It may have been common in AC/DC sets for heaters to open because if the heaters did not all warm up at the same rate one of the tubes had to absorb almost the entire line voltage for a split second, so it would eventually fail. Tubes were made with controlled heater warmup times to avoid this problem, but it only worked if ALL the tubes were of the same brand. Also the 35Z5 or 35W4 rectifier tubes had a tap on the heater to connect a pilot lamp. If the lamp burned out then that portion of the heater would be slightly overloaded and disturb the warmup time of the entire chain.
In radios and television sets that used a power transformer with all the tube heaters in parallel an open filament was very rare, except in the case of certain rectifier tubes such as the 5U4 or 1B3.
That radar caused tremendous interference on the ham short wave bands. It got the name "the Russian Woodpecker" since that is what the interference sounded like, a flock of angry woodpeckers.
Actually an open heater was NOT the way most tubes died. The coating on the cathode that emits electrons when heated gradually decays and emission drops off to the point that the tubes transconductance is too low for it to operate. But the heater rarely burns out, at least not in indirectly heated tubes. Another way they die is that air gradually leaks in and the vacuum becomes too poor. The silver flashing on the side of the tube will then turn a milky white as the chemical "getter" that absorbs air has absorbed all that it can. Once the getter coating is depleted the tube will become gassy. A tube can also die from shorts when closely spaced elements break loose from vibration and touch. Over heating will soften the elements and cause the same effect. Tubes can handle a much higher percent of overload than solid state devices however. Tubes computers were never faster than solid state ones even if the tubes themselves were faster. Because of their size the total wiring in a tube computer is much longer than in a solid state system. In transistors it is the "holes" in the crystal structure that "move" and the speed of light in silicon is lower than in a vacuum for electromagnetic waves. Still these waves have less distance to propergate in an IC than a bunch of interconnnected tubes. Finally note the description of this new tube technology, it is really a "vacuum state" IC. I always wondered when nanotechnology would be applied to thermionic "valves" (as they say across the "pond").
It may be possible to certify the man rating of the Dragon spacecraft before the Falcon launch rocket. So the Dragon may be able to return astronaughts to earth FROM the ISS before it is used to bring them up there (since no ride on the rocket would be required if the Dragon is sent up empty).
Bell invented the telephone. So did Gray. Bell simply got to the patent office a few hours ahead of Gray. Oh well....... The telephone transmitter (microphone element) that was in use for over 100 years WAS invented by Edison.
The phonograph was perhaps the most original of Edison's inventions. His inspiriation for this was his previous invention of a recording telegraph that used depresions in a rotating disk to record the dots and dashs of telegraph transmissions for later playback. The playback was electrical with the depressions in the disk causing a feeler riding on them to open and close an electrical circuit, but Edison (despite his deafness) was able to hear the crud sounds the feeler made while riding on the disk. Strangely enough, while he based the phonograph on this observation, the first phonograph used a cylinder instead of a disk to record sound.
Many have commented on how Edison 'stole' the idea of the electric lamp from others. What Edison did was to take their primative ideas and make two simple but essencial changes to the design, which made the difference between success and failure. Until Edison all previous attempts at an electric lamp used a heavy low resistance element heated to incandecance by a low voltage electrical current. The element was operated in air either in the open, or protected by a glass cover. Sometimes a thermal regulator was used to allow the element to operate close to its melting point to produce as much light as possible. Edison's lamp used a thin high resistance element operating at high voltage. Since such a thin element would burn up quickly Edison sealed it inside a blown glass bulb in a high vacuum. Edison was lucky in that a brand new type of vacuum pump that used the flow of mecury to trap air had just been invented. He bought the first production model available for his experiments. He hired professional glass blowers to produce the sealed bulbs for his lamps. He experimented with various metals to find one that had the same rate of thermal expansion and contraction as glass for use as the lead in wires for the lamp (Edison used platinum). He spend years expermenting to perfect what seems today like such a simple idea. It wasn't so simple at the time. Any complaints about Edison stealing the idea of the electric lamp from someone else is simply sour grapes.
Actually most of Edison's ideas WERE his own. He didn't do much of the actual work of constructing prototypes or models, his hired "technicians" did this work. Edison did supervise the most interesting projects but his employees were simply given some guidelines and did the work themselves in most cases. Comparing him with Bill Gates would be correct, Mr. Gates was very involved with most of Microsoft's technical direction and he contributed to much of the technology they developed, at least in the early days.
