Am I crazy, or does that have implications for long-term space flight?
You're probably crazy, but yes, it does.
Fluorescent lights are not as efficient as LEDs, though they're still more practical for the moment. And they're bulky, the ballasts are heavy, and they're fragile. The LED will first see general lighting use in space, but I don't think it's ready for that yet.
And yes, it's another one of those evolutionary improvements that will improve the technology of space travel. I'm still holding out for the revolutionary ones, like superluminal travel and gravity manipulation.
Any one have any info about the range of light they put out? Cuz I was thinking, no heat and low power, these would make good grow lamps
I think most (ahem!) herbs grow best under a greenish to bluish glow light. You should be able to find that out for sure in any good book on amateur hydroponics... Grow lamps, for example, always seem to be a more blue-green glow than an ordinary fluorescent tube. And incandescents don't seem to do much at all.
If that's the case then, don't bother with an array of white LEDs. They're incredibly expensive. Instead, go for an array of blue (still expensive) or green (common) LEDs.
Hi-intensity green LEDs are fairly available, just quickly checking the back cover of my Digi-Key catalog, you can buy Panasonic green clear LEDs in T-1 3/4 packages for $199.70 per thousand pieces. At 20mcd @ 565nm @ 30mA @ Vf=4, they might grow plants pretty well, if you have enough of them. (There are far more intense and efficient green LEDs out there, I just flipped over a catalog.)
There are also 1500 mcd blue LEDs available from the same source (www.digikey.com). On my older Canadian edition of their catalog, the 1500 mcd blue LEDs put out at 470nm, If=20mA, Vf=3.5V. Panasonic part # LNG992CFBW, if you wanna check out the datasheets on their website. A thousand of them will cost you over three grand.
It would, for sure, be an interesting project. Remember to budget for a large DC power supply to run these, as well as homebrew PC board to wire all these, because you're sure as hell not going to do it by hand.
This won't be the first time that the Japenese help the White LED (the third letter stands for death). I seem to remember a little incident called World War II.
I think the Japanese got to see more than enough white light during WWII. Maybe that served as the inspiration for the white LED?
Around here, most Jews seem to drive German cars; most Chinese people seem to be driving Japanese cars.
Personally, while I wouldn't touch a Japanese car with a ten meter cattleprod, but speaking as a former tech at a TV station, no one has ever made a better TV set than Sony. As long as the Japanese allow North American manufacturers to sell their products there, I have no problem with the Japanese selling their products here. Competition and innovation are mutually beneficial.
Forgiveness is an interesting thing. And a good thing.
Don't they already use banks of LEDs for the red traffic lights?
And lots of buses and trucks are starting to use them for signal and brake lights. New Mercedes S-series are including them, as are the new Cadillac DeVilles.
And, if you're in the Toronto area, you can take a drive through the corner of Eglinton East and Sloan. That's a block west of Victoria Park Avenue. The traffic lights there have LEDs.
HP's Agilent Technologies advertises the benefits of LEDs, besides the obvious energy efficiency and reliability increases.
The best part is that it takes a few milliseconds for the tungten filaments in conventional bulbs to light up when electricity is applied. With a GE 1156 or 1157 (depending on whether or not your car has combined brake and parking lights, either one of these is the defacto standard on about 95% of the cars on North American roads), if you're travelling 75MPH, you will travel about 15 feet in the time it takes for those filaments to light up.
And that means that if some jackass with an SUV and a cellphone planted to the side of his head is tailgating you, he will see the lights as you slow down, possibly giving you and him an extra 15 feet or so. This can make the difference between a small bent-bumper accident and no accident at all.
After some jackass hit me in May - two months after I picked up my beautiful old 1976 Dodge Ram, I took matters into my own hands. My bumper is trashed, but he bought me a new one, which I haven't put on yet. The old bumper is bent, but still strong. Stronger yet since I welded steel angle iron behind it, and then cross-gusseted the rear of the frame. The bumper is now fortified steel attached through soft brass shear pins to the truck's now-reinforced frame.
The plan?
Well, the last jackass who hit me mashed his radiator against his intake manifold. And my Class-4 trailer hitch, which is welded to my frame, didn't have a ball on it, so as my bumper bent, the hitch was rammed through the side of his cylinder block. I could see his connecting rods. Silly little Honda go bye-bye. All because the idiot had to "feed" his Tamagochi. I'd love to sue the government of my province for entrusting anyone who is stupid enough to buy a Tamagochi with the priveledge of operating a motor vehicle.
The next time someone hits me, I expect my bumper not to bend, but to simply fold up or down as the sheer pins snap. This will mean that the impact force of the next silly little tinfoil Japanese unibody car that hits me will be dissipated entirely on the ends of my gussetted Detroit plate steel frame rails. The rear 8 feet of my frame are criss-crossed with steel stock welded in at 2 foot intervals. Sure, I'll have to pick up my bumper and toss it in the back of the truck, but a moment's inattention from the schlep following me will result in catastrophic damage to his vehicle.
When I get around to putting on the new bumper, I'm also going to swap LED brake lights into the truck. I've already planned out most of the voltage regulator that they're going to need, but until I know for sure how many MCDs of light are really necessary for brake lights, I can't choose a diode and therefore can't choose a voltage drop which would allow me to finish the regulator design.
Anyone know of any good automotive-brightness red T-1 3/4 LEDs?
I am not pro-nuclear, so you'll see my bias, and I don't think it's fair to blame environmentalists on (non-US) governments seeking alternatives to nuclear energy (since it IS unsafe, you cannot EVER guarantee that it will be safe,
Nothing is safe. There are varying degrees of risk.
Solar power, for example, is one of those things that is generally viewed as a benign source of energy, awaiting only more advanced solar cells to be practical.
Couple of problems with that. A solar cell must be fairly large to produce a fairly small amount of energy. Since a solar cell is essentially a large silicon die, it is brittle, and when it's exposed to sun and then to night and then to day, it will be expanding and contracting and will eventually fail on its own just due to mechanical fatigue - let alone if something else breaks it.
Basically, you're looking at making a large (let's say 6" round) integrated circuit for each cell (producing 0.6V at maybe 500mA in full sunlight). Assume a 20 year average lifespan before it cracks and fails. 0.6V at 500mA is 0.3 watts of power. What's the electrical load required to power sunny California? How many solar cells would you need? What would be the toxic chemicals produced as byproducts of those cells? Let alone storage systems, inverters, etc.
Nuclear power sucks. Sure. I agree. If something goes wrong, it can go *very* wrong. But usually nothing goes wrong, and it produces lots of efficient and relatively safe power. Building thousands of acres of solar panels to provide power is definitely going to have nasty environmental consequences, simply based on the huge quantities of chemicals and energy needed to build the cells.
and no one wants nuclear waste or a nuclear power plant in their backyards, whether they are environmentalists or not).
I would. The real estate is cheap, the neighbors are quiet, and they won't care if I'm in the garage welding quarter panels onto my car at 4:AM with loud music playing.
I have a geiger counter; I'd probably have several around the house if I lived there. But it's risk management: I'd be safer living there than I would be in a community at the end of a runway, or even living within 200 miles of the San Andreas fault.
And, yes, I believe the government uses nuclear power without taking the appropriate precautions or having decent followthrough - we HAVE had our own nuclear close calls.
Not sure what country you're talking about, but Canada's have been minimal. There have been accidents, but the public has never been at risk. Three Mile Island was also pretty small as reactor blowups go. The worst risk to the world from any nuclear project has been the arms race, and the resulting fallout from all the arms tests. Not from civil power plants, even RBMKs.
Natural uranium is not 100% U-238, it's about 99.3% U-238. The balance, about 0.71%, is U-235. U-238 is not fissile, and if you filled a CANDU with it you wouldn't get a reaction going. (I understand that a CANDU can burn "spent" PWR fuel, interestingly enough. The question then becomes why you'd want to.)
Natural uranium is mostly U-238. The term "natural" comes from the fact that it's not processed to alter the isotopic ratio from when and where it was mined.
CANDU reactors *do* actually consume the natural uranium; I hate to disagree with you, but I've actually refuelled two of them - NRX and NRU at Chalk River, Ontario.
While I appreciate your comments about the quality of the post - who doesn't like a pat on the back every now and then? - I'm reminded as I write this that you're an individual with whom I've had ongoing debates in the past. While you're clearly an intelligent person with enough information in a broad range of subjects that you can create the illusion of being well-informed, you've failed miserably in those previous attempts, with the inability to acknowledge gaps in the (admittedly impressive) book knowledge you've acquired when faced with a disagreement from those who have actually *done* the things you've only read about.
No further postings from you will be acknowledged.
So what is the worst-case failure scenario for a CANDU? Earthquake, terrorist bombing? Is there any conceivable pathway for a significant amount of radiation to spread over an area?
Operator error, I think.
