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Author Topic: Replication of ION's bifilar  (Read 85773 times)

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I agree that we have spent a lot of time on this, maybe neglecting some of our other pet projects.
No i didn't mean this at all, i am here trying to do the bifilar rep because i want to spend time on it, sure other projects will follow, ultimately i will head for the phase pulse stages eventually.

Can i ask would you say that your avalanche mode of operation is causing noise bursts, bit like a burst of white noise.Pulses of varying mark and spacing.



   
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Can i ask would you say that your avalanche mode of operation is causing noise bursts, bit like a burst of white noise.Pulses of varying mark and spacing.


No not white noise, but pulse period follows (is modulated by) the curve of the top of the ringing choke waveform.

I burned the midnight oil in trying to get a handle on what was happening with my original setup.

I was able to replicate it in the lab last night, but my findings show that the violent excursions were due to two things:

1) The ringing choke caused  high voltages in excess of the avalanche breakdown of the SCR. This generated currents into the bifilar at least double the steady state firing mode. Last night I saw currents as high as 1000 amps. This is partly due to the fact that I had to change out the SCR, as the original was blown from an accidental short. The replacement had an even higher avalanche threshold than the original.

2) The bifilar wires interact with the circuit in a manner that helps create the avalanche condition. But this is not due to any feedback of excess energy as I originally thought.As the wires separate from an initial repulsion, the inductance increases and this shows up as a decrease load on the secondary of the matching transformer which pushes the ringing voltage higher and closer to avalanche. You can see this by watching the amplitude of the pulse as the wires are separated manually.

It is easy to see that a relaxation oscillator can occur from this arrangement. When the burst occurs, the power supply takes some time to recover charge into the primary storage capacitor. As this voltage climbs, the ringing choke peak voltage starts approaching avalanche then a burst occurs when it hits avalanche.

The original waveform drawing I made is correct but does not show the magnitude of voltage and current being generated by the ringing choke, as my scope probe wouldn't support the division required to keep the image on screen. I had to use a small divider 10 to 1 on top of the probes 10x setting.

Total casualties on this project included 2 power supplies and 3 expensive SCR's. I was able to repair the power supplies. One of the SCR's failed in an unusual way, it became a power diac with a 200 volt breakdown.

The next step, if there is one, would be a better pulse gen circuit that is not affected by the changing inductance of the wires as they repel. We have identified and fairly thoroughly analyzed the mechanism that created the violent excursions. If there is any value in tapping into the parametric inductance and possible OU as EM suggested, it will require a rethink of how this might be done.

Attached is the configuration I used last night.


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Great work ION, glad you managed to fix the power supplies.

I have seen the effect of increasing voltage when the wires are separated and could see this may cause the Avalanche mode to happen, amazing 1000Amps, i think if there's any magic it will be in very narrow high current pulses, i wonder if it would be possible to use a couple of saturable rings to sharpen the pulse's in the config that i explored in my bench, there was only a 3% loss in energy for a multiple stage pulse sharpener.

I am continuing work here, i want to next get the negative gate turn off working, and may connect up some saturable inductors to the secondary to see what happens.
   

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Could you use a pulse generation circuit that has a delay line to set the pulse width, which also forces shut-off.  You'd effectively isolate the trigger from the pulse power and be able to sweep through the frequency range.
   
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Could you use a pulse generation circuit that has a delay line to set the pulse width, which also forces shut-off.  You'd effectively isolate the trigger from the pulse power and be able to sweep through the frequency range.

Sounds good, got a circuit handy? I have an old Chronetics pulse generator that allows for quite a bit of pulse tuning, maybe just driving a transistor with that will do the job.


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Sounds good, got a circuit handy? I have an old Chronetics pulse generator that allows for quite a bit of pulse tuning, maybe just driving a transistor with that will do the job.

Transistors are probably good, if you don't need a fast rise-time.

See attached paper by Baker with circuits.  "Ferrite bead" means a small ferrite bead, and the pulse will be too low if you use a larger core.   Start with a single avalanche transistor (I use 2N5551's) get your trigger working first.   I use very low current, but you can use them in parallel and series to optimize for current/voltage.

I have other files on my bench.  One has a burn-in procedure.
   

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I've added the negative feedback winding i used 25 turns of lighter gauge,added the diode and 100 Ohm resistor across the gate.
It does work to a degree, the frequency of firing seems to increase as i turn up the supply voltage, and my original pot across the zener seems to not do anything.
Maybe i have the coil the wrong way around, i am not sure, the negative current being fed back to the gate occurs at the same time as the negative drive from the diac, here's 3 shots of the gate vs secondary, i used a high wattage 1k variable resistor in series with the diode and gate, each shot has progressively more feedback, on the 3rd shot the pot is fully on or S/C

I have had it running where it does not latch, but strangely as i increase the supply voltage the secondary pulse remains the same amplitude and all that happens is the mains bulb gets brighter
   
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Peterae

Thanks for the scope shots, they are interesting.