On very interesting fact is that Edison almost invented electronics. He was working on improving the telephone (he did invent the carbon button microphone) at the same time that he was working on improvements to the electric lamp. One problem that plagued the early production carbon filament lamps was a gradual darkening of the inside of the bulb (due to evaportation of the carbon filament). Edison noted that one side of the bulb (the side connected to the positive end of the filament) darkened more than the negative side AND that a shadow appeared behind the positive end where no carbon was deposited. This was partly do to the bulb not having a perfect vacuum. Edison added a free wire into the bulb to which he connected a sensitive ammeter. When the meter was connected between this free wire and the positive end of the filament a current flowed. When it was connected to the negative end of the filament there was no current. This was the "Edison Effect", or thermionic emission, the principle upon which the vacuum tube depends on. If Edison was aware of atomic theories of electricity (IE: that electricity is the flow of negative atomic particles) is unknown. If he had been just a bit more curious he might have inserted a THIRD element into the bulb between the filament and his first electrode and experimented with the effects of both positive and negative charges on it. If he had he would have been able to notice that there was a ratio between the current change on the outer element and the voltage change on the inner, IE: amplification that could have been used as a repeater element for telephone circuits. Edison was just a small step away from inventing the Triode Vacuum tube about 30 years early! He was working on two projects that could have been connected to do this. However it didn't happen. I wonder how the world might have changed if Edison had made this leap of discovery.
That's what the scientists thought in the "Blackjack 21" anime. They created a virius that could produce electricity to run an artifical heart. They ended up creating the incurable Phoenix disease. Dr. Blackjack found the cure just in time.
It takes AT LEAST 20 seconds for the wife and kids to finish in the bathroom after I've put the disk into the player to show up in the family room when we are starting a movie. I can skip though the 'comming attractions' on the disk (though we actually find SOME of them interesting). BTW IIRC the Oppo-video DVD players do have some button press combo that will actually skip all this shit (including the FBI logo) and jump to the main menu. (They also can be hacked via a few button presses to become regionless... it's all in undocumented 'back door' codes in the firmware).
My guess is that Heath was already deep in red ink when they decided to re-enter the kit market. They probably wanted to ride the current maker movement. Maybe if their creditors had given them enough time they could have saved the company with new kit products. Just look at Adafruit.com, Evilmadscience.com, or Sparkfun.com and you will see that there IS a demand for kits. No one ever did kits better than Heath. I'm sorry to be the reporter of the bad news. RIP Heathkit.
The name VAX is actually an acroname. It stands for Virtual Address eXtendion. The VAX is an extention of the PDP-11 instruction set, and extends the word and address size from 16 to 32 bits. Same thing Intel later did to the 80286 microprocessor with the 80386. The VAX was one of the few mini computers with THREE address instructions. (IE: ADD A,B,C) or "add a with b and store the result in c." Most computers have only one or two address instructions (few have even TWO address instructions), the destination and usually one of the operands is a register (usually the SAME register).
For many years as IBM introduced newer and faster computers the instruction sets of the older machines were emulated by the newer ones so that customers code would not be obsoleted. Eventually you might have had several layers of emulation going on.
DEC's vax emulated the PDP-11 instruction set and would run RSX-11 (their most poplular PDP-11 OS) under the VAX OS as a sub task so that customers could migrate from the PDP-11 to the VAX. And DEC's Alpha machines would emulate VAX, PDP-11, and 386 instruction sets (in software). Nothing new here.
For me the problem is using the bulbs with a dimmer. CFL's DO NOT DIM. Period! Even the so called dimable ones simply drop in output maybe 30-40% then flicker and go out. If you have a multi bulb fixture the CFL's don't dim together and usually go out at different settings. In the rooms of my house that require dimable fixtures I have to use incandecents. If the LED bulbs will dim with standard dimmers (I use X10 switches than can be remote controlled) I would consider switching to them. At some point I will try the 75watt LED bulbs in the bedroom or maybe the 60w ones in the family room and see if they work with dimmers. (If they don't they will go back to HomeDepot for a refund!). The LED bulbs should also be more vibration proof than CFL's so they can be used in ceiling fan fixtures.
