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OverUnity Research > Benches > AlienGrey > Dally, Shark & Ruslan workbench
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Author Topic: Dally, Shark & Ruslan workbench  (Read 309151 times)
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img  Itsu
Re: Dally, Shark & Ruslan workbench « Reply #1600 on: 2021-07-24, 15:27:21 »

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The below screenshot shows the Kacher MOSFET gate signal in red and the drain signal in yellow.

Drain diode still bypassed.

There should be more then enough gate signal to activate the MOSFET.

Putting 24V @ 120mA on the drain / primary kacher coil.

Video tour of the whole setup here:  https://youtu.be/2_qfCMo-bFg

Itsu
   
img  verpies
Re: Dally, Shark & Ruslan workbench « Reply #1601 on: 2021-07-24, 15:44:24 »

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Quote from: Sm0ky2 on 2021-07-24, 05:17:01
How many people have this far burnt out one or more gates in their 74HC00?
Not many.

In a properly designed circuit where the input pins are kept from floating (even the unused ones 1,2,4,5,9,10,12,13) and the outputs pins (3,6,8,11) are not negatively or positively spiked by external voltage, which exceeds the IC's supply rails by more than a diode v.drop, and the supply pins (7, 14) are adequately bypassed with 1-100nF ceramic capacitors, then this IC is not overvoltaged and the SCR Latch up is prevented.

The latter can also be caused by ionizing radiation and microwave EMI.
   
img  Vasik041
Re: Dally, Shark & Ruslan workbench « Reply #1602 on: 2021-07-24, 15:54:41 »
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Quote from: Itsu on 2021-07-24, 15:27:21
The below screenshot shows the Kacher MOSFET gate signal in red and the drain signal in yellow.
Drain diode still bypassed.
There should be more then enough gate signal to activate the MOSFET.
Putting 24V @ 120mA on the drain / primary kacher coil.
Video tour of the whole setup here:  https://youtu.be/2_qfCMo-bFg

Itsu,

In the video you said "I not sure where the problem is", what problem do you think is there ?
Small output voltage ?

Vasik
   
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Re: Dally, Shark & Ruslan workbench « Reply #1603 on: 2021-07-24, 16:01:25 »

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I cannot prove it with the data at hand but it looks too me like Itsu's TC/Kacher's primary to secondary coil geometry (and the grounding bar's position and length) does not support a standing wave well at this frequency.

Why is the primary so wide, anyway ?
   
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Re: Dally, Shark & Ruslan workbench « Reply #1604 on: 2021-07-24, 16:06:50 »

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Quote from: verpies on 2021-07-23, 19:48:14
A device does not have to use deliberate means of power control because some components  introduce inadvertent regulation intrinsically.

For example, anytime a device utilizes cored inductors, their ferromagnetic saturation limits their energy output.
So in the device being discussed in this thread, the core IS the power regulator you're referring to while also being a transformer, and IMO other things that shall not be named.
Because only Slavs have access to the special cores.
You might be right.


If only we had a time machine!

There were 3, brand new, still boxed Russian colour televisions in the Technical college stores where I learned my basics of TV and Radio repair in the mid seventies. With the advent of " flat screen " technology they're probably long gone. Rubens ??

Cheers Grum.


---------------------------
Nanny state ? Left at the gate !! :)
   
img  Itsu
Re: Dally, Shark & Ruslan workbench « Reply #1605 on: 2021-07-24, 16:20:12 »

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Quote from: Vasik041 on 2021-07-24, 15:54:41
Itsu,

In the video you said "I not sure where the problem is", what problem do you think is there ?
Small output voltage ?

Vasik

Hi Vasik,


yes, my feeling is that with 24V there should be much more voltage on the secondary top / antenna.

Presently i can pull a 0.2mm spark with a screwdriver which should be mm's i think, even with this low duty cycle the kacher is running on.

Itsu
   
img  Itsu
Re: Dally, Shark & Ruslan workbench « Reply #1606 on: 2021-07-24, 16:23:20 »

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Quote from: verpies on 2021-07-24, 16:01:25
I cannot prove it with the data at hand but it looks too me like Itsu's TC/Kacher's primary to secondary coil geometry (and the grounding bar's position and length) does not support a standing wave well at this frequency.

