Detecting best path?

I can't believe I read the whole thing.

Jamie

Reply to
Jamie
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I'm a writer, and although I keep telling myself I'm still an electronics amateur, I haven't actually touched a soldering iron in years. I hope you'll help me anyway. :)

Partway into a story, I've hit a snag because I'm not positive a necessary 'prop' can be made.

This problem is therefore theoretical in that I won't actually build it, but my internal editor demands that it could be built, and I have to know what, if any, limitations there might be.

(Sorry this is so long, but I hate asking for help and then having to tell people, "That's a great idea, but it won't work here because

Reply to
Jymesion

:) Any chance you'll be able to solve the problem once your mind un-numbs?

Reply to
Jymesion

No one will live long enough to see that happen.

Reply to
Michael A. Terrell

300kV is way more voltage than you need. Current kills, you only need enough voltage to force that current through. Supposedly 12V will do it on a Really Bad Day; I've survived multiple jolts from 120V as have many other folks (but many others have died for it, mostly in accidents involving water and an inability to get disconnected). 500V to 1000V should do it. 300kV at sufficient current would probably leave a smoking corpse, and would require more battery than you have. In fact, 300kV at sufficient current to kill would be sparking, popping and snapping over distances larger than one foot on a humid day.

Some actual research at an actual library may come in handy. Or even Google or Wikipedia.

If Poor Doomed Innocent Guy touches the cross then falls to the floor convulsing without keeping a grip on said cross, then I'll put your book down in disgust -- the convulsions only continue for as long as the cross is in hand. After that the guy will be wherever he was thrown from the shock, or stone dead.

Servo motors driving rotary switches are kind of lame, unless your villain is pretty lame, too, and your Intrepid Hero is to figure it out because of the whirring noises, and the suppressed curses when some of the Poor Innocent Doomed Guys walk away whistling.

Better would be a circuit between each set of contacts, with its own battery, that's switching (for efficiency), current limited to 20mA (or

2-3x fatal), and will go to up to 1000kV. Then when Poor Doomed Innocent Guy grabs it, the circuit will automatically adjust itself for fatality.

Use opto-isolators to turn it all on.

Or better yet, write political speeches -- the audience is much more willing to suspend disbelief.

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Reply to
Tim Wescott

My research was to find a voltage multiplier module with an output equivalent to the stun gun I have and that would fit in the required space. It took all of three minutes -- there were a lot of options.

Funny, none of the advertisements mentioned burning people alive.

Reply to
Jymesion

I don't have a problem with the 300 KV as such, though you could surely get by with a bit less. You just need to punch through the outer skin resistance, which could be high if the victim has dry skin. Note that tasers avoid this by physcially poking through the skin. (But you can easily include moist skin in the plot, since the guy is likely to be stressed out about the whole ceremony thingy.)

You probably aren't getting too much current from your voltage multiplier anyway, but you could mention it if you really feel it's needed. I don't think most people would bat an eye at that, since they know about tasers and such by now.

Tim is dead-on about servos... some sort of solid state switching will sound much more plausible. But I don't think you even need switching.

If it were my story, I'd skip this issue entirely and just make it a part of the ceremony that the celebrant must hold the cross in a specific way. Maybe both hands have to be near the bottom, and his forehead touches the top. Or maybe he has to kiss the top. Or maybe the left had has to be at the bottom, and the right hand has to be above it. There's a lot of room to play with here.

Best regards,

Bob Masta DAQARTA v7.10 Data AcQuisition And Real-Time Analysis

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Reply to
Bob Masta

On 10/15/2012 8:34 AM, Bob Masta wrote: Snip>

Unless he really wants to build it.

Reply to
Tom Biasi

I realized that I assumed you were trying to kill. So, are you trying to kill the guy or just make him shout?

Your stun gun doesn't keep generating 300kV when it's actually connected to a person. And, since it's a _stun_ gun, it doesn't generate much current (I don't know what's considered safe, but chances are it's less than what's considered lethal).

Regardless, unless the guy has some underlying medical condition, once he's off the current he's going to stop convulsing (unless he pulls a muscle, in which case he'll be convulsing in pain as from any other injury).

If you're just going for pain & convulsions, then connect the whole thing together through a resistive divider -- gold - resistor - gold - resistor

- etc. Then wherever your Hapless Victim grabs the thing, a current will be established.

If I sound a bit cynical, it's because I don't think it would work in real life, on a whole bunch of different levels: getting a reliable honkin' big shock without either piercing the skin or risking death is pretty iffy, and isn't something that you can do right out of the chute, even if you're knowledgeable; having everyone in the room be smart enough to get to the ceremony at the appointed time yet dumb enough not to realize that trickery is involved isn't likely (unless there's time travel involved); having someone dumb enough (or evil) enough to get into the situation while still being smart enough to wire the thing up, etc.

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Reply to
Tim Wescott

That's why I think selection of contact plates is important.

If one hand touches two active plates, it'll tingle/burn, and the person will quickly pull their hand away, ending the session.

