, 21:49:13 »

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Quote from: partzman on 2026-07-03, 21:02:04
Let's try this a different manner so we're on the same page!  Specifically state how you wish the voltage probes and grounds to be connected or not connected to the loop plus any other details I may be missing. 
Across the resistor.



Quote from: Verpies on 2026-07-02, 17:19:29
Yes, axially rotate the following planar metal loop in the eye/window of the core when the narrow primary winding is being pulsed and measure the amplitude of the pulses across the rotating 10K resistor using your scope's voltage probe at various angles.
   
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Re: Transformer Induction « Reply #244 on: 2026-07-04, 22:03:30 »

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Quote from: Smudge on 2026-07-04, 15:02:20
The next image shows a lump of dielectric material in the E field.  The magnetic vector potential derived (MVPD) field penetrates the dielectric to displace the orbital electrons so the dielectric gets charged ...

That's right but that dielectric will not stay polarized when the MVPD field is removed (not reversed) - it will relax in picoseconds.
...but it will stay charged indefinitely when free charges are added/removed from its surface ...even when the MVPD field is removed.  This is why charged styrofoam peanuts "hold" the charge.

Quote from: Smudge on 2026-07-04, 15:02:20
so the dielectric gets charged just as it would if we had voltage applied to electrodes on its upper and lower surfaces.
There is a great difference in behavior between bound charges and free surface charges on a dielectric.
A charged capacitor with a dielectric between metallic electrodes has electrons permanently added/removed from these metallic electrodes.  Additionally, the same agency that added/removed them also performed more work polarizing the dielectric dipoles.  Such capacitor "holds" the electrodes' charge imbalance indefinitely because there is no path for it to equilibrize.

The MVPD field will move free charges through space and will deposit them on material objects, but they have to be free to move.  Inside the dielectric the charges cannot move linearly but its electric dipoles can rotate and become polarized preferentially in one direction (this takes work) as long as the force that rotated these dipoles persists.

  The effect of an electric field created by
  a moving magnetic field, on free charged particles.

Our immediate environment does not have many free moving charges but their number can be increased with e.g.: corona discharge and alpha/beta emitters.
https://youtu.be/ZBHIp967TD8?t=65
   
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Re: Transformer Induction « Reply #245 on: 2026-07-05, 09:33:17 »

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You are right to challenge my lecture, I had not thought things through enough.
Quote from: Verpies on 2026-07-04, 22:03:30
That's right but that dielectric will not stay polarized when the MVPD field is removed (not reversed) - it will relax in picoseconds.
Is there proof for your picoseconds claim? I ask because you say "its electric dipoles can rotate and become polarized preferentially in one direction (this takes work)" and I agree it takes work, IOW it stores energy.  When the MPVD field is removed what happens to that stored energy?  Where does it go in your picosecond time frame?
Quote
...but it will stay charged indefinitely when free charges are added/removed from its surface ...even when the MVPD field is removed.
So in the case where we have electrodes on the surfaces that are connected to the short we have to consider what the (temporarily constant along the top of the square wave) MVPD E field does where the free charges in the shorting wire move into a stable distribution and the bound charges in the dielectric displace into a stable condition.  I contend that the difference between these does allow the dielectric to become polarised and store energy.  I agree the electrodes will not have the necessary free charges added/removed for this polarisation at the instant the MVPD E field is removed. But the stored energy can't just disappear.  The E field driving the non-uniform distribution of free electrons in the shorting wire does disappear so IMO the energy stored in the dielectric now takes over control of those free electrons in both the electrodes and the short to discharge that energy via a current pulse.  The polarised dielectric rapidly pulls the free electrons in the conductors to the added/removed surface conditions and this movement doesn't involve a significant current flow or capacitance effect with the inductance there (difficullt to come to terms with but the capacitance along conductors is negligible).  Thereafter we have the well known discharge of a conventionally charged capacitor. That may be picoseconds if there is no inductance to consider, but PM adds inductance with his current probe.  That "taking control" drives the current in the opposite direction to the one I showed in my post so I need to edit that.

Smudge
   
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Re: Transformer Induction « Reply #246 on: 2026-07-05, 11:37:33 »

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Quote from: partzman on 2026-07-04, 20:38:14
Smudge,

The caps used to form the 8uf total capacitance in my resonance test are wound foil types.  With the foils placed vertically in the core window, both are charged separated equally with no energy being generated in the cap.  This makes your lesson above different as you appear to have horizontal plates in your capacitor which allows for energy to be developed during charge separation.
I realize that.  I was trying to develop an understanding for your large resonant current pulses from something unexpected.  The wound foil plates will have the induced E field along the foil width so putting electron diplacement from top to bottom (your tubular capacitor being vertical).  This is polarizing the dielectric along an axis that is not the usual polarisation.