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Maybe i have the coil the wrong way around, i am not sure, the negative current being fed back to the gate occurs at the same time as the negative drive from the diac

The GTO pulse looks too large, as if it is the actual firing pulse. Have you tried reversing the connection?

If you are getting some type of regenerative feedback that is triggering the SCR, it could be that the phase of the new winding is backwards.

Or maybe too much capacitance in the diode is doing the triggering on the forward pulse. The GTO signal should be applied on the ringback pulse, the diode should block the forward pulse.

Always put a current limiting safety resistor on series with the pot so that you don't blow the gate with too much current.

When it is working properly, you should still have triggering control from your frequency adjust pot.

Thanks for trying this, when I get back to the bench I will also.


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Hi ION
Thanks, yes i ran out of time last night to get my head around what's going on, i will try switching the polarity of the coil tonight, i am using a 1n4007 diode.
The first little positive pulse is from the diac, this must be the turn on pulse as it's positive, the coil i have added is reinforcing the negative pulse as can be seen by the 3 different amplitudes when i turn my 1K pot.
   

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I managed to put a bit more time in tonight, although i really need to get my camera home again to video the result, it does not seem to stop latch up though, but certainly worth a try, my next move is to start playing with the choke/resistor and see how this affects the running.

   

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If SM discovered the basic effect for the TPU during his work with speaker voic coils and his spatial audio work, then the coils wre probably in a magnet. 

Use of a magnet may allow you to use less current than your current approach.
   

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This is just an idea, but i think i may know why i have been getting the crackling from the wire in my other experiments.

I have long suspected that by varying the pulse delay between 2 pulses it is the same as driving the coil with a known set frequency, for instance if i was driving a coil at 1MHz then the period between each peak would be 1uS, if i was to drive at 10MHz then i would have a peak spacing of 100nS.

So if i pulse and then wait for 100nS and then pulse again, it's the same as pulsing the coil at 10MHz but i can have a long relaxation time after this second pulse, my master frequency can be anything, let's say 100Hz, so every 10mS i would send 2 pulses with a 100nS delay between them.
So in this case the coil's properties are flipping from being run at 10MHz but with a long relaxation period in between this, the coils impedance is all over the place, so now if i have a coil that has a self resonant frequency of 1MHz and i send 2 pulses with a 100nS delay between them then the coil takes on the properties as if momentarily it's being driven at 10MHz, wouldn't the impedance suddenly become very high if not open circuit for a very short time, but as soon as that second pulse stops, bang the coil's properties revert back to not being driven at all for 10mS, i am in effect flipping the properties of the coil from one extreme to another, i am not sure how long a coil takes to change it's properties but if this was extremely fast.

There may not be OU causing the explosion, i have never been able to prove this, but if by varying the time suddenly became a short circuit from an open circuit impedance then this may cause a violent tug.

I have previously proven that by varying the delay time between the pulses that the amount of current the coil draws varies with regard to the ringing that would be seen if the coil twangs.
   

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Based on my own "explosion" experience, I am convinced that space itself becomes locally saturated and discharges (dissipates). 

You can make a sparkgap pulser using a MOT or Ignition Transformer (10kv) with a dual series gap and some distance between the gaps.  Keep the supply ungrounded.  With a little adjustment of the gaps, you can make energy reflect back towards the supply. 

This energy will be outside the wire, in space, you will be able to feel it like the air is thicker.  It will build and dissipate at a slow cyclic rate, taking several seconds or even minutes. If you are not careful it will ground through your body like a wave of strong pressure moving across your body, arm-chest-arm.  I grounded it to me scope, no harm done, but scared the Hell out of me.

This shows several things that are not immediately evident:

The first two were discovered by Tesla and included in a couple of his patents.
1. a spark gap projects particles of the medium itself, with positive pulses projecting positive particles
2. the projected particles will reflect off metal
3. The particles will accumulate if supply excedes dissipation
4. if a sink, such as a circuit, is provided, the particles will move along the conductor as a current (take a look at kapandze's grounded systems)
5. the efect produced by the particles vary with frequency as does the nature of the particles itself.  The particle frequency varies with the properties of the system, such as the self-inductance, capacitance, etc.
6. Feynman, Nipher, Rendtorff, Jefimenko, Galilia, Goihbarg, and others have demonstrated that energy flows into a circuit at the supply and out at the load.  The old "Drude" model of electrons flowing through a wire is obsolete.

and much more.
   
