PopularFX
Home Help Search Login Register
Welcome,Guest. Please login or register.
2024-11-26, 11:24:09
News: Check out the Benches; a place for people to moderate their own thread and document their builds and data.
If you would like your own Bench, please PM an Admin.
Most Benches are visible only to members.

Pages: 1 2 3 4 5 [6] 7 8 9
Author Topic: DSRD pulse generator  (Read 200855 times)
Group: Elite
Hero Member
******

Posts: 3537
It's turtles all the way down
Itsu:

You could try making a simple impedance matching autotransformer transformer e.g. 10 turns of heavy wire wound on a cardboard tube. The first turn would be the DSRD output, the last turn  would feed the cell. This would give you about 1:10 step up of the pulse and a better impedance match. You could vary the primary  tap or output tap on the coil to find the best match.

It is best to keep the DSRD operating into a low inductance primary tap to preserve pulse "crispness".

This is just an example. Your autotransformer could be whatever ratio desired.


---------------------------
"Secrecy, secret societies and secret groups have always been repugnant to a free and open society"......John F Kennedy
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159

Thanks ION, i tried your autotransformer idea.

50:1800 = 1:36, so i made a 72 turns autotransformer of 2mm copper wire.
The DSRD is across the bottom 2 turns representing 50 Ohm, and the tube is on the top (72) and bottom turns representing 1800 Ohm.

 
The DSRD produces a nice pulse now (650V at 13ns with 81V on the drain), but the HV noise (caused by the autotransformer?) feeds back into the scope making it go crazy.

When measuring across the tubes, i only have a ringing like signal of 130V p2p, so again the pulse is gone.
Probably the inductance of the autotransformer is causing this.

Nice try, but no cigar  ;-)

Video here:  http://www.youtube.com/watch?v=qeBkNhFDeLA&list=UUdJ2A-075yx9y4bKqu_8Q8A&index=1

Regards Itsu
   

Group: Professor
Hero Member
*****

Posts: 3499
The DSRD produces a nice pulse now (650V at 13ns with 81V on the drain), but the HV noise (caused by the autotransformer?) feeds back into the scope making it go crazy.
Does it mess up the new electronic electric energy meters from your power company (electric utility), too ?
   
Group: Elite
Hero Member
******

Posts: 3537
It's turtles all the way down
Have you measured the capacitance of the cell?  It may be resonating the pulse at the output of your autotransformer.

I was thinking of a lower turns ratio, like 1:5 or 1:10 using a single turn primary.


---------------------------
"Secrecy, secret societies and secret groups have always been repugnant to a free and open society"......John F Kennedy
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159
Does it mess up the new electronic electric energy meters from your power company (electric utility), too ?

Not really, it only makes it turn in the opposite direction; is that bad?   ;D

Regards Itsu
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159
Have you measured the capacitance of the cell?  It may be resonating the pulse at the output of your autotransformer.

I was thinking of a lower turns ratio, like 1:5 or 1:10 using a single turn primary.

Not sure i can measure the capacitance with this residual voltage in it, but i will try.

I will also try to use a 1:10 transformer.

Thanks,  regards Itsu
   

Group: Professor
Hero Member
*****

Posts: 3499
Have you measured the capacitance of the cell?
Yes, the electrolysis cell with pure water should be measured like a capacitor.  See Capacitive Reactance.
You can do it even with the low voltage signal from your signal generator and the oscilloscope across a CSR.

If you are getting some residual voltage generated by this cell then it means that your water is not clean enough and that you are using dissimilar metals that had some residual contamination on the surface from previous experiments.  
If you scrub the surfaces with sanding paper and wash them well with deionized water, the residual voltage will disappear.
   

Group: Professor
Hero Member
*****

Posts: 3499
But as i had some double distilled water available, i just poured a cup and did some testing.
The nano-pulser behaves much better now with this water, i have a 1160V / 40nS pulse with some ringing.
It would be very interesting to see if this ringing waveform changes a little in the presence of a magnet outside of the glass beaker in this configuartion.
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159
It would be very interesting to see if this ringing waveform changes a little in the presence of a magnet outside of the glass beaker in this configuartion.

