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Author Topic: Kapanadze Cousin - DALLY FREE ENERGY  (Read 11715637 times)

verpies

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #360 on: October 14, 2012, 01:26:26 AM »
I now have a nice sharp 200V pulse of about 70ns which can be varied by a 10Kohm trimpot till 500ns.
Repetition rate of the pulse can be varied between 700Hz till 350Khz (not shown in the video).
This range of frequencies and pulse widths should be sufficient to tune into the DSR effect in wide selection of suitable DSR Diodes.

The gate spikes are due to the drain voltage spikes coming through the drain-gate capacitance of the MOSFET.
Those pulses are dangerous because they can turn-on the MOSFET or keep it conducting longer than you want to (a.k.a. Miller turn-on). 
Try to supress these pesky pulses. A half-solution is to connect a pull-down resistor from gate to ground in the range between 100Ω - 4Ω (experimentally chosen to suppress the gate spikes but not degrade your drain fall-time {off→on transition} too much).
A full-solution to this pesky drain-gate capacitance is a better MOSFET driver, designed to combat the Miller turn-on effect, by pulling the gate hard to ground when the MOSFET is supposed to be off (e.g. the UCC27512 or UCC27511).

Next step will be to hookup the small toroid and the DSRD diodes and hunt for the 1ns/1KV/1Khz pulse
Really protect your scope at this point! The HV spikes can damage its input amplifiers.

The first thing to do is to connect the primary winding of T2 and a series 0.1Ω current sensing resistor (CSR) instead of that 100Ω load resistor, you have now, and scope the current in that CSR (without any load on the secondary) to observe the saturation point in the ferrite core, as shown here.  You must know the saturation point unless you want to proceed blindly.
Begin the saturation measurement with very short pulse widths and 20V HV power supply on the drain and increase them carefully while watching the scope for any signs of saturation, excessive spikes and heating.
If V/R limit manifests itself before saturation, then add more turns.

P.S.
Your "spike remover", made of the 1kΩ & 1nF parts (pt.4a), may be incompatible with the DSRD driver using the saturable transformer (pt.4d), so prepare to remove it when you get to the DSR Diodes, later.
« Last Edit: October 14, 2012, 11:22:20 AM by verpies »

verpies

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #361 on: October 14, 2012, 02:04:43 AM »
No worries; so I guess the back spike is the field behind collapsing
You have worse then spikes. You have reversal of the collector current due to LC oscillations!.

Of course those aren't right... I couldn't have luck and pick the part that was high enough current  and not be inductive :)   
Just Murphy's law at work.
However those current sensing resistors do not need to be rated at more than 4 Watts.
A 0.1Ω resistor at 12V will dissipate 14W of heat, however the current in the T2's primary does not have this value 100% of the time because of the duty cycle and current ramping in the inductor, so at 50% Du.C. it will dissipate only 25% of 14W which amounts to 3.6W.

Just to confirm, was looking at dally pics,... and the power wire would be one of the white wires coming off the toroid, but disappearing beneath the tl494 board;  the other two from two different posts go to a green screw down connector on the edge of that board... those are all thinner wires than the wires on the atx power supply... so they don't have to be so thick?
Maybe they don't but for testing they should be unless you want to be blind to what's going on in your circuit

Most of it is rewired, but :) What I do have is 8 inches of 32 gauge wire which should be .1 ohm... but it's far from high current...
The current in the orange wires can be many times higher than the current draw from your power supply, when the transistors are pulsing. Also don't forget about the mutual inductance between long wires with high di/dt.

Compare with Itsu's setup and notice how powerful and clean his waveforms are at T2.
He even thinks of rewinding T1's secondary because he is getting 800Vp-p there... although I think it is much easier to adjust the trimpot P2 in this circuit than rewind a transformer.

mihai.isteniuc

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #362 on: October 14, 2012, 08:46:10 AM »
Hello,

My TL494 converter it's done. I still don't have a transformer with 2x150V secondary windings, but with the one I used right now I'm able to light very easy at about 3/4 full brightness a 230V/60W light bulb.

Without any load the converter needs 0,5Amps@12V to run. With the light bulb connected as load the current taken from the source goes up at 4.5Amps. The good news: transistors stay cool. I'm holding back for the moment 'til I will find a suitable transformer. I will start working on the nanopulser - the high power part, because I really have to know how much power it needs to run.