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Peterae,

It is easy to forget that a 'space' between pulses is the same as a pulse between 'spaces'.

Relative to the peak of the pulse zero is an equal and opposite value.

You can ring a bell with a single stroke  ;)

In your case, you may be pushing the child in the swing from both sides  :o

Hmmm... Enough of that.

Energy is best converted during cancellation. If your following pulse is in opposition to a previous pulse (perhaps reflected and meeting with cancellation) then the energy must manifest itself in some way.

It wouldn't be the first time for a pulse generator designer to use collision of following and reflected pulses to create incredibly short leftover pulses.
   

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t is easy to forget that a 'space' between pulses is the same as a pulse between 'spaces'.

I am not so sure about this, the reason is that there is definitely an upper boundary to the time that a pulse has to occur, for instance with the large pulse this can clearly be seen to ride in amplitude a sort of sine wave which almost seems to relate to ringing, this all occurs in the first 300nS very little happens after this and nothing can be seen after 600nS

There always has to be a relaxation period of at least 300nS-600nS to get the explosions to occur, this is why my first experiment was so good at creating the explosion effect, the fet's random re-triggering was causing RF bursts with relaxation periods in between, and just sometimes the timing and relaxation was just right to create the explosion, bizarrely these explosion did not occur that often as can be seen from the video.

Something i never managed to video, i found a phase delay setting, that was causing these RF burst at random intervals of 1-2 bursts every 10 seconds, how weird was that, i could not get my head around the triggering event causing these, my mA meter would read 10-15mA and bang it would hit the end stop for a brief moment while the fet's re-triggered and then back to 10-15mA all at random timing.
   

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Try tapping into the explosion zone:

Lay a wire along side the bifilar pair as a collector, connect it to your load and the other end of the load to ground.
   

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This simple clue would permit the configuration of a limited sized device in all the device packages we have seen.
This would also permit the 'A new type of induction and the way coils work'.
This would also permit the 'Ramp up' as the capacitance on the outer stages charge up.
This would permit '3 phase segmentation' but interleaved.
This would also permit the use of 2 switches as seen in the LTPU.

Try tapping into the explosion zone:

Lay a wire along side the bifilar pair as a collector, connect it to your load and the other end of the load to ground.


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Hey ION look at this circuit i just found, it's an open source CDTI thyristor ignition system, it charges a cap and uses the energy to drive an HV coil and it's digitally triggered. It also has a handy 12V to 220V inverter system, nice simple circuit.

http://www.me.iitb.ac.in/~ems/dccdi.pdf

I love this circuit, it even shuts the inverter down when it fires the HV so only the charged cap energy is delivered to the coil, by varying the 220K feedback resistor and adding more secondary turns to the inverter transformer then it would be possible to make it a variable supply.

Would i be correct in saying that this circuit cannot suffer from thyristor latch up. and is pretty efficient as well although i guess it's not so good for you 200 Amps pulse or is it?

I would guess it has a pretty low repetition firing rate which would be a shame
« Last Edit: 2012-01-15, 22:17:59 by Peterae »
   
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If the CDI circuits are that complicated, I'm not sure I would like one in my car, unless of course they are supper reliable and the benefits outweigh the costs, i.e, the long term costs when one has to get the car towed to the shop for fixing!   
   
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Hey ION look at this circuit i just found, it's an open source CDTI thyristor ignition system, it charges a cap and uses the energy to drive an HV coil and it's digitally triggered. It also has a handy 12V to 220V inverter system, nice simple circuit.

http://www.me.iitb.ac.in/~ems/dccdi.pdf

I love this circuit, it even shuts the inverter down when it fires the HV so only the charged cap energy is delivered to the coil, by varying the 220K feedback resistor and adding more secondary turns to the inverter transformer then it would be possible to make it a variable supply.

Would i be correct in saying that this circuit cannot suffer from thyristor latch up. and is pretty efficient as well although i guess it's not so good for you 200 Amps pulse or is it?

I would guess it has a pretty low repetition firing rate which would be a shame

It is a nice circuit.
The scr is a 2 way device, which will allow the cap and coil to stay connected to make use of oscillation and provide greater output. It is more eff to charge the cap to 200v than it is to hold direct battery current to the primary until the switch opens in a point ignition setup.

Similar to a points system ignition, the capacitor across the points(switch) becomes the charged primary coils path after the points open, then oscillation. Without the cap, the spark is very weak.
In a way, a simple point system ign is  a multi spark ignition.

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