bad premonitions

[Alexismex]

Hello, Deemon is a "monster" in electronic knowledge ,may be he has the answer!!!

[Riss]

That's right , but let's see the computer simulation first . Then analysis of the processes at the physical level . That's all I have left - in my region , and with the latest detectors of Minelab , or Deus2 to work - there is nothing - everything was removed from the soil a long time ago... Again- my oscillogram is the same as in the thread ,, PI metal detector with energy recuperation " from deemon (06-04-2012 )- circuit_4.gif- https://www.geotech1.com/forums/atta...1&d=1338765051 -section A-B-C-D-, but there deemon has not indicated which is observed when the circuit works in reality .
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[Tinkerer]

That's right , but let's see the computer simulation first . Then analysis of the processes at the physical level . That's all I have left - in my region , and with the latest detectors of Minelab , or Deus2 to work - there is nothing - everything was removed from the soil a long time ago... Again- my oscillogram is the same as in the thread ,, PI metal detector with energy recuperation " from deemon (06-04-2012 )- circuit_4.gif- https://www.geotech1.com/forums/atta...1&d=1338765051 -section A-B-C-D-, but there deemon has not indicated which is observed when the circuit works in reality .
,

I am not sure I understand what you want.
The "triangular" TX uses a continuously changing coil current. That means that it induces eddy currents in the targets at all times during the cycle.
If you want to insert a time where no eddy currents are induced, you need to cut the changing current and switch to either zero current or a non zero current that is not changing like for example a continuous of 200mA and maintain that current for the time you want for measuring the decaying eddy currents in the targets.
If you switch to zero current, you need to drain the existing current completely, otherwise you will get oscillations.

[Riss]

Up to this point the dialogues in this thread they remind me of the comedy series Hello Hello -https://www.youtube.com/watch?v=OtQxugFYQqs , or Benny Hill -https://www.youtube.com/watch?v=aPAQk3zT6Rw , https://www.youtube.com/watch?v=GA5kVb--oY8 and similar... I take all the blame . For any unbiased bystander it is clear that there is reluctance to discuss the following ,,If you switch to zero current, you need to drain the existing current completely, otherwise you will get oscillations '' .I know the reasons for not wanting to comment and I understand the professionals in this forum . You, Tinkerer ,for example, have 2200 posts - equivalent to Doctor of Science, Professor. I am respected by your knowledge ..
.,, I am not sure I understand what you want '' - I wanted to see what modern simulation software would show for this delicate moment . Only this . I very precisely indicated the oscillogram . I also provided a link to the thread on deemon , where there is extreme clear both the circuit and the oscillogram - drawing on paper . Moment correlates with the commented oscillogram of Deus 2 , as well as dave johnson's circuit - https://www.geotech1.com/pages/metde.../US4868504.pdf . Azis -didn't he point to a computer simulation in CW mode ?

[Carl-NC]

Riss, it would help tremendously if you included all relevant information (schematics, waveforms, etc) in this thread. I can usually help with stuff like this but I don't want to have to work long and hard digging through other threads (one of your links gave a 404-error) to try to figure out what the problem is in the first place. There's rarely any reluctance to discuss anything around here, it's a matter of available time and clarity of the question.

[Riss]

Thanks Carl , now it won't give a 404-error https://www.geotech1.com/forums/showthread.php?19273-PI-metal-detector-with-energy-recuperation&highlight= deemon+recuperation > 06-04-2012, 02:13 AM , post #7 > circuit_4.gif (137.5 KB, 1987 views) . Here is the schematic and oscillogram , but without the damping oscillations which are observed after the section C-D , precisely -after point D . I don't need to waste a lot of time to take pictures of the oscillogram and the circuit . Tinkerer -,,you need to drain the existing current completely "- of course it's like that , but again we will have damping oscillations because at the moment when the last energy from the coil goes into the power supply eddy currents are self-induced in it ( coil ) - the coil ,,catches" itself . Even if it is of the highest quality Litz wire . I will be glad if someone shows with an oscillogram that they have solved the problem without the dynamic inclusion of a damping resistor . Even if he doesn't reveal how he did it .
P.S. The situation is like a joke ,, resident of the city of Gabrovo- Bulgaria never takes a whole Viagra, he licks the tablet until he gets an erection... "
-in our case - since the Viagra dose is small - the effect is short-lived, the pill must be licked again , and so - again and again...and again

[kt315]

all kitties in Gabrovo have very shot tails. they are cutted by gabroveces. so anyone can speedy close his door for a cat and keep the warm in his home.