Mihai

verpies

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #363 on: October 14, 2012, 10:18:30 AM »
My TL494 converter it's done. I still don't have a transformer with 2x150V secondary windings, but with the one I used right now I'm able to light very easy at about 3/4 full brightness a 230V/60W light bulb.

Without any load the converter needs 0,5Amps@12V to run. With the light bulb connected as load the current taken from the source goes up at 4.5Amps. The good news: transistors stay cool.
Three questions:
1) What is your switching frequency?
2) What transistors are you using to drive the primaries of T2 ?
3) What are the inductances of your T2's primary windings without anything connected to the secondaries? (if you don't know the inductance, at least let us know how many turns on what core).
« Last Edit: October 14, 2012, 11:25:56 AM by verpies »

mihai.isteniuc

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #364 on: October 14, 2012, 11:52:16 AM »
As mentioned before the frequency can be varied between 6khz up to 200khz with a maximum of 40/60 duty cycle. The transformer I'm using it's taken from a computer power supply. I cannot provide any tech specs regarding it.
Variations from Dally's unit:
MJE13009 replaced by some 2SC9245 (I'm not at home and I don't remember exactly). The main difference it's the power dissipared by the 2SC....-80W
2N5401 replaced with BC327
TL494 supply line has a 7812 regulator with some caps for better filtering.
The radiator for the main transistors has a cooler (btw the current at no load posted previously 0.5Amps@12V included also the working cooler).
As expected increasing the frequency and the duty cycle light the bulb brighter and brighter. Maximum was obtain around 150khz and40/60 duty cycle. The bulb wasn't at full brightness only because my secondary wasn't deliver 230V because it didn't has enough turns.

Mihai

verpies

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #365 on: October 14, 2012, 04:30:46 PM »
@Itsu

I just realized that you had your yellow probe in the input of the MOSFET driver, not on its output.
What happens when you increase the drain power supply to +200V and scope the power supply pins of U3 ? 
Do you still have pure DC between U3 pins 14 and 7 ?

verpies

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #366 on: October 14, 2012, 04:44:55 PM »
As mentioned before the frequency can be varied between 6khz up to 200khz with a maximum of 40/60 duty cycle.
But at what frequency did you have that light bulb connected as load and the current taken from the source at 4.5A ?
150kHz or did you mean that it stayed at 4.5A BETWEEN 6kHz and 200kHz ?

The transformer I'm using it's taken from a computer power supply. I cannot provide any tech specs regarding it.
What about the inductance of the primary winding of this transformer?
If you do not have an inductance meter, at least write us the current slope (di/dt) in the primary winding without any load on secondary, as shown on your scope.

Variations from Dally's unit:
MJE13009 replaced by some 2SC9245 (I'm not at home and I don't remember exactly). The main difference it's the power dissipared by the 2SC....-80W
2N5401 replaced with BC327
TL494 supply line has a 7812 regulator with some caps for better filtering.
That's clear enough

As expected increasing the frequency and the duty cycle light the bulb brighter and brighter. Maximum was obtain around 150khz and 40/60 duty cycle.
Was this most efficient 150kHz frequency determined during a sweep while the Du.C. was kept constant?

itsu

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #367 on: October 14, 2012, 05:00:39 PM »
@Itsu

I just realized that you had your yellow probe in the input of the MOSFET driver, not on its output.
What happens when you increase the drain power supply to  200V and scope the power supply pins of U3 ? 
Do you still have pure DC between U3 pins 14 and 7 ?

Well,  not really, 5V DC with the same nasty ringing, (yellow probe across pins 7 and 14) see picture:
(by the way, i now have a 10 Ohm resistor across gate-ground of the MOSFET)


Meanwhile i tried to find the saturation point of the small toroid, but probably my 0.1Ohm resistor is too inductive as i see a lot of ringing on this CSR.
Video:  http://www.youtube.com/watch?v=Xvq5FV6SC1A&list=UUdJ2A-075yx9y4bKqu_8Q8A&index=1&feature=plcp

Guess i have to find me a suitable CSR first.

