HIGH QUALITY TPU DVD Video Released from Jack Durban

[aleks]

Terfenol-D is comparably brittle so it can be cut with even a wood saw I think.

[Vortex1]

 Regarding common mode chokes:

I have seen this type of common mode choke years ago in at least one of the surplus stores I used to visit. They are pulled from equipment complete with leads and mounting bracket.

I can say with almost certainty that they are common mode chokes (two matched dielectrically isolated windings, 1500 VAC minimun per U/L , CSA for 240 VAC line operation) But in SM's application, I don't believe they were for filtering noise because no other parts of the device are shielded in any way and will radiate beyond belief.

The common mode chokes are potted for two reasons;  to fix the core to the plastic insulating assembly which is part of the white separator and "washer" seen between the core and the mounting plate and to secure the "flying" leadwires, which were part of the assembly. These devices were made for mounting rigidly to the side wall of a chassis when space on the pc board is at a premium. These are rather large devices, perhaps too large to reliably mount vertically to a pc board using adhesive as is common on smaller units. There might be a "PEM" insert or stud on the opposite face of the mounting bracket or the mounting screw taps directly into the center of the plastic insulator. What is being interpreted as mounting feet are male terminals for grounding by solder or "faston" type disconnects, but could temporarily hold the core to the pc board before final rigid mounting to the sidewall..

Better questions to ask are: why would someone nead a toroidal transformer that has tight coupling between 1kHz and 100 kHz, excellent turns matching and high dielectric withstand? Which of these features are incidental, which are of prime importance?

these are just a few possible reasons, I'm sure others can think of more:.

1. Signals between the windings are in phase and must maintain electrical insulation in the required passband.
2. Signals between the windings are inverted and must maintain electrical insulation in the required passband
3. One side of the core is pulsed, producing a mirror image inverted pulse on the other winding. These identical opposite phased pulses drive "some other parts of the device".
4. A "fringe field" is produced by "bucking the windings". Possibly this is rotated in some manner.
5. This is a cheap way of getting a pre-wound transformer for an oscillator that can be driven many ways (Colpitts, Hartley, Armstrong, blocking ,etc)
6. It is easily biased or saturated with a small weak magnet.

just an opinion offered, not necessarily fact........V

[Spider]

@Vortex1,

Very nice! This is the kind of hands on knowlegde that is needed.

I just finished reading Otto's post about his description of a tpu runaway situation.
Maybe the inverted pulse into the control coils is the only way to brake the rotating magnetic field to keep things in check.

Just a thought.

Greetings Rene

[aleks]

3. One side of the core is pulsed, producing a mirror image inverted pulse on the other winding. These identical opposite phased pulses drive "some other parts of the device".

I had an idea connected to "inverted" signal and the acoustic stimulation I'm was posting about. The quickest way to "counter" the present standing wave is to change polarity of acoustic stimulation (instead of simply stopping it). Just an idea.

[wattsup]

@poynt99

For the 6TPU or the OPTU, it is practically impossible to understand what you are seeing via a single photo grab. This has to be looked at in motion, back and forth a few frames to actually realize this is a protruding toroid structure inside the 6TPU inner wall. Of course there will always be a level of "assumptions". But let me say that if you went back to day one of the SM saga and counted how many assumptions were made until today, I think we are doing pretty good work here in cutting out the fat. Yes I may ave jumped the gun on the 4TPU but spider has explained it pretty well.

Assumptions are made. tests are done and assumptions are changed. I made an assumption that the core was a speaker magnets, wound two speaker magnets, did some tests and have concluded that they are not speaker magnets. A ferrite toroid with two coils will transfer power form one to the other very neatly. Doing the same thing with a speaker magnet with two coils produces absolutely nothing. Pulse one coil and see on the scope the other and there is nothing., The magnet just cancels any potential exchange between the coils. Also, trying to displace the magnet field with a one layer winding is impossible. You would require a thick coil winding to do this and this does not concord with the TPU toroids one layer wind. So, this cannot eb a speaker magnet even though the dimension are very close to that of the TPU toroids.

You know this is not easy stuff. Just to discover one little morsel of new information, it sometimes requires hour and hours of obs, close ups, etc., etc.

@all

One question to ask is why would the FTPU use a toroid with four wires going to different locations on the TPU, whereas the LTPU is using two toroids but each toroid coil pair is in parallel. I had very closely mapped those wires going into their respective tapped wire bundles and had included these in my original LTPU wiring diagram. After the wires are connected together, and go towards the back end of the tpu ring where they are again re-bundled with other wires that I am now convinced are going to the control coils, you can see that at the midway of the wire travel from the toroids to the back, there are only two wires really connecting each toroid to the back.

Vortex1 put up some good info and this is the type of interrogations we need to hone in on plausible toroid uses. I am sticking with the FTPU as the target because it is the most open design.

We also need someone with good EE skills to help design a few control circuits given some basic function parameters and limitations on components that I am now preparing. I am at that stage where is want to start putting these parts together. I just wound a new toroid using the bucking winds and a nice new ferrite core that has some great transfer action. I will try this in my FTPU control coil and collector build I posted previously.

I am also looking to buy a real professional DC pulser that you can simply adjust pulse type, on time, off time going up to 100,000 cps. I need this badly because my EE stinks so much and I am tired of struggling any time I want to pulse something. lol