... and I do too much.
Going to be leading ("teaching" is too strong a word, given my own skill level) a really really neat class/group in Faux Painting (level 1) dealing with basics, metals, and textures. Gonna be great! Gotta figure out how to wedge a dozen people into my workspace! In such a way that they can work!
So, I need to post step 2 of my Tesla project, which will address the Primary and the DC Power supply, but I'm still researching the DC power supply ("you want HOW many volts at WHAT current? HAHAHAHAHHAHAH!" is pretty much what I get out of most references)...
... in so doing, I stumbled across this Gem:
"PM-SRC operates in three modes, namely, mode-1, mode-2, and mode-3."
Now I see why those PhD engineers get the BIG BUCKS.
Oh yeah, those atheists, violating all of God's laws, of course our country and much of this world is collapsing around us.
I mean, how can the natural order operate with such Godless behavior everywhere; not to mention, it's just undignified. I feel sick when I even think about the Babylonian excesses these people get up to. I fear for the punishment that will be handed down to us... soon, I fear. Soon.
For example, gravity. Gravity is a law I can get behind, and it just makes sense; but here we have people, sometimes even deemed to be heros, "astronauts", recklessly floating above the land in frank denial of one of the fundamental laws handed down to us from on high.
And let's not even talk about airplanes; those infernal devices may pretend to follow the laws, but really, they are just flaunting our secular ingenuity, a sure rise of hubris just as surely to be followed by a fall.
Then there is the speed of light. But modern "scientists", who choose to ignore the limits and regulations that govern all of life, try to flaunt even this vital cornerstone of our universe -- just recently, in fact, they used "entangled" photons (a perversion of the light if I ever heard of one) to "see" an object without even seeing it properly, as God intended. One of the photons was sent out to a mask of a toy figure, and the other one, immorally entwined with the first, was detected and used to fill in details at a distant site. A thousand such pairs were used, building an image of the mask using poor innocent photons who had never even touched the source image.
Indeed, things are in dire straits.
Atheists, of course, are at the heart of it all -- without the constant threat of divine wrath and eternal suffering, they run rampant, causing horrible immoral acts that are bent on destroying the very fabric of our nation.
Bob, for example, to pick one prominent atheist. Fearing no eternal damnation, no divine paranoia or forced external conformance to arbitrary laws via the interpretation of those who decide they are his betters, well, I'm sure he is out there eating babies and fornicating with unclean creatures (and I don't mean Mo; Mo bathes regularly, I hear).
Doubtless. For how could any person be a good person, or find their way to feel sympathy for and cooperate with their fellow man, if they didn't feel coerced to do so by some overwhelming, over-arching father figure, poised to mete out harsh punishments at any arbitrary transgression?
As a people, as a nation, there is no need for us to grow up and take responsibility for our lives, like aduls; such a suggestion is laughable, and even perverse! We, in a fine tradition, need, deserve even, a Father figure to guide us, to think for us, to tell us how to feel and how to live. I mean, to move beyond the level of a four year old, to think for ourselves, and to make decisions based on empathy and a desire for a greater good? That is crazy talk! People won't ever do that! Better for them to be treated as children, or sheep, and to herd them and guide them with threats of torment and promises of some future reward. After all, it's for their own good.
It's worked so well so far. The Catholic Church, to take one example, has shown themselves to reflect the perfection of God that they claim, all through their history; Galileo, the inquisition, the crusades, the stance of "breed as much as you can and don't worry about the consequences"; all of these were part of a divine, and unimpeachable plan.
And our current government leadership, all very devout Christians, religious to a fault, and ardent proclaimers of their belief in all things heavenly and divine; they have surely proven themselves to be capable and compassionate stewards of God's gardens, our environment; the air and water and land which nurtures and supports us all. And they have shown compassion and sympathy to those less fortunate, of course, as Jesus has done, offering a helping hand to those in need; and chastising those who would make obscene profit at the expense of others.
