Donald Smith Devices too good to be true

[Farmhand]

Here in this clip at 3:15 I tune the primary to over 150 volts peak to peak the
primary has only 0.5 Ohms resistance, lets say it has 1 Ohm so that would
mean the peak current would be about 150 Amps I think, and with 3.6 Watts input,
the increased voltage on the tuned primary is normal and high oscillating
current in the tank is normal from an accumulation of energy.

The video with the RMS measurements from the scope I can't find, it's a
mystery, I probably will need to remake it. I have an external drive to search,
but I was sure I uploaded it.

Two Receivers and Armstrong Oscillator Transmitter - YouTube

If a circuit is tuned to resonance and there is no load the voltage will be high
and the oscillating currents will be high, but the output is nothing.

If the circuit is tuned to resonance and there is a load the voltage will be less
and the oscillating currents should also be less but there will be an output.

Cheers

[Gedfire]

Time to build 2

To: Boguslaw,Peculian,Sinergicus,Farmhand,

Could we come up with an ideal schematic based on the discussion on this page (throw in Sergy for more spice if necessary).Just got some copper tube as I prepare for hf,hv,gdt, fun..Was actually thinking about the Shoebox device and the Build Your Own Version during the last section of Don's 1998 Interview.

Too bad I dismantled the flyback device, now based on the general discussion going on at this time,I am going to revisit it with the ideas here and my own.

Keep the discussion going guys!Thanks!

By the way, is it really true that I can get 50Hz on my transformer L1 and L2 by just adding the required capacitor? Don said a resistor but that was disputed a long time ago.

How do I truly convert from High Frequency (30khz) current to low frequency,50Hz current that I can use with my iron core transformer?

[sinergicus]

By the way, is it really true that I can get 50Hz on my transformer L1 and L2 by just adding the required capacitor? Don said a resistor but that was disputed a long time ago.

I remember Zilano says we can using capacitor in place of the resistors because capacitors in an AC circuit exhibits a kind of resistance called capacitive reactance, measured in ohms. This depends on the frequency of the
AC voltage ,read more here AC Circuits but because, in time ,capacitors are prone to lose their capacity and change their resistance, resistors is recomended....this is what I understand from my readings...

From my readings also, I understand, we can use the method of resistors or capacitors mentioned above or we can using high voltage high power diodes
make the output DC and after that we can using common inverters to transform DC in AC at desired frequency and voltage ....

[sinergicus]

Hello Sinergicus.
There are no contradictions in the schematics you are refering to.
It is simply a matter to understand the whole circuit first on how it operates then conclusions can be made.
For example:


1.First off, there is no low voltage, not that low at least,it is called low voltage in respect to the more high voltage of the flyback
trasformer, and you also can see a cap parallel to the second spark gap the same as at the first spark gap.
The spark gap in both instances is used to "activate" or make-and-brake the circuit as well to protect devices connected to the circuit, especially at
the secondary side.
At this point try to figure out why Don used extensively Varistors in his circuits, and you get the point in here... the spark gap is not useless.
Think a bit why Tesla used spark-gaps in his experiments.Study, maybe a bit more the different functions a spark gap can have in a given circuit etc.



2.No, it is not the same design as the one above. As per the capacitor at the primary & secondary
of the flyback they are capacitors to "force" this particular design to "resonate" at a selected
frequency by the operator of the circuit. But the thing is, that in this one circuit one should make use of the nomograpg Don had mentioned about
radio frequencies chart of ARRL (american radio relay league) just so you combine the circuit to oscillate or resonate at for example 35kcps or KHz..
In order to do that the right capacitance is needed for every coil to make dance/resonate/oscillate at that frequency. Every coil is different,
so a different capacitor is needed in combination for it to to do the job.

3.Each of the connections to the ground showed are right for the design you see it attached to.
The second, below design with the ground in the midle of the spark gap was also used by Don himself.Yes.
Have a look to his videos, and you will capture the point here also.the bonus videos btw, in case you don`t know what videos.

The reason you see spark gap arranged the way you see it is because each circuit is different
as I mentioned above so not the same design.. in short: the above circuit is not precisely "tuned" so to say
the second schematic is more "tunned" like a radio receiver in a particular frequency! A more cleaner "signal" goes by.

But, you know what ?
Do not struggle on others design, instead study excessively the work of Don Smith himself and at any cost the work of our great Master Nikola Tesla.
Do not take my word, or others around but make up your own understanding, and then apply that knowledge.
Experiments will "show you the way" for example to wind cw or ccw ? etc.
Have a nice building experience!
Cheers!

