DON'T BUY this HV Generator! Build this one instead....please
Summary
TLDRIn this video, the host critiques a cheap, uncertified high voltage generator sold on Amazon, deemed unsafe and illegal in Germany. Instead, he recommends a small, affordable high voltage transformer for safe experiments. The video explores its construction, the theory behind its operation, and demonstrates various arcs with different circuits, including a self-oscillating BJT circuit and a more efficient ZVS circuit. The host also investigates the effects of frequency on arc behavior, highlighting the educational value of proper high voltage experimentation.
Takeaways
- 😡 The script criticizes the sale of a dangerous high voltage generator on Amazon, highlighting the lack of safety certifications for such products in Germany.
- 🔌 The high voltage generator is compared to a taser, emphasizing the potential harm of high voltage arcs to the user.
- 🚫 The lack of legal certification on the device makes it illegal in Germany, which is a key concern raised in the script.
- 🔬 The script suggests that high voltage can be explored safely in a scientific context, with proper knowledge and precautions.
- 🎥 The video focuses on a safer alternative, a small high voltage transformer, which can be used for experiments to create different types of arcs.
- 🛠️ The script describes the construction of a transformer, including its ferrite core and windings, and the importance of understanding its electrical properties.
- ⚡ The video demonstrates the creation of an arc using a 4V input and a 2.8A current, showing the practical application of the transformer.
- 🔍 The script discusses the failure of a transistor in the circuit and the reasons behind it, such as high heat dissipation and voltage spikes.
- 🛑 The video attempts to replace the BJT with a MOSFET but finds that the circuit is not compatible due to the reliance on feedback current and low voltage levels.
- 🔄 The script explores the effects of different frequencies on the transformer's performance, noting the decrease in current draw at higher frequencies.
- 🔥 The final circuit presented is a ZVS (Zero Voltage Switching) circuit, which is more efficient and powerful, with a focus on safety and educational value.
Q & A
What is the main concern the speaker has about the high voltage generator sold on Amazon?
-The speaker is concerned that the high voltage generator sold on Amazon is dangerous and potentially illegal in Germany due to the lack of certification marks. They believe it's being sold under the guise of a science experiment but could cause harm if mishandled.
What does the speaker suggest as an alternative to the unsafe high voltage generator?
-The speaker suggests using a small high voltage transformer, which can be purchased cheaply online, to safely experiment and create different types of arcs.
What is the purpose of the plastic fins in the high voltage transformer?
-The plastic fins are used to isolate high voltage sections from each other to prevent unintentional arcing over.
Why does the speaker believe the high voltage transformer is not suitable for use with MOSFETs?
-The speaker explains that the circuit relies on feedback current and low voltage levels on the primary side, which makes it unsuitable for MOSFETs due to their different characteristics.
What is the approximate winding ratio of the high voltage transformer mentioned in the script?
-The speaker calculates an approximate winding ratio of 1 to 3750 for the transformer, based on the assumption that it transforms 4V input to 15,000V output.
What is the role of the transistor in the high voltage transformer circuit?
-The transistor in the circuit allows current to flow through the feedback coil into the base of the transistor, which in turn allows current to flow through the main primary coil, creating an oscillating cycle that induces voltage into the secondary coil.
Why did the speaker's initial circuit fail and what was the cause of the failure?
-The initial circuit failed because the transistor burned out due to overheating, which is a result of the high collector-emitter voltage drop and large voltage spikes when the transistor turns off.
What is the significance of the different frequencies in the speaker's experiments with arcs?
-Different frequencies affect the current draw and the behavior of the arcs. The speaker found that certain frequencies, such as 80, 120, and 250kHz, allowed for arc creation, while others did not. Additionally, the sensation of being shocked versus burnt changed with the frequency.
What is a ZVS (Zero Volt Switching) circuit and why is it used in the speaker's last experiment?
-A ZVS circuit is known for its high efficiency due to its switching behavior at zero voltage. The speaker used it in the last experiment to achieve a more efficient and powerful arc creation, with the frequency set by the inductance of the transformer and the utilized capacitance.
What precautions does the speaker suggest when dealing with high voltage circuits?
-The speaker warns that dealing with high voltage can lead to fatal injuries if not handled correctly, emphasizing the importance of safety when conducting experiments with high voltage transformers and circuits.
How did the speaker's experience with the high voltage transformer and different circuits contribute to the video?
-The speaker's experiments were both entertaining and educational, providing insights into the behavior of high voltage circuits and the effects of different components and frequencies on arc creation, which was more valuable than the initial unsafe high voltage generator.
Outlines
🚫 Critique of Unsafe High Voltage Generators
The speaker expresses concern over the sale of an unsafe high voltage generator on Amazon, noting its potential to cause harm due to the high voltage arcs it produces. They argue that such devices should carry a certification mark to be legal in Germany, which the product lacks. The speaker suggests that the device is being marketed under the guise of scientific experiments, which they find irresponsible. Instead, they propose focusing on a small, affordable high voltage transformer for safe and educational experiments, introducing a video sponsored by Altium that will demonstrate the proper use of such a transformer.