Why is the primary so wide, anyway ?

The kachers secondary to primay coils diameters suppose to be 1:1.6 (PHI?) ratio which it should be the last time i measured it.

Or do you mean the primary windings spacing?

Itsu
   
img  NickZ
Re: Dally, Shark & Ruslan workbench « Reply #1607 on: 2021-07-24, 16:32:14 »
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   Can some one verify what the max voltage/current should be on Itsu's mosfet gate.
   Itsu has mentioned something about 19v, or so. But, I'm not sure that I understand.
   Seams to me that the gate signal does not need to be that high, but I don't know for sure.
It also seams like he has a glitch somewhere. As the device seams to cut out, and back again, unstable.
   
   Verpies, Itsu is following the same form factor and shape of the Kacher primary coil, as shown by Ruslan/Akula/Stalker, etc...

   Itsu: Can you please post an image of the Kacher signal, at the antenna output. I would like to see the shape of the signal. Thanks.
    Perhaps Utopia Now can also upload an image of his Kacher signals, to compare. Especially the Fet's gate signal.

    NickZ
   
img  Thaelin
Re: Dally, Shark & Ruslan workbench « Reply #1608 on: 2021-07-24, 16:44:38 »
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Hi Nick:
    Was just at the ESTC convention in Idaho, USA and had a talk with Paul Babcock witch peeps say is the man to see about switching. My question was about can you parallel mosfets and not burn them up. He said a resounding yes, I do it all the time. He also added that you can use individual drivers  for each mosfet and drive them with a 1 to 4 ttl gate chip. That meaning it will trigger just fine at ttl levels. You do not have to put 18v on the input to the gate drivers.  On the Fets, you should go with what ever the voltage levels are recommended. Current ones are 18v. Hope this helps you a bit in some way. My fets are being used as a cap dump system and not the Akula thing.
thay
   
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Re: Dally, Shark & Ruslan workbench « Reply #1609 on: 2021-07-24, 16:44:59 »

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Quote from: verpies on 2021-07-24, 16:01:25
I cannot prove it with the data at hand but it looks too me like Itsu's TC/Kacher's primary to secondary coil geometry (and the grounding bar's position and length) does not support a standing wave well at this frequency.

Why is the primary so wide, anyway ?

I agree, I think it is too wide, around a 5mm space would be better, IMO.

On another point, all these circuits are, IMO, to neutralise the ionic charge, ( extract ) from the ambient. With ref: to SM TPU he stated that the electronics had to be within the toroid, in other words shielded from the positive and negative ION exchange and neutrality, neutrality caused by the extraction. Placing a shield over the electronics might make a huge difference in the case of the "TPU", for the Russian type I,m not sure!!! but they are both achieving the same end IMO.

Regards

Mike 8)

PS.  There should be at least 2KV on the Tesla part of this to create the ionic movement.


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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
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As a general rule, the most successful person in life is the person that has the best information.
   
img  Itsu
Re: Dally, Shark & Ruslan workbench « Reply #1610 on: 2021-07-24, 16:50:03 »

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Quote from: NickZ on 2021-07-24, 16:32:14
   Can some one verify what the max voltage/current should be on Itsu's mosfet gate.
   Itsu has mentioned something about 19v, or so. But, I'm not sure that I understand.
   Seams to me that the gate signal does not need to be that high, but I don't know for sure.
It also seams like he has a glitch somewhere. As the device seams to cut out, and back again.
   
   Verpies, Itsu is following the same form factor and shape of the Kacher primary coil, as shown by Ruslan/Akula/Stalker, etc...

    NickZ

Nick,

according to the IRFP460 datasheet ( https://www.vishay.com/doc?91237 ), the maximum gate-source voltage is 20V, so with my 15V (plus some spikes) i am well within its limit.

ABSOLUTE MAXIMUM RATINGS TC
PARAMETER             SYMBOL LIMIT UNIT
Gate-Source Voltage   VGS    ± 20  V


Also the minimum threshold voltage at which the MOSFET is fully switched on is stated as 2 - 4V which is also complied to with the 15V.

