Well, it certainly killed the MISSION, and nearly killed the crew in the process. If the failure happened at any other point in the mission, they most likely wouldn't have survived. If it happened closer to the moon, they may not have had time to adjust their trajectory for a return to earth. If it happened during or after the lunar landing, they wouldn't have had any "lifeboat" to get home in.
Not to mention that I was modded redundant when there was only ONE OTHER POST in the topic, posted one minute earlier. I was writing mine while the other one was being posted....
The smell of ozone is more associated with high voltage corona and arcing than with a short circuit.
Given enough available energy, a short circuit will heat wires enough to melt/burn insulation, or even vaporize the metal conductor itself. The typical smell associated with letting the magic smoke out of something isn't ozone, but burning plastic and phenolic insulation.
There is a BIG difference between being able to design a circuit on paper (or SPICE) and actually being able to put components together and make them work in the real world.
While the basics of design can be learned from books (another plug for the "Art of Electronics" and the ARRL handbook here), when you go to actually put your creation into physical form, you are dealing with mechanical skills (soldering, PCB fabrication, wiring harness fabrication, chassis/packaging work, etc.)that can only be learned through practice. And troubleshooting problems that have their roots in the "grey area" between how circuits act in theory and real world considerations like EMI/RFI, parasitic reactances, heatsinking, etc. will be a real steep learning curve. Bob Pease's book "Troubleshooting Analog Circuits" is a good read, even if you want to work with digital logic (which is actually analog on the fundamental level anyway).
A good way to learn what works and what doesn't is to tear apart as many different pieces of junked electronics as you can (every good hardware hacker needs a "junkbox" to scrounge bits and pieces from), and pay attention to the way components are laid out, mounted, cooled, etc. Get a feel for track widths and ground planes used on PCBs in different types of circuitry. Observe how minor differences in layout and construction can effect ease of troubleshooting/repair. If you can get some surplus industrial/military gear to tear apart, you can compare it to typical consumer electronics, to see how designing for the cheapest price point effects component selection and packaging decisions.
In a swamp cooler, the evaporation is an integral part of the operation. A scaled down version of the cooling towers seen at powerplants, etc. Water is sprayed out of something like a showerhead, and the mist created is cooled by a large volume of air being blown across it.
In the system described in the article, evaporation of the pool water has no significant effect on the cooling obtained. The amount of power being dumped into the pool isn't enough to significantly raise the temperature of the entire pool, which is simply acting as an approximation of an "infinite heat sink". The heat loss from the water into the concrete pool walls/earth would be far more significant than any cooling of the water from evaporation at the surface.
A swamp cooler relies on evaporating water to remove heat. What the article describes is a system that simply uses a swimming pool full of water as a massive heat sink.
The "bong coolers" that are used by some overclockers are much closer to a swamp cooler than this rig is
To avoid the problems with chlorinated pool water corroding the waterblocks and other hardware, he really needs to install a water-to-water heat exchanger in the system. Pool water would run in the primary side of the exchanger, with distilled water or glycol on the computer side. A second circulating pump would also be needed.
Mountaneering and other "Extreme Sports" exempted.
on
Darwin Awards 2006
·
· Score: 4, Informative
"Those who participate in extreme sports are not automatically eligible, as they knowingly assume an increased risk of death. They are, in a sense, correctly applying their judgment that the entertainment is worth the risk. However bizarre the sport, an additional misapplication of judgment must be present in order for the deceased to qualify for a Darwin Award."
I wasn't saying ANYTHING about China or the quality of their products, you asshat.
I was critiquing the ability of the audiophool crowd to distinguish worthwhile products from technobabble, marketing scams, and flat-out bullshit. And how an endorsement by said group says absolutely NOTHING about the technical merits of a product. Here are only a few examples of the utter BULLSHIT that the audiophools buy into:
A wooden volume control KNOB for $500 (need 2 for stereo, BTW) that promises buyers that "The sound becomes much more open and free flowing with a nice improvement in resolution. Dynamics are better and overall naturalness is improved.":
A $1500 POWER CABLE that is described like a glass of fine wine. "The Clairvoyant's signature is engaging, energetic, and bristling with light and microdynamic life"; "lifelike timing and pace" coupled with "clarity, definition, lithe touch, and articulation throughout the lower registers."