Let's say an earthquake takes the calandria off its base and it rolls around. Fine, the heavy water will leak and the reactor will stop. There'd be some release, but since the fuel is in ceramic pellets in zirconium-alloy fuel bundles, it's unlikely to escape too far.
More likely - and more sinister - is the possibility of a used fuel bundle somehow getting out. That would be very dangerous, high-level radioactive waste, and could expose thousands of people to lethal doses of radiation.
I've held new CANDU fuel bundles; they're quite harmless. They're heavy, for sure. And they're very radioactive, but it's all U-238, which occurs commonly in nature, and while it's chemically purified, it's also chemically stable. So, it's no worse than a big chunk of good uranium ore. And you can go to the north shores of the Great Lakes and find that easily, if you know what you're looking for.
Like all reactors, the concept and operation is quite simple. A kid can do it in his back yard. But the problem is that they become complicated with all the monitoring and safety systems required to make them practical and actually harness the energy. At the Pickering Nuclear Power Plant - one of three (Pickering, Darlington and Bruce) that powers Toronto, Canada - a plumber made a mistake and hooked a water fountain up to the wrong pipe. Instead of fresh clean tapwater, the plumber managed to run into reserve heavy water. Not a problem to drink - it's water with extra neutrons in the hydrogen, not radioactive - but it's very expensive to isolate. But the big uproar that hit Toronto's media after the incident was that these workers had been drinking "radioactive" water. Indeed, the water had a little more than background radiation - it had run through the reactor core a few times before and had dissolved trace amounts of fuel - but it still posed no serious health risk. Mistakes happen, they have to be carefully monitored.
I think it's fair to say that the biggest risk with a CANDU reactor is accidental release of radioactive materials. I've never seen anyone come up with a failure mode that could cause a CANDU to pull a Chernobyl, or even a Three Mile Island.
I'd live, quite happily, next to any Canadian or American nuclear power plant. Real estate would be cheap, and the neighbor is quiet.
Hey is that where they make Cobalt-50? I know my school imports Co-50 from Canada for the gamma cell in our nuclear lab. (About 10000 Curies' worth every 10 years or so!).
Co-60, and yup. In fact, that's where most of the world's Co-60 is from.
I'm not sure what percentage of it comes from the Whiteshell, Manitoba labs, but I know a lot is made at Chalk River.
Now, I feel like a loser. As far as I got was being able to find steel rebars in concrete walls with an x-ray machine that I built using a microwave oven transformer and a tube I made with a blowtorch and a vacuum pump.
the IFR Integral Fast Reactor recycles its waste over and over until essentially all of the fuel is spent. the very small amount of remaining waste that is not consumable has a half life of only 300 years and is no more radioactive than the original ore from which it was mined. additionally the IFR has passive safety features which makes meltdown impossible.
Yeah, they're a great idea. I haven't read much on the actual operation of them, but I think they show promise.
About breeders in general, I understand that for the physical size and cost of the facility, they provide minimal energy. I don't want to call them inefficient - I don't think that's really an accurate statement - they just don't put out much power.
But, I see them as an excellent way to dispose of radioactive waste and provide a little bit of power back to the grid, even if they're not good as primary power reactors. And they've got to be great for getting rid of nuclear weapons.
Sadly, I think the "not-in-my-backyard" syndrome will prevail - as it does with most reactor construction - as well as the low MWh-output per $$ in construction, maintenance and staff - will limit their application. I hope - and expect - that someone will come up with a breakthough design that will address the dollar efficiency.
The radon from the decay series can be bitch though, keeping you rooms well aired, if you live granite area, could save the a few cigerettes a day of lung cancer risk.
*Very* good point.
I grew up in Ottawa, Canada. Radon is a *big* deal in parts of Ottawa, as it is in uranium country.
Did you know that, because radon is very heavy, some *solid* objects will float on it? It's very creepy the first time you see it (in a lab). Evidently, you wouldn't want to have this occur in your home. In practice, it would be tough, since it will tend to diffuse throughout the room, staying in the lowest parts of the house because it's so dense. Dense objects will just displace the radon and sink. But a little paper boat will float in it, appearing to just hover in the air.
Not sure what the critical mass of radon is... Whatever the case, you don't want to breathe it. Radon 222 is an alpha emitter, so keep that basement well ventilated, and don't spend any time really close to the floor down there.
Cesium is not a daughter product of natural uranium decay (although the heavier radioactive alkali metal francium is a daughter product in the U-235 decay series). Cesium is however a very common product of fission
Cool. Nah, I don't have a decay series in front of me, and even when I interned in the field, I didn't memorize the series. I would have thought it was a common product of decay, not just fission. Thanks for the correction.
Yes nuclear does produce waste, but it can be contained with less environ impact than that of coal. What represents a pinprick on the map of the US can store a lot of nuclear waste. Coal devastates far more space (eg. a lot of the state of WV).
Yup. Now, not that nuclear waste isn't without its risks. Certainly, it is. But it's small and containable, though highly dangerous stuff.
This being said, if there were a nuclear waste handling facility near my home, it wouldn't bother me. The real estate would be cheap, and it would be a lot safer (and quieter!) than living under a big airport's flight path. It's just a question of risk assessment.
Yeah, I'd have to put a new tube into my geiger counter and keep it on, but that's just part of my way of dealing with the risk of being in that location. Same thing if I were living on the Pacific rim: there'd be a seismograph bolted to my basement floor. It's a risk. Still less than driving my truck on the freeway to work every day.
Lastly, nuclear waste does not spontaneously explode like a nuclear bomb unlike a depiction in a crummy made for tv movie that people probably take for fact. Nor do plants themselves.
No. Nuclear waste gets hot and changes chemically as elements are transmuted from one to another. But this process is well understood and managed.
As for the exploding plants, Chernobyl, being graphite-moderated enriched uranium, is an extremely dangerous design. (Can we think all the stereotypes of the Ford Pinto and the Chevrolet Corvair built into one car, only a thousand times worse? That's how dangerous an RBMK is.) And, even so, it took a *lot* of safety violations and operator stupidity to cause that thing to run away. A staggering number of things that you just don't do, were done there.
You know, things that you just don't do. Like in a car, doing 100 miles an hour, you just don't turn the wheel as hard in either direction as you can. Basic sense of having been around a car and knowing how hard to turn the wheel around a corner at 10 miles an hour give you some measure of understanding of what would happen at 100 miles an hour.
And yet at Chernobyl, they kept trying and trying and trying, doing one stupid ill-advised thing after another, in flagrant violation of all common sense when running a nuclear reactor, until it finally blew up.
This is like driving a 1971 Pinto with a full tank of premium gas down the Santa Monica freeway, and slamming on the brakes as hard as you can when you see an 18-wheeler behind you.
Actually, at least for Uranium-238 (the most common isotope) has a half-life of about 4.5 billion years. Just a tad longer than Carbon-14.
Fortunately, though, the longer the half-life, the less radioactive the isotope is.
Why?
The more unstable the isotope, the faster it will decay. That means more alpha, beta and gamma emissions over a shorter time, which means more energy released, more geiger counter or cloud chamber activity, and more risk of cancers to you!
Essentially, a stable (non-radioactive) isotope of anything just has an infinite half-life.
U-238 isn't harmless, but it's barely above background radiation. It's also a very common element in some places of the world. Eastern Manitoba and Western Ontario in Canada have huge uranium deposits. You can dig the ore out of almost any hole in the ground. Yes, it's radioactive. No, it won't hurt you. Just make sure you wash your hands before you eat or smoke, because you don't want it in you.
Like lead or mercury, it's a heavy metal, and tends to do unfriendly things when it gets inside you.
Wasn't it a cloud of cesium (sp?) that drifted over the Ukraine and on over the rest of Europe?
Yes, cesium is a common decay daughter of virtually all isotopes of uranium. Fortunately, most radioactive isotopes of cesium have relatively short half-lives and transmute into something else. Because cesium is probably the nastiest element that there is, and that's even when it's not an isotope that pegs your geiger counter with gamma radiation. Imagine sodium (remember your high school chemistry classes?) but an order of magnitude worse.
Cesium ozonate (Cesium trioxide)
Formula: CsO3.
Molecular Weight: 180.9
Description: Unstable, bright red compound. Strong oxidizer. Decomposes with release of Oxygen. Reacts vigorously with water. Highest known oxide of Cesium, at the opposite end of the spectrum from Cs7O. Prepared by reacting Cesium or its lower oxides with ozone.
Uses: Curiosity, Exploding red ink.
Cesium Chloroxenate
Formula: CsClO3Xe
MW: 347.66
Properties: Explodes
Uses: Chemical curiosity, possible rodenticide
Toxicity: Unknown
Comments: One of the few known compounds involving a noble gas, a halogen, and an alaklai metal. Explodes if you look at it cross-eyed.
Heheh... Positive control coefficient, and a moderator that doesn't boil away.
It was an *insane* design, bordering almost on the criminal.