SPECIFICATIONS
PARAMETER                       SYMBOL  TEST CONDITIONS          MIN. TYP. MAX.   UNIT
Gate-Source Threshold Voltage   VGS(th) VDS = VGS, ID = 250 μA   2.0   -   4.0     V


Itsu
   
img  Vasik041
Re: Dally, Shark & Ruslan workbench « Reply #1611 on: 2021-07-24, 16:50:52 »
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Quote from: Itsu on 2021-07-24, 16:20:12
Hi Vasik,
yes, my feeling is that with 24V there should be much more voltage on the secondary top / antenna.
Presently i can pull a 0.2mm spark with a screwdriver which should be mm's i think, even with this low duty cycle the kacher is running on.
Itsu

Hi Itsu,

Well, this is Tesla coil, not kacher, you will need tune everything yourself :)
I would suggest you disconnect antenna coil and measure Tesla's secondary coils resonance with signal generator.
Then measure antenna coil capacitance, just for reference.
Then you can try use Gorchilin's calculator to calculate resonance and you will need adjust it to match gradient coil resonance.
Verpies rigth about geometry, center of inductor should be close to first turn of secondary (place where current node will be).

Vasik
   
img  Itsu
Re: Dally, Shark & Ruslan workbench « Reply #1612 on: 2021-07-24, 17:00:19 »

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Thanks Vasik,

the present location of the primary is a result for tuning for max output.
Positioning it more to the first turn of the secondary reduces the output (and signal shape) drastically.

But i will look more careful to the kacher / tesla coil setup....

Itsu
   
img  NickZ
Re: Dally, Shark & Ruslan workbench « Reply #1613 on: 2021-07-24, 17:06:11 »
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Quote from: Itsu on 2021-07-24, 16:50:03
Nick,

according to the IRFP460 datasheet ( https://www.vishay.com/doc?91237 ), the maximum gate-source voltage is 20V, so with my 15V (plus some spikes) i am well within its limit.

ABSOLUTE MAXIMUM RATINGS TC
PARAMETER             SYMBOL LIMIT UNIT
Gate-Source Voltage   VGS    ± 20  V


Also the minimum threshold voltage at which the MOSFET is fully switched on is stated as 2 - 4V which is also complied to with the 15V.

SPECIFICATIONS
PARAMETER                       SYMBOL  TEST CONDITIONS          MIN. TYP. MAX.   UNIT
Gate-Source Threshold Voltage   VGS(th) VDS = VGS, ID = 250 μA   2.0   -   4.0     V


Itsu


   Itsu:  Thanks, that is what I needed to know. For now, I'm out of ideas... Perhaps UN can help.

   PS. After watching your video again, I notice that your TC secondary coil is very close to the grenade. Maybe, too close, and affecting the output?
I also noticed that you have much less output before the ferrite rod, compared to at the antenna. Perhaps Vasik is right, and some tuning is needed.
   
img  picowatt
Re: Dally, Shark & Ruslan workbench « Reply #1614 on: 2021-07-24, 18:21:54 »
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Quote from: verpies on 2021-07-24, 15:26:55
What is that aluminum foil for ? :
https://youtu.be/tnb8gUifKgk?t=81

Verpies,

Looks to be tin plated copper tape with solid wires soldered along the length used for a ground strap throughout his circuit.

Note that this version grounds one end of the grenade secondary, one end of the grenade primary, and the "cold end" of TC secondary to that ground strap.

PW
   
img  Itsu
Re: Dally, Shark & Ruslan workbench « Reply #1615 on: 2021-07-24, 20:45:55 »

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Quote from: Vasik041 on 2021-07-24, 16:50:52
Hi Itsu,

Well, this is Tesla coil, not kacher, you will need tune everything yourself :)
I would suggest you disconnect antenna coil and measure Tesla's secondary coils resonance with signal generator.
Then measure antenna coil capacitance, just for reference.
Then you can try use Gorchilin's calculator to calculate resonance and you will need adjust it to match gradient coil resonance.
Verpies rigth about geometry, center of inductor should be close to first turn of secondary (place where current node will be).