🔬 Experimenting with High Voltage Transformers
The script details the examination and testing of a small high voltage transformer, which the speaker purchased online. They describe the transformer's construction, including its ferrite core and windings, and calculate an approximate winding ratio based on assumed voltage transformation. The speaker also discusses the importance of insulation in high voltage applications and the weaknesses of the transformer's fin design. After assembling a driver circuit and experimenting with connections, they successfully create an arc, but the circuit fails due to a burned-out transistor. The speaker explains the heat dissipation issues with the NPN BJT and attempts to replace it with a MOSFET, finding that the circuit is not compatible due to its reliance on BJT characteristics.
🔧 Exploring Different Circuits for High Voltage Arcs
The speaker continues their exploration by building a basic flyback converter circuit with a MOSFET to test different frequencies and their effects on arc creation. They observe the relationship between frequency, current draw, and the ability to create arcs, noting specific frequencies that allowed for arc formation. The experiment reveals that at higher frequencies, arcs change from being shocking to burning the skin. The speaker then builds a ZVS (Zero Voltage Switching) circuit for a more efficient and powerful outcome, setting a goal frequency of 80kHz. They successfully achieve the desired frequency and are pleased with the circuit's performance, efficiency, and safety, concluding that it provides a stark contrast to the initial high voltage generator discussed.
Mindmap
Keywords
💡High Voltage Generator
💡Taser
💡Certification Mark
💡Tesla Coils
💡Plasma Arc
💡High Voltage Transformer
💡Ferrite Core
💡Winding Relation
💡Breakdown Voltage
💡NPN BJT
💡MOSFET
💡ZVS Circuit
Highlights
A high voltage generator sold on Amazon for under $10 is criticized for its lack of safety and legality.
The generator is compared to a taser, indicating its potential to cause harm.
In Germany, the device lacks necessary certification marks, rendering it illegal.
The device is being sold under the guise of being used for science experiments.
High voltage can be explored safely and beautifully with proper knowledge and equipment.
The video introduces a small high voltage transformer as a safer alternative for experiments.
Altium is sponsoring the video, promoting its professional PCB designer software.
The transformer's ferrite core and windings are examined for their construction and function.
An approximate 1 to 3750 winding ratio is calculated for the transformer.
Plastic fins are identified as a means to isolate high voltage sections and prevent unintended arcs.
The breakdown voltage can be significantly increased with the use of plastic fins or epoxy resin.
The transformer comes with a driver circuit, and the correct wiring is determined through testing.
A successful arc is created with an input voltage of 4V and a current of 2.8A.
The circuit's abrupt failure is attributed to a burned-out transistor.
The video explores the limitations of replacing BJTs with MOSFETs in the circuit due to its operation.
A basic flyback converter circuit with a MOSFET is built to test different frequencies and their effects on arcs.
At certain frequencies, arcs no longer shock but burn the skin, demonstrating the importance of frequency in high voltage applications.
A ZVS (Zero Volt Switching) circuit is introduced for its high efficiency and power.
The ZVS circuit is set to oscillate at 80kHz, providing a more powerful and efficient alternative.
A warning is issued about the dangers of high voltage and the importance of handling it correctly.
The video concludes with the presenter's satisfaction with the ZVS circuit's performance and safety.
Transcripts
I have a question.
Who in their right mind would sells this on Amazon?
I means this is ridiculous!
You can get this high voltage generator for under 10$ from Amazon and I can guarantee
you that it will hurt pretty badly when you touch the high voltage arcs.
So that basically means it is some kind of taser, right?
But that means that here in Germany where I live it needs to come with a certification
mark to be considered legal and guess what there is no mark to be found on the device.
So they are using the only for science experiments excuse to sell those things which I think
is terrible because high voltage can be such a beautiful thing to explore if you know what
you are doing.
I mean yes you can create some scary arcs with tesla coils, but then you can also make
music playing plasma arcs, arcs that you can use as a lighter or arcs that you can even
touch without getting shocked.
So let's ignore this garbage device and instead focus on this small high voltage transformer
that you can also get for cheap from the internet.
With it you can experiment properly and create all kinds of different arcs which is exactly
what I will be showing you in this video.
Let's get started This video is sponsored by Altium.
If you are looking for a professional PCB designer software that can fulfill all your
PCB design wishes then look no further than the Altium designer software.
After getting used to it, it offers pretty much everything you could ever need when it
comes to designing a PCB.
So feel free to test the Altium Designer for free by yourself by following the link in
the video description.
First off let's have a closer look at the transformer.
After removing the adhesive tape, it was clear that its ferrite core consist of 2 pieces
that hold two primary windings and one secondary winding.
But by simply measuring the resistance of those coil pairs we can not determine the
winding relation between the primary and secondary because the high voltage side uses way thinner
wire.
But by assuming that the circuit transforms around 4V on the input to 15.000V on the output,
we can calculate an approximate relation of 1 to 3750 which is quite a bit.
And I think the plastic fins exist in order to isolate high voltage sections from one
another so that nothing unintentionally arcs over.