Indeed. Or, perhaps, instead; the dominant religious paradigm is completely broken, our religious and political leaders are for the most part full of shit, and our people need to grow the fuck up and learn to live their own lives by their own decisions, and tell these jackasses to go fuck themselves.
You decide. After all, it's your life, and you only get one chance at it. Make it worth something.
Also, read my "God's Laws" column and think "irony". It should read better then.
There is No Law but God’s Law.
All of our man-made laws are just a construct of our human pride and ignorance; and those laws that actually work are those laws that were written in conformance with God’s will. To follow the laws of man above the laws of God is a sin (“sin” meaning “to miss the mark”, e.g. "oops, you can do better there sunshine"). The hell you are cast into for missing that mark is a hell of your own creation... and believe me, I've seen that hell and it's no place for the timid.
But what are God’s laws? I know that there are a bunch of holy books out there that are reputed to have been written under the direct and irrefutable influence of God’s hand -- and they include such oddities as serious (on-pain-of-death) rules such as to not trim the corners of your beard, or to not wear fabrics of mixed fibers, along with some very sensible ones about not killing your neighbor or stealing their stuff (or wives, though wives are often lumped in with “stuff” in many cultures).
Given that God permeates _everything_, is in fact the source and origin, the motivating force and reason for existence of this entire universe of ours (pretty much by definition; anything less would be an insult), you would think that it would be pretty darned easy to discern what God’s wishes were, to know what was one of God’s laws versus just random thoughts in our own heads.
Of course, it’s not that easy; and some of the more introspective religions note that our perceptions of the world around us are akin to seeing the world through a warped, dirty, and cracked window. We see it, but we don’t see it _correctly_. So the prophets are those among us who have a cleaner window, and can report back that yes, trees do in fact have individual leaves (or the spiritual equivalent). Of course, it can be tricky to tell the difference between a true prophet and the schizophrenic fellow ranting on the street corner -- a problem that I have to assume existed back in the good old days as well, if not more so.
There is always, of course, the issue of miracles -- but all the popular religions had miracles, hardly a discerning factor. Also I myself have personally performed miracles, at least that is what I heard after the fact when I had done some magic tricks for a relative I later learned was not entirely stable. Miracles are easy; ask me, I'll do one for you. And second-hand reports of miracles? These are garbage! Worse than useless! I've heard reports from intelligent and reliable people of miracles (er, magic tricks) that they had seen... that had almost nothing to do with the actual trick that was performed. And yes, I have an extensive collection of magic references, and have engineered magic tricks that were used in television specials, so I know wherefore I speak.
So we can't rely on heresay. It is a good thing that God’s laws are there inside your heart for you to discover. It could, in fact, be no other way! You are a part of God, God permeates you, and a true listening of God’s voice speaking to you from your heart has got to be a good place to look for truth.
Mormon’s use this test -- to have you look deep inside your heart, from a quiet and respectful state of mind, to listen to that quiet voice deep inside you, and see if it tells you that your chosen faith, your spiritual path, is the correct and true one, in Jesus’ name, Amen. (As a side note, you know it's prayer and not ritual magic if you invoke the correct demon's, er, spirit's, er, God's or Jesus' name when you do it; otherwise, prayer and ritual magic are almost entirely indistinguishable; bet you didn't know that!)
You know what? That quiet voice says yes! I bet it says yes to... damn near everyone, regardless of their religion.
Maybe they are _all_ correct? Or _all_ wrong but instead fulfilling some deep-seated psychological need of humanity, something that made sense as we developed but may have been hijacked in modern society?
God’s laws are the laws that _work_; that are in harmony with society and with human nature; they serve to keep the social structure working and reduce conflict. God’s laws will promote both the individual spirit (and our need to be unique) and the needs of the whole (and our need to be part of something bigger than ourselves). God’s laws will see the big picture. God's laws should be irrefutable, otherwise, what's the point?