Regards Itsu

mihai.isteniuc

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #368 on: October 14, 2012, 06:33:02 PM »
But at what frequency did you have that light bulb connected as load and the current taken from the source at 4.5A ?
150kHz or did you mean that it stayed at 4.5A BETWEEN 6kHz and 200kHz ?
At 150KKz the light bulb was the brightest and the current taken from the source was 4.5A
What about the inductance of the primary winding of this transformer?
If you do not have an inductance meter, at least write us the current slope (di/dt) in the primary winding without any load on secondary, as shown on your scope.
I will post some pictures. Also I will connect a condenser in parallel with one of the primaries and try to determine the inductance based on the ringing frequency. I can tell you that the primaries are made from 3 parallel wires at around 0.5 diameter. That can be seen near the connection pin of the transformer.
Was this most efficient 150kHz frequency determined during a sweep while the Du.C. was kept constant?
Yes that is correct

Mihai

verpies

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #369 on: October 14, 2012, 08:29:11 PM »
Well,  not really, 5V DC with the same nasty ringing, (yellow probe across pins 7 and 14) see picture:
Aaaaaa, get rid of it!
Supply must be pure DC.  You already know the drill: bypassing capacitors in parallel, small thick-wire chokes (or ferrite beads) in series, starpoint ground and power distribution.

(by the way, i now have a 10 Ohm resistor across gate-ground of the MOSFET)
Did it worsen the off→on transition of the MOSFET much ?

Meanwhile i tried to find the saturation point of the small toroid, but probably my 0.1Ohm resistor is too inductive as i see a lot of ringing on this CSR.
Video:  http://www.youtube.com/watch?v=Xvq5FV6SC1A&list=UUdJ2A-075yx9y4bKqu_8Q8A&index=1&feature=plcp
I'll watch it as soon as YouTube resumes working.


itsu

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #370 on: October 14, 2012, 09:37:45 PM »

Quote
Aaaaaa, get rid of it!   

Okay, working on it, but it looks like these pesky little spikes slip through anyhow :-)

 
Quote
Did it worsen the off→on transition of the MOSFET much ?

i think it even improved it, see the picture above, almost symmetrical 200V pulse.

 
Quote
I'll watch it as soon as YouTube resumes working.


Ok, guess these spikes/ringing i see is from the inductance of the toroid, and not from the resistor.

I blew up a third MOSFET so am down to the last one, guess they are not up to all that abuse.

regards Itsu


verpies

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #371 on: October 14, 2012, 10:31:31 PM »
@Itsu
I just managed to watch your latest video.

The ringing after the drain pulse is due to that 1kΩ and 1nF "spike remover" which forms an LC tank with the primary inductance of the T1 and the eventual inductance of the CSR.
A 250V transil would be more effective in suppressing these oscillations, but they can be ignored for now, if they do not interfere/damage anything. 

A non-inductive CSR can be quickly made out of straight piece of Nichrome wire squeezed between two small brass bolts
The Nichrome wire can be obtained from the heating element of a broken iron (for ironing clothes) or any other heating element (household or automotive).

The attached snapshot shows the portion of the waveform that we are interested in (the rest we ignore).
The slope (di/dt) of the almost vertical red trace tells us the inductance of the primary.  L=V*dt/di
Where the V is the power supply voltage (e.g. +200VDC) and dt is the current rise time (e.g. 10ns) and di is the current change (e.g. 2A) occuring during the rise time.
I wish the horizontal scale of the scope was set to less ns/div so I could see that slope better.

As it is now, I do not see any signs of saturation at this scale (unless it happens very early).
Thus the natural course of action is to wind more windings on that core to artificially increase the inductance for testing.
(2 equal layers of course, both CW but one of them in opposite direction along the outer circumference ;) )
« Last Edit: October 15, 2012, 12:04:48 AM by verpies »

Hoppy

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #372 on: October 14, 2012, 10:32:55 PM »
Okay, working on it, but it looks like these pesky little spikes slip through anyhow :-)

 
i think it even improved it, see the picture above, almost symmetrical 200V pulse.

 

Ok, guess these spikes/ringing i see is from the inductance of the toroid, and not from the resistor.

