New PI technology proposals.

[Aziz]

- Very fast early sampling (2 µs) with MONO coil
- High target signal stimulation
- High immunity to noises
- Fully differential signal lines
- Ultra high coil voltage generation
...

See my proposal on the following site:

http://goldprospecting.invisionplus....showtopic=2227


Aziz

[Unregistered]

That site requires registration. Why don't you post a copy of your proposal on Geotech?

[Aziz]

I am sorry, but you need the context to understand the idea behind of this new proposal. The idea will give a chance to further improvements on PI technology!

This will be:
- increased signal-to-noise ratio
- higher target signal stimulation
- ultra early sampling (1 µs after switch-off) at maximum target response time
..

Improvements also for MONO coils available:
- 2.3 µs sampling after switch-off with amplifier gain of x100
..

You have to register in the forum to read my proposals and comments.

Aziz

[gwzd]

You have to register in the forum to read my proposals and comments.

Aziz

Why? You are going to tell us here anyway. You just can't resist, can you?
Regards,

[Aziz]

Hi gwzd,

Why? You are going to tell us here anyway. You just can't resist, can you?
Regards,

you need the chronology order of the information on the forum, I have posted there. Then you can see the birth of the idea and this gives the opportunity to understand it.

Regards,
Aziz

[gwzd]

Hi gwzd,



you need the chronology order of the information on the forum, I have posted there. Then you can see the birth of the idea and this gives the opportunity to understand it.

Regards,
Aziz

I usually skip to the end! History is not one of my favorite subjects ;-)
Regards,

[Aziz]

Hi gwzd,

the main reason for the idea is to damp the flyback voltage as fast as possible. As the damping resistor (Rd) is only a function of the coils inductivity and capacitance (+parasitic capacitances), we can not change the damping resistor for critical damping of the coil. It is fixed to the transmitter parts system.

The magnetic energy E = 0.5*L*I*I built on the transmit on phase must be converted to heat on the coils resistive elements (damping resistor, coils resistor, coil cables, ..).

This can be achived effectively by using a higher flyback voltages to allow more current flow through the damping resistor.
P = I*I*Rd = U*U/Rd.

Then the magnetic energy will be converted much faster to heat and will allow decaying the high voltage quicker. This makes the early sampling faster and has also the ability to cause higher target signal stimulation (higher dI(t)/dt). Doubling the flyback voltage has an effect of 4 times!!!

But there are more inherent effects that have big benefits!

I hope, I have called your interest a bit to dig in the history...

Aziz

[Carl-NC]

The flyback voltage is an artifact of pulsing the coil, and not something you can "use" to speed things up. Fundamentally, di/dt is controlled by the 'on' current, the inductance, and the damping resistor (which is, in turn, dependent on capacitance). Probably you are changing one of these, and getting a faster di/dt and a higher resulting flyback.

- Carl

[Aziz]

Hi Carl,

we have to recapitulate and rewrite some topics on the PI technology.

I have a totally different sight of this. This is the reason for, why nobody found the evident solution till now. I am sure, this will bring some new products and coils in the future. (And Mr. Tesla would be very likely proud of me.)

The flyback voltage is an artifact of pulsing the coil, and not something you can "use" to speed things up. Fundamentally, di/dt is controlled by the 'on' current, the inductance, and the damping resistor (which is, in turn, dependent on capacitance). Probably you are changing one of these, and getting a faster di/dt and a higher resulting flyback.

- Carl

The flyback voltage isn't an artifact! It is an essential process for "kicking the target". It is the process (damping), where the target's eddy currents will be actually generated.

The TX on-time is merely used, to build a magnetic energy around the transmitter coil. The inductor is a typical energy conserving element (L,C). Once loaded the element with magnetic energy (E=0.5*L*I*I), this energy is not lost immediately after switch off-time. The nature physics does not like any physical changes when in some stable stationary state. As a consequence, the coil current wants to flow in the same direction as before or the magnetic field wants to stay at same state as before. This is the reason for high flyback voltage when the nature is getting stressed! Is causes also some stress reaction.

