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safety hints for experimenting with violet wands
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Best solution is NOT to connect it to the line at all! Consider it as an old curiosity and put it behind glass...
What? You want to "play" with it??? Then you really should get a safe (and mobile) solution consisting of a battery pack and a converter! Read on at the bottom end of this page on how I equipped a small suitcase with a violet wand, battery pack (lead acid), battery charger, converter and a rubber bulb on a tube connected to a pressure switch.
A violet wand can only be considered as safe if the wiring of the secondary is completely separated from the primary coil and earthed so that there is no direct connection between the line current and the output of the device. But some brands (even the new ones!) have a connection between the high voltage output and the line side of the current (depicted in the next schematic). This is very dangerous as it can lead to instant electrocution if you plug it in the wrong way into an unpolarized outlet and touch any earthed device (eg. water pipe or any other device plugged in)! Please be aware that the high voltage of the output can damage the isolation of the wires in other devices like bedside lamps and create a dangerous current path this way...
Just using a standard isolation transformer in its original wiring will not help here. A separate return path to earth for the RF-HV of the VW has to be provided if you have a VW with only two wires. If the return path for the RF is the plug and you put an isolation xfmr between the wall outlet and your VW, the return path would be "broken". Well, not completely, the RF can flow via the capacitive coupling between the two windings of the isolation transformer. But the insulation of those windings is NOT suited for the high voltage generated by our violet wand! So there is a big risk that an arcing might occur between the two windings. This could connect the deadly line current again to the output of the violet wand!
Complete data of a modern violet
wand (US product):
Short summary of the output values of this violet wand:
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| C3= 9,9pF |
With my cheap RLC-meter I measured Cp, R1, L1 and R2.
Since the value for L2 was at the lower end of the range of my meter, I made
a guess of ~ 5µH for L2.
After R3 and L3 I measured Ls=L2+L3+2*M23 (series of L2 and L3 plus mutual
inductance).
From that we can calculate M23 (with assumed L2 = 5 µH) with the formula
M23 = 0.5 * (Ls - L2 - L3).
The coupling between L2 and L3 is k=M23/SQR(L2*L3)
We can use this equation to iterate L2 if we assume a certain k:
| L2 | = | M23² / ( L3 * k² ) |
| = | 5 µH for k=0.58 |
With that we can calculate the ringing frequency of the primary circuit:
| fp | = | 1 / (2*Pi*SQR(L2*Cp) |
| = | 175 kHz for k=0.58 and L2=5µH |
The measurement also gave a frequency for the primary circuit of 175kHz, so the 5µH for L2 and k=0.58 seem to be a good estimation.
Measurement of the frequency of the secondary (high voltage coil):
With the peak voltage rectifier I described
here, I measured the peak output voltage
Ûmax_out to be 17.5kV.
(I've seen scope traces from a violet wand set where the peak output voltage
was up to 25kV at 180kHz!)
From L3=12.94mH and fo=444kHz I calculated C3 to be C3=1/[L*(2*Pi*f)²], that means C3 = 9,9pF.
With Ûmax_out = 17.5kV, the output pulse energy Epmax_out = 0,5*C3*(Ûmax_out)2 therefore can be calculated to Epmax_out = 1,5mJ.
Be careful, a violet wand could deliver an average current
Iavg_out of up to 45mA, so the peak current will be much higher
(see next paragraph)!
I let the spark of my new wand run through a 15W incandescent light bulb.
It made a faint glow.
I did a comparison by connecting the bulb to my variac. Similar
glow was achieved at 45mA@100V.
That is nearly 5W of pure RF power (I had a 0.22nF@50kV capacitor in that
circuit which acts as a resistance of 3.6kOhms at assumed 200kHz, so I'm
sure it was pure RF power). So please be aware that there is really a lot
of power on the output side of your wand!
We've seen that Epmax_out =
0,5*C3*(Ûmax_out)2 which is Epmax_out
=1.5mJ from the secondary values as calculated above.
Calculating that backwards with Epmax_out = 0,5*L3*
Îmax_out2 we get the maximum peak output current
Îmax_out = 480mA.