As i did not test this present stainless steel 316 tubing i am not sure, but all my other stainless steel 316 tubing was nonmagnetic, and i expect this one also to be nonmagnetic and therefor i doubt a magnet will change the signal.
But i will try to test this.

Regards Itsu

 
   

Group: Professor
Hero Member
*****

Posts: 3499
i expect this one also to be nonmagnetic and therefor i doubt a magnet will change the signal.
But i will try to test this.
I hope the stainless tubing is nonmagnetic. I don't want it to move in response to the magnet!
I had something else in mind, namely proton precession in that pure water...
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159
I hope the stainless tubing is nonmagnetic. I don't want it to move in response to the magnet!
I had something else in mind, namely proton precession in that pure water...


OK, i repeated that specific experiment (nano-pulser with short leads to the cell), and used a stack of neo's to approach the beaker and even the tubing.
But no change is to be seen in the waveform or the amplitude.

Video here: http://www.youtube.com/watch?v=OY5hVtiIDwM&feature=youtu.be

Regards Itsu
   

Group: Professor
Hero Member
*****

Posts: 3499
Thanks for checking this out.
The setup had the wrong geometry for proton precession but I thought that the strong nanopulses might fringe out in the water and interact with the static magnetic field slightly.
As it is now, the LC resonance simply overshadows any proton precession signals (the stainless steel tubing forms the capacitance C, with water as a dielectric and the rest of the circuit and wires form the inductance L).

To see the proton precession, you'd have to feed the nanopulses to the thin copper tubing coil, that you have sitting nearby, and put the beaker of water inside that coil.
Also the water would have to be inside a large perpendicular Maxwell Coil supplied with DC, in order to generate a static uniform field throughout the water (because magnets do not generate uniform magnetic fields).
« Last Edit: 2013-05-09, 10:29:47 by verpies »
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159

To see the proton precession, you'd have to feed the nanopulses to the thin copper tubing coil.................

Right, so a different setup alltogether.

I will leave that for some future experiments,  thanks.

Regards Itsu
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159

I tried to make some measurements of my cell, but only could find that the coaxial tubing has a capacitance (outside the water) of 30pF.

When putting it into the water, the voltage on this tubing raises to 300mV which makes any resistance and capacitance measurements present wrong info.

I then used a 8 turns copper tubing coil as an autotransformer, but we see the same problem as with the earlier used autotransformer, nice pulse across the DSR diode, but a ringing like signal (3.3Mhz) on top of the cell and no HHO.

Got severall comments/advices also on my youtube channel, so need some time to follow them up, like this:
http://www.dtic.mil/dtic/tr/fulltext/u2/a567653.pdf (thanks kleeph)

Video here: http://www.youtube.com/watch?v=JWm1IHSnyVA&feature=youtu.be

Regards Itsu

 
   

Group: Professor
Hero Member
*****

Posts: 3499
When putting it into the water, the voltage on this tubing raises to 300mV which makes any resistance and capacitance measurements present wrong info.
That really should not happen with a very clean cell.
Anyway if a DC offset interferes with your capacitance measurements then connecting a LARGE non-polarized capacitor in series with the electrolysis cell would make the measurement possible.
« Last Edit: 2013-05-08, 18:16:53 by verpies »
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159
I brought the cell together with the 8 turn air coil in resonance by loosely coupling my FG signal via a 1 wire loop.
It resonates at 3.190Mhz.

Then i substituted the cell by a variable air capacitor and was hunting for the same 3.190Mhz resonance frequency.
When found, i measured the variable air capacitor to be 500pF.

An online calculator calculated the 8 turn coil to be 5uH
 
So there it is;

cell capacitance 500pF
auto transformer inductance 5uH
resonance frequency 3.190Mhz

So how do i get my 1200V / 12ns nano-pulse effectively transferred into this 500pF cell?
Could i use a capacitive matching network?

known data:

input impedance 50 Ohm
output impedance 1800 Ohm
output capacitor 500pF

input capacitor?