Current flowing through the body will make the muscles in the hands contract. Not only will this prevent their letting go, it'll also improve contact. (I vividly remember a junior high school science fair entry where you gripped two handles and someone pressed a button -- it was impossible to let go of the handles until they released the button, stopping the current.)

I think initial contact will be sufficient to allow current flow because the suspect is in a tense situation (sweaty hands), and there's good pressure because they're holding it tightly enough to raise it above their head.

Even if there is only a slight flow at first, muscle contraction and increased sweating will improve contact.

There's a risk of death when sending current through the body because it'll pass through the heart, but the majority of people live, and it should only be for a few seconds.

It's only necessary to drop the person and have their agony be obvious. In the scene, the protag (after turning it off remotely), takes it from the suspect's hands, raises it high, says a prayer asking for mercy if the sinner repents and confesses, and lays it on the suspect's chest. The suspect immediately starts naming his cohorts.

Reply to
Jymesion

I need to know both for confidence and defense.

Unless I know it could actually be built, it'll nag at me, and at some point, I might decide to cut the scene. That would necessitate a replacement scene with exactly the same plot elements, motivations, and characterizations. Writing is hard enough without having to create within such a rigid framework.

If/when it's published, there will surely be readers who question it. If I can't trot out a decent description, they'll brand it a mistake, and even a few reviews which question the author's accuracy can hurt sales.

If it was a disintegrator ray, no one would question it, but when a character in present-day builds something using off-the-shelf components, it better be buildable. :)

Reply to
Jymesion

For me, it's a matter of readers crying foul. It's fine to introduce any absurdity (as long as it's believable), but when including something which existed in the real world, it's immutable unless you can show why/how history was different/changed.

Example: tobacco and potatoes in The Lord of the Rings. How pipeweed was introduced is in the text, so that's fine. But readers, a lot of readers, deplore there being potatoes because they didn't exist in that latitude before a certain date.

Since my writing is nowhere near that of Tolkein's, my stories will suffer more if the readers see mistakes.

Reply to
Jymesion

Well, I'm sorry for insulting you but I just don't buy your story. Writers don't give a Damn about whether or not something is plausible to an expert group, only that the audience will accept it. I really think you want this device for what ever reason. JMNSHO, Tom

Reply to
Tom Biasi

You must have been exposed to a lot of utter crap.

A good author, or one who wants to be good, researches anything that might be called into question and agonizes over not recognizing that something might be questionable.

This is so ingrained there's even the question of whether it's better to actually be accurate or to be believable. When discussing a different aspect of this work with other writers, they called into question my use of the terms 'serfs.' It's technically correct for the particular era and area, but serfdom had declined so significantly within that general time frame that most readers would see it as a mistake.

Even if an author didn't care, the agent would, because a novel full of errors is harder to sell, and publishers know any good reviews of a novel can sink out of sight if readers can point out mistakes (and some people love to talk about finding errors because they think it makes them look smart).

Readers' awareness of mistakes is so high that writers, like E.B. White, who can justify creative anachronisms are usually hailed as geniuses.

Reply to
Jymesion

too complex.

it would be possible to stuff the tube with photoflash style capacitors, trigger them with a SCR. How to arrange the terminals would be the issue, but it's possible people would grab it the same way dues to its size or how it's positioned.

No gadget is going to generate 300kV, and if if did, it's not going to be discrete at all.

Reply to
Cydrome Leader

Ivory is a pretty good insulator itself. I put about 1000V across 2mm of ivory-faced mahjongg tile and wan not able to measure any current flowing with my cheap equipment, I would not be surprised if it was as good as dry wood - near perfect. Ivory is also tougher than ceramic, ceramic is likely to shatter if banged on a stone floor etc. Ivory coloured plastic tube is another option

You can use spark gaps to route the current. Just put a 0.1mm spark gap between each segment and apply the voltage between the ends. the gaps will arc and connect the segments in series until the current reaches each hand and then the current will take the easier path through the hands and arms,

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Reply to
Jasen Betts

There's the rub -- they didn't. I found a period account which described the ritual. One person picked it up with one hand on the stalk and one hand on the crossbar, another held the stalk in both hands. The first passed, the second nearly failed because it slipped down (I assume the weight and his sweaty hands were a bad combination).

It's basically a rigged-out stun gun. The 300kV is without load.

Reply to
Jymesion

Ivory isn't practical in this situation because there's no good excuse for him to have it. He can order ceramic tubes in a variety of sizes from a company where he buys items for his electronics hobby. As long as it seems mainstream, and can't be used to build an obvious weapon, it slips under the radar of those watching him.

Wouldn't the easiest path be though a hand which touches two plates?

If that happens, the suspect will let go. While that would establish his guilt, it wouldn't be as frightening. I assume anyone who'd plot to assassinate his king would be made of stern stuff, and it'd take a combination of pain and fear to make him confess and start naming names.

Reply to
Jymesion

Can you point me to something you have written?

Reply to
Tom Biasi

--
What seems to me to be a glaring error is that if only one hand 
gripped the cross, then there'd be no way for current to flown through 
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Reply to
John Fields

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