And yeah, there are still more than a dozen of the damned things running.
<sigh> I know that the RBMK reactor was designed for three goals: price, efficiency, and plutonium production (for weapons). And since that didn't include safety, I guess the engineers got what they wanted.
I'm all for nuclear power. You can't burn fossil fuels because of price per MWh and emissions. You can't build damns everywhere, because there are great environmental consequences to those - and they're only practical where there's a large river. (ie. Hoover Damn powers a lot of L.A., but how far from L.A. is it, with resulting efficiency losses in the lines?) You can't build tidal, wind or solar plants yet, because the technology still isn't practical even in the parts of the world that energy is abundant enough to effectively harness.
Western Europe has been shutting down its nuclear plants and increasing its reliance on natural gas. Fine, gas is easy to manage and it's clean as far as fossil fuels go. It's also abundant in neighboring Russia.
Ironically, as Western Europe shuts down its reactors, Russia keeps on commissioning and retrofitting their pressurized water and dangerous RBMK reactors so that they don't have to divert any natural gas that would otherwise be sold to Europe.
As is usual with the policies enforced by environmental lobby groups, it backfired. Fine, the reactors in Western Europe are being shut down. And replaced with far more dangerous Russian reactors. Good work, you stupid long-haired hippie tree-huggers. (Ooops. I have long hair and I like Five Man Electrical Band, I guess I can't insult hippies.)
Before you moderate me down for saying that environmentalists are idiots, check out this link, which has to do very specifically with the Russian reactors vs. Western Europe natural gas fiasco. While environmentalists are full of great intentions, they're generally ignorant of science or the basic fundamentals of how a marketplace economy works.
Like it or not, nuclear power is going to be here for a while.
Let's encourage safe and responsible use of nuclear power, at least until something more practical comes along. Let's try to not ban nuclear power, but to ban RBMK reactors.
Let's see a day when all the running nuclear reactors in the world have *negative* control coefficients (ie. won't run without a moderator) and use a moderator that will boil off and shut down the reactor in the case of an overheat.
Back when I was in high school, I got a summer internship down the road from Ottawa at a place called Chalk River Nuclear Laboratories. This was the home of Canada's nuclear program, and is one of those rare things that makes me proud to be a Canadian. Canada still leads the world in civilian nuclear technology.
At the time, they had three big research reactors there - the decommissionned "ZEEP" (Zero Energy Experimental Pile, put out *one watt* of heat, built in 1944 for the war effort and has a colorful history), the vertical-loading National Research eXperimental "NRX" (since decommissionned) and the horizontal-loading NRU. All three were of the CANDU design, though the ZEEP and NRX were very primitive.
I was assigned to the NRX. Every day, I'd travel from Deep River to Chalf River, don my dosimeter, walk through the checkpoints and head to the reactor. It was great fun, helping out with experiments. And irradiating golf balls for increased driving distance.
There was a Commodore PET on top of the reactor, and it used to record and monitor the temperature throughout different parts of the reactor vessel. Then, there were the tube computers (no kidding!) with ferrite core memories which were used to provide more critical functions. (Semiconductors don't like ionizing radiation if the reactor leaked, tubes are a lot more forgiving.)
And, let me tell you, there's no feeling in the world quite like standing there, on top of the reactor, looking down 30 feet or so to the people below you, feeling the slight vibration of the pumps running all around, and the sheer sense of power in the room as the reactor below you runs.
Food was forbidden in the reactor buildings, because ingestion of bits of radioactive dust was an (unlikely) possibility. Even so, people did eat there occasionally, and I was no exception, though you become very careful with the geiger counters before you put it in your mouth. Because there was (officially) no food allowed in the building, there was no kitchen, so hot snacks were a rarity. Canned stew was a special favorite: the cans fit right into the (sealed) sample tubes. Drop them in at the top, lower them slowly through the reactor, and then retrieve them at the bottom. If you timed it just right, the can was nice and warm. If you got distracted, the can burst and you'd have to clean out the sample tube. (And no, this was not a good idea, but it didn't put anyone at risk besides those of us who ate the food, and we all knew perfectly well how the food had been cooked.)
I'd have gone into nuclear physics as a career if I could have handled the math. <grin>
My favorite reactor design is the CANDU (CANadian Deuterium-Uranium). It's an elegant design. Uranium 238 ("natural uranium") is used instead of the U-235 used in most other reactors. U-235 requires the added steps of processing and is also vulnerable for use in weapons.
The moderator in a CANDU reactor is heavy water; deuterium instead of ordinary hydrogen. Deuterium is a rare but naturally-occurring isotope of hydrogen. It's ordinary hydrogen in every respect, except for the fact that there's a neutron in the nucleus. It's not radiactive (unlike hydrogen with two neutrons, called "tritium", which *is* radioactive). Deuterium water is heavier than regular water, simply because of that neutron in the hydrogen.
The heavy water serves as the moderator. It slows down the fast-moving neutrons coming off the U-238 so that they can sustain the fission chain reaction. Light (ordinary) water will not sustain this reaction - nor will no water.
Let's say everything fails. The computers go down, the control rods are all jammed out of the core, and the operators are idiots. A Chernobyl accident still cannot occur. It's physically impossible.
If a CANDU reactor gets out of control and overheats, the moderator (heavy water) can be drained away, shutting down the reactor. You can't do that with blocks of graphite like an RBMK reactor. With a CANDU, if there's a problem and the operator doesn't drain the moderator away, eventually a pressurized pipe will burst and the moderator will boil away. With no moderator, the reactor will cease to work. Since the fuel is uranium in non-water-soluble ceramic pellets, there will be minimal decay daughters in the resulting steam cloud. Which will be contained anyway in the concrete reactor house, which is held under a vacuum to prevent release.
Unlike Chernobyl, which drastically overheated. The solid graphite moderator began to burn. And still the chain reaction continued to produce heat, because the graphite moderator was still there... it burned for 9 days.
Let's take all those unemployed Chernobyl workers to see a CANDU or similar reactor in operation, train them extensively on it, and then help them build them to replace their aging and rickety designs.
(Oh, and what were your favorite Lotto numbers again?)
Yeah. I'd never win the lottery, so I don't bother.
But *this*, yeah, I stand a very good chance of "winning" these odds.
My 1976 Dodge Ram will be sitting in my driveway, looking pretty, its chrome heliographing in the sun, the fresh paint sparkling. It's survived 24 years on the road in the Toronto area, over 200,000km, an errant Toyota Camry whose driver had to be extracted from the wreckage of his car with the jaws of life, and more recently a voltage regulator failure that sent my electrical system to the possible world record of 26 volts while I was driving home but didn't do any more damage than blowing out my left headlight.
And then, clear out of the blue, there will come an Iridium satellite.
Believe it or not Radio Shack has a pretty good series of one panel kits full of mounted electrical components & springs for running wires. The manuals are decently written and are understandable by most youngsters. They can usually do a fairly large number of projects with each kit and most of the projects are fairly interesting.
When I saw this subject on Ask Slashdot, I thought immediately of Radio Shack. I'll never forget the Christmas that, under the Christmas tree, my Aunt Margaret had sent me a Radio Shack 160 in 1 Electronic Project Kit.
I played with nothing but for the two years between when I got that and when I got my first computer.
Wow. That was one of the best presents anyone ever gave me.
Yes, many of the projects can be duplicated with something pre-made from the local store but heck, there's nothing like doing it yourself & impressing one's parents ( parents - you claimed you liked the clay ashtrays - now get ready to go bonkers over the photoelectric light switch!)
In grade 5 - 9 years old - I built the "High Voltage Power Supply" project they had in there. It was a relay, wired as a vibrator, driving the Audio Output Transformer on the board. There was an electrolytic capacitor across the relay coil to keep the frequency reasonable. It put out a nice solid jolt on your fingers, but posed no safety risk. For my school science fair project that year, I got an old wooden chair, some old belts, and made up some "electrodes", and built probably the single most famous science fair project ever presented at any Ottawa-area elementary school science fair. It was an electric chair. The brave were encouraged to try it out. Not coincidentally, it was also the first time I made the cover of the local newspaper, the Ottawa Citizen.
Actually, this does bring one thing to mind. Back in those days, I was running all my projects on a 9V battery or two AAs. Today's alkaline, NiCd or NiMH batteries - in a Radio Shack kit like that - could be very dangerous. Use the old Eveready Classics ("Cat of 9 Lives") and other cheap carbon-zinc batteries instead. If your kid shorts that out, it's not going to cause a fire the way a new Energizer or Duracell or something would.
As a non-parent, not-a-big-kid-fan these are great gifts. The kids really do seem to appreciate them, I get to feel I'm doing something good, and aside from the occasional "come look at what I made" it keeps the rugrats out from underfoot while the adults visit. Remember, toys are unisex & they're just as good for your niece as well as your nephew!