That's the same group that will spend money for a bottle of "magic pebbles" to put on top of an amplifier to improve sound quality. Green CD markers, specially "treated" digital clocks, megabuck speaker cables, wooden volume control knobs, and other assorted audiophool insanity have pretty much destroyed any credibility that "audiophiles" ever had as far as judging the objective worth of a product.
If the audiophool market is purchasing Chinese products, it is out of last resort. The Chinese are among the last countries still manufacturing some types of vacuum tubes used in high-end sound gear.
While I agree with your overall view of the FCC abdicating its responsibility for regulating the spectrum to prevent interference, focusing instead on "wardrobe malfunctions" and Howard Stern, the existence of Part 15 devices isn't really the problem here.
Without the Part 15 rules allowing various low power equipments to share spectrum with each other, as well as other services, you would need to buy licenses for your garage door opener, cordless phone, car alarm remote, WiFi gear, etc. There would only be as many licenses available for a given area as there were reserved channels, so if all your neighbors got theirs first, you would be SOL.
Po210 is an alpha emitter, so the radiation from it won't penetrate the walls of a Geiger tube to register a reading. Geiger counters are only useful for Beta and Gamma sources.
What you need to detect an Alpha source is a scintillation detector.
and you can be sure that while the basics of squirting molten plastic into a mold and squeezing it with hydraulics haven't changed since the '50s, there are plenty of high tech temperature/pressure controls, servomotors, PLCs, etc. controlling that seemingly simple process. Factory automation has come a long way since injection molding started.
Most people have absolutely no idea how something as simple as a Lego brick is made. Or the amount of skilled labor that is involved in making the molds and tooling used.
I'm not sure what more you might see from looking at production of their more modern products, as at their core they are still injection molded plastic parts. Illustrating the process with the basic brick is probably a good idea, as nearly everyone has seen one at some point in their life.
What the modern stuff adds is a lot of electronics, which is also mass-produced by automated machinery. If you want to see a typical example of a machine that stuffs and solders PC boards, look here:
You can actually buy small amounts of the stuff OTC, in the form of a "Staticmaster" brush for removing dust from film negatives or other sensitive surfaces.
Lacking something like a heart condition, the charge stored in a CRT's anode capacitance is very unlikely to be lethal in and of itself. A shock from a charged CRT is similar to a really strong "carpet shock" from touching a doorknob, or the kick you get from touching a spark plug wire on a lawnmower. Painful and memorable, but not really dangerous.
Where a charged CRT can present a real hazard is when you go to pick up a tube and carry it across the shop. If you get "bit" then, you just might drop the tube, possibly smashing your foot and/or causing the tube to implode violently, throwing shards of glass and toxic phosphor dust everywhere. I know someone who was in the hospital for several days because of this type of accident.
A CRT is a VERY low leakage capacitor, because it has a glass dielectric (similar to an old Leyden jar). Disconnected from the rest of the set, it can hold a charge for months/years in low humidity conditions. They are also prone to partially "recharging" due to dielectric absorption or "soakage". Whenever a CRT is removed from a chassis, it is good practice to leave a shorting wire connected between the anode cup and the outer aquadag coating to prevent this.
Back when I was in HS (and VCRs were still expensive and worth repairing), I worked in a local TV repair shop (remember those?). We would get the occasional VCR in that had matchbox cars, loose change, or even a PB+J sandwich jammed into the slot. Usually a simple repair, but sometimes kids forcing foreign objects (or even a tape inserted incorrectly with force) into a front-load slot would damage the loading mechanism and cost $$$ to repair.
Slashdot Mirror
Just because the corporate media has him under a blackout, doesn't mean that /. has to follow suit....
http://www.kucinich.us/
Well, it certainly killed the MISSION, and nearly killed the crew in the process. If the failure happened at any other point in the mission, they most likely wouldn't have survived. If it happened closer to the moon, they may not have had time to adjust their trajectory for a return to earth. If it happened during or after the lunar landing, they wouldn't have had any "lifeboat" to get home in.
, not in the command module.
Sounds like the technique used to try repairing the TV camera on Apollo 12.
Unfortunately, "percussive maintenance" was no match for a vidicon tube that got aimed into the sun...
Not to mention sending probes to various planets, comets, and other parts of the galaxy.
And then there was that whole "men on the moon" thing. Let me know when a magazine is offering THAT as a prize...