Peculian I don,t contradict you ;my knowledge in this stuff is very limited so to understand things I try to using my readings ,my intuition ,and my brain to make the connections between different informations,sometime contradictory ...

In the collected zilano posts made by vrand you can see the following picture



You can see in the schematic, Zilano has modified the position of spark gap (now being like in hand sketch drawing but with grounding electrode in the middle of spark gap that missing in first one ) ...so in my opinion ,is the same circuit like hand sketched one ( that is made with bought nst and the second schematic involve the same circuit but with home made nst )...

Anyway your opinion is respected and your comment is welcome ...
Cheers

[Peculian]

Lets keep rolling..

Greetings guys.

@Farmhand
Maybe the trick is to draw "some" of those high currents in a resonant circuit without disturbing it as a whole
That is what Don and Kapanadze are doing. The question is, How ? Nice work and video you had there.

@Gedfire
I fully agree with you. In fact I think we are late somehow on doing it, we should have already messed with all this.
However the more one understands how it works the more we will be able to do it.
I have collected some HV stuff around me. Time and apetite is requested only.
The problem with all this is that the ones who have actually successfully replicated it to some extent
do not "come" here anymore to show to the rest the "arrows" to follow up. :\
Yes, Ged. The resistor does indeed change the frequency. That`s why Don used some big resistors
at the poles of his Table-Top Device without coils and with only the NPS/NST and the huge caps.
As I have already mentioned it here at this thread somewhere back on posts I have actually tried
the resistor in an experimental setup (low volts hf btw) and it changed the frequency.
Think about this: Why the heck the nomograph would be needed in an ARRL book for, if not for
practical integration ? See ? We need to keep this setup into the HF or RF area if coils are used.

Use the nomograph to calculate your Voltage + your Frequency to find the right value of resistors
you might need to use.
Or, try an oscillator circuit with low volts, like an Alexkor setup or Groundloop`s setup.
And then if you have a scope see it changing output frequency when you put different resistor
to the output of the circuit. If you do not have a scope (the same goes for me here) then try to "listen " it.
As always experiments will show something useful along the way.

@Sinergicus

From my readings also, I understand, we can use the method of resistors or capacitors mentioned above or we can using high voltage high power diodes
make the output DC and after that we can using common inverters to transform DC in AC at desired frequency and voltage ....

Don Smith used both ways with spectacular outputs.

If you think that only you are of a limited knowledge, I say don`t stick to that idea mate.
We all have limited knowledge about this stuff, so nothing keeps us trying to figure out what is goin on at these circuits.
You see that as contradictions from Zilano to herself. That`s OK with me.
This is how I see Zilano and her circuits:
I`ve already stated at this topic enough pages back that Zelina might have had a great understanding
on how these devices work. If she actually has build some different devices with 5KW to 10KW output
I`m not aware of that, but at the same time I cannot say that Don`s devices are not replicable just because
we cannot & don`t know how to exactly replicate his devices.

We all need to first have a good grasp on how these devices work in order to implement that to a practical level.
That`s what I think/believe.

Ciao guys!

[SunofFather]

Hi folks.
@Serg.V
Can we have more info on this, in english, if possible.

If somebody can translate the Russian words on the schematic, please
re-edit the picture that Serg.V posted and post it here again with english words would be great.
T-1000, can you please do that ?

To whom which will do this, many thanks in advance.

Untitled.png - Speedy Share - upload your files here

[Peculian]

Hi all.
SunofFather, many thanks for translating the picture diagram to english.
Much appreciated.
This schematic seems to be woth a try..

Best Regards.

[sinergicus]

problem with my oscilator

I have problem with my custom made nst...I am using 2n3773 transistor ;when I short the output of secondary, my circuit stop to work...to start again I need
to remove the power source from circuit and connect it again...why this happens..

Also I tried with BU508AF transistor but not working at all....

[gyula]

I have problem with my custom made nst...I am using 2n3773 transistor ;when I short the output of secondary, my circuit stop to work...to start again I need
to remove the power source from circuit and connect it again...why this happens..

Also I tried with BU508AF transistor but not working at all....

Probably the oscillator stops working when you short the secondary and unable to self-start again: it needs a "kick" by unconnecting and connecting the supply voltage again. This indicates the DC operating pont of the transistor needs some refinement, try to change a little one of the base resistors value or use a trimmer pot to find a stable working point. Be careful and change but a few kOhm at a time (depending on the actual value of course). If you have a schematic on the nst inner circuit and can show it I could comment it better.

The BU508AF may have a much lower Beta, DC transfer gain (hfe=dIc/dIb) than your 2N3773 happens to have, this can explain why it cannot oscillate.