Absolutely. That was one of the very few things that could keep me busy for weeks on end.
I found a predecessor to my 160 in 1 - it was a 150 in 1 kit - at a garage sale. It was about 10 years old, but all the components still worked. The two kits were quickly merged into one: the photoelectric switch turned on the three transistor radio. The Morse code practice oscillator was quickly connected to the AM Transmitter.... And then there were my own inventions. When you're 10 years old, two SPDT relays and four transformers can keep you occupied for days at a time.:)
I see the 200 in 1 - the expensive version of my 160 in 1 - lives on! Cool! The photos take me back, too... the familiar little transformers, the pretty little relay...
Ain't Nothin' Like the Real Thing, Baby.
on
Wine In New Skins
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...which would allow windows users to run linux in a box (just like we can run windows in a box on linux now).. anyone know of something like this?
Hmmm... Well, I can't think of anything much easier than downloading and installing ZipSlack or BigSlack. Both of these distros are UMSDOS-native, which means that their whole filesystems live as a file in an existing FAT16 or FAT32 partition.
They're great for novices, since the default installations will run with a minimum of tweaking.
Of course, that's not what you wanted: while it would be cool to have a little Linux box running in a window on your Windows Me (yuck!) machine, this seems to me to be a task much more satisfyingly accomplished by simply using Windows to telnet in to the real thing.
I run Windows 95B on my main machine at home and at work, mostly because I need the Windows applications. I run Windows 95B specifically because it includes FAT32 support, it has a better 16 bit subsystem than its successors, and I don't have to put up with crap like the Active Desktop and other later "enhancements". I barely trust Windows as it is, let alone trying to operate a full virtual machine inside it.
However, an X client for Windows would be great, so that the connection to the real Linux box could also be graphical. That way, I could use my Linux server for other stuff without having to move the nice monitor from my main system.
And yeah, I know telnet is insecure, but I like it both on my home and work LANs. (Neither one of which includes people who would be capable of rooting a box.) I haven't looked around for this, but has anyone seen a telnet client for Windows 9x that will provide pretty colors like RedHat's directory listings or so that I can actually use Lynx?
Beg borrow or steal a telecom tone generator. This clips onto one end of a pair of wires, and you can use the probe to trace where these wires go.
Triplett Fox and Hound set. Yeah, I've got one, it's wonderful when you're trying to figure out which piece of Cat-5 running though the suspended ceiling in the office is the one that you wish to drop to your boss' office. But in the confines of a pinball machine, mine doesn't work: the sensitivity is too great.
(On the other hand, I can trace a wire on the other side of a cinderblock wall, which comes in handy more often than less sensitivity.)
well, now i'm really curious about your job... what do you do?
That's not really easy to describe.
I work for a division of Litton. Primarily, we design and build radar, navigation, communications, closed-circuit TV and engine management systems for ships.
The navigation product line used to include Very Low Frequency (VLF) navigation systems, and in the 1970s, Decca Radar bought out a company that built RF insulators that were used by the Decca Navigator system.
Decca Radar was bought up by Racal Electronics, which then finally sold Racal-Decca Radar to Litton, who merged it with Sperry Marine and C-Plath.
And, alongside everything, is this little insulator manufacturing facility. Even though the Decca Navigator is long obsolete - like, as obsolete as calling up Apple and asking their help desk for Apple IIe assistance - the Insulators division continues to make insulators and associated tower parts for big AM radio broadcasters, defence submarine communications, shortwave broadcasters, etc.
A lot of low-frequency (AM band and lower) radio transmitting towers are live. Unlike a TV tower, or a cellular tower, or an FM broadcasting tower - which simply supports an antenna - the output of the transmitter is actually hard wired to the steel structure of the tower. It usually *is* the antenna. Given that many thousands of watts of RF energy is on the tower, it must be insulated from ground. When the tower is 1,500 feet tall, the base insulator and all the guy wire insulators involved become rather formidable.
And you can imagine the problems when you have FAA-mandated obstruction lights that have to be powered, even though the lights will be operating at a potential of 250,000+ volts higher than the powerline supplying them. So, we make huge oil-filled isolating transformers with sufficient ratings to couple 525 volt 200+ amp power for the lights across across to the tower. And when half the lights blink and the other half don't - and when the transformers are inefficient because of the distant coupling required in order to make them work with that potential difference between the windings - you need a regulator.
Therein lies the problem. Redesigning it is even less practical than building something that requires semiconductors that were discontinued 20 years ago.
Further, my boss likes to keep his fingers in every pie, and Litton allows this, because it was allowed under Racal-Decca. So not only is there Marine and Insulators, we also have a small flight information system on the side - which I administer (really crappy quickly-designed website here) - and (get this) because our insulators manufacturing plant will soon be quiet (not a booming industry), the boss is ramping up for us to start making small quantities of specialized car parts.
Not only that, but I also administer the office LAN, webserver, mail server, file server, etc. And I write technical documentation for a large number of items in our product line, including a radar video processing system that I designed.
It's incredibly convoluted. But it all seems to work somehow.
Sorta. I'm not someone who likes to badmouth my boss - I do like the guy, and this is nothing against Litton - but he's a bit of a bumbler and not well liked by our head office; so, frankly, there's nowhere to go within this division of Litton.
So, if you know anyone who is hiring, and looking for a diverse and eclectic mix of skills, send an e-mail. Please. Resume and references are available upon request.
If you're building the hardware anyways, and your RAM/demultiplexers are fast enough, you can make pretty much any addressing scheme look like any other addressing scheme. I bet you wouldn't even have to get very creative, though, 'cause I'll bet those old games all use 8-bit words.
Ugh. Kludge! Kludge! Yeah, I know, sometimes it's the only way to get the job done.
And yes, Virginia, there is still such a thing as a 74138.
Off topic, but there is no longer such a thing as a 2N1671. Or a 2N5755. And I challenge anyone to find a 10 watt zener diode that isn't from ECG or NTE. (Sorry, I'm at work, and I have to build a fairly sophisticated regulator that was designed in the 1960s. We're deathly afraid of changing the design because it's FAA-approved and works well in *high* RF fields, and we don't have time to prototype and test a new design.)
At least I can "make" the 10 watt 10 volt zener (1N2974) by wiring two 5V 5W zeners in series. Modern triacs to replace the 2N5755 either burn up with the gate current that I feed this thing, or are so overrated that they handle the gate current but don't latch with the load that we're running at it. And the UJT? Feh. No one has used a UJT in a new circuit in 20 years.
Electro-Mechanical machines are very interesting...
Indeed! And they make the coolest noises when they're running. Ya know, like a Tandon 5.25" SSSD full-height disk drive to one of today's mute and impotent 3.5" drives. Even if they're only capable of storing 90k/disk, they're still a lot of fun to fire up every now and then.
Or a 20-year-old VCR, compared to today's. Cool.
Chances are if the game is blowing a fuse you have one of the 16 or so solenoid coils that pull in the relays, (should be two rows) that are going bad.
As in, the varnish on the copper is deteriorating, shorting the windings, and causing them to draw more current than they should? It sounds like that might be the problem; I do have a few that are looking a little blackened, but when I've swapped in the solenoids off another pinball machine, that doesn't cause the problem to go away. I think I've already been suckered into rewinding a few of them for my roommate anyway...
The contacts on the "score motor run" (the timed bank of contacts with the motor) are very rarely known to blow fuses as they essentially have little power to them. If something quits working without blowing fuses then the contacts on the score motor run are the first ones to check.
Cool. Yeah, it's been hard to know where the high-current areas of the circuit are, since all the wiring is the same color and same gauge. Even so, I'm sure 20 AWG can carry enough current to pop the fuses no matter where in the circuit they're going.
It strikes me that the flipper solenoids are probably the highest current devices on the game, if they're controlled by those relays you mentioned earlier, maybe one of those is sticking.
The problem manifests itself in that when the flipper reaches the end of its travel, the switch which is supposed to turn it off doesn't work. Now, the switch appears to be properly aligned with the cam on the flipper shaft, and the switch appears good. It just seems that it should be turning off a relay that controls the flipper, perhaps - that's not happening. The flipper stays on, the laminates in the power transformer rattle with the current load of the flipper staying on too long, and suddenly pop, dead game with pretty backlights. When the power goes out, the flipper retracts, so the mechanical linkage between the solenoid and the flipper's shaft is free. Happens to either flipper.
<grin> I'll get to it one of these days. Like, shortly after Mike gets his welder out of the kitchen. (It's been there for months.)
Slashdot Mirror
Am I crazy, or does that have implications for long-term space flight?
You're probably crazy, but yes, it does.
Fluorescent lights are not as efficient as LEDs, though they're still more practical for the moment. And they're bulky, the ballasts are heavy, and they're fragile. The LED will first see general lighting use in space, but I don't think it's ready for that yet.
And yes, it's another one of those evolutionary improvements that will improve the technology of space travel. I'm still holding out for the revolutionary ones, like superluminal travel and gravity manipulation.