Not to mention that I was modded redundant when there was only ONE OTHER POST in the topic, posted one minute earlier. I was writing mine while the other one was being posted....
Booth Babes!
The smell of ozone is more associated with high voltage corona and arcing than with a short circuit.
Given enough available energy, a short circuit will heat wires enough to melt/burn insulation, or even vaporize the metal conductor itself. The typical smell associated with letting the magic smoke out of something isn't ozone, but burning plastic and phenolic insulation.
The downloadable .PDFs or CDs cost money, but the HTML version is free. The first "module" starts here:
m
http://www.tpub.com/neets/book1/chapter1/index.ht
A good introduction to the subject, an available for free at:
http://www.tpub.com/content/neets/
There is a BIG difference between being able to design a circuit on paper (or SPICE) and actually being able to put components together and make them work in the real world.
While the basics of design can be learned from books (another plug for the "Art of Electronics" and the ARRL handbook here), when you go to actually put your creation into physical form, you are dealing with mechanical skills (soldering, PCB fabrication, wiring harness fabrication, chassis/packaging work, etc.)that can only be learned through practice. And troubleshooting problems that have their roots in the "grey area" between how circuits act in theory and real world considerations like EMI/RFI, parasitic reactances, heatsinking, etc. will be a real steep learning curve. Bob Pease's book "Troubleshooting Analog Circuits" is a good read, even if you want to work with digital logic (which is actually analog on the fundamental level anyway).
A good way to learn what works and what doesn't is to tear apart as many different pieces of junked electronics as you can (every good hardware hacker needs a "junkbox" to scrounge bits and pieces from), and pay attention to the way components are laid out, mounted, cooled, etc. Get a feel for track widths and ground planes used on PCBs in different types of circuitry. Observe how minor differences in layout and construction can effect ease of troubleshooting/repair. If you can get some surplus industrial/military gear to tear apart, you can compare it to typical consumer electronics, to see how designing for the cheapest price point effects component selection and packaging decisions.
In a swamp cooler, the evaporation is an integral part of the operation. A scaled down version of the cooling towers seen at powerplants, etc. Water is sprayed out of something like a showerhead, and the mist created is cooled by a large volume of air being blown across it.
In the system described in the article, evaporation of the pool water has no significant effect on the cooling obtained. The amount of power being dumped into the pool isn't enough to significantly raise the temperature of the entire pool, which is simply acting as an approximation of an "infinite heat sink". The heat loss from the water into the concrete pool walls/earth would be far more significant than any cooling of the water from evaporation at the surface.
A swamp cooler relies on evaporating water to remove heat. What the article describes is a system that simply uses a swimming pool full of water as a massive heat sink.
The "bong coolers" that are used by some overclockers are much closer to a swamp cooler than this rig is
To avoid the problems with chlorinated pool water corroding the waterblocks and other hardware, he really needs to install a water-to-water heat exchanger in the system. Pool water would run in the primary side of the exchanger, with distilled water or glycol on the computer side. A second circulating pump would also be needed.
From the Darwin Awards rules page at:
http://darwinawards.com/rules/rules2.html
"Those who participate in extreme sports are not automatically eligible, as they knowingly assume an increased risk of death. They are, in a sense, correctly applying their judgment that the entertainment is worth the risk. However bizarre the sport, an additional misapplication of judgment must be present in order for the deceased to qualify for a Darwin Award."
A terrorist who builds really small bombs, right?
I wasn't saying ANYTHING about China or the quality of their products, you asshat.
a nt.mvc?Screen=PROD&Product_Code=NOB_C37_C
i rvoyant.htm
I was critiquing the ability of the audiophool crowd to distinguish worthwhile products from technobabble, marketing scams, and flat-out bullshit. And how an endorsement by said group says absolutely NOTHING about the technical merits of a product. Here are only a few examples of the utter BULLSHIT that the audiophools buy into:
A wooden volume control KNOB for $500 (need 2 for stereo, BTW) that promises buyers that "The sound becomes much more open and free flowing with a nice improvement in resolution. Dynamics are better and overall naturalness is improved.":
http://www.referenceaudiomods.com/Merchant2/merch
Special "secret mojo" paint to apply to the D/A chip inside your CD player to create the mystical "tube sound":
http://www.altmann.haan.de/tubeolator/
A $1500 POWER CABLE that is described like a glass of fine wine. "The Clairvoyant's signature is engaging, energetic, and bristling with light and microdynamic life"; "lifelike timing and pace" coupled with "clarity, definition, lithe touch, and articulation throughout the lower registers."
