And yet ... what is mathematics about? What do HS algebra, Euclidean geometry, game theory, information theory, the theory of transfinite numbers, ergodic function theory, and all the rest have in common? What underlies it all?
The answer, dear grasshopper, is -patterns-. At its core, mathematics -is- the study of patterns.
It's a lot easier than a CT, I'm sure. I'm not claiming to have mastered transmission line theory.
"Mr. Heaviside, your books are very hard to read."
"Yes, young man, but they were much harder to write."
(In his lifetime, Oliver Heaviside advanced the practical sciences of electromagnetism by roughly one lifetime. He gave us vector calculus and applied notations more or less forgottten since Euler. Truly a Sage in Solitude--and that's the title of the best biography of him.)
No admittance. No suscecptance, no permeance.
Have you met Mr. Smith and his Chart?
Any brand of battery can leak, unfortunately. There are some things that might make it harder, but I don't know that any manufacturer does them. A deep labyrinth at the seal with the can would make it harder for the reaction to consume its way past the seal. I'm sure someone has thought of it; it's got to be harder to manufacture.
Oh, and it's mostly because I don't like worrying when the busy signal goes on for hours.
And where do you go accusing me of thermodynamic crimes?
Not bolts? What about quarrels?
I think I know those Laws well enough. Which one do you accuse me of violating?
Go read about a circuit design called the Joule thief. Note that it works with short, bright flashes. With the battery depleted it can run at over a megacycle.
Edit: Better yet, go build one! For greater efficiency put a capacitor across the resistor (Circuit B, here).
Edit: Oh, I forgot to mention the Schottky flywheel diode and the tantalum snubber capacitor around the LED.
dont use eveready batteries. They blow up when stored in devices for a long time at room temperature. We can't have them scorching your hard-won design.
You've seen the alkaline Energizers blow up? Not just leak?
Not sure if you've mentioned this already, if you had, I missed it. But where do you intend to use this?
Off-hook alarm for a phone. Specifically my elderly mother's phone. She leaves the bedroom extension on the bed, it gets rolled up in the blankets and goes off-hook, and nobody can reach her by phone. I used to be 90 minutes away; now I'm 8+ hours away. My brothre and his wife are nearer, but they can't go racing over there.
The square IC you see at the top of the drawing is a CD4541 timer. I have it set up to run for 25 minutes before it fires the alarm. I also have a test/reset button planned.
No, I didn't find a COTS product for the job.
At some point in NS, someone is going to be punched hard and will land flat on their back. The puncher will then shoot the punchee with a crossbow through the neck/throat, pinning him to the ground basically.
Aren't crossbow bolts quite short? Too short to pin someone in place?
If you mean to pin someone, you probably want to shoot them through the big part of a big muscle and hope you don't hit an artery or a nerve.
But Amy will probably tell us that even that's improbable, and that anyone who does it deliberately means for the victim to die there.
Three multivibrators. I described some of it in the Sorcerer's Progress thread.
First is an astable, using a diode trick to be sure it doesn't lock up on startup. (Here and in other places I use Schottky barrier diodes because the larger voltage drop of standard PN diodes would kill the circuit's operation.) It's asymmetric, periods of about 300 msec and 1300 msec. (Flash-flash, flash-flash, flash-flash.) Characteristically, turn-on is much sharper than turn-off, so turn-on gets through the coupling caps into the second multivibrator, a monostable. Each turn-off pulse from the first mv results in a pulse of about 7.3 msec from the second mv. That pulse removes the pull-down that holds the third mv off. All three are on a 3v power rail, but the unregulated voltage, from four batteries, will range from about 6.4 volts down to about 3.6 volts.
The third mv is an astable producing narrow pulses, whose width varies with the unregulated voltage (used for one side of the timing). At 6.4 volts, the pulses are about 65 or 70 u-sec wide, at 3.7 they are about 135 or 140 u-sec wide. They drive a mosfet that gates current from the unregulated line (with about 2000 low-esr microfarads to deal with resistance in the batteries and the mosfet that turns the whole thing on) through an Osram Platinum Dragon LED rated at 700 mA. In fact, the pulses can break 5 Amps at the higher voltages. (The mosfet drive has a capacitor sized to ensure that if for some reason the circuit stays on it won't fry the LED.)
The pulse spacing is about 630 to 640 u-sec. It's hard to keep the wide side constant because the recharge of the timing circuit has to be accomplished rapidly and when the recharge period varies by 2x it's hard to get to about the same point on the curve. That same recharge also slows the rise time of the output voltage when the transistors turn off. The rise time problem is dealt with using the diodes (1n914) and recharge resistors separate from the collector resistors. Even this isn't enough unless you make one of the recharge resistors very small--small enough that with the transistor on that side on it would draw more charge in the off period than the LED draws in the on period, so there's another recharge resister, quite small, parallel with the first one--only it's gated by a mosfet switched from the other side. (All the mosfets are 'logic level'.)
This arrangement, without the specified heat sink on the Platinum Dragon, will flash for over 48 hours on four very cheap carbon-zinc AAA cells. On the four alkaline C cells, I plan for it, I'm guessing it's good for well over 800 hours of flashing. But it's only supposed to be allowed to flash for a few minutes at a time. If the rest of the box works as planned, those four C cells should last about 6 years. (My standby draw budget is 135 u-A. I don't think I'll quite make it, but 160 u-A is quite reachable.)
My first attempt to use photobucket has been ... disappointing. Tried with two browsers, got the same misfunction from both. Web pages load and take you to the bottom of the page. The upload page doesn't do uploads. Drag-and-drop causes the browser to load the image for a page rather than having it captured by programming in the page. Select mode is unresponsive.
