I've plugged 2 similar 3,5" plasma globes as yours instead of my 5" but kept tantratron circuit with flyback of 5" and 13,8V PSU. In other words, only replace 5" globe by 3,5" here
Guess what: I get strong plasma resonance at 20,5KHz with PWM 10% duty cycle and it just draws 10mA. If I increase PWM up to 15%, I still get 10mA then current will increase if I go beyond 15%. If I decrease PWM below 10%, it will start increasing current then shutdown which is normal. So between 10-15%, it acts as current regulator showing very stable & power efficient plasma resonance.
I must have hit negative differential resistance of plasma where it is able to self-sustain partially without much external power coming from the flyback driver
What fascinates me: using a modified Hartley oscillator as in your circuit made in china, you get 20.5KHz resonance but my results shows the 20,5KHz comes directly from plasma reactor and NOT from LC of Hartley oscillator. This confirms the non-linear parametric resonance of plasma as explained on my YouTube channel.
Please do monitor overheating of the trafo eventhough it can handle higher voltage.
On a side note, look at my webpage where you'll find out there exists a knee point of the nonlinear B-H as well as a knee point of the plasma tendrils nonlinear behaviour able to make an overunity oscillator. Of course to not blow out the OU system once engaged, you need a diode plug extractor otherwise the excess energy has no way to exit hence it will kick back as extreme destructive back-EMF.
OK, be careful because at some point by increasing the PSU voltage, you'll saturate the ferrite core of your transformer so a sudden drop of inductance hence rise of current that could destroy the trafo because it ferroResonate on non-linear mode. Another aspect to consider is also high voltage isolation inside the trafo where ok, the trafo can handle higher PSU but this increase of HV might spark gap inside trafo then destroy insulation.
the author just really provides information on how to build an oscillator but this is not a Tesla coil. What he explains is really how to make a high voltage inverter which can be seen as classic Hartley oscillator with capacitor coming from stray cap of trafo. In fact you can also intuit this because he talks so much about heat sink whereas a real tesla coil creates current & voltage nodes hence no heat would be lost in the switch.
Regarding the circuit on 3" plasma globe, I've looked deeper to discover it is just a "modified Hartley oscillator" which happens to be also used as a sub-system of a Zero Point Energy research circuit referered "Joule Thief" except most don't deal with High Voltage. The only problem whith this ciruit is you can't vary the duty cycle so you'll miss many tendrils patterns & plasmic resonance explaining why I use arduino + isolation mosfet drivers
The flyback transformer does trigger the base of the NPN D882P transistor; the system naturally oscillates at 20kHz
Hey kas, Since i only have deconstructed & modified 5" and 8" plasma globe, i've just bought the small 3" globe that you've been playing. As i mentionned before, both 5" or 8" have their own IC oscillator hence not based on any signal coming from flyback trafo. One reason I'm interested to play with this small plasma globe is your above remark quoted. Is it possible for you to detail more precisely how it self-oscillates, the precise role of the flyback trafo, does some plasma energy inducted back signal is fed to maintain the oscillations. Any detailled info on this self-osciallting woudl be appreciated so i could save analysis & experimental time. Albert
I suggest you develop an arduino software in order to explore different frequencies & duty cycle so you'll reach different resonances of your globe. At that moment, you'll realize it was worthwhile beyond just knowledge to have invested more than 200$ of equipment. To really make full exploratory, i suggest you also play with voltage control of your PSU because there is a sweet resonance plasma spot depending on a triplet <frequency, duty cycle, voltage>. Now, you'll also discover with professional isol-driver (IL610-MCP1403-IRF540) the resonance plasma impact of very sharp pulsing voltages impossible to obtain with a 4N25 and logig level fet
Sorry kas, i did not fully read your post #11 so yes, what you're doing is correct
I suggest you also try inverting polarity of LV side of trafo so you'll see diode effect hence different plasma tendrils eventhough you pulse same PSU pattern. In other words, you'll get either plasmic diode Kathode in center of globe or outer of globe.
What do you think about the 14.7V peak to peak as per scope diagram ?? back EMF ??
Where exactly in your circuiy scope view is plugged ?
Yes BEMF but you might also pick-up some Free Energy coming from iron core and / or plasma tendrils depending frequency so be careful to not damage some of your semiconductors components.
I shall publish soon a new video serie on my YouTube channel to extract & convert that BEMF so mosfet will remain COLD and many other applications so stay tuned.
Hey kas, it seems your circuit is about pulsing on-off the plasma ball unit USB connector hence pulsing on-off the local oscillator inside plasma ball? If I'm right then I suggest you rather do the real stuff: remove inside plasma ball electronic then pulse directly the transformer with your driver. Happy New Year
For those of you interested to deconstruct 5" and 8" plasma ball all made in China, here are the trafo P/N: FBT-18 and BSM04-D02. I personally do not recommend using BSM04-D02 which has lower quality, tend to over heat if pushing frequency either up or down from its designed frequency. FBT-18 is much bigger & stable but ultimately, for those of you seriously interested in plasma engineering wether for visual entertainment or Zero Point Energy devices as i'm doing, best to build your own flyback trafo which then can really make sure of another issue raised by THINGS (corona destructive effect inside trafo). Always remember that when attempting Tesla Coil design, a HV trafo has an internal capacitor between windings so even if it looks like an inductor, it can become an incredible LC resonance circuit interacting either with backwards current through PSU via mosfet switching or plasmic diode & negative resistor
In all cases, always isolate signals between arduino pins and isolated-driver (mosfet or IGBT) otherwise HV could destroy arduino & computer connected via USB port to arduino.
Interesting, i did not see that specific comment of natural oscillation. I feel then the method you propose is just having arduino turn off or turn on that specific oscillation.
Personnaly, I rather generate HV via direct pulsing the frequency, pulse length & voltage amplitude. This gives access to a very wide range of plasma tendrils types but also optimizes the power supply versus level of plasma generated. To do this, i just deconstruct a standard plasma globe, only keep the globe & trafo then connect an isol-mosfet driver between arduino & trafo, the arduino generating whatever triplet (Frequency, duty cycle and amplitude ) of interest.
As a reminder, the real plasma secret is to control three parameters in order to make chaos or non-linear or parametric oscillators going beyond classical Maxwell equations of electro-magnetism: - voltage amplitude of flyback transformer - pulse length excitation - frequency of pulse length
N.B. Plasma ball was patented by Nikola Tesla in late 1800's as one plasma device without electrode wear & dangerous ozone O3 coming from air spark gaps.
P.S. Please be careful with fly-back transformer: very high voltage that can kill, strong Back-EMF so make sure to use isolator (4N25 or best IL610) between arduino pins output and mosfet or IGBT driver.