Any one have any info about the range of light they put out? Cuz I was thinking, no heat and low power, these would make good grow lamps
I think most (ahem!) herbs grow best under a greenish to bluish glow light. You should be able to find that out for sure in any good book on amateur hydroponics... Grow lamps, for example, always seem to be a more blue-green glow than an ordinary fluorescent tube. And incandescents don't seem to do much at all.
If that's the case then, don't bother with an array of white LEDs. They're incredibly expensive. Instead, go for an array of blue (still expensive) or green (common) LEDs.
Hi-intensity green LEDs are fairly available, just quickly checking the back cover of my Digi-Key catalog, you can buy Panasonic green clear LEDs in T-1 3/4 packages for $199.70 per thousand pieces. At 20mcd @ 565nm @ 30mA @ Vf=4, they might grow plants pretty well, if you have enough of them. (There are far more intense and efficient green LEDs out there, I just flipped over a catalog.)
There are also 1500 mcd blue LEDs available from the same source (www.digikey.com). On my older Canadian edition of their catalog, the 1500 mcd blue LEDs put out at 470nm, If=20mA, Vf=3.5V. Panasonic part # LNG992CFBW, if you wanna check out the datasheets on their website. A thousand of them will cost you over three grand.
It would, for sure, be an interesting project. Remember to budget for a large DC power supply to run these, as well as homebrew PC board to wire all these, because you're sure as hell not going to do it by hand.
This won't be the first time that the Japenese help the White LED (the third letter stands for death). I seem to remember a little incident called World War II.
I think the Japanese got to see more than enough white light during WWII. Maybe that served as the inspiration for the white LED?
Around here, most Jews seem to drive German cars; most Chinese people seem to be driving Japanese cars.
Personally, while I wouldn't touch a Japanese car with a ten meter cattleprod, but speaking as a former tech at a TV station, no one has ever made a better TV set than Sony. As long as the Japanese allow North American manufacturers to sell their products there, I have no problem with the Japanese selling their products here. Competition and innovation are mutually beneficial.
Forgiveness is an interesting thing. And a good thing.
And, of course, the big bank of neon lamps that would come on to indicate a low battery state.
Fortunately, small plasma discharge lamps like neon indicators are almost as efficient as LEDs.
<grin>
Don't they already use banks of LEDs for the red traffic lights?
And lots of buses and trucks are starting to use them for signal and brake lights. New Mercedes S-series are including them, as are the new Cadillac DeVilles.
And, if you're in the Toronto area, you can take a drive through the corner of Eglinton East and Sloan. That's a block west of Victoria Park Avenue. The traffic lights there have LEDs.
HP's Agilent Technologies advertises the benefits of LEDs, besides the obvious energy efficiency and reliability increases.
The best part is that it takes a few milliseconds for the tungten filaments in conventional bulbs to light up when electricity is applied. With a GE 1156 or 1157 (depending on whether or not your car has combined brake and parking lights, either one of these is the defacto standard on about 95% of the cars on North American roads), if you're travelling 75MPH, you will travel about 15 feet in the time it takes for those filaments to light up.
And that means that if some jackass with an SUV and a cellphone planted to the side of his head is tailgating you, he will see the lights as you slow down, possibly giving you and him an extra 15 feet or so. This can make the difference between a small bent-bumper accident and no accident at all.
After some jackass hit me in May - two months after I picked up my beautiful old 1976 Dodge Ram, I took matters into my own hands. My bumper is trashed, but he bought me a new one, which I haven't put on yet. The old bumper is bent, but still strong. Stronger yet since I welded steel angle iron behind it, and then cross-gusseted the rear of the frame. The bumper is now fortified steel attached through soft brass shear pins to the truck's now-reinforced frame.
The plan?
Well, the last jackass who hit me mashed his radiator against his intake manifold. And my Class-4 trailer hitch, which is welded to my frame, didn't have a ball on it, so as my bumper bent, the hitch was rammed through the side of his cylinder block. I could see his connecting rods. Silly little Honda go bye-bye. All because the idiot had to "feed" his Tamagochi. I'd love to sue the government of my province for entrusting anyone who is stupid enough to buy a Tamagochi with the priveledge of operating a motor vehicle.
The next time someone hits me, I expect my bumper not to bend, but to simply fold up or down as the sheer pins snap. This will mean that the impact force of the next silly little tinfoil Japanese unibody car that hits me will be dissipated entirely on the ends of my gussetted Detroit plate steel frame rails. The rear 8 feet of my frame are criss-crossed with steel stock welded in at 2 foot intervals. Sure, I'll have to pick up my bumper and toss it in the back of the truck, but a moment's inattention from the schlep following me will result in catastrophic damage to his vehicle.
When I get around to putting on the new bumper, I'm also going to swap LED brake lights into the truck. I've already planned out most of the voltage regulator that they're going to need, but until I know for sure how many MCDs of light are really necessary for brake lights, I can't choose a diode and therefore can't choose a voltage drop which would allow me to finish the regulator design.
Anyone know of any good automotive-brightness red T-1 3/4 LEDs?
I am not pro-nuclear, so you'll see my bias, and I don't think it's fair to blame environmentalists on (non-US) governments seeking alternatives to nuclear energy (since it IS unsafe, you cannot EVER guarantee that it will be safe,
Nothing is safe. There are varying degrees of risk.
Solar power, for example, is one of those things that is generally viewed as a benign source of energy, awaiting only more advanced solar cells to be practical.
Couple of problems with that. A solar cell must be fairly large to produce a fairly small amount of energy. Since a solar cell is essentially a large silicon die, it is brittle, and when it's exposed to sun and then to night and then to day, it will be expanding and contracting and will eventually fail on its own just due to mechanical fatigue - let alone if something else breaks it.
Basically, you're looking at making a large (let's say 6" round) integrated circuit for each cell (producing 0.6V at maybe 500mA in full sunlight). Assume a 20 year average lifespan before it cracks and fails. 0.6V at 500mA is 0.3 watts of power. What's the electrical load required to power sunny California? How many solar cells would you need? What would be the toxic chemicals produced as byproducts of those cells? Let alone storage systems, inverters, etc.
Nuclear power sucks. Sure. I agree. If something goes wrong, it can go *very* wrong. But usually nothing goes wrong, and it produces lots of efficient and relatively safe power. Building thousands of acres of solar panels to provide power is definitely going to have nasty environmental consequences, simply based on the huge quantities of chemicals and energy needed to build the cells.
and no one wants nuclear waste or a nuclear power plant in their backyards, whether they are environmentalists or not).I would. The real estate is cheap, the neighbors are quiet, and they won't care if I'm in the garage welding quarter panels onto my car at 4:AM with loud music playing.
I have a geiger counter; I'd probably have several around the house if I lived there. But it's risk management: I'd be safer living there than I would be in a community at the end of a runway, or even living within 200 miles of the San Andreas fault.
And, yes, I believe the government uses nuclear power without taking the appropriate precautions or having decent followthrough - we HAVE had our own nuclear close calls.Not sure what country you're talking about, but Canada's have been minimal. There have been accidents, but the public has never been at risk. Three Mile Island was also pretty small as reactor blowups go. The worst risk to the world from any nuclear project has been the arms race, and the resulting fallout from all the arms tests. Not from civil power plants, even RBMKs.
Natural uranium is not 100% U-238, it's about 99.3% U-238. The balance, about 0.71%, is U-235. U-238 is not fissile, and if you filled a CANDU with it you wouldn't get a reaction going. (I understand that a CANDU can burn "spent" PWR fuel, interestingly enough. The question then becomes why you'd want to.)
Natural uranium is mostly U-238. The term "natural" comes from the fact that it's not processed to alter the isotopic ratio from when and where it was mined.
CANDU reactors *do* actually consume the natural uranium; I hate to disagree with you, but I've actually refuelled two of them - NRX and NRU at Chalk River, Ontario.
While I appreciate your comments about the quality of the post - who doesn't like a pat on the back every now and then? - I'm reminded as I write this that you're an individual with whom I've had ongoing debates in the past. While you're clearly an intelligent person with enough information in a broad range of subjects that you can create the illusion of being well-informed, you've failed miserably in those previous attempts, with the inability to acknowledge gaps in the (admittedly impressive) book knowledge you've acquired when faced with a disagreement from those who have actually *done* the things you've only read about.
No further postings from you will be acknowledged.
So what is the worst-case failure scenario for a CANDU? Earthquake, terrorist bombing? Is there any conceivable pathway for a significant amount of radiation to spread over an area?
Operator error, I think.
Let's say an earthquake takes the calandria off its base and it rolls around. Fine, the heavy water will leak and the reactor will stop. There'd be some release, but since the fuel is in ceramic pellets in zirconium-alloy fuel bundles, it's unlikely to escape too far.
