Kapanadze Cousin - DALLY FREE ENERGY

[TinselKoala]

I'm starting to get the feeling something is being "lost in translation" here. Pin numbering error? Some mistake in translating the Stalker schematic to the actual circuit on the board? Solder bridges where they shouldn't be? Or none, where they should be? Cold (aka dry) solder joint(s)? Fake or damaged TL494 chip? Or many more possible "slips twixt cup and lip".

It "might" be possible to diagnose possible errors on your circuit board if we had good, high resolution photos of both sides of the board. Scopeshots would help immensely too.

If you are getting the correct signals on pins 9 and 10 of the 494 and the driver chips and snubbers and gate pulldown resistors are correctly wired, the mosfets should be behaving properly, unless the driver chips just aren't providing the necessary gate current pulses for some reason. (But as I mentioned earlier the P260n mosfets need a greater Gate charge than the Stalker's specified IRF3205 mosfets.)

[pomodoro]

@mgpwr: OK< ty.

The high-frequency output from secondary, using LF input from primary, is probably due to resonant ringing, and to get this to work properly the secondary must be loosely coupled magnetically to the primary. This is how Tesla achieved HF outputs from his LF spark-gap-interrupted primary supply. The idea is this: the primary drive circuit produces a fast risetime and falltime short pulse at a relatively low frequency. This causes the secondary to ring at its higher frequency of 1/4-wave resonance and allows VRSWR (voltage rise due to standing wave resonance). Like striking a bell with a hammer. A single strike produces a lot of vibration cycles in the bell. If the primary is too closely coupled to the secondary this causes the secondary to induce back into the primary and damps the resonant rise. If the secondary and its associated capacitance are carefully built for "high Q" then there is little or no decay of the secondary ringing, until the next LF pulse comes along from the primary.
But this is different from the way modern solid-state TCs work, where the primary is pulsed at the same HF rate as the resonant frequency of the secondary. So you get a primary pulse and a secondary sinus cycle, just one, and then another primary pulse comes along. In this setup the primary can be much more closely coupled to the secondary since you aren't worried about mutual damping.
I think the circuits you are working with are trying to do the first, older Tesla method of pulsing primary at a relatively low frequency with short pulses of fast rise and fall times, and allowing the secondary to ring freely at its higher quarterwave resonant frequency. So you might try actually reducing the electromagnetic coupling constant "k" between primary and secondary. Also think about "Q" of the secondary and try to maximize that with careful construction and low-loss components after the secondary output.

Just my "two cents worth" based on my experience with TCs and SSTCs and drive circuitry. Good luck!

TK this seems very related to the Ringdown of the primary and the corresponding Ringup discussed on Richie Burnets site. I've seen the same loosely coupled diagrams on old spark gap telegraphy books. While I have not spent much time on it, I can't figure out how a decaying primary is able to inject ever increasing juice, till its gone, into a secondary that's already got plenty of current going through it. I thought Its a bit like  a stationary person on the ground pushing a swing higher and higher with a small push ,you have to keep shifting your stationary pisition to the point where the swing is about to swing back down and give the little push there.As you said, modern circuits are closely coupled and you don't see this behaviour, the damping of the primary causes a damping in the secondary, not a growth in amplitude.

[NickZ]

  I disconnected the two MUR1560 diodes, to see if they were what was hanging up the signal at the fets, but the fets still get very hot, and the signal is still as you see it below. The scope probes are on the output pins 9 and 10, and ground.
  I still haven't found the snare, as to why the two channels are on at the same time. Raising the frequency, tops out at about 12kHz.
Good thing that I like turning knobs, and tuning away. Once I find the error, things are going to be sweet. 
  Is that plasma on the bulb on the left...?

[TinselKoala]

Er... OK.... But...

Can you please show a photo of _just the scope screen_ and make sure your camera is actually focussed on the scope itself?  The combination of the small part of the photo showing the scope, the scope traces themselves being blurry and the camera not being focussed on the scope makes your photos uninterpretable.

An experienced scoposcopist can tell a lot about circuit behaviour from a properly made scopeshot. But what you've shown in those photos can only be interpreted like this : He has a scope, and it is showing something.

It will also be necessary to tell us the channel voltage/division settings and the horizontal timebase setting, when you get around to making some more scopeshots.

We are trying to help you, but you've got to help us help you!   

[AlienGrey]

Er... OK.... But...

Can you please show a photo of _just the scope screen_ and make sure your camera is actually focussed on the scope itself?  The combination of the small part of the photo showing the scope, the scope traces themselves being blurry and the camera not being focussed on the scope makes your photos uninterpretable.

An experienced scoposcopist can tell a lot about circuit behaviour from a properly made scopeshot. But what you've shown in those photos can only be interpreted like this : He has a scope, and it is showing something.

It will also be necessary to tell us the channel voltage/division settings and the horizontal timebase setting, when you get around to making some more scopeshots.

We are trying to help you, but you've got to help us help you!   

Hi and re this scope shot, looks a bit weird here, if you look at his 'pic' one trace appears to have propagation delay that is what you would expect if one driver chip is an inverted driver and the other not or the drive to both is s/c ! can you please show us the outputs from the TL494 pins 9 and ten 'simultaneously' and the output pins of the drivers in and out. Many thanks