Because as you might know in air we need above 1kV per mm in order to create an arc or plasma
tunnel.
Due to the isolation of magnet wire however this voltage can go up to for example 3kV
and with such plastic fins or for example epoxy resin which often gets used for such
purposes, the breakdown voltage can go up to 20 to 40kV.
The fin design however does comes with some weak points.
But enough already with the theory and let's get to something more practically because
often times the transformer comes as a kit with suitable driver circuit.
So after soldering all the obvious components into place, I got to the two primary windings.
Now the markings of the PCB made it look like I had to short the two inner wires but that
would have definitely not made any sense.
So I did a small test with my interpretation of how to hook things up and that worked flawlessly.
The solution was to short the far left wire with the second one from the right in the
middle.
This way the final result on the PCB looked like this and the schematic for the circuit
looks something like this.
And after powering the circuit with an input voltage of 4V and a current of 2.8A, we successfully
created an arc, awesome.
Now this is the kind of arc that will shock you quite a bit and is capable of being used
as a lighter.
But before I was able to investigate the circuit to show you why exactly this arc shocks you,
the circuit just abruptly died on me.
It seems like the used transistor burned out; so I replaced it with a same model one and
powered the circuit once again while having a look at the most important voltage waveforms
and measuring the temperature of the transistor.
And as it turns out it overheats way too fast which was actually not a surprise since we
are dealing with an NPN BJT that due to its high collector emitter voltage drop dissipates
quite a lot of heat.
Combine that with the fact that the transistor has to withstand big voltage spikes when it
turns off and you start to realize why it got destroyed so soon.
Now you might be thinking: “Why not just replace the BJT with a MOSFET that comes with
a low drain source voltage and a high breakdown voltage to solve those problem?
Well, I actually tried exactly that but had to find out the hard way that this circuit
pretty much only works best with BJTs.
The reason is the way this circuit works which as soon as voltage gets applied, let's current
flow through the feedback coil into the base of the transistor and thus let's current flow
through the main primary coil.
This not only induces a voltage into the secondary but also in the feedback coil which opposes
the input voltage.
That means at some point the current through the base stops and the primary current falls
abruptly.
Afterwards there is no more opposing feedback voltage and thus the cycle repeats.
And because of the dependence on feedback current and the low voltage levels on the
primary side, this circuit is not a good fit for MOSFETs.
Also it is self oscillating at currently a frequency of around 19kHz which we can not
easily change in this circuit.
That would be desirable though because with different frequencies the transformer as a
whole does not only react differently due to its impedance but at a certain frequency
and above arcs no longer shock us but only burn our skin which I definitely wanted to
try out.
So I built up a basic flyback converter circuit with a MOSFET according to this schematic.
I will be using my function generator to control the gate but a basic 555 timer circuit could
easily do this job and even include a bit of audio modulation if you want your arcs
to sing.
But never forget to add an RC clamp to the mix which limits the voltage spikes across
the MOSFET that would otherwise destroy if fairly quickly.
And after this obligatory pre banter it was time to play around with different frequencies
and it was quite fascinating to see how the current draw decreased with a higher frequency
due to the impedance of the coils while still featuring frequency plateaus in which the
current draw increased probably due to some resonance behavior.
I also found out that at around 80, 120 and 250kHz it was easily possible to create an
arc while with other frequencies this was a lot more difficult if not impossible.
And while the arcs shocked me at frequencies below 200kHz it was truly weird to find out
that at 250kHz the arc no longer shocked me and only burnt my skin which was still a bit
painful.
So all in all this circuit is pretty awesome for testing but the arcs were not super powerful
and the MOSFET also heated up noticeably.
That is why for my last circuit I wanted not only a more efficient one but also powerful
one and I was able to build one in a matter of seconds because I actually created it before
during my Induction Heater video.
It is a ZVS circuit or Zero Volt Switching circuit which are notorious for achieving
a high efficiency due to their switching behavior.
The frequency at which it oscillates is set by the inductance of the transformer and the
utilized capacitance and I wanted to go with a frequency of 80kHz since I knew from earlier
experiments that this was a suitable frequency for my transformer.
But as you can see I am using a capacitance of 133nF and the inductance of my primary
coil is around 113uH which would equal a resonance frequency of only 41kHz.
And after powering the circuit with 12V we can see that the oscillation frequency is
close to the theory but what we have not considered yet is that the inductance decreases when
an arc is formed and thus I was able to reach my 80kHz goal frequency without a problem.
Needless to say this kind of circuit is way more powerful than anything before so now
I have to warn you that dealing with high voltage can lead to fatal injuries if not
handled correctly.
But anyway I am super happy with this circuit since the input power is reasonable, the created
sine waveform is beautiful and the MOSFETs also stay pretty cool .
So all in all those experiments with the HV transformer and the different circuits were
not only entertaining for me and hopefully for you but also educational which is way
more than you could ever expect from the High Voltage generator we started with.
So I hope you enjoyed this video and if you did then consider supporting me through Patreon.
As always don't forget to like, share, subscribe and hit the notification bell.
Stay creative and I will see you next time.
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