More likely - and more sinister - is the possibility of a used fuel bundle somehow getting out. That would be very dangerous, high-level radioactive waste, and could expose thousands of people to lethal doses of radiation.
I've held new CANDU fuel bundles; they're quite harmless. They're heavy, for sure. And they're very radioactive, but it's all U-238, which occurs commonly in nature, and while it's chemically purified, it's also chemically stable. So, it's no worse than a big chunk of good uranium ore. And you can go to the north shores of the Great Lakes and find that easily, if you know what you're looking for.
Like all reactors, the concept and operation is quite simple. A kid can do it in his back yard. But the problem is that they become complicated with all the monitoring and safety systems required to make them practical and actually harness the energy. At the Pickering Nuclear Power Plant - one of three (Pickering, Darlington and Bruce) that powers Toronto, Canada - a plumber made a mistake and hooked a water fountain up to the wrong pipe. Instead of fresh clean tapwater, the plumber managed to run into reserve heavy water. Not a problem to drink - it's water with extra neutrons in the hydrogen, not radioactive - but it's very expensive to isolate. But the big uproar that hit Toronto's media after the incident was that these workers had been drinking "radioactive" water. Indeed, the water had a little more than background radiation - it had run through the reactor core a few times before and had dissolved trace amounts of fuel - but it still posed no serious health risk. Mistakes happen, they have to be carefully monitored.
I think it's fair to say that the biggest risk with a CANDU reactor is accidental release of radioactive materials. I've never seen anyone come up with a failure mode that could cause a CANDU to pull a Chernobyl, or even a Three Mile Island.
I'd live, quite happily, next to any Canadian or American nuclear power plant. Real estate would be cheap, and the neighbor is quiet.
Hey is that where they make Cobalt-50? I know my school imports Co-50 from Canada for the gamma cell in our nuclear lab. (About 10000 Curies' worth every 10 years or so!).
Co-60, and yup. In fact, that's where most of the world's Co-60 is from.
I'm not sure what percentage of it comes from the Whiteshell, Manitoba labs, but I know a lot is made at Chalk River.
I was looking for an article that I had seen somewhere where some kids had found an old radiotherapy machine in a South American garbage dump, and had later died as a result of having painted themselves with glowing paint made from the cobalt they found inside... But I happened on this instead. It's not about cobalt - it's about a kid in Michigan who appears to have gotten quite close to building his own breeder reactor, before the Feds got involved.
Now, I feel like a loser. As far as I got was being able to find steel rebars in concrete walls with an x-ray machine that I built using a microwave oven transformer and a tube I made with a blowtorch and a vacuum pump.
the IFR Integral Fast Reactor recycles its waste over and over until essentially all of the fuel is spent. the very small amount of remaining waste that is not consumable has a half life of only 300 years and is no more radioactive than the original ore from which it was mined. additionally the IFR has passive safety features which makes meltdown impossible.
Yeah, they're a great idea. I haven't read much on the actual operation of them, but I think they show promise.
About breeders in general, I understand that for the physical size and cost of the facility, they provide minimal energy. I don't want to call them inefficient - I don't think that's really an accurate statement - they just don't put out much power.
But, I see them as an excellent way to dispose of radioactive waste and provide a little bit of power back to the grid, even if they're not good as primary power reactors. And they've got to be great for getting rid of nuclear weapons.
Sadly, I think the "not-in-my-backyard" syndrome will prevail - as it does with most reactor construction - as well as the low MWh-output per $$ in construction, maintenance and staff - will limit their application. I hope - and expect - that someone will come up with a breakthough design that will address the dollar efficiency.
The radon from the decay series can be bitch though, keeping you rooms well aired, if you live granite area, could save the a few cigerettes a day of lung cancer risk.
*Very* good point.
I grew up in Ottawa, Canada. Radon is a *big* deal in parts of Ottawa, as it is in uranium country.
Did you know that, because radon is very heavy, some *solid* objects will float on it? It's very creepy the first time you see it (in a lab). Evidently, you wouldn't want to have this occur in your home. In practice, it would be tough, since it will tend to diffuse throughout the room, staying in the lowest parts of the house because it's so dense. Dense objects will just displace the radon and sink. But a little paper boat will float in it, appearing to just hover in the air.
Not sure what the critical mass of radon is... Whatever the case, you don't want to breathe it. Radon 222 is an alpha emitter, so keep that basement well ventilated, and don't spend any time really close to the floor down there.
Cesium is not a daughter product of natural uranium decay (although the heavier radioactive alkali metal francium is a daughter product in the U-235 decay series). Cesium is however a very common product of fission
Cool. Nah, I don't have a decay series in front of me, and even when I interned in the field, I didn't memorize the series. I would have thought it was a common product of decay, not just fission. Thanks for the correction.
Yes nuclear does produce waste, but it can be contained with less environ impact than that of coal. What represents a pinprick on the map of the US can store a lot of nuclear waste. Coal devastates far more space (eg. a lot of the state of WV).
Yup. Now, not that nuclear waste isn't without its risks. Certainly, it is. But it's small and containable, though highly dangerous stuff.
This being said, if there were a nuclear waste handling facility near my home, it wouldn't bother me. The real estate would be cheap, and it would be a lot safer (and quieter!) than living under a big airport's flight path. It's just a question of risk assessment.
Yeah, I'd have to put a new tube into my geiger counter and keep it on, but that's just part of my way of dealing with the risk of being in that location. Same thing if I were living on the Pacific rim: there'd be a seismograph bolted to my basement floor. It's a risk. Still less than driving my truck on the freeway to work every day.
Lastly, nuclear waste does not spontaneously explode like a nuclear bomb unlike a depiction in a crummy made for tv movie that people probably take for fact. Nor do plants themselves.No. Nuclear waste gets hot and changes chemically as elements are transmuted from one to another. But this process is well understood and managed.
As for the exploding plants, Chernobyl, being graphite-moderated enriched uranium, is an extremely dangerous design. (Can we think all the stereotypes of the Ford Pinto and the Chevrolet Corvair built into one car, only a thousand times worse? That's how dangerous an RBMK is.) And, even so, it took a *lot* of safety violations and operator stupidity to cause that thing to run away. A staggering number of things that you just don't do, were done there.
You know, things that you just don't do. Like in a car, doing 100 miles an hour, you just don't turn the wheel as hard in either direction as you can. Basic sense of having been around a car and knowing how hard to turn the wheel around a corner at 10 miles an hour give you some measure of understanding of what would happen at 100 miles an hour.
And yet at Chernobyl, they kept trying and trying and trying, doing one stupid ill-advised thing after another, in flagrant violation of all common sense when running a nuclear reactor, until it finally blew up.
This is like driving a 1971 Pinto with a full tank of premium gas down the Santa Monica freeway, and slamming on the brakes as hard as you can when you see an 18-wheeler behind you.
You just don't.
Actually, at least for Uranium-238 (the most common isotope) has a half-life of about 4.5 billion years. Just a tad longer than Carbon-14.
Fortunately, though, the longer the half-life, the less radioactive the isotope is.
Why?
The more unstable the isotope, the faster it will decay. That means more alpha, beta and gamma emissions over a shorter time, which means more energy released, more geiger counter or cloud chamber activity, and more risk of cancers to you!
Essentially, a stable (non-radioactive) isotope of anything just has an infinite half-life.
U-238 isn't harmless, but it's barely above background radiation. It's also a very common element in some places of the world. Eastern Manitoba and Western Ontario in Canada have huge uranium deposits. You can dig the ore out of almost any hole in the ground. Yes, it's radioactive. No, it won't hurt you. Just make sure you wash your hands before you eat or smoke, because you don't want it in you.
Like lead or mercury, it's a heavy metal, and tends to do unfriendly things when it gets inside you.
Wasn't it a cloud of cesium (sp?) that drifted over the Ukraine and on over the rest of Europe?
Yes, cesium is a common decay daughter of virtually all isotopes of uranium. Fortunately, most radioactive isotopes of cesium have relatively short half-lives and transmute into something else. Because cesium is probably the nastiest element that there is, and that's even when it's not an isotope that pegs your geiger counter with gamma radiation. Imagine sodium (remember your high school chemistry classes?) but an order of magnitude worse.
Want to know more about cesium? Sing the songs of cesium? Check those links out.
Neat cesium compounds:
Cesium ozonate (Cesium trioxide)
Formula: CsO3.
Molecular Weight: 180.9
Description: Unstable, bright red compound. Strong oxidizer. Decomposes with release of Oxygen. Reacts vigorously with water. Highest known oxide of Cesium, at the opposite end of the spectrum from Cs7O. Prepared by reacting Cesium or its lower oxides with ozone.
Uses: Curiosity, Exploding red ink.
Cesium Chloroxenate
Formula: CsClO3Xe
MW: 347.66
Properties: Explodes
Uses: Chemical curiosity, possible rodenticide
Toxicity: Unknown
Comments: One of the few known compounds involving a noble gas, a halogen, and an alaklai metal. Explodes if you look at it cross-eyed.
