Domain: 4hv.org
Stories and comments across the archive that link to 4hv.org.
Comments · 7
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Re:Nigh impossible
6 pounds is unlikely at the claimed range/power, but something less impressive is definitely possibly. I remember this guy's project from a couple years ago, only about 10% of the power but if nothing else it still 'looks cool'.
http://4hv.org/e107_plugins/fo...
Ignore the complete disregard for eyeballs.
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Re:Going Cable!
Still have nearly-perfect hearing, minus the really odd gap at 15kHz-16kHz
...Not odd at all. Were you exposed to CRT TVs or old monitors for an extended amount of time? Their flybacks operated at one of several freqs: NTSC is 15,734 Hz, PAL is equal to 15,625 Hz, PAL M is equal to 15,750 Hz I wondered if TV/monitor technology was getting better over the years - the flyback scream got quieter and quieter as I got older. Turns out my ears were losing their sensitivity to it. I have a gigantic notch at those frequencies.
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Re:Non-grandfather here also interested
I was going to say the same thing. And if a tesla coil is too pedestrian, there are plenty of other "macro-scale" electrical projects to build, like quarter shrinkers or Marx bank capacitor set-ups for crushing cans. Check out 4HV and the Geek Group for ideas and communities to bounce other ideas off of.
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Re:Use calibrated radiation sources
"Point it at a smoke detector" won't work: the americium in smoke detectors emits alpha radiation
Most of your post is sooo good but this tiny part is soooo far off. I can tell you're quoting some simplified "book learning" not having done experiments in a lab with some Am241 and even a cheapy scintillator MCA. Trust me, you get a nice assortment of gammas from Am-241.
http://wiki.4hv.org/index.php/Americium-241
Go to google image search, enter "am 241 gamma spectrum" and see pretty graphs of Am241 gamma emission.
Also, never forget that there is no such thing as a chemically pure (or especially isotope pure) substance. The instant that miraculously 100% pure Am-241 target was refined, 237Np started building up, and 237Np leads inevitably to 233Pa, 233Pa leads inevitably to 232U while emitting a nice strong beta, etc. So, in any "real world" sample you'll have a whole vegetable soup of pretty much
... everything.Now ratios, yeah, you're gonna see exactly one zillion alphas for every geiger detectable gamma. That in no way excludes the detection of gammas and betas from a chunk of 241Am.
Radiology is a very analog science... the digital 1s and 0s types have a rough time in radiology.
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Re:No useful details in the article.
Might want to talk to the guys that play with induction heating... There are different heating mechanism than you pretend to know.
From http://4hv.org/e107_plugins/forum/forum_viewtopic.php?80493
>Copper requires much more workcoil current/reactive power because copper has no hysteresis losses while iron does have. So all we have here is eddy current losses to be play with.
I personally don't think placing such a magnetic field to the delicate circuit next to a chip is good.
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Re:transporting electricity
if the magnetic field from adjacent conductors can't penetrate each other, they couldn't induce a current in each other.
Think of it this way. All conductors try to arrange their internal free charges (usually the electrons) to produce a net E=0 inside, because if there were a nonzero E, then it would apply a force to the free charges until the charges were arranged so as to cancel out the applied E within the conductor. Also, a changing B field outside the conductor induces a current in the conductor that tries to oppose the change in magnetic flux through any closed loop made by the conductor (Lenz's Law.) All conductors do these things; superconductors are just better at it. -
Re:not 6 KV, more like 2 KV
2 KV at 500mA is seriously dangerous. Those voltages should only be handled with 'one hand in your pocket' to prevent that currents might go trough the hart when a mishap occurs. 2KV will jump a good distance from bare contacts, so you don't even have to touch them. But you are welcome to prove me wrong; Darwin will take care of you I suppose
;-)
There is a good safety thread @ 4hv.org. Read that before you start taking that spare MO apart.