Gyula

[sinergicus]

Thanks gyula for your observations....the circuit is made with HV transformer from old black and white television...I used the same winding number of turns 8 and 4 turns recomended by zilano...the resistors are the same 220 ohms respectively 270 ohms...maybe I should use 2n3055 transistor....

Anyway would be good some online calculator (if exist) to calculate the correct resistors for different transistors ....


Another problem what I have is regarding calculation of resonant capacitor...I measured many times the inductance of flyback primary coil (8 turns) and used online calculator for 35 khz... inductance was 1000 uH and calculated capacitor
20.68nF ....I used 20 nF capacitor but the frequency was in practice much higher so was needed by trial ad error to find the right LC combination to obtain 35 khz...at this moment I measured 39.20 khz with 70 nF capacitor ;measurement was made betwen colector and emiter and also across primary ( 8 turns ) of the flyback ..somebody told me to wrap 3-4 turns on some free space of the flyback and measure the frequency acros that liitle coil...that was with 70 uF cap 13 khz...so what is the correct measurement?

At this time I have 3 2n3773 in parallel and I hear the transistors oscilating;when I connect the frequency metter clips bettwen colector and emmiter and after that across primary ,the sound is changing a little ;this tell me the multimeter will influence the correct measurement.I am curious how others are doing the correct frequency measurement ?

Also I observed , using the same capacitor value for one transistor, the frequency will be different ,with more transistors conected in paralell ( like I am using now....)...so problems going to be complicated for me...

[SunofFather]

Thanks Serg V! I see some key elements on the device you posted which has my interest.Any replications and/or links to more detailed reports on this device? Any hope for us getting full english version?

I try, but not exatly replicate and not sucsesfull. I think if it works, need wery good find resonanse like in tesla coil. Here good info how find resonance Javascript Tesla Coil Designer Oscilloscope Tuning a Tesla Coil for Resonance
Need ajusting capasitor, ajusting spark gap and ajusting wire lengh or turns in primary coil (sliding over turns with crocodile gap let say. Then resonance be found, then streamers on end without load to any objects near theam must be bigest, I think.

[gyula]

Hi sinergicus,

I have found the schematic in this pdf file and guess you use the circuit in page 10: http://www.tuks.nl/pdf/Reference_Mat...lano-Posts.pdf but as I just noticed the schematic is included some posts above..

It has the resistor divider R1 and R2 as 270 and 220 Ohm and you have the same values as you wrote. I suggest to place a 1 kOhm trimmer potmeter (two legs: wiper and any one of the fix legs) in parallel with the 270 Ohm and set the wiper to full 1 kOhm as a start to see if the 2N3773 can recover in this new bias point again after a load on the secondary. And slowly turn the wiper in say 100 Ohm increments at a time towards the lower resistance settings but do not turn further than half way (i.e. below its 500 Ohm) because it will burn out (even so it may warm up so a wire wound trimpot of a few watts rating would be best) and also the transistor may cook. And after each trim pot settings, check the oscillator whether it is able to recover already. A notice here: a 'brute force' direct short across the secondary is not really good but just place a load of say a few kOhm high wattage resistor across it what the step down transformer's primary coil (if it is connected as shown) would represent (transformed impedance) when the spark gap fires, ok?

This bias point adjustment could be tried for the BU508 too. A notice: the bias resistors have a low value hence they dissipate heat, I think you could double both and use 520 Ohm for R1 and 470 Ohm for R2 to reduce their self-consumption from the 12V battery. Then use a 2.2 kOhm or 3.3 kOhm trimmer pot in parallel with the 520 Ohm to further adjust the bias current for the transistor if needed.

There are online calculators but the problem is they use Beta (hfe) values of 100 or higher and your transistors have less than that, look for their data sheet, maybe 40-50 for 2N3773 and 10-15 for the BU508. This low Beta influences the bias resistor values, making bias point difficult to adjust. in this simple simulator the Beta is adjustable: Common-Emitter Amplifier you have to figure out how it works... it shows a common emitter transistor circuit with emitter and collaector resistor of course and it works up to 500 Hz? do not know. Here is another simulator, also needs some learning: The Common Emitter Amplifier Circuit (Java applet is to be enabled for them to work.)

Regarding the frequency, I ask whether you have any tuning capacitor across the secondary coil too? indicated as CT in the above circuit link. Or you mean only the capacitor across the primary coil, CL which is in the collector of the transistor? Because if you have a tuning cap across the secondary too, then your transformer may have two resonant frequencies, and question is which tuned coil dominates: the primary or the secondary? Otherwise what you calculated for the 1 mH primary is correct for 35 kHz: 20 nF... possibly the DC current via the primary may change the 1 mH to another value or the secondary coil also influencies the frequency. What is the total DC current drawn from the 12V supply?