Quote
Therefore, in my experiment as shown in post #192, when the very first positive pulse is applied, the H-Field from the primary induces the amount of current shown in the bare wire connected to the cap at resonance.  As seen with each successive pulse to the primary, the resonant current builds to a continuous peak level as determined by the overall circuit losses.  The cap receives a small amount of energy during the positive half cycles to the primary with this energy being discharged during the negative half cycles.  The average is therefore zero when running in resonance continuously and stabilized.

I do adhere to the notion that the H-Field can also be called leakage flux but I prefer the former.
Then you must accept that the leakage field passes through your shorted capacitor closed loop, or Verpies wire loop, to induce in a conventional way not associated with variation in induced E fields, i.e by V=dPhi/dt where Phi is total flux through the loop.

Quote
Now, I will make a statement that will get me classified as a heretic I'm sure!  When Faraday did his original induction tests using an iron toroid with a primary and secondary, he created his induction formula from his readings taken with his equipment at the time.  His resultant induction law we know is accurate and not in question.  However, he had no means at the time to measure the overall voltage differential around the perimeter of the core.  IMO therefore, one can apply his induction law to a solenoid coil and the E-Field will be linearly distributed around the perimeter of the coil.  However, when we have a folded or closed flux loop as in a toroid core, "U" core, or "E" core, the E-Field is not distributed linearly so we have to be careful if we apply his induction law to such.
His induction law deals with total flux passing through the loop, independent of whether the magnetic field there is uniform or non-uniform.  You have jumped to the E field where its closed integral is Faraday's induced voltage.

Quote
My experimentation seems to show that the E-Field (in a rectangular cross sectioned toroid) is nearly all contained between the top and bottom surfaces of the core.  I know this is a real point of contention so I am attempting to devise experiments to prove or dispel this apparent anomaly.  I already have some to show but I have another test to try before disclosing anything at this time.
But simulations show this not to be the case, the E field there supplying only about 0.4 of the volts per turn.  The problem comes in trying to measure the voltage on things in that part of the core where the routing of ground connections become important. It is very easy to be misled.

Smudge
   
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Re: Transformer Induction « Reply #247 on: 2026-07-05, 15:29:13 »
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Quote from: Verpies on 2026-07-04, 21:49:13
Across the resistor.


OK.  Using CH3(pnk) with the ground connected across the 10K resistor as you show, the loop is then rotated in 45 degree increments as 30 degrees was difficult to do accurately.  The CH3 offset was measured at -300uv with the vertical deflection set to 20mv/division.  The loop was then rotated cw as viewed from the top and the device was run continuously.

This is the data with the first column being the degrees, the second being the average voltage measured across the 10K during the positive pulse application to the primary, and the third being the average voltage measured during the negative pulse application to the primary.

0, -5.20mv, +4.42mv
45, -3.70mv, +3.32mv
90, +57uv, +560uv
135, +2.87mv, -1.62mv
180, +5.20mv, -4.27mv
225, +2.09mv, -960uv
270, +380uv, +160uv
315, -991uv, +2.37mv

These measurements were taken with hand positioning of the loop and are therefore subject to variations as if compared to a more accurate mechanical positioning method.  Hopefully they will be helpful as is!

Regards,
Pm

 
   
img  partzman
Re: Transformer Induction « Reply #248 on: 2026-07-05, 16:46:01 »
Group: Experimentalist
Hero Member
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Posts: 2307
Smudge,

I lost my detailed response to your last post so here is my overall response showing one proof IMO of my position.

Here is a test where the scope probe is charge separated in the toroid core window and appears to indicate that the ~V/T to the primary exists only in the core window.

First pix is the actual test set, second pix is the circuit schematic, and the third is the scope results.

What is seen here is a wire that covers the outsides of the toroid with a scope probe CH3(pnk) placed in the core window and attached to one end.  The other end is connected to circuit ground with the scope probe ground wire also connected to this same circuit ground.  So, we have zero volts at the probe tip due to the grounded outer wire on the toroid and zero volts at the coax shield of the probe cable. 

We now see that there is a voltage across the probe as indicated on the scope pix that is the opposite polarity from the applied voltage on the primary.  This is due to the fact that the internal 10M resistor and remaining wire within the probe tip are charge separated by an amount very close to the V/T of the primary.  Notice this occurs within the upper and lower surfaces if you will of the toroid's core window.  Little to no voltage appears across the open circuited outer wire on the toroid.

Regards,
Pm
   
img  Verpies
Re: Transformer Induction « Reply #249 on: 2026-07-05, 19:21:24 »

Group: Administrator
Hero Member
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Posts: 4856
Quote from: partzman on 2026-07-05, 15:49:04
What is with the timeout of a user???  After spending some time preparing a response to a user and then trying to post, I was forced to again sign-in and after doing so, I lost all my responding post!  Very $@#*^&%* irritating >:(
Indefinite until the server's resources are exhausted if you check the "Always stay logged in:" checkbox ...and they are getting exhausted with thousands of Guests hammering.
   
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