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Author Topic: Dally, Shark & Ruslan workbench  (Read 85102 times)

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Result:
disconnect Grenade L5,  tune inductor L4 for 24KHz (600nF)
disconnect inductor L4, tune grenade L5 for 24KHz (233nF)
reconnect both grenade L5 and inductor L4, need to retune for resonance which seems around 21Khz now, so resonance dropped.
So need to remove some capacitance to get back to 24KHz.
Why is this different then your procedure you think?
Below screenshot is Grenade voltage (across cap) in yellow and current in green (97° phase shift at zero crossing).
I have a 25W bulb as load running at 200V dc.
Still in resonance at 21KHz.
Itsu
Itsu,

I don't know :)
I was tuning to 15.6KHz.
Could you please show one MOSFET drain signal also ? (where it located relative to grenade current)
Also, do you have 28 turns coil connected or not ?

Thanks,
Vasik


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I can put up a MOSFET drain signal instead of the Grenade (cap) voltage signal (because of grounding problems) later today.

I have my 18 turn secondary L2 connected yes.

Itsu
   

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I can put up a MOSFET drain signal instead of the Grenade (cap) voltage signal (because of grounding problems) later today.
I have my 18 turn secondary L2 connected yes.
Itsu

That's probably a reason. I gave up using 18-25 turns coil because I can't get any reasonable tuning with it connected.

Vasik


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Ok,  so you do not have a 18-25 turns secondary coil L2 at all?

Itsu
   

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Below screenshot is with:

yellow: MOSFET-1 drain
blue:   MOSFET-1 gate
green:  Grenade L5 current

200V dc on the output bulb (25W) brightly on.

Itsu
   

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    Itsu:
    With only a 25w bulb, and 28 percent duty cycle, you are drawing almost 11 amps? It that correct?
Seams to me that you should be drawing about 1/2 of that amount of current. What does it draw with no bulb on, and full duty cycle?
Are your fets or anything else getting hot?

    NickZ
   

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Ok,  so you do not have a 18-25 turns secondary coil L2 at all?

Itsu

I have a coil, but I decided not use it, at least for now.


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The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
   

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Below screenshot is with:

yellow: MOSFET-1 drain
blue:   MOSFET-1 gate
green:  Grenade L5 current

200V dc on the output bulb (25W) brightly on.

Thank you Itsu,

Idea behind tuning (as understand it) is to get signals looking more like this (see attached).
So kacher/TC can "strike" on a falling slope of grenade coil current just after MOSFET closed.

Vasik


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The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
   

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Enjoy your trek through life but leave no tracks
Itsu'

Strange stuff or is it, I see the gate is turned off on one part but the Drain is still drawing current during ringing
is that right?

Itsu while i think of it I have some info that will help you Is it ok if I send it to you ? Its too big and RPTed and i dont
know or have any hyper links for it.

Sil
   

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    Itsu:
    With only a 25w bulb, and 28 percent duty cycle, you are drawing almost 11 amps? It that correct?
Seams to me that you should be drawing about 1/2 of that amount of current. What does it draw with no bulb on, and full duty cycle?
Are your fets or anything else getting hot?

    NickZ

Hi Nick,

yes and no, there is indeed 10.5A pp sloshing back and forth in the resonant Grenade series LC circuit in which i measure this current.
But this is reactive (not real) current.

Input to the whole circuit is 24V @ 4A, the MOSFETs (cooled by fan) stay around 56°C.

Without the (a) bulb the reactive current increases a little 11.5A pp.

The 25W bulb is running on dc 202V @ 101mA = 20W.

Increasing the duty cycle increases everything, like current, heat, spikes, so i stay away from that.


Itsu
   

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Thank you Itsu,

Idea behind tuning (as understand it) is to get signals looking more like this (see attached).
So kacher/TC can "strike" on a falling slope of grenade coil current just after MOSFET closed.

Vasik

Hmmm,  i have no kacher running, so those spikes are coming from the primary yoke coils L1a and L1b. 