Found some "matching capacitor calculators" on the net, but they all need to know frequency and Q, while i think that would not be needed


Regards Itsu


   

Group: Professor
Hero Member
*****

Posts: 3499
cell capacitance 500pF
auto transformer inductance 5uH
resonance frequency 3.190Mhz
<<impedance 1800 Ohm>>
Your, cell capacitance seems to be measured properly using the LC resonance circuit and substituting known C.
I don't question your 3.19MHz resonance if you used a sine waveform to stimulate the LC.
With the 5μH inductance of the coil, I just have to trust your inductance meter, however it is unclear whether this inductance refers to the primary of this autotransformer or to the inductance of the primary + secondary.

The "impedance 1800Ω" most likely refers to a DC measurement and should be called DC "resistance 1800Ω". 
For non-DC signals, the capacitive reactance of your cell and the inductive reactance of your coil matters as well. They can be subtracted from each other and they are dependent on the frequency of your stimulating signal (the nanopulse spectrum - not the PRF alone!). Think of them as frequency-variable resistances.  See here.

BTW:  Resistance + Reactance = Impedance.

Finally, don't forget about getting the signal from the pulser to the cell - a transmission line gotcha.  See this video.


Itsu:
You could try making a simple impedance matching autotransformer transformer e.g. 10 turns of heavy wire wound on a cardboard tube. The first turn would be the DSRD output, the last turn  would feed the cell.
So how do i get my 1200V / 12ns nano-pulse effectively transferred into this 500pF cell?
Since it was ION's idea to go with an autotransformer, I will leave it to him to do the impedance calculations.  Without the knowledge of nanopulses' spectrum, I wish him good luck.
« Last Edit: 2013-05-09, 10:54:01 by verpies »
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159

Quote
I don't question your 3.19MHz resonance if you used a sine waveform to stimulate the LC.

I used both sine and square wave, showing both the sine wave resonance of 3.19Mhz

Quote
With the 5μH inductance of the coil, I just have to trust your inductance meter, however it is unclear whether this inductance refers to the primary of this autotransformer or to the inductance of the primary + secondary.

The 5uH was calculated with an online calculator using the now known 500pF and 3.19Mhz.
My inductance meter was not able to measure this low inductance.
As the LC was over the whole coil, its the inductance of both primary + secondary.


Quote
The "impedance 1800Ω" most likely refers to a DC measurement and should be called DC "resistance 1800Ω". 

Right, calculated in an earlier post from the measured peak voltage.

Quote
BTW:  Resistance + Reactance = Impedance.

i know, but you are right, i keep mixing them up.

Quote
Finally, don't forget about getting the signal from the pulser to the cell - a transmission line gotcha.  See this video.

Good info, i have some copper tape which i could use to do some experiments with.

So basically, its not that simple to get this nano-pulse transferred to the cell without losses or signal corruption and probably would take lots of experiments.

Thanks,  regards Itsu
   

Group: Professor
Hero Member
*****

Posts: 3499
I used both sine and square wave, showing both the sine wave resonance of 3.19MHz.
You were lucky. A square wave has many frequency peaks (lobes) that can confuse the measurement.

The 5uH was calculated with an online calculator using the now known 500pF and 3.19Mhz.
That's even better if the 500pf is trustworthy.

Right, calculated in an earlier post from the measured peak voltage.
Peak voltage at what frequency?

Good info, i have some copper tape which i could use to do some experiments with.
Remember that you have 1kV pulse and that is very different from the 1V pulse on that video.  You don't need a 1Ω transmission line at that voltage

So basically, its not that simple to get this nano-pulse transferred to the cell without losses or signal corruption and probably would take lots of experiments.
If your pulse is 10ns wide then it means that is similar to a 50MHz square wave. (20ns period).

For 50MHz square wave, a 5μH inductance has an inductive reactance of 1273Ω.
XL=5.09*f*L  for square voltage source (here is why)
XL=6.28*f*L  for sine voltage source
The coil is a low pass filter.  It has low reactance at low frequencies and high reactance at high frequencies.

The capacitance of the cell behaves oppositely. It is a high pass filter. It has high reactance at low frequencies and low reactance at high frequencies.
In this case, a 500pf capacitor has 8Ω capacitive reactance to a 50MHz square wave.