Vasik


I disconnected the ferrit / antenna from the secondary and carfully measured the secondary resonance frequency to be 2.809MHz.
The antenna coil capacitance compared to ground is 34pF.

so data on secondary:

Secondary coil Fres is 2.809MHz,
Former diameter is 53mm
secondary coil length is 16.6cm
secondary coil number of turns is 216
secondary coil inductance is 685uH (measured)
secondary coil length of wire is 35.9m (calculated)

Using Gorchilin's calculator (http://gorchilin.com/calculator/coil14?lang=en) using this data i get:





With antenna (34pF) as capacitance i suppose to get:






Itsu
   
img  Vasik041
Re: Dally, Shark & Ruslan workbench « Reply #1616 on: 2021-07-24, 21:05:09 »
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Itsu,

I think frequency is too low, you need 1.2Mhz if I remember correctly.
You can change capacitance a little by adjusting distance between turns in  antenna coil, if that is not enough, I guess you will need cut one turn from it.
If you measure resonance with signal generator with antenna coil connected, are measurements match calculations ?
What frequency you feeding to MOSFET ?

Vasik

PS please check input data, do you really have wire 0.77 mm ?
   
img  Itsu
Re: Dally, Shark & Ruslan workbench « Reply #1617 on: 2021-07-24, 21:33:34 »

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Vasik,

yes, grenade resonance we measured / calculated was at 1.2MHz

When doing the same resonance frequency measurement with ferrite / antenna connected i get 1.018Mhz so slightly low.

Not sure what you mean by "What frequency you feeding to MOSFET", but the pulses fed are at about 1.3MHz, see screenshot (red) here: https://www.overunityresearch.com/index.php?topic=3926.msg93803#msg93803

I have 0.72mm diameter as secondary wire, but its not really tightly wound.

Itsu
   
img  Utopia Now
Re: Dally, Shark & Ruslan workbench « Reply #1618 on: 2021-07-24, 22:56:38 »
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Hallo Itsu  I see now where we have different outcomes.
I follow a bit Alexeew`s setup ..  or at least what i think is like his set up of coils.
I have a 19m Tesla that runs at a higher freq of its own .. but with shnyaga and antenna connected it resonates at about 1,76MHz.
I can put a long ferrite rod (1cm x 15 cm) in de Tesla and than go down to 900kHz res freq (Tes, Shny, Ant).
If i want max output at antenna  than i also have to adjust the puls freq. down to 900kHz.

I noticed that when doing so i got less pulses  because 4 pulses  at 1,7MHz need a less amount of on time than 4 pulses at 900kHz. differently stated: at 900kc 4 pulses take more time than 4 p. at 1,7MHz ( so i had to readjust to get exactly 4 pulses again )
Thats also probably the reason why you use more amps at 25 volts (lower freq bigger on time) than i use (higher freq smaller on time) . ( and also because my former measurements were with 4 pulses and you used 5 i think.

I also noticed that my drain signal is getting les clean with the ferrite rod in the Tesla  .. I think than i also heve to adjust the duty cycle from the pulses a bit for optimum performance.

Furthermore i did some measurements with 4 pulses compaired to 5 pulses. at 1,7MHz Mosfet frequency ( even though res freq of Tes. Shny. Ant. was 1,76MHz as I noticed only later. )

Volt      mA   Vtop drain  Antenna   pulses

25V      60     316V        1760Vpp      4
40        91     480          2990           4
70       150    592          5720           4
100     245    784          8kVpp         4
119     300    864          9040           4
 
now with 5 pulses notice the drain voltage is not bigger.

25V     69mA  312V       2120           5
40       125     480         3680           5    0,5mm streamer, spark
70       214     588         6440           5    4   mm  ..  but you have to start by touching and then move away to get 4mm
100     314     768         8800           5
119     370     848         9840           5
   
img  verpies
Re: Dally, Shark & Ruslan workbench « Reply #1619 on: 2021-07-24, 23:01:18 »

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Quote from: Thaelin on 2021-07-24, 16:44:38
He also added that you can use individual drivers  for each mosfet and drive them with a 1 to 4 ttl gate chip. That meaning it will trigger just fine at ttl levels. You do not have to put 18v on the input to the gate drivers.
Indeed, TTL chips run at 5V and that is usually more than the gate voltage (VGS-th) needed to turn on the MOSFET.