So the blue gate signal when moved, will also move the yellow drain signal and also the green current trace, they are interlocked.

I can of course use the variable delay function (pots) of the 4093's to move the kacher trigger point to anywhere (falling slope) i want, do you mean that?

Itsu

 
   

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Itsu'

Strange stuff or is it, I see the gate is turned off on one part but the Drain is still drawing current during ringing
is that right?

Itsu while i think of it I have some info that will help you Is it ok if I send it to you ? Its too big and RPTed and i dont
know or have any hyper links for it.

Sil

AG,

it only looks strange, but remember what verpies mentioned some years ago already:  "you have to look at the current to "see" if a MOSFET is open or closed, not the voltages" and i am not measuring current in the MOSFET circuit, only voltages (the current seen is in the Grenade LC).

If you think that your info will help us, then yes please send it to me (us), my email is in my profile here.

Itsu
   

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Hmmm,  i have no kacher running, so those spikes are coming from the primary yoke coils L1a and L1b. 

So the blue gate signal when moved, will also move the yellow drain signal and also the green current trace, they are interlocked.
I can of course use the variable delay function (pots) of the 4093's to move the kacher trigger point to anywhere (falling slope) i want, do you mean that?
Itsu

Itsu,
Yes, I understand that kacher is not running yet, I am talking about preparation to run it.
My idea is that by changing grenade circuit capacitor you can adjust grenade current's phase relative to MOSFETs.

Vasik

Edit: updated picture


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Ok, below i added in purple the MOSFET 2 gate signal.

I also put the original Grenade current trace now in white and added the green Grenade current trace with an extra 100nF cap on the series capacitor.

We do see the Grenade current move in phase but out of resonance.

Itsu
   

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Ok, below i added in purple the MOSFET 2 gate signal.

I also put the original Grenade current trace now in white and added the green Grenade current trace with an extra 100nF cap on the series capacitor.

We do see the Grenade current move in phase but out of resonance.

Itsu

I think if you reduce a little duty cycle it will be ok.
You can also put TC signal instead of second gate to see where it actually is.

Vasik


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Duty cycle TL494 reduced a little (26%), purple is now the TC pulse (IR2113 pin 12) signal.

Reducing the duty cycle has major impact on rectified output voltage, now only 165V dc on the bulb.

TC pulse set to falling slope Grenade current.


Itsu
   

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Duty cycle TL494 reduced a little (26%), purple is now the TC pulse (IR2113 pin 12) signal.
Reducing the duty cycle has major impact on rectified output voltage, now only 165V dc on the bulb.
TC pulse set to falling slope Grenade current.
Itsu
Itsu,

It looks ok for me, but I don't know for sure what is correct tuning.
I am waiting for capacitors to try this tuning (to push pull frequency).
I tried tuning for 3x push pull frequency. It gives smaller voltage and current. Without 18-25turns coil signal looks better (pure sine).
Some trials needed to figure out what is best tuning here.

I have this picture supposingly from Alexeev's archive. Text says:
red - one of push pull transistors,
yellow - grenade current with 30nF capacitor,
dead time marked with big arrows,
tesla coil need to "strike" on the second hump

I guess this is what he mean when talked about 2x frequency.
Also not sure if it is correct.

Regards,
Vasik


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Thanks Vasik,

Those "red - one of push pull transistors," signals look so clean  :D


I will be retuning with some new capacitors when they arrive, try to see what happens when removing L2 and be building a MOSFET kacher driver (the Tesla control board in the rk_rev3.pdf).

Itsu
   

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     Guys:
    Yeah, new tuning caps is what I need, as well. I've had to pay $30 each for the 0.47uf wima caps, at one time.
At least the 0.15uf for the grenade coil are much cheaper. But, those are the one that cracked on me.
   What Geo did was to use brown 0.33uf AC caps and just kept adding more as needed, for the inductor coil tuning.
But, those caps aren't the 2000v WIMA ones. As I have over 5.000v coming out of my Kacher.