http://www.soundstage.com/revequip/audiomagic_cla
The previously mentioned bottle of magic pebbles to increase listening pleasure:
http://www.machinadynamica.com/machina31.htm
That's the same group that will spend money for a bottle of "magic pebbles" to put on top of an amplifier to improve sound quality. Green CD markers, specially "treated" digital clocks, megabuck speaker cables, wooden volume control knobs, and other assorted audiophool insanity have pretty much destroyed any credibility that "audiophiles" ever had as far as judging the objective worth of a product.
If the audiophool market is purchasing Chinese products, it is out of last resort. The Chinese are among the last countries still manufacturing some types of vacuum tubes used in high-end sound gear.
While I agree with your overall view of the FCC abdicating its responsibility for regulating the spectrum to prevent interference, focusing instead on "wardrobe malfunctions" and Howard Stern, the existence of Part 15 devices isn't really the problem here.
Without the Part 15 rules allowing various low power equipments to share spectrum with each other, as well as other services, you would need to buy licenses for your garage door opener, cordless phone, car alarm remote, WiFi gear, etc. There would only be as many licenses available for a given area as there were reserved channels, so if all your neighbors got theirs first, you would be SOL.
Po210 is an alpha emitter, so the radiation from it won't penetrate the walls of a Geiger tube to register a reading. Geiger counters are only useful for Beta and Gamma sources.
What you need to detect an Alpha source is a scintillation detector.
and you can be sure that while the basics of squirting molten plastic into a mold and squeezing it with hydraulics haven't changed since the '50s, there are plenty of high tech temperature/pressure controls, servomotors, PLCs, etc. controlling that seemingly simple process. Factory automation has come a long way since injection molding started.
5 044780908&q=pick+and+place&hl=en
Most people have absolutely no idea how something as simple as a Lego brick is made. Or the amount of skilled labor that is involved in making the molds and tooling used.
I'm not sure what more you might see from looking at production of their more modern products, as at their core they are still injection molded plastic parts. Illustrating the process with the basic brick is probably a good idea, as nearly everyone has seen one at some point in their life.
What the modern stuff adds is a lot of electronics, which is also mass-produced by automated machinery. If you want to see a typical example of a machine that stuffs and solders PC boards, look here:
http://video.google.com/videoplay?docid=-80014702
CDLXXXVI, no?
You can actually buy small amounts of the stuff OTC, in the form of a "Staticmaster" brush for removing dust from film negatives or other sensitive surfaces.
l
http://www.2spi.com/catalog/photo/statmaster.shtm
The alpha particles emitted from the source ionize the surrounding air, and neutralize any electrostatic charge holding dust particles to a surface.
Lacking something like a heart condition, the charge stored in a CRT's anode capacitance is very unlikely to be lethal in and of itself. A shock from a charged CRT is similar to a really strong "carpet shock" from touching a doorknob, or the kick you get from touching a spark plug wire on a lawnmower. Painful and memorable, but not really dangerous.
Where a charged CRT can present a real hazard is when you go to pick up a tube and carry it across the shop. If you get "bit" then, you just might drop the tube, possibly smashing your foot and/or causing the tube to implode violently, throwing shards of glass and toxic phosphor dust everywhere. I know someone who was in the hospital for several days because of this type of accident.
A CRT is a VERY low leakage capacitor, because it has a glass dielectric (similar to an old Leyden jar). Disconnected from the rest of the set, it can hold a charge for months/years in low humidity conditions. They are also prone to partially "recharging" due to dielectric absorption or "soakage". Whenever a CRT is removed from a chassis, it is good practice to leave a shorting wire connected between the anode cup and the outer aquadag coating to prevent this.
Back when I was in HS (and VCRs were still expensive and worth repairing), I worked in a local TV repair shop (remember those?). We would get the occasional VCR in that had matchbox cars, loose change, or even a PB+J sandwich jammed into the slot. Usually a simple repair, but sometimes kids forcing foreign objects (or even a tape inserted incorrectly with force) into a front-load slot would damage the loading mechanism and cost $$$ to repair.
The older top-loaders were more "kid-proof".