Measuring the frequeny may be done with using an air core coil of 50-100 turns ( multiturn multilayer or single layer) and couple near to the transformer and connect its picked up voltage to your frequency meter or better to an oscilloscope if you happen to have. If the pick up voltage cannot drive the frequency meter, then try to use a ferrite core in the pick up coil to increase its sensitivity. Again, the problem may be: you do not know if you deal with the primary or the secondary coil resonance? but positioning the pick up coil very near to either the primary or the secondary may help to figure it out. So if you have a cap across the secondary, remove it to see whether the 1mH primary obeys correctly to the tuning cap across the primary? If you find the secondary coil also resonantes somewhere then try to bring the two frequrncies into the same value by tuning both. Unfortunately the secondary coil needs HV capacitor for tuning...
One notice with the frequency measurement: the waveform in the collector, although the primary coil is tuned, may have an uggly shape and may trigger the frequency meter in a false way? A scope would help sure.
Sorry for some rambling but some pitfalls are inherent in this circuit... and could be solved step by step. I do not wish to be seem here as if I built this exact circuit, I did not but I built several, similar oscillators in the past, this is why I can comment.

Perhaps other members here may also wish to comment your problems.

rgds, Gyula

[Gedfire]

50Hz

I remember Zilano says we can using capacitor in place of the resistors because capacitors in an AC circuit exhibits a kind of resistance called capacitive reactance, measured in ohms. This depends on the frequency of the
AC voltage ,read more here AC Circuits but because, in time ,capacitors are prone to lose their capacity and change their resistance, resistors is recomended....this is what I understand from my readings...

From my readings also, I understand, we can use the method of resistors or capacitors mentioned above or we can using high voltage high power diodes
make the output DC and after that we can using common inverters to transform DC in AC at desired frequency and voltage ....

@singergicus.Thanks man!
@peculian,I will follow your advice.

Yes, online team work is indeed good for us.I am very open to suggestions from anyone might suggest alterations or mods to what I am doing.For example,Zilano suggested bringing L1 and L2 to resonance.Maybe if I tried that with the 60Hz 110 to 12VAC transformer.

Any idea as to how one can achieve or what is meant by "automatic resonance" as stated by Kapandanze?

Ged

[Gedfire]

Aspects of Resonance

I try, but not exatly replicate and not sucsesfull. I think if it works, need wery good find resonanse like in tesla coil. Here good info how find resonance Javascript Tesla Coil Designer Oscilloscope Tuning a Tesla Coil for Resonance
Need ajusting capasitor, ajusting spark gap and ajusting wire length or turns in primary coil (sliding over turns with crocodile gap let say. Then resonance be found, then streamers on end without load to any objects near theam must be bigest, I think.

Thanks for this.It is appreciated along with your suggestions. I agree Resonance is what we need.I have started exploring how I can get L1 and L2 to resonate automatically without any tuning at all.Don suggested that in his 1998 Interview.But it sounded like 1/4 turn even division or multiple of L1 suff.I am thinking Joule Thief, Flyback Oscillator like setup (very similar to the driver on the Zilano Schematics above).You know like a feedback coil from ferrite core back to the transistor.No capacitors needed.Maybe if we put the ferrite cored section into the second (stepdown transformer assembly).The feedback to transistor would sample the general inductance and capacitance of the entire coil assembly thus achieving automatic resonance.Any tuning would be inner coil movement relative to the stepdown transformer.Which would be made larger than the ferrite assembly with the feedback.Crazy stuff, would it work? I have other configurations so maybe I should get busy again.

I have drawn up some schematics.I will try for pictures if anyone is interested.The next thing is to test them.I found that all of my Flyback Device was "dancing" at the same frequency,I believe I needed to add the large copper L1 coil,bifilar windings as L2,earth ground and Sparkgap.

Ged

[sinergicus]

Hi sinergicus,

I have found the schematic in this pdf file and guess you use the circuit in page 10: http://www.tuks.nl/pdf/Reference_Mat...lano-Posts.pdf but as I just noticed the schematic is included some posts above..

It has the resistor divider R1 and R2 as 270 and 220 Ohm and you have the same values as you wrote. I suggest to place a 1 kOhm trimmer potmeter (two legs: wiper and any one of the fix legs) in parallel with the 270 Ohm and set the wiper to full 1 kOhm as a start to see if the 2N3773 can recover in this new bias point again after a load on the secondary. And slowly turn the wiper in say 100 Ohm increments at a time towards the lower resistance settings but do not turn further than half way (i.e. below its 500 Ohm) because it will burn out (even so it may warm up so a wire wound trimpot of a few watts rating would be best) and also the transistor may cook. And after each trim pot settings, check the oscillator whether it is able to recover already. A notice here: a 'brute force' direct short across the secondary is not really good but just place a load of say a few kOhm high wattage resistor across it what the step down transformer's primary coil (if it is connected as shown) would represent (transformed impedance) when the spark gap fires, ok?