If we assume no losses, the peak voltage at Cp should be Ûmax_Cp = SQR( 2* Epmax_out/C3) = 135V. This is much lower than expected (expected value was >162V which is the peak voltage of the 115V line voltage), therefore it has to be verified with the peak voltage meter. One of the reasons might be the losses incorporated. Electrical energy is converted into unwanted heat in the spark gap and the resistance of the wires.
Future measurements (with f-gen & o'scope):
Some people sell so called "spark gap isolation" probes for use with violet wands. These only can be of help if the "spark gap" is made of a short glass discharge tube like the "neon test tube" which can be found in many violet wand sets. A "spark gap" from the technical side is a short gap between electrodes, allowing a current to flow if a threshold voltage is exceeded. For our violet wand we need a high voltage capacitor instead! The "neon test tube" can be considered as a capacitor. Exactly, it is two capacitors in series. The first capacitor is formed by the metal socket outside the glass tube and the glowing neon inside the glass tube. The glass tube itself is the insulator which will prevent low frequency current from the handle to enter the plasma. The second capacitor is on the opposite side, where the high frequency current will leave the glass tube via the second metal socket. I'm not sure if all the "spark gap isolation" probes are made this way, so please don't trust them blindly!
I also have to state that all the modern "violet wands" sold today are from one manufacturer. And this manufacturer doesn't sell them as "violet wands" for use on living humans but as leakage detectors for use on (dead) glass vacuum equipment. So please decide for yourself if you you want to put yourself (or your partner) at risk by "playing" with these devices!
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Safety hints and
some technical basics |
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If you are not willing to read the technical
part, |
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wordings:
| box | houses the interrupter (line voltage coil with "Wagnerschem Hammer") and capacitor of the primary circuit of the Tesla generator |
| handle | in the handle, the primary coil of the Tesla generator is located as well as the high voltage coil (secondary coil) |
| DC | direct current |
| AC | alternating current |
| TENS | Transcutane Electrical Nerve Stimulation |
| EMS | Electronic Muscle Stimulation |
You often can read that you should use electrical devices like muscle stimulators, violet wands or TENS devices only below the waist. But in the manual of e.g. TENS devices, you can see pictures where the electrodes are placed even on the neck. So it depends on the device and the use of it! Every device has its own safety guidelines (depends on current, voltage, waveform, frequency, electrodes etc.). Therefore you should NOT build your own electrodes for using them with your device of choice (e.g. don't change a double terminal electrode into two single terminal electrodes) because you will not know what will happen. You should not trust things written on private websites (even not on my website, but I try to explain so you can build your own opinion about things said). If you don't have the knowledge to understand if the statements are right, you should ask a professional or buy and read some good science literature. Of course this is difficult when it comes to violet wands. There are only a few manufacturers out there. Most people who sell those devices have bought it from them and the sellers themselves most often don't have a good knowledge of the dangers involved with their products! Example: most of them will tell you something about skin effect, static electricity or output currents in the sub-mA range (read this section to learn that the cururent is up to 480mA!). But these are myths! Read on to get some insights... |
direct current:
DC means, the current flows only in one direction. If you remember how the human body is buildt, this would mean that the ions (charged atoms or molecules, being part of all the fluids in our body) will be driven only in one direction. This is really bad, because when they will leave the cell they belong to (on their way to the battery), the cell will die.
=> don't apply direct current to human body!
technical alternating current (50Hz or 60Hz):
You all will know the line current: in your outlet it is AC with 230V and 50Hz (115V and 60Hz in the US). 50Hz means, the current changes its direction 100 times per second, it is flowing 50 times per second in one direction and 50 times per second in the other direction. Thinking of the cells in our body one could think that the ions will not travel far in only 1/100th second, because even when they leave the cell they will return after 1/100th second, so nothing spectacular should happen, right? WRONG!!! Unfortunately, the rythm of our heart is driven by electrical impules generated by the so called "Sinusknoten" at the tip of the heart. Currents in the µA-range (0,000001 Amperes!) are responsible for a correct function of the heart. Have you ever seen an electrocardiogram? There is a negative peak, which looks exactly like a halfwave of a sine. And its frequency is in the range of 50-60Hz, the same as our line current. If you supperpose an external current to the hearts internal current, 1µA (applied directly at the heart) can kill. Of course not every electrician who thas touched the line has died instantly, this is because the timing was "bad" (good for the electrician). You have to disturb the heart in the vulnerable phase to get a bad effect. But you don't know this when you touch the line... And if you can't let go because the muscles are cramping due to the current, the heart will see the current over several cycles. If you understand german language, be sure to read the article about Unfaelle durch elektrischen Strom on my website!!!
