ESD Gun - Shocking? Yes!

The device described would be quite dangerous if it functions in the manner described. What would be interesting, as I've just discussed with a couple of workmates, would be the discussion of components in the system, and what there functions would be. Would you care to expand on details and explain in a deeper sense.

Here is the link for details: http://www.edn.com/archives/1996/091296/19di1.htm

Explaining or giving details of devices wich can be used for other purposes than engineering is something that should not be allowed... I think that we have enough violence in our dayly life to start giving ideas to people who may use this forum for harming or treatenig or even kill others .... We should handle this topics in a more responsible and mature way...It is a very thin line between an inocent coment and some wich may direct you or others into more evil toughs....

Piezoelectric gas lighter or similar device, usually gives very mild shock and won't kill any one. However, if energy is stored on a capacitor, then it can hurt if not kill some one. Those of you have to work for ESD testing will find this ESD gun rather safer than actual HV supplies used for the job and it is only for US$1. No one is scared of gas lighters.

In fact EDN users voted in favour of the design idea and appreciated the design and also the editors were impressed. I have their letters with me. Piezoelectric gas lighter is something that easily does not fail even if you use many times daily for several years. While it can be purchased for US$1, all professioanl things for ESD testing under human model otherwise difficult designs and cost thousands of dollars.

Static charge can cause explosion anywhere and it is worth that we all know about it and do not fear knowledge. Your cloths can cause enough static charge when you move and if it discharges near explosive fuel like oil tanker then you know what to expect. Cloths can acquire near 10kV to 100kV due to insulated surface and high tribo-electric nature. Piezoelectric devices are made for this purpose. If you couple them many in series then can generate million volt pulse and lightning spark.

One of my friend who actually touched a capacitor of the laser power supply which was switched OFF was instantaniously killed by high voltage shock as capacitor can hold charge up to several days even after high voltage is switched OFF unless there is safe discharge circuit to remove charge quickly. Colour TV has > 15kV high voltage supply which may be fatal. Hence, this area is not for non-professionals.

Communication ICs these days come with 15kV ESD protected. Look for some details on http://www.maxim-ic.com/appnotes.cfm/appnote_number/639

There are three factors in high voltage shock that make difference

Voltage, current flow through body and time of exposure

I think 400V shock pulses are used to bring back heart into action if it failes due to uneven polarization. Shock is not all that bad. Just right use is what we need to know.

You got it right. I was a nuclear scientist then working for Indira Gandhi Center for Atomic Research, kalpakkam, India. That is why that IGCAR, Kalpakkam listed there. See www.igcar.ernet.in for the website of the power plant FBTR. That is the only fast breeder nuclear reactor in India.

is it possible to fit a voltmeter or ampmeter to this setup to monitor how much electricity is stored in the capacitor? This device sounds like it could be quite dangerous in amateur hands - and yet very simple to make.

virtually a lethal taser.....

That is one way to say it. That is why there is that caution note.

So saying you had a huge & high density capacitor, what is the maximum distance that the arc will discharge from?

Isn't there a good chance of the current choosing the user as it's fastest route to ground (given that you would inevitably be holding the device). And what is the trigger mechanism you are using? (or are you just touching the device to the "target".

you didnt answer my question RE: attaching a volt/amp meter :-)

It is 4kV per mm to spark in air. Hence 3mm for 12kV to 15kV is what you will see here even without capacitors.

This technology is very similar to the "shock rounds" currently under development to increase the effective distance of tasers. Except that they are using an explosive charge to compress the piezoelectric material to generate the charge which discharges through electrodes into the "target".

Not to say that I wholly support weapons development, but I do like your idea better.....it allows for more adjustability as to the charge involved. You may have missed the boat on this one though, hehe

http://www.newscientisttech.com/article.ns?id=dn9996&feedId=online-news_rss20

I wonder what the storeable charge would be if you used a piezoelectric capacitor. I'm unfamiliar with these....

If you use 1000pF 15kV cap then it will pump 1.5A for about 50us through the body. This sure will make the person numb for a while. 10nF cap perhaps has a chance to kill.

I suggested 100pF which will give a 10us pulse which is a human body model for testing the IC. This instruments is only US$1, while professional instrument may cost US$5000 range for the same test. I had only one dollar at that time and tested this one and EDN published perhaps my several different design on this US$1 device and made me very rich for a while. I even made a zero power number of trucks on the road counter using this device. Imagine having instrument without battery or power and generating electricity and also giving you information you wanted.

This device was never meant for killing. However, to avoid accident, I need to put that note for user's safety. I do not like unsafe designs.

well, that said - there is still an opportunity for you to get some more $$$ out of it, hehehe

I've quickly designed a concept 'variable charge taser bullet' in my mind from the information you've supplied, and whereas I won't do anything with the info, I'm sure you could design something similar quite easily.

it would be much more useful than a use once and throwaway round as yours could be re-used after discharge rather than ruined with an explosive charge.......

Dear sir.

It is the Charged capacitor NOT the Hi-V Piezo-Disk which is a danger.

**** Quote ***

"mechanical energy you apply in impulse hit## on a Piezoelectric Crystal."

*******

More over note it that #impulse hit## is not a mech-strike but you feel it, like Electro-Magnetic Lighter in which a Trigger like a revolver's is loaded against spring & releases at the end point @ very fast speed; which disturbes a magetic-field [having a coil in] & generated Hi-potential {remember Induced v is directly proportional to "RATE OF CHANGE OF FLUX".

The Piezo-crstal or disc produces Hi-Pot under pressure [Piezo-electric-effect] & it increases till the arc-over in Gap occures. At this instant the pressure on the disk is released which is felt as a mech-strike.

Regards

Haajee

Yes, only after storing the charge on a capacitor it becomes a serious problem or dangerous to use. Without capacitor, you can easily put your finger and sqeeze the trigger and can sense a small shock pulse which is not at all dangerous. Larger capacitor means greater harm.

When I developed this device, people were not aware of ESD testing. The Fox Bat fighter aircraft of USSR has given many ideas to people of the world and ESD and EMP became part of the electronics research.