I blew up a third MOSFET so am down to the last one, guess they are not up to all that abuse.

regards Itsu

Itsu,

Check your gate voltage is at least 12V, preferably a bit higher. I go for 14v to 15V when using mosfet chip drivers. The two transistor driver shown on a couple of the schematics will not provide enough gate voltage if supplied from a 12V rail.

I've had little success so far in raising the voltage across L4 using the Dally spec coil.

Regards
Hoppy

verpies

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #373 on: October 14, 2012, 10:42:22 PM »
Check your gate voltage is at least 12V, preferably a bit higher. I go for 14v to 15V when using MOSFET chip drivers.
I agree. The closer the supply voltage of the gate chipdriver to the maximum rating of the MOSFET's gate voltage - the better.
I did not mention it because I did not want to complicate Itsu's design with yet another supply voltage (e.g. 15VDC) and deviate from Dally's design.

Of course it never occurred to me that Itsu might not supply the gate chipdriver from the main 12VDC power supply, since the original gate driver, made out of Q3 and Q4 transistors, was supplied from this 12VDC supply. 
Supplying the gate chipdriver from the 5VDC supply of the TTL Logic (U2 , U3) would be a huge mistake! 
That's what we get for working without a decent up-to-date schematic.

Since the TL494 works well up to 40VDC and the TTL Logic (NAND gates in U2 & U3) have their own separate 5V voltage regulators, then the main 12VDC power supply can be increased to 15VDC (or maybe even to 20VDC). 

Also, some of the crappy gate chipdrivers treat any input below half of their supply voltage, as low logic level, which makes their inputs incompatible with TTL outputs.
I did not check if Itsu's driver belongs to that category.
« Last Edit: October 15, 2012, 10:19:52 AM by verpies »

d3x0r

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Re: Kapanadze Cousin - DALLY FREE ENERGY
« Reply #374 on: October 15, 2012, 03:13:02 AM »
@Verpies; re Itsu's back ringing, the toroid is unloaded, and the other winding open, the field generated there is collapsing back into the primary more than the resistor and other inductances are playing a factor....


is there a huge difference between FJL4315OTU-ND and the KT926?

I have a tunable 50ns-anything higher pulse from the logic chips, but that translates into an on time of 2us for the FJL4315... I've tried changing the cap and resistor on the gate, but it's always the same...

Last night, I was playing with the tuning of the TL494 oscillator, and put a large resistor[from high voltage source to ground] (100k) started with smaller ones (4.7k) but nearly burned it up when I got the primary tuned... the load matters a lot in tuning the primary; but I had a very nice square wave which yields the most power, but it's wasn't best for high voltage... power in that I was able to keep a voltage in the caps above 0 with the resistor in place... so I tuned it so I had the most voltage in the neon caps that I could with a good load on it... this setting is very bad for charging the cap from 0... it gets about 30% and then stalls, I have to slow down the frequency, and as it goes up, increase the frequency to get best voltage buildup.  So once I was able to maintain that high voltage with a load, I connected it to the nanopulser, and was able to see quite well the voltage between collector and emiiter, go from 150 to 0 and recover... but I had left my 100k ohm resistor in-line, so I wasn't getting a good signal through the toroid.  Removing the resistor, or replacing with a lower value, the voltage drain is much too much with 2us (2000+ns)... and a few times I drained it past the point it would want to fill the cap back up...


----
Well since noone posted, I can continue...


I put a circuit similar to the high current driver on the TL949, and got the pulse down to 1 microsecond maybe less... I tuned my nanopulser down to about 4.2khz (when I'm at that, my toroid starts ringing just ever so slightly); It's a balancing act though... if I go too high in frequency, the high voltage invert isn't quite enough to keep it supplied, and if it falls below say 60% voltage, it's not very good at recovering... if I go all the way to zero, I can turn the nanopulser down , turn the frequency of the TL949 down, get a square wave on the collector/emitter of a E13009, and as the voltage charges, have to keep increasing the frequency to keep the square wave... I can maintain almost 200V, with nanopulser, and get about 48 volts, and maybe 30ma draw on L4; input is 12.7V at about 0.60A... so it lookw like a net increase, pretty sure I have my TR2 backwards though.
« Last Edit: October 15, 2012, 09:38:58 AM by d3x0r »