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Author Topic: Controller No5 With Protection - Looking for Explosions  (Read 231536 times)

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tExB=qr
place a grounded sheet of metal (foil is good) between the source and collector plate

then try both the gronded sheet and the plastic and measure between the grounded sheet and collector to see if you have a potential difference between them.

These are tests for beta and gamma (without going into details).   Conversion of virtual particles to real ones emulates particles, but any slight differences will shed light on how they are converted.  Capacitors do it all the time...  O0
   

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I must pick up on this coil soon , with the dual avalanche pulser.
   

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I received 2 PCB's from Peterae which he presented here:   http://www.overunityresearch.com/index.php?topic=3345.msg57701#msg57701

In that post you will also find the circuit diagram.

I decided to build on one of those PCB's the original circuit which was intended to drive a special coil to produce crackling sounds and 80Watt spikes across a 20 Ohm resistor.
I used this original thread to continue so that all previous info is close by.
 
Another short thread which contains coil building specifications is this one:  http://www.overunityresearch.com/index.php?topic=366.msg5348#msg5348
The PIC's white noise program comes from this website:  http://electricdruid.net/white-noise-source/   but need some tweaking.

I build up the PCB so it has a 5V regulator for the PIC12F629 controllers (generating the white noise) and a variable LM317 regulator using a 10K potmeter to set the MOSFET driver to 20V
MOSFETs are put on print connectors so can easely be swapped out in case of damage or if needing different type of MOSFETs (currently 2x IRFP260N's are in).

I will continue building the special coil, but it needs prefferable some thick copper cladded steel inner conductor coax cable (I have RG316, but it is thin, so could perhaps use
multiple turns to build a rigid base to wind the bifilar coil around it).

Anyway, here a short video of the PCB setup and the MOSFET driver output signals on the scope:  https://www.youtube.com/watch?v=7Uq8Y7qtfkk

Regards Itsu
 
   

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Dear Itsu.

I'm not sure if the info following will be of any use.....

DIY mig welder wire is Copper coated steel and comes in 0.6 and 0.8 mm diameter. The coating is very thin.

Just musing whether you could easily substitute the centre conductor?

Kind regards, Graham.

PS . My apologies if this has been previously mentioned.


---------------------------
Nanny state ? Left at the gate !! :)
   

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Hi Graham,

well i did not know that, so thats good, but i think another requirement is that it needs to have an isolation around it, like the inner conductor of a coax cable has.

But thanks anyway,   Itsu
   

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Hi Graham,

well i did not know that, so thats good, but i think another requirement is that it needs to have an isolation around it, like the inner conductor of a coax cable has.

But thanks anyway,   Itsu

Hi Itsu.

What length of Coax is needed for the experiment? This might sound daft but you could sleeve the mig wire with a tube, fish keeping air tube for example and by carful dissection of some standard coax by pushing the braid back upon itself slide it onto your new inner cable.

This idea would only work for a few meters though, absolute nightmare for a long length.

Kind regards, Graham.


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Nanny state ? Left at the gate !! :)
   

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Graham, 

the diameter of the coax loop is around 16cm, so that makes the circumference 50cm, so very doable.
Not sure what quality the isolation has to be.

On the other hand, there is a cheap supply of RG11 coax cable available on Ebay (per foot $1) which also has the AWG 14 inner conductor made of copper clad steel.

Regards Itsu
   

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Anyway, here a short video of the PCB setup and the MOSFET driver output signals on the scope:  https://www.youtube.com/watch?v=7Uq8Y7qtfkk
Can these MOSFET gates really tolerate >20V ?
   

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20V seems to be the limit for the IRFP260N, so indeed, i need to tone it down a bit to 15V or so.


Thanks,   Itsu
   

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I normally use 18V
   

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try 2kv
   

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Frequency equals matter...


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try 2kv

I foresee alot of great equipment going up in smoke.
It was just this kind of setup that got me divorced. And that was after I blew up the house and neighborhood.