Sticking your fingers in your ears and going "nah nah nah I can't hear you" while burying yourself in random scriptures in your particular holy book does NOT count as a valid refutation. Just so you know. 'cause I have MY holy book, and it contradicts yours; my prophet can kick your prophet's ass! As you can see, appeal to authority gets us... nowhere.
There are some of God’s laws that are very nearly universal, and pretty darned hard to argue against: Don’t kill people, for example. The trouble comes in with the details -- how about when you are attacked? What serves as a “person”? What about yourself? How about for legal punishment for murder? Baby raping? Writing bad checks? Voting for Ralph Nader? It goes on and on, but still, the basic principle is sound.
Light travels at 186,000 miles per second. That is absolutely one of God’s laws, and it is in fact so serious a Law that it can not be broken, whether you want to or not. The really fun laws are not these immutable truths, though, but those trick questions that God lays into your path, to try to trip you up and test your soul. The American Indians may have had it right with their Coyote trickster! Not to mention Loki, et. al.
For every action there is an equal and opposite reaction. Interestingly enough, this works as a social law as well -- when my HOA sends me a rude or impersonal letter, I automatically set myself into the stance of the disobedient rebel, whether I want to take that role or not. More discussion on this rule can be found in “The Lucifer Effect” by Philip Zimbardo (though I am seriously mischaracterizing his research, I think it fits).
Animals will reproduce until they exceed the ability of their environment to support them, and as a result not all of them will survive to reproduce further. Those animals that are better suited to their environment are more likely to reproduce and hence send their descendants into the future. Reproduction, moreover, is an imperfect transaction, causing changes, both good, bad, and neutral, to the organism through time.
Simple stuff. Hard to refute. But with incredible repercussions, especially when considered in a geological timeframe (which humans are, by nature, nearly incapable of doing; how long _is_ 50,000 or 100,000 generations, anyway? What does that _mean_?)
The Earth, from direct observation and some clever thinking, can be seen to revolve around the Sun. When the Church refuted this, fearing it would be too scary for their congregations, they were in fact violating God’s law and were in sin.
They got better. Some.
Not all of God’s laws are so clear, and our record of what we THINK are God’s laws is equally impure -- these holy books (yes, your holy book too, Mr. My Holy Book Is Perfect) have been written, edited, carefully and selectively amassed from scores of conflicting manuscripts, and even blatantly forged, by both madmen and by cynical bastards with a cause to support. Lying, in fact, was considered to be a noble act if it “brought people to God”. But which God?
I like my God to be a God of Truth.
Some people like to decry science as being anti-religion, of being atheistic at its core (or, even more laughable, as being a religion in itself; these folks have no idea what they are talking about, so it’s hard to hold a discussion with them). Science, however, is nothing more than the act of asking the right question, and keeping track of the answers.
That’s it. Pretty radical, huh?
Finding the right question is an art, and reflects both the interests and the biases of the question-asker, but if the right question is found, and the scientist has both the skill and capacity to hear the answer, the answer is part of science.
The body of science is composed of thousands, millions!, of questions and their answers; and, when we get better at listening to God (typically through better eye and ear surrogates) we get better answers.
It is our logical mind, that part of our mental anatomy that gets so little use amongst the greater public (when AI researchers model intelligence based on logical expressions, I both cringe and laugh at them), that helps us discern what is a true answer and what is noise or internal bias swamping God’s voice.
The same happens with spiritual questions and their answers. That inner voice may be telling you that Mr. Evil Politician is a Bastard, and that killing him will both (a) serve the greater public and (b) get you the attention of Natalie Portman (hubba hubba!)... you need to engage some of that rational thought to recognize that your inner voice perhaps needs to see someone and maybe take a nice pill, put the gun down quietly please and we'll get past this nice and easy.