   Itsu can you or Vasik please post a link to the Stalker video that the rk_rev3.pdf transcript is refering to.  Yes, 70 pages is a bit too long.
 A short summary of the tuning aspect would be good. Even though Stalker never showed any of the self running results, we just have to trust him.
 I guess...

   NickZ
   

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Yes, 70 pages is too long.

 :(


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The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
   

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:(


 Vasik:  It's not too long if someone is actually going to follow it to the T.  But, otherwise, maybe just the main more important details would be enough.
It's not that the transcript is long, it's that Stalker's video is long. But, he does explain things better than anyone else.

   NickZ
   

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     Guys:
    Yeah, new tuning caps is what I need, as well. I've had to pay $30 each for the 0.47uf wima caps, at one time.
At least the 0.15uf for the grenade coil are much cheaper. But, those are the one that cracked on me.
   What Geo did was to use brown 0.33uf AC caps and just kept adding more as needed, for the inductor coil tuning.
But, those caps aren't the 2000v WIMA ones. As I have over 5.000v coming out of my Kacher.

  Itsu can you or Vasik please post a link to the Stalker video that the rk_rev3.pdf transcript is refering to.  Yes, 70 pages is a bit too long.
 A short summary of the tuning aspect would be good. Even though Stalker never showed any of the self running results, we just have to trust him.
 I guess...

   NickZ


Nick,

see rk_rev3.pdf at page 8.

There you see this link:   https://www.youtube.com/watch?v=Bhc1xFNgrVA    and from 50 seconds into this video he is discussing the "Tesla coil control board" using a pulsed MOSFET.


Itsu
   

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   Itsu:
   Ok, thanks for the link. So, I watched it, but it's pretty hard to understand what is really going on. In any case, it's not the three mosfet, 2sc5200 transistor circuit that we contemplated some years ago. But, instead the single mosfet kacher circuit. So, we'll see how it goes with your new Kacher circuit. Seams a much simpler build. But, I wonder which version actually works best, or even at all, to actually interact properly.

   Vasik:  I think that in order to fully understand your transcript of the above mentioned kacher circuits, I would need to watch the Stalker video, while reading your pdf's on my phone, at the same time. Yet, I think that the actual tuning part is the most difficult and most complicated to understand from his videos.  But, my intention is to adapt my existing TL494 induction circuit to control my existing simple kacher. If possible, as I'm not trying to reinvent the wheel, just trying to make it work like it should.

   NickZ
   

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   Itsu:
   Ok, thanks for the link. So, I watched it, but it's pretty hard to understand what is really going on. In any case, it's not the three mosfet, 2sc5200 transistor circuit that we contemplated some years ago. But, instead the single mosfet kacher circuit. So, we'll see how it goes with your new Kacher circuit. Seams a much simpler build. But, I wonder which version actually works best, or even at all, to actually interact properly.

   Vasik:  I think that in order to fully understand your transcript of the above mentioned kacher circuits, I would need to watch the Stalker video, while reading your pdf's on my phone, at the same time. Yet, I think that the actual tuning part is the most difficult and most complicated to understand from his videos.  But, my intention is to adapt my existing TL494 induction circuit to control my existing simple kacher. If possible, as I'm not trying to reinvent the wheel, just trying to make it work like it should.

   NickZ

Nick,

you saw this https://www.overunityresearch.com/index.php?topic=4154.msg93067#msg93067 ?
or it is also too long ?  :)

Vasik


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Received my range of 2000V WIMA caps and am trying to find a match on 24.4KHz with the inductor L4 and grenade L5 connected.

Things are slow due to a full blown bacterial infection on my left hand due to a playful bite of one of our cats a week ago.

I followed this procedure: https://www.overunityresearch.com/index.php?topic=3926.msg93444#msg93444  and now am proportional lowering the caps to reach 24.4KHz, presently at 23.8KHz, so just a few percent to go i hope.

Itsu
   
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