[Tinkerer]

Thanks Carl , now it won't give a 404-error https://www.geotech1.com/forums/showthread.php?19273-PI-metal-detector-with-energy-recuperation&highlight= deemon+recuperation > 06-04-2012, 02:13 AM , post #7 > circuit_4.gif (137.5 KB, 1987 views) . Here is the schematic and oscillogram , but without the damping oscillations which are observed after the section C-D , precisely -after point D . I don't need to waste a lot of time to take pictures of the oscillogram and the circuit . Tinkerer -,,you need to drain the existing current completely "- of course it's like that , but again we will have damping oscillations because at the moment when the last energy from the coil goes into the power supply eddy currents are self-induced in it ( coil ) - the coil ,,catches" itself . Even if it is of the highest quality Litz wire . I will be glad if someone shows with an oscillogram that they have solved the problem without the dynamic inclusion of a damping resistor . Even if he doesn't reveal how he did it .
P.S. The situation is like a joke ,, resident of the city of Gabrovo- Bulgaria never takes a whole Viagra, he licks the tablet until he gets an erection... "
-in our case - since the Viagra dose is small - the effect is short-lived, the pill must be licked again , and so - again and again...and again

Tinkerer -,,you need to drain the existing current completely " To drain the current from a coil within a short time, you add a damping resistor. You can find many damping schemes on this forum if you search among the PI threads. Moodz even shows his patented method of speeding up the damping time. Green shows a method with a snubber.
However, Deemon shows a method where he does not use damping, because he retains the current and the magnetic field produced by the current in the coil for the next cycle. The PI becomes a resonant circuit. In electronics, it is well known that resonant circuits are very energy efficient.

I still do not really understand what you want. Do you want me to build an LTSpice simulation of the circuit that Deemon gave? Looking at the circuit, I guess it would take me a week s work. I see no sense in that since Moodz posted a very elegant square current wave simulation quite recently.

I posted a simulation of a square wave current PI here: https://www.geotech1.com/forums/show...888#post294888
The simulation is here: https://www.geotech1.com/forums/atta...4&d=1655034974
Just open it and play with it.https://www.geotech1.com/forums/show...915#post294915

You can download LTSpice here: https://ltspice.en.softonic.com/

I understand that the language barrier is difficult to overcome. It is much more than the language it is a different mentality. It is a different way to look at life and everything. You are not alone in this struggle, we are millions facing the same problem.

[Riss]

all kitties in Gabrovo have very shot tails. they are cutted by gabroveces. so anyone can speedy close his door for a cat and keep the warm in his home.

- https://petkeen.com/cat-breeds-with-no-tail/ -a friend from Gabrovo told me that they have such cat breeds in this city .Unfortunately the current through the coil always has a tail .I came to the conclusion that this is the case even with an ideal coil - without its own capacity .

[Riss]

https://www.geotech1.com/forums/show...=moodz+damping
An avalanche breakthrough will occur in this scheme - BSS123 works steady probably up to 120 volts .May God forgive the sins of the input op amp LT1364...

[Tinkerer]

- https://petkeen.com/cat-breeds-with-no-tail/ -a friend from Gabrovo told me that they have such cat breeds in this city .Unfortunately the current through the coil always has a tail .I came to the conclusion that this is the case even with an ideal coil - without its own capacity .

The drain of every coil follows the exponential curve.
Every real coil also has capacitance and resistance.

Traditional PI drains the TX energy at every cycle.
The advanced PI does not drain the current, it recycles the TX coil energy in the next cycle. It is resonant. I tried to explain this process in detail in my thread https://www.geotech1.com/forums/show...ced-PI-project
I suggest you read and study this whole thread thoroughly and maybe put up for discussion in the thread any point you do not understand or you do not agree to. I gave it a try to explain how I see and understand the function of my circuit.
It is well possible that I made a mistake or even several mistakes.
I make mistakes all the time and made countless mistakes all my life.
It makes me happy if someone helps me to see where I made a mistake, where I do not understand what I am trying to do.
It is the only way to make progress.

[Riss]

https://www.geotech1.com/forums/show...-project/page3
- No doubt there is quite a lot of fun in this thread , especially in several posts after #29 . You said you would need at least a week to do a computer simulation of the circuit which is the subject of this thread - bad premonitions. It took me about two hours working with the soldering iron to make sure that the circuit works, but so badly that it is inapplicable to broadcasting of the type a classic PI - with periods during which no current flowing through TX coil . And as I had the in utmost imprudence to start this thread on the 13^th -fatal number I suspect this problem can be partially solved ( as it occurred to me to try when I find time ) , but not in general . I could be wrong . On the other hand- CCPI - it not been novelty for many years , and the topic CCPI is boring for a lot of people . Merry Christmas everyone .

[Riss]

So they don't gnaw me dark thoughts anymore - Thread: BIPOLAR ALTERNATIVE TO H BRIDGE , moodz (that there is no way to get it clean DC ) , I took 6 pieces IRF630 and the soldering iron to see how the circuit works on the oscilloscope ? The key phrase in this thread is What's missing? 06-03-2021, 09:47 AM#4 , Carl -NC . My coil is about 1.5 millihenry / 4,5 ohm , i added 4.7 nanofarads cap. in parallel . Frequency - about 1 khz . Power supply - 2.5 volts . I really liked how it worked - there was little difference between the starting current and its magnitude before the reversal . Of course something is missing - this is not PERPETUUM MOBILE - a simple compensation circuit must be added to compensate active losses in L and C ( when the current through the coil reverses ) . Current generator ideas are unreasonable -heating energy became more expensive .