This bias point adjustment could be tried for the BU508 too. A notice: the bias resistors have a low value hence they dissipate heat, I think you could double both and use 520 Ohm for R1 and 470 Ohm for R2 to reduce their self-consumption from the 12V battery. Then use a 2.2 kOhm or 3.3 kOhm trimmer pot in parallel with the 520 Ohm to further adjust the bias current for the transistor if needed.

There are online calculators but the problem is they use Beta (hfe) values of 100 or higher and your transistors have less than that, look for their data sheet, maybe 40-50 for 2N3773 and 10-15 for the BU508. This low Beta influences the bias resistor values, making bias point difficult to adjust. in this simple simulator the Beta is adjustable: Common-Emitter Amplifier you have to figure out how it works... it shows a common emitter transistor circuit with emitter and collaector resistor of course and it works up to 500 Hz? do not know. Here is another simulator, also needs some learning: The Common Emitter Amplifier Circuit (Java applet is to be enabled for them to work.)

Regarding the frequency, I ask whether you have any tuning capacitor across the secondary coil too? indicated as CT in the above circuit link. Or you mean only the capacitor across the primary coil, CL which is in the collector of the transistor? Because if you have a tuning cap across the secondary too, then your transformer may have two resonant frequencies, and question is which tuned coil dominates: the primary or the secondary? Otherwise what you calculated for the 1 mH primary is correct for 35 kHz: 20 nF... possibly the DC current via the primary may change the 1 mH to another value or the secondary coil also influencies the frequency. What is the total DC current drawn from the 12V supply?

Measuring the frequeny may be done with using an air core coil of 50-100 turns ( multiturn multilayer or single layer) and couple near to the transformer and connect its picked up voltage to your frequency meter or better to an oscilloscope if you happen to have. If the pick up voltage cannot drive the frequency meter, then try to use a ferrite core in the pick up coil to increase its sensitivity. Again, the problem may be: you do not know if you deal with the primary or the secondary coil resonance? but positioning the pick up coil very near to either the primary or the secondary may help to figure it out. So if you have a cap across the secondary, remove it to see whether the 1mH primary obeys correctly to the tuning cap across the primary? If you find the secondary coil also resonantes somewhere then try to bring the two frequrncies into the same value by tuning both. Unfortunately the secondary coil needs HV capacitor for tuning...
One notice with the frequency measurement: the waveform in the collector, although the primary coil is tuned, may have an uggly shape and may trigger the frequency meter in a false way? A scope would help sure.
Sorry for some rambling but some pitfalls are inherent in this circuit... and could be solved step by step. I do not wish to be seem here as if I built this exact circuit, I did not but I built several, similar oscillators in the past, this is why I can comment.

Perhaps other members here may also wish to comment your problems.

rgds, Gyula

When I had one transistor on my circuit the consumption was around one amp and half without any shorting at secondary ;when i made sparks in secondary the consumption increased at around 3 amps.... at this time with 3 2n3773 in paralel I didn,t measured the consumption but with calculated capacitance acros primary ,20 nf ,the power suply is shorted and stoped....have protection when circuit is shorted....output of the power supply is 12vdc at 16 amps...and the transistors becomes warm so this mean they are in on state and not oscilating;so I think you have right the resistors must be changed....maybe because of that zilano says we need to using any high hfe transistors...2n3773 seems to be to not have high enough hfe.....

Across high voltage section at secondary of the flyback I have no capacitor..
I made one ,tunable,using kitchen AL foil and some plastic foil special one that is used in motors to protect windings from core but when I made a test the corona discharge formed at the margin of outside foil and capacitor start to became warm....so need to re think my capacitor to eliminate the corona discharge..

In most of the similar schematics found on the internet R2 resistor are much smaller ;see here Transistor Driven High Voltage Flyback Transformer Page.

and the consumption and waste from power source will be bigger of course... so the only solution at this time is by trial and error to find the right resistor combination for different type of transistors...or maybe first using just what zilano recommended 2n3055....

Regarding that little tuning circuit,recomended by zilano that using 1n4007 diodes and one led to verify the resonance of coils ;in our case we have an LC tanc that we ned to tune it so how we ned to conect the led -diode tuner ? like in the picture below?