Kapanadze Cousin - DALLY FREE ENERGY

[itsu]

Itsu,

The only change is the connection of the clamps.



Regards

OK,  i understand now.

I have double checked my setup, but as i use speaker wire which i tagged with tape i am pretty sure i did not mix up any connections.

Itsu

[itsu]

   Itsu and All:
   Perhaps you can help me out, if possible. As I'm still having mayor problems with my set up, and I can't seen to find the cause. At one time you helped me with my Mazilli circuit overheating, and now I have a similar issue, but with the TL494/Tc4420 drivers.
   To explain how I have things connected:
   I have connected the positive rail of my 24, 10A PSU directly through the choke and then going to the center tap of the yoke. The primary coil of the yoke going out to the center pin of the three pin IRFP260P mosfet. And the negative rail of the PSU to the right pin of the mosfets. Is that correct? Or not?
   I have also connected the 1000k resistor as well as the facing 18v zener diodes between the left pin of the mosfet (gate) and the right pin of the mosfets.
   I also have the MUR1530 diodes going from the right pin of the fets to the center pin. This with the diodes facing me, as well as the fets.
   If needed I can post a close up of my driver circuits, or anything else on the device which may help. I just can't see what I've done wrong. But, this thing has gone haywire, (and me too) even without the yoke connections from the yoke primary to the fets disconnected, to see if the fets stay cool when I try this test, which they do stay stone cold.
  It must be something simple, but I've spent much time overlooking the cause of this frustrating situation.

  Verpies: Thanks for the correction as to the lossless clamp circuit. I may have to make one myself, If I can't get this fet overheating problem solved, before I pull the rest of my hair out. As it is acting like a short circuit, while yet, I can still light some bulbs. But, I have no output on my 3t coil circuit at this time.



  EDIT: Verpies, at one time I mentioned what I had read about the TC4420 mosfet drivers from their data sheet concerning their function of impeding the fets from being both on at the same time. You mentioned that their job was not that, but to add current to the fets, instead.
   Below is the description you posted from the lossless clamp, point #5:
   "Pins #6 of the UCC27511 drivers (U1 and U2) are used to ensure that two power MOSFETs (Q1 and Q2) are not conducting both at the same time. The voltage on pin #6 must be above 2.4V in order for the driver to be enabled (this happens only when the opposite MOSFET stops conducting. This is sensed by R6 and R8)".

   So, I ask you again, is that not the same function provided by the TC4420 fet drivers, besides providing additional current to the mosfets?
   And could this be why apecore's fets are now not firing at the same time, along with the lossless clamp, as they were previously.
   My fets are still both on at the same time, at times. Depending on the duty cycle, and frequency controller settings.
Varying the setting by only slightly on my device, can cause them to both fire at the same time, still.
   

Nick,

your setup as you mention it looks OK by me, i have drawn it, see attached.
For now i can only suggest to connect 2 resistors (100K or so) instead of the primary coils and feed them in the middle with your 24V.

You should be able to scope around and see some nice waveforms on the gates and drains without the MOSFETs getting hot.

If that works OK your setup is basically good and we need to check on the yoke / coils to see if they are wired up OK etc.

Make sure your 24V is filtered enough by having a good choke and some electrolytic and film capacitors.

Itsu

[verpies]

Verpies, at one time I mentioned what I had read about the TC4420 mosfet drivers from their data sheet concerning their function of impeding the fets from being both on at the same time. You mentioned that their job was not that, but to add current to the fets, instead.
Below is the description you posted from the lossless clamp, point #5:
"Pins #6 of the UCC27511 drivers (U1 and U2) are used to ensure that two power MOSFETs (Q1 and Q2) are not conducting both at the same time. The voltage on pin #6 must be above 2.4V in order for the driver to be enabled (this happens only when the opposite MOSFET stops conducting. This is sensed by R6 and R8)".

So, I ask you again, is that not the same function provided by the TC4420 fet drivers, besides providing additional current to the mosfets?

They are not the same.  The TC4420 gate drivers do not have an Enable pin like the pin #6 of the UCC27511 gate driver, thus the TC4420 gate drivers cannot be simply cross connected to ensure that both gates are not driven at the same time (causing what is known as FETs' "cross conduction").

But, but it is not even the job of these gate drivers to prevent this cross conduction. This is the job of the signal generator ! (e.g. the SG3525, TL494, NE555, Arduino, etc...)

The main job of the gate drivers is to provide more current for charging the FET gates quickly.

I have cross connected the UCC27511 gate drivers to prevent FETs' cross conduction only because they had the Enable pins available and unused.  It is merely a safety feature in case the signal generator fails, or Miller's turn-on happens, or severe EMI occurs e.g. from  the "Kacher", or some other such catastrophe...
That safety feature is not required for the functioning of the lossless clamping.

And could this be why apecore's fets are now not firing at the same time, along with the lossless clamp, as they were previously.

I don't even understand what signal generator he is driving his gate drivers with and why he gas reversed some windings.
...but if it ain't broke - don't fix it, ...so I'm refraining from negative feedback.

[apecore]

I don't even understand what signal gegerator he is driving his gate drivers with and why he gas reversed some windings.
...but if it ain't broke - don't fix it, ...so I'm refraining from negative feedback.

Good day Verpies,

I m using a SG3525 instead of the TL494 due it has more safety functions.

for each channel i use a UCC37322 (non-inverting driver) with ENABLE function using also.
Each UCC is driving a GDT which feeds the gates of the FET's  (and some extra Zener/diode/cap/resistor to create also a negative voltage for the gates)

I reversed the clam windings because connecting inductive loads my fets where firing at same time (as Nick mentioned), driving 12V bulbs it was OK.

I hope you have enough information te clarify why i had to reverse the clams.... and that the original drawing is not false.
Just for information and understandings

Regards

[T-1000]

Hi all,

In regards to grenade windings, at least Sergey Alexeew and Dniester used additional winding.
Sergey's additional winding was under whole grenade and direction same as L1 and tuned to half frequency of grenade
Dniester additional winding was between L2 and L3 and under inductor(continued from L2 on same direction until middle then other way around for L3).

You might also test  those combintations as well.

Cheers!