Good, it was an unsafe design anyhow
Heheh... Positive control coefficient, and a moderator that doesn't boil away.
It was an *insane* design, bordering almost on the criminal.
And yeah, there are still more than a dozen of the damned things running.
<sigh> I know that the RBMK reactor was designed for three goals: price, efficiency, and plutonium production (for weapons). And since that didn't include safety, I guess the engineers got what they wanted.
I'm all for nuclear power. You can't burn fossil fuels because of price per MWh and emissions. You can't build damns everywhere, because there are great environmental consequences to those - and they're only practical where there's a large river. (ie. Hoover Damn powers a lot of L.A., but how far from L.A. is it, with resulting efficiency losses in the lines?) You can't build tidal, wind or solar plants yet, because the technology still isn't practical even in the parts of the world that energy is abundant enough to effectively harness.
Western Europe has been shutting down its nuclear plants and increasing its reliance on natural gas. Fine, gas is easy to manage and it's clean as far as fossil fuels go. It's also abundant in neighboring Russia.
Ironically, as Western Europe shuts down its reactors, Russia keeps on commissioning and retrofitting their pressurized water and dangerous RBMK reactors so that they don't have to divert any natural gas that would otherwise be sold to Europe.
As is usual with the policies enforced by environmental lobby groups, it backfired. Fine, the reactors in Western Europe are being shut down. And replaced with far more dangerous Russian reactors. Good work, you stupid long-haired hippie tree-huggers. (Ooops. I have long hair and I like Five Man Electrical Band, I guess I can't insult hippies.)
Before you moderate me down for saying that environmentalists are idiots, check out this link, which has to do very specifically with the Russian reactors vs. Western Europe natural gas fiasco. While environmentalists are full of great intentions, they're generally ignorant of science or the basic fundamentals of how a marketplace economy works.
Like it or not, nuclear power is going to be here for a while.
Let's encourage safe and responsible use of nuclear power, at least until something more practical comes along. Let's try to not ban nuclear power, but to ban RBMK reactors.
Let's see a day when all the running nuclear reactors in the world have *negative* control coefficients (ie. won't run without a moderator) and use a moderator that will boil off and shut down the reactor in the case of an overheat.
Back when I was in high school, I got a summer internship down the road from Ottawa at a place called Chalk River Nuclear Laboratories. This was the home of Canada's nuclear program, and is one of those rare things that makes me proud to be a Canadian. Canada still leads the world in civilian nuclear technology.
At the time, they had three big research reactors there - the decommissionned "ZEEP" (Zero Energy Experimental Pile, put out *one watt* of heat, built in 1944 for the war effort and has a colorful history), the vertical-loading National Research eXperimental "NRX" (since decommissionned) and the horizontal-loading NRU. All three were of the CANDU design, though the ZEEP and NRX were very primitive.
I was assigned to the NRX. Every day, I'd travel from Deep River to Chalf River, don my dosimeter, walk through the checkpoints and head to the reactor. It was great fun, helping out with experiments. And irradiating golf balls for increased driving distance.
There was a Commodore PET on top of the reactor, and it used to record and monitor the temperature throughout different parts of the reactor vessel. Then, there were the tube computers (no kidding!) with ferrite core memories which were used to provide more critical functions. (Semiconductors don't like ionizing radiation if the reactor leaked, tubes are a lot more forgiving.)
And, let me tell you, there's no feeling in the world quite like standing there, on top of the reactor, looking down 30 feet or so to the people below you, feeling the slight vibration of the pumps running all around, and the sheer sense of power in the room as the reactor below you runs.
Food was forbidden in the reactor buildings, because ingestion of bits of radioactive dust was an (unlikely) possibility. Even so, people did eat there occasionally, and I was no exception, though you become very careful with the geiger counters before you put it in your mouth. Because there was (officially) no food allowed in the building, there was no kitchen, so hot snacks were a rarity. Canned stew was a special favorite: the cans fit right into the (sealed) sample tubes. Drop them in at the top, lower them slowly through the reactor, and then retrieve them at the bottom. If you timed it just right, the can was nice and warm. If you got distracted, the can burst and you'd have to clean out the sample tube. (And no, this was not a good idea, but it didn't put anyone at risk besides those of us who ate the food, and we all knew perfectly well how the food had been cooked.)
I'd have gone into nuclear physics as a career if I could have handled the math. <grin>
My favorite reactor design is the CANDU (CANadian Deuterium-Uranium). It's an elegant design. Uranium 238 ("natural uranium") is used instead of the U-235 used in most other reactors. U-235 requires the added steps of processing and is also vulnerable for use in weapons.
The moderator in a CANDU reactor is heavy water; deuterium instead of ordinary hydrogen. Deuterium is a rare but naturally-occurring isotope of hydrogen. It's ordinary hydrogen in every respect, except for the fact that there's a neutron in the nucleus. It's not radiactive (unlike hydrogen with two neutrons, called "tritium", which *is* radioactive). Deuterium water is heavier than regular water, simply because of that neutron in the hydrogen.
The heavy water serves as the moderator. It slows down the fast-moving neutrons coming off the U-238 so that they can sustain the fission chain reaction. Light (ordinary) water will not sustain this reaction - nor will no water.
Let's say everything fails. The computers go down, the control rods are all jammed out of the core, and the operators are idiots. A Chernobyl accident still cannot occur. It's physically impossible.
If a CANDU reactor gets out of control and overheats, the moderator (heavy water) can be drained away, shutting down the reactor. You can't do that with blocks of graphite like an RBMK reactor. With a CANDU, if there's a problem and the operator doesn't drain the moderator away, eventually a pressurized pipe will burst and the moderator will boil away. With no moderator, the reactor will cease to work. Since the fuel is uranium in non-water-soluble ceramic pellets, there will be minimal decay daughters in the resulting steam cloud. Which will be contained anyway in the concrete reactor house, which is held under a vacuum to prevent release.
Unlike Chernobyl, which drastically overheated. The solid graphite moderator began to burn. And still the chain reaction continued to produce heat, because the graphite moderator was still there... it burned for 9 days.
Let's take all those unemployed Chernobyl workers to see a CANDU or similar reactor in operation, train them extensively on it, and then help them build them to replace their aging and rickety designs.
I've found that a pretty good way of not going to jail is not to commit crimes like theft or forgery. Works for me.
Agreed.
I hope Bubba likes his delicate features and then doesn't use lube when he consumates his relationship with the spammer.
(Oh, and what were your favorite Lotto numbers again?)
Yeah. I'd never win the lottery, so I don't bother.
But *this*, yeah, I stand a very good chance of "winning" these odds.
My 1976 Dodge Ram will be sitting in my driveway, looking pretty, its chrome heliographing in the sun, the fresh paint sparkling. It's survived 24 years on the road in the Toronto area, over 200,000km, an errant Toyota Camry whose driver had to be extracted from the wreckage of his car with the jaws of life, and more recently a voltage regulator failure that sent my electrical system to the possible world record of 26 volts while I was driving home but didn't do any more damage than blowing out my left headlight.
And then, clear out of the blue, there will come an Iridium satellite.
I know it. I can feel it.
I'm building a bunker.
here's the commercial for those interested. It's in
Pervert.
Believe it or not Radio Shack has a pretty good series of one panel kits full of mounted electrical components & springs for running wires. The manuals are decently written and are understandable by most youngsters. They can usually do a fairly large number of projects with each kit and most of the projects are fairly interesting.
When I saw this subject on Ask Slashdot, I thought immediately of Radio Shack. I'll never forget the Christmas that, under the Christmas tree, my Aunt Margaret had sent me a Radio Shack 160 in 1 Electronic Project Kit.
I played with nothing but for the two years between when I got that and when I got my first computer.
Wow. That was one of the best presents anyone ever gave me.
Yes, many of the projects can be duplicated with something pre-made from the local store but heck, there's nothing like doing it yourself & impressing one's parents ( parents - you claimed you liked the clay ashtrays - now get ready to go bonkers over the photoelectric light switch!)In grade 5 - 9 years old - I built the "High Voltage Power Supply" project they had in there. It was a relay, wired as a vibrator, driving the Audio Output Transformer on the board. There was an electrolytic capacitor across the relay coil to keep the frequency reasonable. It put out a nice solid jolt on your fingers, but posed no safety risk. For my school science fair project that year, I got an old wooden chair, some old belts, and made up some "electrodes", and built probably the single most famous science fair project ever presented at any Ottawa-area elementary school science fair. It was an electric chair. The brave were encouraged to try it out. Not coincidentally, it was also the first time I made the cover of the local newspaper, the Ottawa Citizen.