Another value for comparison:
The current which will flow when you touch the line with both hands can be
calculated with the help of Ohm's law: I=U/R
R = body resistance, approximately 2000 Ohms (with sweaty fingers)
U = 230 Volts line voltage
resulting current I = 0.115 Amperes!
You can see from the third picture in the mentioned article that dangerous effects start above 0.01A (area 3)! You also can see that the calculated 115 mA are deadly when applied for more than one second (a bit longer than a heartbeat). Keep yourself away from the outlet!!!
Some people say: I use a transformer for line current (iron core with windings on it) to generate high voltage to perform my "stunts". This is even more dangerous! You can see from Ohm's law that the curent will rise with applied voltage. And, even worse, the resistance of your body will drop with applied voltage! The resulting current will kill in even shorter time of application.
=> don't apply technical alternating current (50/60Hz) to human body!!!
high frequency current:
You often can read that "violet wands" produce "static electricity" with the meaning of direct current (DC) coming from your wand. This myth was born due to the fact that a spark from a violet wand feels like a jolt you get when charged up by walking over a dry synthetic carpet and earth yourself at the doorknob afterwards. The german name "Hochfrequenzheilgeraet" is a hint to the fact that the wand will produce high frequency current (also called radio frequency, RF). You know low voltage DC coming from a battery, alternating current (AC) from your outlet (50Hz = 50 cycles per second in Europe). The RF from our violet wand is in the range of 200.000 Hz!
TENS-devices also use AC instead of DC as some people will tell you. The AC voltage from TENS devices is not symmetrically in amplitude and time. If you draw the positive voltage on the y-axis and the time on the x-axis, you will get something like this:
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_____| | _____| | _____
|____| |____|
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So the positive pulse is short but of high voltage, the following negative pulse is of longer duration but with lower voltage (depending on which eletrode you consider as reference, polarity might be other way round). In detail, the intergral value of voltage over pulse duration is equal for positive and negativ pulses. The frequency will be different in many devices.
Here is a text, "nightwind" posted on the Yahoo-"violetray"-group:
Although TENS (Transcutaneous Electric Nerve Stimulation) and EMS (Electronic Muscle Stimulation) Units are similar in basic operation their design functions differ, in simple terms:
TENS units are designed to stimulate the nerves involved in the transmission of pain and sensation and by doing so blocking/restricting/slowing the transmission of pain signals and/or stimulating the production of endorphins reduce the perceived level of pain.
EMS units are designed to stimulate the nerves controlling muscular function and by doing so cause the muscles to contract and relax over a repeated cycle thus exercising them.
The degree of difference between particular TENS and EMS units varies widely as there are a large range of models available in both categories including some dual purpose units which combine both functions [...]
[...] TENS units generally produce effects which are perceived by the subject as a range of sensations (this can vary from a mild tickling through a sharp tapping/throbbing up to sensations that are actually painful), whilst the effects of EMS units are more visible with involuntary movement of muscles and less perceived sensation [...]
(place here
the material from the discussion with K.)
CONTRA-INDICATIONS OF TENS
On http://www.veritymedical.co.uk/modes/TENS.htm, I found some CONTRA-INDICATIONS, which apply to all other electrical stimulation devices as well, including violet wands:
Mobile solution (battery pack) for added safety
Ok, there seems to be a need for a safe way to operate the old (and even new) violet wand devices. My best suggestion is to use a battery pack in conjunction with a converter and some other safety elements:
Never ever connect a violet wand to the line for playing with it! Only the mobile solution will provide enough safety since there is no path for dangerous 50/60Hz line current to flow through the body.
Of course you still can damage other 230/115V-lines with the high voltage output, so please be careful and choose the playing area carefully BEFORE you start playing russian roulette with your wand...
If any question is left open, ask someone who has proper knowledge BEFORE doing stupid things! Some faults might be fatal...
