Ideas to tinker

[Tinkerer]

Traditional PI compare TINKERER_TEM

I was thinking to act like a PI Tx current needs to be constant(not changing). Tx current your reply#4 looks like a saw tooth. Is my thinking wrong?

attached is a simulation, comparing Tinkerer_TEM with traditional PI

[Jose]

I am trying to understand the TEM method.
The second TX transmission pulse starts right at the end of the high voltage pulse, so it does not oscillate.
Unlike the traditional system, (and by way of comparison), the TX pulse is usually 10% of the duty cycle. In the TEM method, the transmission pulse is 90% of the duty cycle.
It is right?

[Tinkerer]

Right.

I put the 2 simulations together to make it easier to compare.
Look at the target response and compare the power consumption. for the target response click on the inductors of the targets. This shows the eddy currents in the target, related to what the RX coil will see.

I made the Flyback and the peak TX current roughly the same level. Try changing each of the parameters at the time.

[Jose]

Thanks Tinkerer, I'm done downloading LTspice. I'm watching the simulations, trying to learn

[Jose]

It is clearly seen in the simulations that the response to the objectives is greater in the TEM method.
I wonder how samples are taken at the receiver, with a TX pulse that takes up the longest time in the transmission cycle.
I assume samples are taken during the TX pulse, perhaps similarly to the Tinkerer V1.

[Tinkerer]

It is clearly seen in the simulations that the response to the objectives is greater in the TEM method.
I wonder how samples are taken at the receiver, with a TX pulse that takes up the longest time in the transmission cycle.
I assume samples are taken during the TX pulse, perhaps similarly to the Tinkerer V1.

Probably the best way is if you post pictures of the simulation and then we look at what is happening step by step.

The circuit looks extremely simple, but it hides many secrets. The time has come to unveil the secrets.

[Jose]

The first image shows the response of both methods to target 50 us.
In the second image, the target response 50 us and current in the coil in the TEM method.
It was also observed that at the moment the target signal is reaching zero, the current in the coil is increasing.

[Tinkerer]

The first image shows the response of both methods to target 50 us.
In the second image, the target response 50 us and current in the coil in the TEM method.
It was also observed that at the moment the target signal is reaching zero, the current in the coil is increasing.[ATTACH]50935[/ATTACH][ATTACH]50936[/ATTACH]

Excellent.
You can see that the traditional PI decay curve goes to about 0 and stays there until the next TX pulse.
On the TINKERER-TEM, the decay goes to about 0, but does not stay, it crosses over. So your 0 is the crossover point.
For the TINKERER-TEM you need a separate RX coil. You can use an IB or Induction Balance setup like a DD coil, or a concentric RX coil. There are several variations.

[eclipse]

Excellent.

On the TINKERER-TEM, the decay goes to about 0, but does not stay, it crosses over. So your 0 is the crossover point.

The crossover point can be manipulated. If the TX cycle is too long the coil starts ringing soon after reaching 0.
But if you increase the frequency the ringing time overlaps with the next TX cycle.

[green]

Normal PI looks at R signal. Ground from my back yard and ground from California cancel with the same sample settings. They don't if I look at the X signal(when Tx current is changing). How does the TEM cancel ground? Is it looking at the X signal or am I missing something?

[Jose]

Thanks Tinkerer, it looks clearer now and the use of a balanced coil is justified.
As Eclipse says, the TX width must keep a certain relationship with the frequency, so that it does not oscillate, I think of a relatively higher frequency than traditional PIs.
I would like to see how the EFE field is controlled, or the GB, but I already asked many questions. Thanks again.

[Tinkerer]

Normal PI looks at R signal. Ground from my back yard and ground from California cancel with the same sample settings. They don't if I look at the X signal(when Tx current is changing). How does the TEM cancel ground? Is it looking at the X signal or am I missing something?

You are right.
In this sense it is like a VLF, TX current is always ON and changing. VLF demodulation looks at the 0 crossing.

[green]

Added Rx coil to simulation. Looks like it would be worth trying with real circuit.

[green]

Changed 24in_DD normal PI to what I think is TEM? Looks good.

[Tinkerer]

Changed 24in_DD normal PI to what I think is TEM? Looks good.

Interesting experiment.

This is not TEM. TEM recycles the Flyback power. This makes it more power efficient than traditional PI.
The side effect is that it becomes more VLF like. I have run it with up to 15 Amps peak current, (real circuit, real 6ft diameter coil, #10AWG wire) at high repetition rate, while consuming a fraction of what a traditional PI would consume.