When the preacher tells you that you must vote for So and So or THE COUNTRY WILL GO TO HELL in a blaze of EVIL, well, maybe they are full of shit and maybe you need to analyze their motives and intents rather than drink that particular coolaid. Which is tough, because it's a BLAST to be part of a dynamic, relevant, and angry movement that is out to change the world... ask any teenager, ex-teenager, or especially any person who grew up in the sixties.
In fact, here is one of God’s Laws, that I’m sure is true: When someone is absolutely positively sure of their position on a spiritual point, then they are absolutely and with the same magnitude as their belief... wrong. "For every spiritual belief, there is an equal and opposite..." well, maybe not quite so formulaic, but still; I think a thoughtful person has more true perspective than the demagogue.
It’s like that restaurant on the highway called “Joe’s Good Eats”. It might have belonged to Joe once, there’s an off chance that they do indeed sell “eats”, but will it be good? No. The more the sign proclaims their excellence, the worse it will be. The _truly_ good restaurants rely on more subtle cues... such as actually serving good food and not beating you about the head and shoulders with proclamations of its goodness.
Unfortunately, we as a species love to follow leaders who are sure of themselves, who are confident of their direction and who exude belief like a sweaty athlete oozes saltwater (or Gatorade, depending on their sponsors). Such leaders can also be dead wrong (and often are; note current politics in the US), even though they themselves know deep in their hearts that they are right.
So be careful out there, and use both your heart and your mind. These are the tools that God gave us, and you wouldn’t want either of them to get rusty from disuse; otherwise there will be Hell to pay later.
Here are some more laws that I’ve found:
I must not fear.
Fear is the mind-killer.
Fear is the little-death that brings total obliteration.
I will face my fear.
I will permit it to pass over me and through me.
And when it has gone past I will turn the inner eye to see its path.
Where the fear has gone there will be nothing.
Only I will remain.
An it harm none, do what ye will.
If anyone harms (others), God will harm him, and if anyone shows hostility to others, God will show hostility to him.
Those actions that you perform, those thoughts that you think, your memories and your intents, are reflected in your spirit (and face, and mind, and even posture); such that others will see you and react to you in ways that depend on your past actions, your thoughts, and your memories. That which you cast out onto the waters (good and bad), will return to you many-fold.
The most excellent Jihad (struggle) is that for the conquest of self.
Do with these laws what you will.
Namaste.
I has them:
http://www.simreal.com/content/IGDAPicnic
Because I’m a glutton for punishment, I am designing a Tesla coil from scratch. I’ll be using the work of those that came before me of course, because while I like to do things the hard way, I’m not entirely insane. This installment of my build notes is the starting point in my thinking; from a desired arc length, I will work backwards through the design until I reach the wall plug. Then I’ll refine and construct the coil, and hope that it works!
At first, I thought it would be useful to simply bring up the relevant theory, maybe run some calculations, throw up some graphs, make a SPICE model, and then the various parameters might be made obvious. As it turns out, there are quite a few models of operation for the Tesla coil; piecewise, you can assemble an amazing mathematical model of the entire thing (though poking around in these models made my brain hurt). The trouble is that there appears to be a lack of agreement on exactly what is the _right_model.
Corum & Corum wrote a detailed paper to refute the simple lumped-component model in favor of a distributed-inductor model [1][2], thereby throwing the gauntlet down between the two primary camps: radio people and non-radio people. The radio people tend to see the Tesla coil secondary like an antennae (and there is good reason to do so). However, the Corum^2 paper had a nicely-worded rebuttal by Terry Fritz [3] and work by Ćosić et.al. seems to show that the simpler lumped model does in fact work fairly well [4], which bodes well for easier SPICE simulations.
These two models only matter when it comes time to find the correct operating frequency of the coil. On the one hand, the inductor (coil) + capacitor (topload) LC circuit has a characteristic resonance in the lumped model. On the other hand, the wire length of the secondary coil (in conjunction with mysterious speed-of-electricity-in-copper issues [5]) gives a characteristic quarter-wavelength frequency for optimal voltage amplification on the top end of the coil.