Be very very careful. I cant believe this config is coming back to light.
What works even better is a partial winding just at the ends of the horizontal, thanks to Wattsup.

Is this a test or conspiracy?


---------------------------
   

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try 2kv
Did you know that it is actually possible to apply 2kV to the gate of a MOSFET without damaging it?

The key to this is the fact that it is not the voltage applied to the gate terminal, that breaks down the gate insulator, but the voltage that the gate-source junction gets charged to.
Since the gate is essentially a capacitor of several nF, it is possible to hit it briefly with 2kV without damage, if you interrupt the process before the gate-source junction reaches 20V.
It is a way to quickly turn on a single MOSFET. 

P.S.
With an array of parallel MOSFETs, the transmission line effects might charge up some gates before the others.
   

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Interesting, but it probably takes more logic to control the timing then it takes to design an other way of fast switching.





Anyway, i put up something like the needed coil setup.
Basically it a RG316 (thin) inner conductor with its isolation (Silver-Plated Copper Clad Steel) with some isolation / hose over it to create some distance for the bifilar wound (the
green/red dual bonded magnet wire), coils, see picture.

The hose i used has some spiral like shape in which the dual bonded magnet wire falls nicely, but there is some spacing between the wires which i think decreases the
overall inductance of the bifilar coils to much, as they measure only 9uH each.

The in the diagram used R1 (10 Ohm / 10W) gets hot within minutes at 12V and without this R1, the circuit acts like a short.
Any idea what the inductance needs to be for the bifilar coils?

The drain signals in this situation are like in the screenshot1.

The signal across the inner coax cable (loaded with 10 Ohm to) is shown in screenshot 2.

Itsu
   

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Interesting, but it probably takes more logic to control the timing then it takes to design an other way of fast switching.
If you do it by measuring the voltage to which the gate got charged to and reacting to that information in real time in order to interrupt the charging process, then it is a lot of work  ...but it works with any FET.

However, if you do it the lazy way and just precharge some pF cap to HV and then dump it into the MOSFET's gate at a proper moment, then the charging process terminates when the voltage in the pF capacitor equalizes with the voltage across the nF capacitor, that constitutes the gate.
The downside of the latter method is that the pF capacitor needs to be matched to the capacitance of the gate, so it is not universal and works only with the MOSFETs that it was matched to.  Also the pF HV cap needs to be one of these high-current caps for radio transmitter applications.
   

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Anyway, i put up something like the needed coil setup.
It is a very good looking coil.
I do not know if it is suitable for what Peter was suggesting, but it is good looking nonetheless.
   

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If you do it by measuring the voltage to which the gate got charged to and reacting to that information in real time in order to interrupt the charging process, then it is a lot of work  ...but it works with any FET.

However, if you do it the lazy way and just precharge some pF cap to HV and then dump it into the MOSFET's gate at a proper moment, then the charging process terminates when the voltage in the pF capacitor equalizes with the voltage across the nF capacitor, that constitutes the gate.
The downside of the latter method is that the pF capacitor needs to be matched to the capacitance of the gate, so it is not universal and works only with the MOSFETs that it was matched to.  Also the pF HV cap needs to be one of these high-current caps for radio transmitter applications.


Right, the "lazy way" seems like a novel idea, and there are many high-current pF caps for radio transmitter applications available.
But how do we "dump it into the MOSFET's gate at a proper moment",  by using a MOSFET?    :o


Itsu
   

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It is a very good looking coil.
I do not know if it is suitable for what Peter was suggesting, but it is good looking nonetheless.


Thanks,  i think   ;D


The bifilar coils need more inductance and the radius needs to be smaller too, so i will be looking for a smaller radius hose without the spirals so the windings can be closer together.


Itsu

   

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Itsu
Good work.
Try to increase the whitenoise bandwidth by adding a 20MHz crystal and 2 22pf caps across the pic pins 2 & 3, i think a cap could be soldered across the under pads, maybe a xtal as well, do this for both pics, it will increase the bandwidth of the whitenoise greatly.

