Kapanadze Cousin - DALLY FREE ENERGY

[NickZ]

Nick,

thanks, i guess you mean 16.7KHz, not Mhz.

Blurry pics indeed, but it shows you have 2 different drain signals, the upper (hotter) one has a spike followed by low amplitude ringing, while the lower one has just the ringing, but
with higher amplitude. (or did you not have the vertical setting (amplitude) the same on both channels??)

The expanded pics shows the ringing nicely, but to calculate the frequency of this ringing, i need to know the time base setting (5us/div.??)
If it is 5us/div., then i measure about 9us between two tops of the lower trace in the expanded screenshot, meaning a frequency of about 111Khz

That 111Khz seems very low to me, so i really need to know the time base setting of the scope during that expanded screenshot.

Try to give with each screenshot the settings of the scope (time base and vertical settings of both channels) and the probe (x1 or x10).

I have no idea why your drain signals look different (why one has a spike and the other not) but for me it points to some asymmetry in the system (yoke).

Try to give the above requested data,  thanks.


Itsu

   Itsu: Yes, I meant 16.7KHz, not MHz.
   I couldn't finish posting all the pics yesterday, as I had to go to a birthday party for a friend.
   So, here are some more images taken yesterday, that are showing the scope shots of the settings.
As well as a vertically expanded view of the frequency, (also at 20us setting). Horizontally expanded view is at 5us setting.
   The vertical settings are the same on both channels of the scope.
    Using the 10x probe setting.
   The fets do test out a bit differently when tested out of the circuit, using the meter on the diode test.
One of the fets has a higher resistance value than the other. They also tested that way, new and unused.

   My yoke coils are wound all in the same direction. Perhaps I need to change that? Or the relation each of the coil directions in the RC circuits.
   The 3t coil to the grenade inductor circuit is showing very low output, at the 0.47uf cap, depending on the frequency settings. Sometimes, 3t to inductor circuit has no output.
   But, the main thing is the fet overheating issue that I really need to resolve.

[NickZ]

|Nick Z Re your scope shot of both channels !   if you look at the image on your shot the one wave backs up onto your 2nd wave form showing an over lap !  can I suggest you check your resistors on the TL494 to ground are both the same ! and any capacitors you have between the MOS FET driver inputs and zero volts are the same value and any resistors from your TL494 to your drivers are also the same ! CHECK THEM WITH A METER IF NESASARY as this could and will cause a time delay mismatch in one or both phases ! as the driver input impedance of them is high and if you don't take care and pay attention this kind of problem will arise, Re Itsu's observation comments, as that would account for the loss of one overshoot and over heating is shown up on your scope shot!

PS tip! from T1000 that works, why don't you bi-filar wind the 2 primaries, this would limit the overshoot and feed energy back into the system saving wasted energy considerably?

Regards AG
                   end quote.


   AG:  You were right about checking the TL494's resistors. I found that the 9 and 10 pins of the TL's output pull down resistors were not right. They are 10k resistors, and should be 1k or 1.5k resistors, instead. I'll correct that and report back.
   Thanks for the tip. 

[itsu]

Nick,

thanks for the pictures, so 5us/div. it is for the expanded view.
But you mention using x10 probe setting, but the x10 Volt/div. knobs are showing blanks, so what volts/div. did you use you think?

The MOSFETs should measure almost the same value, if they deviate from each other something is wrong.
My IRFP260N MOSFETs measure 320KOhm with a DMM in the Ohms setting (red to source, black to drain).
When removing the red lead, touching the gate and putting the red lead back onto the source should have flipped the reading from 320K to 0 Ohm.
Removing the black lead, touching the gate and putting it back onto the drain should have flipped it back to 320K.
Please double check this, verpies also showed a testing setup using a DMM and a 9V battery.

My old yoke primaries were also wound all in the same direction, so that should be fine, make sure the primaries are both the exact same number of turns (12).

Is that 16.7KHz the resonance frequency of the wima cap/ inductor?   I don't think so.

AG also mentioned to check for unbalans in your system (TL494 resistors etc.) so when changing the TL494 pins 9 and 10 pull down resistors, i would recommend to go to 100 or 150 Ohm.
68 Ohm is the minimum according to the data sheet, so do not go lower then 68 Ohm.   10K is way to high.
The link resistors from your TL494 pins 9 and 10 to the UC4420 drivers should be low as well,  like 10 Ohm,  please check they are at least the same value.

If possible, take a screenshot of the both gate signals when running, give the data of the knobs that goes with them.


Thanks,   Itsu

[NickZ]

Nick,

thanks for the pictures, so 5us/div. it is for the expanded view.
But you mention using x10 probe setting, but the x10 Volt/div. knobs are showing blanks, so what volts/div. did you use you think?

The MOSFETs should measure almost the same value, if they deviate from each other something is wrong.
My IRFP260N MOSFETs measure 320KOhm with a DMM in the Ohms setting (red to source, black to drain).
When removing the red lead, touching the gate and putting the red lead back onto the source should have flipped the reading from 320K to 0 Ohm.
Removing the black lead, touching the gate and putting it back onto the drain should have flipped it back to 320K.
Please double check this, verpies also showed a testing setup using a DMM and a 9V battery.

My old yoke primaries were also wound all in the same direction, so that should be fine, make sure the primaries are both the exact same number of turns (12).

Is that 16.7KHz the resonance frequency of the wima cap/ inductor?   I don't think so.

AG also mentioned to check for unbalans in your system (TL494 resistors etc.) so when changing the TL494 pins 9 and 10 pull down resistors, i would recommend to go to 100 or 150 Ohm.
68 Ohm is the minimum according to the data sheet, so do not go lower then 68 Ohm.   10K is way to high.
The link resistors from your TL494 pins 9 and 10 to the UC4420 drivers should be low as well,  like 10 Ohm,  please check they are at least the same value.

If possible, take a screenshot of the both gate signals when running, give the data of the knobs that goes with them.


Thanks,   Itsu

      I changed the 10k pull down resistors to the ones that I had on there before. So, now I've got the 460 ohm ones on again, for the pull down resistors. But, things look and work pretty much the same as they did before the change.
   Here's a scope shot of the gates, now. I've ordered some 100-150 ohm resistors, as I don't have any of that value.
   All the other resistors and components match up in values.
   My fets are reading 118 ohms on one fet, and 138 ohms on the other fet. One fet still heats up very much in just a few seconds. I'll order up some more new fets, and try to match two fets up, that are of the same exact resistance values.

   One of our forum members has kindly offered to send me his Siglent digital scope. 
So hopefully I'll be able to show some clear scope shots, as well as all the readings on the scope.
   My old Tektronics scope has seen better days. And his Siglent DSS1052 DL has all the right stuff on it, with a big color screen,
and looks and works great, as well. 
   So... Thanks a lot for that offer Dog One.   I'll PM you back in a little while.

   Dog-One, If you don't get the PM, just let me know. I didn't receive a confirmation from OU.com of having sent the PM.
                                                                                                               
     NickZ

[NickZ]

   Dog-One:
   I've sent you a PM, so please look for it. Let me know if you got it.
   Thanks for the offer. Much appreciated.
   
                                 NickZ

   EDIT:  Here a video review of that scope.  Pretty nice!  Love it already...
             https://www.youtube.com/watch?v=lwP75VW2XmI