Some calculators (and coilers, I assume) simply punt and adjust the circuit so that the LC resonance simply matches the quarter-wave resonance and brush the whole argument under the carpet.
Theory, it seems, is not the place to start. What we do have, however, are a number of rules-of-thumb guides that define the working space of the average coiler, and a whole raft of electronics formulae that can be used to crunch out the details later.
There are many assumptions that I make right up front. Since I’m coiling to make pretty sparks for display purposes, I want to optimize for zap factor. Other choices could include stable high voltage for physics research, or a high-frequency plasma discharge with low noise characteristics to make a plasma speaker.
Given the purpose, you now get to choose a technology. I’m choosing the DRSSTC (dual-resonant solid-state Tesla coil pioneered by Jimmy Hynes, Steve Ward, and others, and kitted up by Daniel McCauley (which makes a really nice entry point to the field, thanks Dan!). Of course, you could also go with the traditional spark gap coil, vacuum-tube control, the so-called “online” configuration, and so on.
First Decision:
9 to 10 foot sparks using DRSSTC technology.
Okay, maybe I _am_ insane.
How much power will that take? D.C Cox of Resonant Research Labs has an extended mix version of John Freau’s spark-length-to-power formula [6]:
d = k’ * sqrt p
Where d is spark distance in inches, p is input power in watts (or VA as metered from the wall), and k’ is a “fudge factor” coefficient based on the secondary coil diameter:
Dia. k’
3-10” 0.85
11-16” 1.00
17-20” 1.30
21-36” 1.70
37-48” 2.0
But what should our secondary coil diameter be? In other guides, they say you can expect a spark length 2 to 3 times the height of the secondary coil (needs reference), and looking ahead a bit, we see that a diameter of about 1/4 the secondary height is reasonable.
Given a 9’ (108”) spark, that is 2 to 3 times longer than the secondary winding, we have a winding height of 36 to 54”, and with a height/diameter ratio of 4:1 that leaves us with a 9” to 12” diameter coil. Plugging that in to the k’ table, we can just pick something near 1.
p = (d/k’) ^ 2 = (108/1.0)^2 = about 12kVA
12kVA is a big chunk of power. From a 15A outlet running at about 115V RMS (though I’m not entirely sure my voltmeter is given me RMS here; a 125VAC peak-to-peak calculates out to about 90VAC RMS) for 1.7kVA (or 1.3kVA), we should be able to get 12kVA bursts from a capacitor bank if we only fire for 10% (giving some allowance for inefficiency). So it might be possible. Especially if I use a 20A circuit and not the lame 15A.
The RRL guide also indicates we need a toroid major diameter of 1.7 to 2.0 times the secondary’s diameter, with a minor to major diameter ratio of 3.8 to 5.0, which is eerily similar to the guidelines for the secondary coil aspect ratio.
For example, Daniel McCauley’s Eastern Voltage Research guide [7] gives aspect ratios for various smaller coil diameters:
Dia. h/d
<=4” 4.5:1 to 5:1
to 6” 4:1 to 4.5:1
>6” 3:1 to 4:1
Deep Fried Neon [8] gives similar advice, recommending secondary diameters for various powers, and then ratios from diameter:
Power Dia.
<500W 3” to 4”
to 1.5kW 4” to 6”
to 3kW 6” to 10”
>3kW 10”+
Dia. h/d
3” 6:1
4” 5:1
6” 4:1
8”+ 3:1 to 5:1
Given all this, where are we now?
9’ (108”) sparks
12kVA power
3:1 to 4:1 secondary aspect ratio
3’ to 4’ (36” to 48”) winding height
9” to 12” winding diameter
Various guides, such as Richard Quick’s archived discussion on Pupman [9] and TeslaMap’s guide [10], among others, indicate that 800 to 1,000 turns on the secondary are optimal (though when it comes down to actual coils in hand, I’ve seen winding counts of 2,000 and more). My Mini Brute has roughly 1,000 windings (I didn’t count; my next coiler is going to have a quadrature counter in it, that will be handy) and generally follows the guidelines for a 3:1 aspect ratio.