However!, merely turning it on is not enough in this application - the speed matters, too.

The +15V which Itsu has elected to use allows his MOSFET to turn on much faster than with +5V.
Also, the current that a dedicated driver is capable of delivering to the MOSFET's gate is much greater than the current which can be sourced out of a TTL gate. A high current source charges the MOSFET's gate capacitance much faster, too.

To discharge the MOSFET's gate capacitance maximally quickly and turn off the MOSFET, up to -20V can be applied to the MOSFET's gate by a high current sink, but applying the maximum allowable voltages to the gate is a bad idea because of overshoots.  So the 15V he has chosen is a good compromise.
   
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Re: Dally, Shark & Ruslan workbench « Reply #1620 on: 2021-07-24, 23:20:52 »

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Has everyone voted in the poll at the top of this page ?
It is anonymous...
   
img  picowatt
Re: Dally, Shark & Ruslan workbench « Reply #1621 on: 2021-07-24, 23:26:20 »
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Quote from: verpies on 2021-07-24, 23:20:52
Has everyone voted in the poll at the top of this page ?

No...
   
img  Utopia Now
Re: Dally, Shark & Ruslan workbench « Reply #1622 on: 2021-07-24, 23:50:31 »
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Re: Dally, Shark & Ruslan workbench « Reply #1623 on: 2021-07-24, 23:58:46 »

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Quote from: picowatt on 2021-07-24, 18:21:54
Looks to be tin plated copper tape with solid wires soldered along the length used for a ground strap throughout his circuit.
That ground strap has a lot of surface area.
I'd expect the proximity of the coils to such wide strap, to greatly influence their capacitance to ground, resonance frequency and standing wave geometry.
   
img  picowatt
Re: Dally, Shark & Ruslan workbench « Reply #1624 on: 2021-07-25, 00:12:53 »
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Quote from: Itsu on 2021-07-24, 16:20:12
Hi Vasik,


yes, my feeling is that with 24V there should be much more voltage on the secondary top / antenna.

Presently i can pull a 0.2mm spark with a screwdriver which should be mm's i think, even with this low duty cycle the kacher is running on.

Itsu

Itsu,

Did you have more voltage on the secondary with the diode connected between the primary and MOSFET drain?  If so, perhaps consider using a higher voltage MOSFET.  The On Semi part #NVH4L160N120SC1 is a 1200 volt MOSFET with less capacitance and faster switching than your current part number.

If your 24V supply voltage is indeed remaining at 24V, about the only possible explanation for the "ratcheted up" voltage would be rectification of the primary oscillations by the primary-to-drain diode and storage of that rectified voltage via the MOSFET drain capacitance.

I see that other similar TC drivers use a diode in that location as well, and it is likely there to allow the TC primary to ring more freely during the MOSFET off time.  The "ratcheted up" voltage seen at the drain during MOSFET off times will bias and prevent the body diode and the primary-to-drain diode from being biased on during larger primary oscillation excursions. 

Clamping the drain as you did with the TVS was a good idea, and I would leave the primary-to-drain diode in the circuit with that "cure".

Another possible "cure" would be to add a diode between the MOSFET drain and the 24 volt supply.  Anything over 24 volts plus a diode drop will be bled off to the 24 volt supply.  The large filter caps on the 24 supply will "probably" not be charged up very much at the duty cycle and inductance involved.  However, no other TC designs related to this device use a diode so located and as stated above, many do use the primary-to-drain diode as per the schematic you followed.  And, if as above, that primary-to-drain diode is there to allow the primary to oscillate more freely during MOSFET off times, this additional clamping clamping diode would likely reduce the TC's output.

If the TC worked better with the primary-to-drain diode installed, and if the peak voltage observed at the drain was 1 kilovolt or less, consider using the higher voltage MOSFET mentioned above.  However, what the voltage seen at the drain will be with primary voltages above 24 volts is another question that needs to be considered.

As always, just food for thought...

PW
   
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