Is there any crackling coming from the coils, try holding a magnet next to the coils.
I think you need to get some thinner wire for your bifilar and greatly increase the turns if possible, but first do the xtal to see how it performs.
   

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Thanks Peter,

you mean adding a 20Mhz x-tal and 2 x 22pF caps to each Pic pins 2 and 3 like in the attached diagram?

Presently both Pics have their pins 2 and 3 directly connected to ground, so i have to remove that and install the xtals / caps (which i happen to have).

But do the pics not need to be reprogrammed as probably they are set to run on their internal clocks (4Mhz)?


Running now with 40V on the drains via a 220 OHm / 25W resistor, but no crackling noise heard, also not when using a stack (4) of ceramic magnets next to the coils.


Itsu
   

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The bifilar coils need more inductance and the radius needs to be smaller too, so i will be looking for a smaller radius hose without the spirals so the windings can be closer together.
As you probably know every bifilar coils can be connected in two ways - aiding and opposing (bucking).  The former yields more self-inductance and the latter yields less (ideally zero).

Also, decreasing the radius decreases the inductance.  Bringing the windings closer together will foremostly increase the coil's self-capacitance.
Increasing the turn count will increase the self-inductance squarely (L∝n2)
   

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Yes, i did know, but it is funny how some things are just taken for granted without giving it any further thoughts.

Off course i need to take a closer look at this bifilar coil, to see how it ticks (is connected) before throwing in my first comments.

Thanks,   Itsu
   

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Hi Itsu
Thats right xtal as per the above diagram, there is an unfortunate error in the pcb, with one of the pics pin was connected to pin1, cut that accidental track underneath on the pic that has this error, then you will notice underneath the board there is a way to solder surface mounted caps to earth across pin 2 & 3 of each pic, they are not connected to ground or should not be, if you look at the track layout.

Then you will need to find a way of soldering a 20MHz xtal onto pins 2 & 3 you could solder directly on to the chip pins so the xtal sits on top of the pic, or you could solder underneath the pcb but make sure the metal case does not touch anything and short it.

Then you will need to re-burn the software with the configuration bits set for HS which is how it was before we got it currently going.

I don't remember being able to get the high current spike with the pic running at 4mhz like you have at the moment.

Unfortunately i cannot guarantee you will find the pulse, this pcb setup has never been checked as working by me, but my intention was to give it a go to try and make it easier, when i got the current spike i kept the current low by limiting the whitenoise pulse width to 100nS by feeding 2 digital monostables, It's the clashing of the rising or falling edges occasionally that seems to create the spike but i could never track it exactly down which is why i use whitenoise because it covers every random pattern once in a while creating the spike.
   

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Quote
Hi Itsu
Thats right xtal as per the above diagram, there is an unfortunate error in the pcb, with one of the pics pin was connected to pin1, cut that accidental track underneath on the pic  that has this error, then you will notice underneath the board there is a way to solder surface mounted caps to earth across pin 2 & 3 of each pic, they are not connected to ground or should not be, if you look at the track layout.



Peter,

i must of have a different (later?) pcb as none of the 2 pcb's i have, show the pin 2 to pin 1 track you mention and which can be seen in your above pcb layout picture.


Concerning the pins 2 and 3 to ground which i presently have, this is clearly stated in the diagram below, there both Pics have their pins 2 and 3 connected to ground
via 0 Ohms (bridge) SMD resistors (R5, R6, R7 and R8), so i used a solderbridge to put them to ground.


Anyway, i will rearrange the PCB so that it runs with the 20Mhz x-tals and reprogram the pics to use this external timer.


Thanks,  itsu
   

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Ah ok thats good pin 2 is not grounded, i am only looking at the photo of the layout and it looks like it is shorted, so thats good.

Pin 2 & 3 show a resistor or a zero ohm link, but these have not been fitted, they should 0800 footprints for surface mount resistors which are the same size as the surface mount capacitor, in your case instead of a resistor you want to fit the 2 crystal caps 22pf.
   
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