Picking a nice round number of n=1,000, we need a wire spacing of .036” to .048” (36 to 48 mils). This lands us right around 18gauge [19] (17..19ga; 18 is a common size though). 18ga is 40.3 mils, and Classic Tesla’s Turn Calculator [11] gives a single-layer enamel thickness of 1.5 mils. Taking into account some inefficiency in winding, and we have about a 43” heigh coil. At the aspect ratio chosen, we need about a 10” diameter form.
The easiest to find material to use for the form is PVC (polyvinyl chloride) or PE (polyethylene) water pipe. The _best_ material, electrically, is polystyrene or polypropylene; but we can make PVC or PE work, and coating it with epoxy or polyurethane helps improve its dielectric performance as well (or so say the guidelines).
Schedule 40 PVC is easily found in 3” and 4” diameters (with actual ODs of 3.5” and 4.5” due to obscure historical reasons). Harder to find is schedule 40 in 6”, 8”, 10”, and 12” trade diameters (OD of 6.625”, 8.625”, 10.75”, and 12.75”).
Whereas all ANSI “schedule” pipes are listed as having the same ODs [12], however I’ve discovered that “green” plumbing pipes are different (and, as best I can find, metric). This green-colored plumbing is apparently based on smooth-wall polyethylene, which is popular in Europe, but deeply confusing when purchased as (what I thought was) schedule 20 PVC, but which in fact did not conform to ANSI dimensions. So stay alert! It’s a jungle out there.
Assuming I can find it, I can use 10” trade PE sewer pipe, which has an actual outside diameter of 10.75”, a perfectly acceptable size according to all accounts. If I can’t find that, I might be able to modify a Sonotube, or start trolling the local plastics suppliers [13]. I’d love to use some of that transparent PVC, but the cost is a killer [14].
Of the many parameters that can be used to define the secondary coil, the guidelines in fact give us answers to most of them, and the rest can be easily calculated:
Form Diameter, Length, Wall thickness, Material, & Dielectric behavior
Wire Gauge / diameter, insulation thickness, and length
Coil Height, avg. Diameter, Winding count and spacing
Coil DC Resistance and AC Reactance, Inductance and Capacitance
Quarter-wave resonant frequency
Coil Q factor
Most of these values are constrained by the original desire for a 9’ spark, the availability of secondary form materials, and the rules of thumb listed above.
The design so far:
9’ (108”) sparks
12kVA power
4:1 secondary h/d aspect ratio
43” winding height
10.75” form diameter
18 gauge (0.0403” + 0.0015”) wire
1,000 windings
TeslaMap’s calculator [15] says that 43” of 18ga wire will give me 998 turns, using 2,800 feet of wire. Deep Fried Neon’s calculator [16] agrees, and gives me an inductance of 59.8mH and a self-capacitance of 18.3pF. Tesla Coil CAD 2.0 [17], with similar secondary values, gives me 950 turns, 2,670 feet of wire, 54.4mH, and 20.2pF, adding the interesting detail of a 92.11kHz quarter wave resonance (but did they take into account the slowdown of electricity in copper [5]?) and a need for a 34 to 35pF topload capacitor to make it resonate at this rate.
Note that 100kHz is a decent frequency to run at, well within IGBT limits when soft switched (though 50kHz would have been even more friendly, and the IGBTs do tend to be rated at 25kHz or less when hard switched).
The secondary circuit consists of a coil of wire, with a given inductance L and possibly quarter wave resonance lambda/4, plus a capacitor and discharge terminal, typically a sphere or toroid, with a capacitance C.