Of course, your waveform is not square but a low DUC rectangular waveform, consisting of a dense comb of frequencies from 1kHz to 50MHz (see attachment)
Also, the transformer action decreases the primary winding's inductance of any loaded transformer (Lenz Law).


P.S.
The frequency at which the inductive reactance is equal to the capacitive reactance is your LC resonance frequency (in your case 3.19MHz).
« Last Edit: 2013-05-09, 13:40:33 by verpies »
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159

Quote
Peak voltage at what frequency?

Well, peak voltage was not the correct wording, i mean i calculated the DC resistance of the cell by Ohms law when i used
my maximum DC voltage of my PS (363V) and measured the current to be 200mA (via a 0.1 Ohm csr).

Regards Itsu
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 1593
Frequency equals matter...


Buy me a drink
The effect of the nanopulse is easily subducted.


---------------------------
   

Group: Experimentalist
Hero Member
*****

Posts: 2982


Buy me a beer
Hi Itsu

do you still have your pulser? let me know, what you were trying to do with the cell was missing certain things for it to work.

I will be explaining how this works in the near future once I have got a few things together, and also another European replication being built right now.

regards

Mike 8)

Ps I think you are away for a couple of weeks, no problem, when you return. O0


---------------------------
"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860

As a general rule, the most successful person in life is the person that has the best information.
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159
Oops,   did not see that one recently.

Yes, still have it and i did fire it up just last night using 12V on the MOSFET driver logic and 24V on the drain.
Here a screenshot of the output pulse in a 56 Ohm resistor with a pulse repetition rate of 100KHz using my FG as pulse source.

Regards Itsu

   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159
Hi all,

i am experimenting with a circuit to produce 1 nanosecond wide pulses (with 350 picoseconds rise time) using a 2n2369 transistor and a Lt1073 dc-dc chip.
The circuit used is found in the LT1073 datasheet on page 14.

First tests shows it produces 15ns wide pulses (rise time 4ns) of about 4V in 50 Ohm.

Looking closer to the circuit shows that the LT only provides the needed 90V bias voltage, so can be omitted.
But using a barebone circuit with only the 2n2369, 3 resistors and a trimmer cap using very short leads on a ground plane pcb does not improve the situation,  we still have 15ns wide pulses and not the promised 1ns with 350ps rise time.
Is the probe/scope the limiting factor here?

When using a breadboard shows the same data, but makes it more easily to swap transistors etc.
It shows that the only transistor producing these pulses in this circuit is the 2n2369, many others show nothing, see video for transistors used.

Any idea why this 2n2369 is so special in this case?
Any suggestions for an other (better) one?

Anyway, first video here:   https://www.youtube.com/watch?v=WGdBW2NLR1Y&feature=youtu.be

Next will be to change the fixed resistors (base 10K and emitter 56 Ohm) to variable potmeters and to add more capacitance across the collector.

Regards Itsu

PS, for a good answer on the above questions why the 2n2369 is so special (avalanche transistor), see the reply from muDped here:
http://www.overunityresearch.com/index.php?topic=2578.msg41178#msg41178

For an additional circuit to play with, see this answer from Les Banki here:
http://www.overunityresearch.com/index.php?topic=2578.msg41180#msg41180
   

Group: Elite Experimentalist
Hero Member
*****

Posts: 4159

I made some changes yesterday by changing the fixed 10K and 56 Ohm resistors to variable ones.
Also the capacitor was increased from 4pf via 16pF till finally about 80pF.

The change of the 10K base resistor to a 20K pot did not do much, only at the lower end (300 Ohm) a change to lower amplitude was seen.
The change of the 56 Ohm emitter resistor to a 500 Ohm pot was more noticeable as the amplitude of the pulse went up considerable.
The change of the 4pF cap to finally 80pF made the amplitude increase even more till 36V with a pulse width of 44ns.

Video here:  https://www.youtube.com/watch?v=y1Wy4ef4EiI&feature=youtu.be

Regards Itsu
   
Pages: 1 2 3 4 5 [6] 7 8 9
« previous next »


 

Home Help Search Login Register
Theme © PopularFX | Based on PFX Ideas! | Scripts from iScript4u 2024-11-26, 11:24:09