Of course, during TX on-time there is also some eddy currents in the target. But they have no real role in the PI technology as supposed. The effects of the damping process predominating this.

The genuis of this idea is to use the flyback voltage more efficiently. So a fast conversion from magnetic energy into heat is necessary. As you convert energy in the nature, the nature isn't making any stress. The nature likes energy conversion (we are also somehow energy converters - aren't we?).
The higher the flyback voltage is, the more efficiently and faster will be the damping process. A 400 V IRF740 for instance is used, to manage a ~1.6 kV coil voltage! And this without going beyond the avalanche breakdown voltage. This high coil voltage is intentionally generated. The result is, I can decay much faster than the natural decay behaviour. This will have the effect of stimulating the target more effective and will generate more eddy currents.

We can achieve just with simple anti-parallel clamping diodes superior early sampling timings on MONO coils. Even they are clamped.

New PI coils must be developed by the industry to use the benefits of this wonderful finding. I call this type of coils "Tesla coil". The function of the new coil is like the original Tesla coil: producing high voltages! The transmitter coil will therefore be a splitted winding coil. Either a center-tapped or a step-up coil. The step-up coil will produce high flyback voltages beyond the hell. A center-tapped coil will have the best performance due to the differential signal line benefits. So the coil cabling can be realized as a twisted-pair cabling. No shielding of the cabling is required in this case and will lower the capacitive load on the coil.


Bbsailor has kicked this wonderful finding. Many thanks to him. He just wished to have a faster sampling. Now, we all will have this feature.

Aziz

[Palamedes]

Hi Aziz,

small reminder about the limit value (100 µT) that the International Radiation Protection Association (IRPA) recommends not be exceeded in exposure of populations to RF magnetic fields.

What level of RF MF would you expect from 1.6 kV coil voltage?
http://www.scantech7.com/EMF_RF_Elec...ety_Levels.htm

[Aziz]

Hi Palamedes,

Hi Aziz,

small reminder about the limit value (100 µT) that the International Radiation Protection Association (IRPA) recommends not be exceeded in exposure of populations to RF magnetic fields.

What level of RF MF would you expect from 1.6 kV coil voltage?
http://www.scantech7.com/EMF_RF_Elec...ety_Levels.htm

there is almost no difference to the common PI's. Same magnetic field energy will be exposed. If we have a coil current of 1 A and 300 µH coil, we would have the magnetic energy of E = 0.5*300µH*1A*1A = 0.00015 J (Joule).

My proposal is using only the small part of the splitted coil. If we use the center-tapped coil, this will allow double current flow (half resistance -> I = 2 A) on a half coil (Lhalf = 300µH/4 = 75µH).
The exposed magnetic energy is: E = 0.5*75µH*2A*2A = 0.00015 J. (1 J = 1 VAs = 1 Ws). So same amount of energy will be exposed. (MOSFET's Rdson and other effects neglected).

As a comparison to the energy exposed: 1 J = 1 Ws = 1 VAs, 1 V with 1 A current and 1 second duration on a resistance will produce the same energy of 1 J. Look at the figures above! It is only a fraction of this.

We are not interested in emitting EMF. The high voltage is used to kill the magnetic energy as quick as possible. This has a law of square of coil voltage (P = U*U/Rd ). The magnetic energy E is then converted to heat energy. If we double the coils flyback voltage, the effect is 4 times! This makes the damping process really fast.

Some PI's are using more coil currents. They exceed the recommendation anyway. But this has the benefit of producing much higher flyback voltages. I tend to use lower inductivities (12..75 µH).


Aziz

[Qiaozhi]

The main question here is - have you actually tried this in practice?

Exploring your new ideas with a simulator is extremely useful, but you must also test these in the real world. Many "remarkable breakthroughs" have been announced in the past, only to fail miserably when tested for real.
An element of caution is needed here ... remember the experience you had with the induction balance breakthrough.

gwzd said that history is not his favorite subject, but without studying history we are doomed to make the same mistakes over and over again.