In theory, I want a topload toroid of approximately the same minor diameter as the secondary coil (10”), and with about the same aspect ratio to its major diameter (40”). Looking at what supplies are easy, and costs, that’s just not going to happen -- though it WOULD give me a nearly perfect effective topload capacitance of about 35pF according to the JavaTC calculator [18].
Instead of the $600 spun toroid of the correct dimensions, let’s try a simpler and cheaper one made from classic 4” trade diameter dryer vent (also about 4.5” actual OD).
A 40” toroid with 4.5” minor diameter gives (via JavaTC again) about 30pF effective capacitance on this coil; adding a second one below it with a 36” major diameter gives us the 33pF capacitance, which is close enough at this stage of design.
The tighter minor diameters will mean an easier breakout, with a lower potential maximum voltage, but it’s such an easy material to find it may be worth it. Anyway, toploads are the easiest part to swap out for experiments.
Secondary Design:
9’ (108”) sparks
12kVA power
4:1 secondary h/d aspect ratio
43” winding height on about a 48” form
10.75” form diameter
18 gauge (0.0403” + 0.0015”) wire
~1,000 windings
~54-55mH inductance
~20pF self capacitance
40” OD 4.5” aluminum duct toroid on top of another
36” OD 4.5” toroid
33-35pF topload capacitance
~92kHz quarter-wave and lump-model resonance
With this rough sketch in place, I could move on to the primary or bog myself down into mathematical and/or SPICE analysis... I’ve leaned on the various calculators pretty hard so far, and haven’t crunched the numbers myself yet... but right now... it’s dinner time!
References:
[1] http://www.ttr.com/corum/
[2] http://www.blazelabs.com/teslacoil.pdf
[3] http://www.pupman.com/listarchives/1999/October/msg00428.html
[4] http://www.tesla2006.org/presentations/other/The%20Analysis%20of%20Tesla%20Coil%20Apparatus.pdf
[5] http://en.wikipedia.org/wiki/Refractive_index
[6] http://www.classictesla.com/download/resonance_tips.pdf
[7] http://www.easternvoltageresearch.com/designfiles/paper_howto.pdf
[8] http://deepfriedneon.com/tesla_guide.html
[9] http://www.pupman.com/listarchives/1995/january/msg00139.html
[10] http://www.teslamap.com/guide.html
[11] http://www.classictesla.com/java/cst.html
[12] http://www.crestwoodtubulars.com/pipe_schedule.html
[13] http://www.regalplastics.net/
[14] http://www.clearpvcpipe.com/
[15] http://www.teslamap.com/download.html
[16] http://deepfriedneon.com/tesla_frame6.html
[17] http://www.richardsplace.net/tesladownload.htm
[18] http://www.classictesla.com/java/javatc.html
[19] http://www.interfacebus.com/Copper_Wire_AWG_SIze.html
http://www.classictesla.com/FormulasForTeslaCoils.pdf
http://www.classictesla.com/download/tc99.pdf
(cross posted to www.4hv.org)
You may or may not know, dear reader, that I've been poking at the problem of creating physical low-frequency resonance for some time now. I've tried a few things, including a subwoofer-driven Helmholtz resonator thrown together from Sono Tubes and Duct Tape (indeterminate results, some possibilities).
I fell back, during past haunts, on using bass-shakers bolted to the crawl tunnels and hand-tuning the frequency generator to get a good subsonic. When that works, it's an amazing and beautiful thing (people refused to go in on early tests, it "just felt weird"). Sadly, that system of open-loop resonance falls out of tune too easily. I should add a microphone or other sonic transducer to it and make it closed loop, and then I'll melt your brain in the tunnels! Bwahahahahahah!
::ahem::
Today, however, I finally succeeded in making an air-powered resonator out of about 32-feet of 4.5" diameter sewer pipe (and some duct tape, of course). It... resonated! First it squawks like a demon-tormented goose, and then if rumbles and shifts and then... tones! Not pure, but pretty nifty nonetheless.