Actually, this does bring one thing to mind. Back in those days, I was running all my projects on a 9V battery or two AAs. Today's alkaline, NiCd or NiMH batteries - in a Radio Shack kit like that - could be very dangerous. Use the old Eveready Classics ("Cat of 9 Lives") and other cheap carbon-zinc batteries instead. If your kid shorts that out, it's not going to cause a fire the way a new Energizer or Duracell or something would.
As a non-parent, not-a-big-kid-fan these are great gifts. The kids really do seem to appreciate them, I get to feel I'm doing something good, and aside from the occasional "come look at what I made" it keeps the rugrats out from underfoot while the adults visit. Remember, toys are unisex & they're just as good for your niece as well as your nephew!Absolutely. That was one of the very few things that could keep me busy for weeks on end.
I found a predecessor to my 160 in 1 - it was a 150 in 1 kit - at a garage sale. It was about 10 years old, but all the components still worked. The two kits were quickly merged into one: the photoelectric switch turned on the three transistor radio. The Morse code practice oscillator was quickly connected to the AM Transmitter.... And then there were my own inventions. When you're 10 years old, two SPDT relays and four transformers can keep you occupied for days at a time. :)
I see the 200 in 1 - the expensive version of my 160 in 1 - lives on! Cool! The photos take me back, too... the familiar little transformers, the pretty little relay...
200 in 1 Project Kit link - working.
Hmmm... Well, I can't think of anything much easier than downloading and installing ZipSlack or BigSlack. Both of these distros are UMSDOS-native, which means that their whole filesystems live as a file in an existing FAT16 or FAT32 partition.
They're great for novices, since the default installations will run with a minimum of tweaking.
Of course, that's not what you wanted: while it would be cool to have a little Linux box running in a window on your Windows Me (yuck!) machine, this seems to me to be a task much more satisfyingly accomplished by simply using Windows to telnet in to the real thing.
I run Windows 95B on my main machine at home and at work, mostly because I need the Windows applications. I run Windows 95B specifically because it includes FAT32 support, it has a better 16 bit subsystem than its successors, and I don't have to put up with crap like the Active Desktop and other later "enhancements". I barely trust Windows as it is, let alone trying to operate a full virtual machine inside it.
However, an X client for Windows would be great, so that the connection to the real Linux box could also be graphical. That way, I could use my Linux server for other stuff without having to move the nice monitor from my main system.
And yeah, I know telnet is insecure, but I like it both on my home and work LANs. (Neither one of which includes people who would be capable of rooting a box.) I haven't looked around for this, but has anyone seen a telnet client for Windows 9x that will provide pretty colors like RedHat's directory listings or so that I can actually use Lynx?
Beg borrow or steal a telecom tone generator. This clips onto one end of a pair of wires, and you can use the probe to trace where these wires go.
Triplett Fox and Hound set. Yeah, I've got one, it's wonderful when you're trying to figure out which piece of Cat-5 running though the suspended ceiling in the office is the one that you wish to drop to your boss' office. But in the confines of a pinball machine, mine doesn't work: the sensitivity is too great.
(On the other hand, I can trace a wire on the other side of a cinderblock wall, which comes in handy more often than less sensitivity.)
well, now i'm really curious about your job... what do you do?
That's not really easy to describe.
I work for a division of Litton. Primarily, we design and build radar, navigation, communications, closed-circuit TV and engine management systems for ships.
The navigation product line used to include Very Low Frequency (VLF) navigation systems, and in the 1970s, Decca Radar bought out a company that built RF insulators that were used by the Decca Navigator system.
Decca Radar was bought up by Racal Electronics, which then finally sold Racal-Decca Radar to Litton, who merged it with Sperry Marine and C-Plath.
And, alongside everything, is this little insulator manufacturing facility. Even though the Decca Navigator is long obsolete - like, as obsolete as calling up Apple and asking their help desk for Apple IIe assistance - the Insulators division continues to make insulators and associated tower parts for big AM radio broadcasters, defence submarine communications, shortwave broadcasters, etc.
A lot of low-frequency (AM band and lower) radio transmitting towers are live. Unlike a TV tower, or a cellular tower, or an FM broadcasting tower - which simply supports an antenna - the output of the transmitter is actually hard wired to the steel structure of the tower. It usually *is* the antenna. Given that many thousands of watts of RF energy is on the tower, it must be insulated from ground. When the tower is 1,500 feet tall, the base insulator and all the guy wire insulators involved become rather formidable.
And you can imagine the problems when you have FAA-mandated obstruction lights that have to be powered, even though the lights will be operating at a potential of 250,000+ volts higher than the powerline supplying them. So, we make huge oil-filled isolating transformers with sufficient ratings to couple 525 volt 200+ amp power for the lights across across to the tower. And when half the lights blink and the other half don't - and when the transformers are inefficient because of the distant coupling required in order to make them work with that potential difference between the windings - you need a regulator.
Therein lies the problem. Redesigning it is even less practical than building something that requires semiconductors that were discontinued 20 years ago.
Further, my boss likes to keep his fingers in every pie, and Litton allows this, because it was allowed under Racal-Decca. So not only is there Marine and Insulators, we also have a small flight information system on the side - which I administer (really crappy quickly-designed website here) - and (get this) because our insulators manufacturing plant will soon be quiet (not a booming industry), the boss is ramping up for us to start making small quantities of specialized car parts.
Not only that, but I also administer the office LAN, webserver, mail server, file server, etc. And I write technical documentation for a large number of items in our product line, including a radar video processing system that I designed.
It's incredibly convoluted. But it all seems to work somehow.
Sorta. I'm not someone who likes to badmouth my boss - I do like the guy, and this is nothing against Litton - but he's a bit of a bumbler and not well liked by our head office; so, frankly, there's nowhere to go within this division of Litton.
So, if you know anyone who is hiring, and looking for a diverse and eclectic mix of skills, send an e-mail. Please. Resume and references are available upon request.
If you're building the hardware anyways, and your RAM/demultiplexers are fast enough, you can make pretty much any addressing scheme look like any other addressing scheme. I bet you wouldn't even have to get very creative, though, 'cause I'll bet those old games all use 8-bit words.
Ugh. Kludge! Kludge! Yeah, I know, sometimes it's the only way to get the job done.
And yes, Virginia, there is still such a thing as a 74138.Off topic, but there is no longer such a thing as a 2N1671. Or a 2N5755. And I challenge anyone to find a 10 watt zener diode that isn't from ECG or NTE. (Sorry, I'm at work, and I have to build a fairly sophisticated regulator that was designed in the 1960s. We're deathly afraid of changing the design because it's FAA-approved and works well in *high* RF fields, and we don't have time to prototype and test a new design.)
At least I can "make" the 10 watt 10 volt zener (1N2974) by wiring two 5V 5W zeners in series. Modern triacs to replace the 2N5755 either burn up with the gate current that I feed this thing, or are so overrated that they handle the gate current but don't latch with the load that we're running at it. And the UJT? Feh. No one has used a UJT in a new circuit in 20 years.
Electro-Mechanical machines are very interesting...
Indeed! And they make the coolest noises when they're running. Ya know, like a Tandon 5.25" SSSD full-height disk drive to one of today's mute and impotent 3.5" drives. Even if they're only capable of storing 90k/disk, they're still a lot of fun to fire up every now and then.
Or a 20-year-old VCR, compared to today's. Cool.
Chances are if the game is blowing a fuse you have one of the 16 or so solenoid coils that pull in the relays, (should be two rows) that are going bad.As in, the varnish on the copper is deteriorating, shorting the windings, and causing them to draw more current than they should? It sounds like that might be the problem; I do have a few that are looking a little blackened, but when I've swapped in the solenoids off another pinball machine, that doesn't cause the problem to go away. I think I've already been suckered into rewinding a few of them for my roommate anyway...
The contacts on the "score motor run" (the timed bank of contacts with the motor) are very rarely known to blow fuses as they essentially have little power to them. If something quits working without blowing fuses then the contacts on the score motor run are the first ones to check.Cool. Yeah, it's been hard to know where the high-current areas of the circuit are, since all the wiring is the same color and same gauge. Even so, I'm sure 20 AWG can carry enough current to pop the fuses no matter where in the circuit they're going.
It strikes me that the flipper solenoids are probably the highest current devices on the game, if they're controlled by those relays you mentioned earlier, maybe one of those is sticking.
The problem manifests itself in that when the flipper reaches the end of its travel, the switch which is supposed to turn it off doesn't work. Now, the switch appears to be properly aligned with the cam on the flipper shaft, and the switch appears good. It just seems that it should be turning off a relay that controls the flipper, perhaps - that's not happening. The flipper stays on, the laminates in the power transformer rattle with the current load of the flipper staying on too long, and suddenly pop, dead game with pretty backlights. When the power goes out, the flipper retracts, so the mechanical linkage between the solenoid and the flipper's shaft is free. Happens to either flipper.
<grin> I'll get to it one of these days. Like, shortly after Mike gets his welder out of the kitchen. (It's been there for months.)