[Tinkerer]

Hi Carl,

we have to recapitulate and rewrite some topics on the PI technology.

I have a totally different sight of this. This is the reason for, why nobody found the evident solution till now. I am sure, this will bring some new products and coils in the future. (And Mr. Tesla would be very likely proud of me.)



The flyback voltage isn't an artifact! It is an essential process for "kicking the target". It is the process (damping), where the target's eddy currents will be actually generated.

The TX on-time is merely used, to build a magnetic energy around the transmitter coil. The inductor is a typical energy conserving element (L,C). Once loaded the element with magnetic energy (E=0.5*L*I*I), this energy is not lost immediately after switch off-time. The nature physics does not like any physical changes when in some stable stationary state. As a consequence, the coil current wants to flow in the same direction as before or the magnetic field wants to stay at same state as before. This is the reason for high flyback voltage when the nature is getting stressed! Is causes also some stress reaction.

Of course, during TX on-time there is also some eddy currents in the target. But they have no real role in the PI technology as supposed. The effects of the damping process predominating this.

The genuis of this idea is to use the flyback voltage more efficiently. So a fast conversion from magnetic energy into heat is necessary. As you convert energy in the nature, the nature isn't making any stress. The nature likes energy conversion (we are also somehow energy converters - aren't we?).
The higher the flyback voltage is, the more efficiently and faster will be the damping process. A 400 V IRF740 for instance is used, to manage a ~1.6 kV coil voltage! And this without going beyond the avalanche breakdown voltage. This high coil voltage is intentionally generated. The result is, I can decay much faster than the natural decay behaviour. This will have the effect of stimulating the target more effective and will generate more eddy currents.

We can achieve just with simple anti-parallel clamping diodes superior early sampling timings on MONO coils. Even they are clamped.

New PI coils must be developed by the industry to use the benefits of this wonderful finding. I call this type of coils "Tesla coil". The function of the new coil is like the original Tesla coil: producing high voltages! The transmitter coil will therefore be a splitted winding coil. Either a center-tapped or a step-up coil. The step-up coil will produce high flyback voltages beyond the hell. A center-tapped coil will have the best performance due to the differential signal line benefits. So the coil cabling can be realized as a twisted-pair cabling. No shielding of the cabling is required in this case and will lower the capacitive load on the coil.


Bbsailor has kicked this wonderful finding. Many thanks to him. He just wished to have a faster sampling. Now, we all will have this feature.

Aziz

Have you tried this with a real coil?
Tinkerer

[Aziz]

Hi Qiaozhi,

The main question here is - have you actually tried this in practice?

Exploring your new ideas with a simulator is extremely useful, but you must also test these in the real world. Many "remarkable breakthroughs" have been announced in the past, only to fail miserably when tested for real.
An element of caution is needed here ... remember the experience you had with the induction balance breakthrough.

gwzd said that history is not his favorite subject, but without studying history we are doomed to make the same mistakes over and over again.

I haven't tried the idea yet. You know, I am a very poor guy, who hasn't the means for. I made extensive SPICE circuit simulations. The theory behind the idea is just physics. The theory states some good ways. And the circuit simulations are showing the expected results. By the way, I haven't fired my soldering iron for month.

One thing I don't know yet, whether the clamping diodes will survive on such high voltages! But this is quite trivial to test..

You all are welcome to test this proposal.

Aziz

[ToyMaker]

Some guy, a lot smarter than me, said,

"In theory, theory and practice are the same, in practice, they are not".

What this means in the real world is that there can be a BIG step
between the science (theory) of a thing and the engineering (practice)
of it.

If I ever get heat in my lab (it's 20F/-6.7C in there right now ) I'll try
to engineer some of this science

Aziz, keep up the good work. I have much enjoyed following your posts.





robotic regards,

tom