An eight foot pipe produces a surprisingly high tone, and 32 feet of it isn't as low as I would like. However, there are a zillion things to tune -- airflow, back pressure (once I build a back-pressure chamber), elasticity of the membrane, sealing characteristics of the driving tube, and most important for good low frequency amplitude, diameter.
Yup yup yup... maybe a switchback of forty feet of 12" sono tube with tubable back pressure and a durable membrane... mmmmmmm yeah.
My bathroom sink was draining slowly lately, and I finally remembered this during a time of day/week where I could _do_ something about it.
Normally I use a hooked wire and pull mats of hair and soap scum out, no big deal (we Wise mammals do shed a fair amount). But in _my_ sink, I find just a little bit of hair+scum and then a wall of... mycological FLESH, perhaps; a veritable _skin_ growing on my drain pipe. Horrible, horrible skin, with a curdling of hair and soap on its inner passage, like some demonic esophagus. ::shudder::
Speaking of horrific, thinking about water use and this foolish ad I saw for a lawn care service. In this ad, they said "you must water your lawn or it could die! And to resod could take $1,500! And your resale value is heavily tied to the green of your lawn!"
Forgetting for a moment the foolishness of the whole "lawn thing" in such an arid area as Texas, let's look at some assumptions.
We used 3,000 gallons of water in our last billing cycle. We don't water our outside unless things look really desperate.
We have some friends who used 15,000 gallons in their last cycle. Assuming that, for their larger household, they would normally use say 5,000 gallons indoors, that leaves 10,000 gallons of outdoors use.
The watering months, here, are perhaps from June through September -- four months. Lighter watering in other months, heaver perhaps in July and August, let's just average it out and say 10,000 gallons of lawn watering for four months.
The City of Austin rates are currently, for single-family residential customers, in dollars per thousand gallons:
0 - 2,000: $0.93 ($1.86 max)
2,001 - 9,000 $2.43 ($17.00)
9,001 - 15,000 $4.18 ($25.07)
15,001+ $7.63
So for this hypthotical household OF 15,000 gallons, the cost is (rounding up the thousand gallon deltas):
(0.93*2) + (2.43*7) + (4.18*6) = $43.95
Wastewater costs much more than water to process ($3.18 per 1,000 for the first 2,000, $7.18 per 1,000 thereafter), but these rates are calculated for the entire year given your winter water use, so they don't scale here.
Now, for a 5,000 gallon user (e.g. the sample family above without lawn watering) the numbers are:
(0.93*2) + (2.43*3) = $9.15
So, $34,80 per month for watering the lawn, times four months in the calculated period, is almost $140 a year. In eleven years, then, you will have saved enough to re-turf your lawn.
I know our water bill is in fact about nine dollars a month, for about three thousand gallons. Talking around, I'm hearing about water bills for $200 or more, though -- these must include the sewage fees and random fees that are tacked on throughout any given bill.
I was expecting the heavy lawn watering to cost more that $40 -- more like $100 -- which would give $300 to $400 a year in lawn watering costs, the saving of which would pay for a re-turfing in just four years or so (about the time it would take for the lawn to really die a lot).
Anyway, I still don't water my lawn. Instead, I'm aggressively converting it into non-grass coverings.
Woot! I just coiled about 1,000 turns (12 inches of 30 gauge... or was it 32? I should check) in maybe 15 minutes coiling time.
That's some kind of new record. And, the coil is pretty good. Only had to stop twice for gaps (no overlaps); left one gap not fully closed, so it's not perfect yet, but pretty good. And, 15 minutes! That's like eight times faster than the first one.
Now to automate the tensioning/guide process that I currently do with my hand (oooo hand cramps); and THEN to make a ponoko pattern and rebuild it into a nice version. With a turn counter; I'm thinking embedded magnets and hall effect sensors in a quadrature format. Or maybe optical. The pedometers tend to bounce really badly (one step for the lift peg, one or two more steps when they fall off the lift peg, very sad).