Disappointed. May try again, since I've seen another TNBW user successful.
Okay, it works. Photobucket can't deal with more than one tab or window open at once. AAAArrrgghhh! Why in the name of the Great Pumpkin can't people work within the web page programming model instead of running widdershins with the right foot and deasil with the left--all while walking backwards on their hands? It makes it -very- hard to meet them face to face.
It seems to be there to clutter the home pages of other users. Out of consideration, I won't use it, especially with the large cover display sizes.
Looking around, I noticed that another user on TNBW has his images hosted over on photobucket.com. I haven't tried it, but according to the site it has free accounts and very generous space and bandwidth limits on the free accounts.
With an image hosted there (or on a similar site--snapfish?), so long as the site provides an unambiguous URL you can take the URL and plunk it into an img tag pair here, and in theory the image will display here.
I'll try it in the next few days.
Two suggestions: In the My Groups Content page, allow multiple selections from the Genre menu; and replace the heading 'Type' with 'Form', which better describes the distinction in question.
There's also the revised chapter 4. No matter where I move the thing, it's been shaped by your comments, especially the mother-daughter issues. I hope I've explained the inversion in a way that makes sense (without turning mama into a kitten).
I believe you have a word count available for each work or chapter. Would it be too much to display those somewhere, at least in the author's view, if not elsewhere?
Polishing done. It's down to about 4,700 words. I will be working on rearranging those scenes in the next day or two. Don't let that stop you if you feel an itch to review.
Minor edits to the possible future chapter -Books for Pengrit- (now hiding in Vol. 2).
I have a little polishing for v2 of Commotion in Lifspynth/Shogran. I still have to consider moving the first scene after Chapter 1. The polishing/burnishing changes will go in soon.
---Done
When I ask to edit a chapter, I'm taken to the master edit sequence for the work ... main information => cover => content => publish.
In the context of a writer's real workflow, this is a false progression. When I ask to edit a chapter, I don't need to revisit the work's creation. I just need to edit that chapter. When I ask to create a new chapter, I don't need to be brought to a progression that suggests I edit the cover before I get to my work.
Having to fiddle with a drop-down to chose between Edit and View is also a nuisance.
You can cover both without committing to which one you mean by saying that the thread is not available. It might be deleted--permanently not available--or just not available to you. If you want to keep that secret for some security reason, 'not available' is a pretty good description.
Well, the big changes are structural. Low-level structure to be sure, and there are still edits to be made. Don't let that stop you.
I think you went back to the pre-rewrite version. The opening of Melayne's first scene should read ((As Merran practiced her lessons with her father, her mother was in the kitchen, past the chimney that served the kitchen and the upper floors, past the stair and cupboards and storeroom on the other side.))
I've reworked the first Melayne section of Chapter 4. I won't do a repub unless a reviewer needs the points, but it's a little smaller (~350 words) and it might be more to the point. I hope so. It's still too long.
BTW, I'm still working on Amy's chapter 4 suggestions. I'm maybe halfway to edits addressing Melayne's concerns about her daughter's isolation.
I need to finish the thing!
Anyway, I tested the turn-on fix. It works with the AAA alkaline Energizers, at 5.1v total. (One mod: a Schottky barrier diode bypassing the resistor for turn-off.) I just bought some really crappy carbon-Zinc batteries and I will test it with them, too. If it works with those AAAs across a range of voltages, it should work with anything.
Now I have to worry about turn-off, which is slow because of the energy stored in the power-smoothing capacitors on the load side of the switch. I'm thinking that I should switch the LED power and the other power with separate devices. That's more circuit board space to take up.
And THEN I have to debug the detector (I've already got it built on the test article) and work on the pigeon-flasher.
And physical design, especially the layout of the input filter and the placement of the RJ-11 jack.
Gosh, I also have to test that other "works on polyethelene/polypropalene" glue. And thread the posts in the cases. And ....
Aaargh! I should keep a chart like I would on a software project so I'd know what to do when I was stalled on one thing or another.
Now back to the Chapter 4 revisions.
I've been working at cross purposes the last couple of days. My little electronics project is such a success it's keeping me from working on it, even as I'm spending time on it!
I''m trying to do all my work now on a test article that I can run on battery power. Some things I can't do that with, but right now I most need to debug the new voltage level detector in that test article. Problem is, a few days ago I began testing to see how long the flasher could run on battery power. I put four new AAA batteries on it, figuring they would last for 20 to 36 hours. Mirable dictu, I'm past 90 hours and it's just reached the 1.3 volt/cell plateau. AAA page, first discharge curve should be the most representative load in terms of curve shape. That means that the flasher should run for 440 to 480 hours on these tiny batteries, and over two thousand on the C cells I mean to use it with! That's darn good--flashing hours won't take as much as I feared from battery lifetime--but I'll have to cut this test short to get work done.
I also have to work on my much-modified "pigeon" flasher--but I don't want to get tied up in that until I have the detector working. I also have a start-up problem on the flasher: when it's turned on the capacitors draw so much current to charge that the voltage drop resets the timer. I think I can fix this with a resistor that will slow the turn-on of the MOSFETs that feed the flasher. It's just a matter of finding the right value. Thing is, I want to test the fix with the cheapest carbon-zinc batteries I can get my hands on--and it's getting hard to find them nowadays.
And then the pigeon flasher. I promised to send the final circuit drawing to the guy I cribbed it from. It's a surprisingly subtle design that can maintain a steady flash rate over a wide voltage range.
But right now Im going to work on Chapter 4, and then I'll see if I can find those cheap batteries.
From Maxell ad of 30-odd years ago: "With some tapes, you can't tell your brass from your oboe."
My favorite: "He can't tell a burro from a burrow!"
