Re: Safety Considerations

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Illicium Verum <sebas@xxxxxxxxxxxxxxxx>


Hello Chris,

No part of the system should be touched while in operation. 
Especially the primary circuit is very dangerous, because of high 
voltages and currents and the low frequency. Currents at this 
frequency will directly flow through your body. Currents as small as 
50mA can kill you and currents in the primary coil are 2000 times 
higher!  The streamers ("lightning") from the secondary are dangerous 
and even lethal. The radio frequency lies outside the nerve cells' 
detection ability, which means that you don't notice that there are 
100W of power traveling along your tissue and blood vessels, cooking 
you from inside out. Never do a stunt and touch or get close to the 
streamers! Instead, use long plastic rods with an end metal terminal 
that is connected to ground. With this, you can safely draw arcs off 
the coil. Even the switched off unit still contains danger because 
capacitors may still contain enough energy to at least cause a 
powerful shock. Always discharge capacitors. Capacitors should also 
be stored with their electrodes shorted, as they may charge 
themselves over time. Tesla coils are high frequency devices, 
producing strong electromagnetic fields in their environment.

Under any circumstances, ensure that nobody wearing a pacemaker is 
near the Tesla coil while in operation. Sensitive electronic 
equipment may be destroyed by the fields near the coil. This does not 
only apply to pacemakers, but also to computers, VCRs, and other 
sensitive electronics. Radio frequency interference is also possible, 
especially, if the spark breakout is prevented by an over-sized top 
capacitance. However, the most common cause is bad RF grounding. Good 
RF grounding is essential for good Tesla coil operation.


Besides the danger to your own life, there might also be a danger to 
other lives such as your partner, playing children and pets. Never 
work alone and always have an emergency stop installed. It is 
advisable not to allow someone else to operate your Tesla coil 
without your supervision. It might also be wise to do a CPR course 
and have an Automated External Defibrillators (AED) available. An AED 
is a device that allows the most inexperienced user to safe your 
life. Once connected to a person whose heart has stopped as a result 
of electrocution, the AED measures the amount of energy that is 
necessary to reactivate the heart. Ask your local Red Cross office 
for more information.


Best regards,

Sebastiaan


Tuesday, August 2, 2005, 7:45:55 AM, you wrote:


> Original poster: "Chris Fanjoy" 
<<mailto:zappyman@xxxxxxxxxxx>zappyman@xxxxxxxxxxx>


>    After months of work, my VTTC is almost ready to power. But before

> I prepare to bring it to life, there are a couple of important safety

> issues I'd like some info on.

>    First of all, some specs: the coil uses two 813 tubes, powered by

> a (massive) MOT and voltage doubler. Frequency is 157KHz, and the

> expected spark length is anywhere from 1-2 feet. It will be run by a

> staccato controller, rather than continuous wave. Currently I do not

> have a topload on the secondary, save for a long bolt to which a

> toroid could be attached.

>    Question 1: what precautions should I take to protect nearby

> solid-state devices? (TV's, VCRs, my wristwatch, etc). Is it enough

> simply to keep them a good distance away, or are other precautions needed?

>    Question 2: how hazardous is the output of the secondary itself? I

> know very well that the primary side carries lethal current and must

> be avoided at all times. But I've seen pictures of people touching

> the sparks from their coils, and this looks very fascinating to say

> the least. I actually tried it with a small, crudely-rigged VTTC a

> few months ago. It used a single 6146 tube powered by a 400VDC power

> supply. The spark was only about 1/2" long, but was run

> continuous-wave since I didn't yet have a staccato controller.

> Curiousity got the better of me and I just *had* to touch it and see

> what happened. It was a new, and exciting experience, to touch a

> high-voltage arc and NOT receive a painful shock! However, because of

> the CW operation, it would quickly start to burn my fingers if I held

> them in place too long.

>    So before I go touching the sparks on this thing, I'd like to

> advice on safety first. And I'd also like to know how to keep my

> other gadgets from getting fried as well.

>    Thanks for any advice.






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Best regards,

Sebastiaan