The word "hacker" has suffered the same fate as the word "gay". Just as you can no longer say you are 'happy' by using the 'g' word (least you admit you are something else), one can no longer use the word hacker to mean a computer wiz without getting 'cuffed'. GD 5th estate!
Well Intel won't mess with AMD over this because THEY took the AMD-64 instruction set and added it to THEIR processors. So both companies have a bit of each other's copyright in their products.
We toured the MIT campus a few weeks ago during a trip to Boston to visit several schools that my daughters might attend. (My daughter that applied there didn't get admitted though.) Anyway we saw the Green building and the tour guides (some junior and senior students) told us the history of the hacks. (My favorite hack is still the smoot marks on the bridge). They mentioned that the lights in that building are ALWAYS on and if there was a time at night that the building was completely dark it would be a sign of the coming of the end of the world. So I suggested that a good hack would be to black out the building on "Mayan Long count Calendar rollover day". I was told that maybe I should not have said that! (Future hack?)
Too bad their sponsor is one of the worst things that has ever happened to this country. The family involved is worse than the KKK in it's anti american John Birch attitudes. They don't believe in global warming and the environment. FS should tell them to take their money and stuff it where the sun don't shine.
Slashdot Mirror
I wonder what Andy Griffith would have to say about that?
http://www.imdb.com/title/tt0078681/
http://en.wikipedia.org/wiki/Salvage_1
The Voyager spacecraft use an RCA pencil tube in the transmitter that is STILL going strong.
It may have been common in AC/DC sets for heaters to open because if the heaters did not all warm up at the same rate one of the tubes had to absorb almost the entire line voltage for a split second, so it would eventually fail. Tubes were made with controlled heater warmup times to avoid this problem, but it only worked if ALL the tubes were of the same brand. Also the 35Z5 or 35W4 rectifier tubes had a tap on the heater to connect a pilot lamp. If the lamp burned out then that portion of the heater would be slightly overloaded and disturb the warmup time of the entire chain.
In radios and television sets that used a power transformer with all the tube heaters in parallel an open filament was very rare, except in the case of certain rectifier tubes such as the 5U4 or 1B3.
That radar caused tremendous interference on the ham short wave bands. It got the name "the Russian Woodpecker" since that is what the interference sounded like, a flock of angry woodpeckers.
Actually an open heater was NOT the way most tubes died. The coating on the cathode that emits electrons when heated gradually decays and emission drops off to the point that the tubes transconductance is too low for it to operate. But the heater rarely burns out, at least not in indirectly heated tubes. Another way they die is that air gradually leaks in and the vacuum becomes too poor. The silver flashing on the side of the tube will then turn a milky white as the chemical "getter" that absorbs air has absorbed all that it can. Once the getter coating is depleted the tube will become gassy. A tube can also die from shorts when closely spaced elements break loose from vibration and touch. Over heating will soften the elements and cause the same effect. Tubes can handle a much higher percent of overload than solid state devices however. Tubes computers were never faster than solid state ones even if the tubes themselves were faster. Because of their size the total wiring in a tube computer is much longer than in a solid state system. In transistors it is the "holes" in the crystal structure that "move" and the speed of light in silicon is lower than in a vacuum for electromagnetic waves. Still these waves have less distance to propergate in an IC than a bunch of interconnnected tubes. Finally note the description of this new tube technology, it is really a "vacuum state" IC. I always wondered when nanotechnology would be applied to thermionic "valves" (as they say across the "pond").
It may be possible to certify the man rating of the Dragon spacecraft before the Falcon launch rocket. So the Dragon may be able to return astronaughts to earth FROM the ISS before it is used to bring them up there (since no ride on the rocket would be required if the Dragon is sent up empty).
Bell invented the telephone. So did Gray. Bell simply got to the patent office a few hours ahead of Gray. Oh well.......
The telephone transmitter (microphone element) that was in use for over 100 years WAS invented by Edison.
The phonograph was perhaps the most original of Edison's inventions. His inspiriation for this was his previous invention of a recording telegraph that used depresions in a rotating disk to record the dots and dashs of telegraph transmissions for later playback. The playback was electrical with the depressions in the disk causing a feeler riding on them to open and close an electrical circuit, but Edison (despite his deafness) was able to hear the crud sounds the feeler made while riding on the disk. Strangely enough, while he based the phonograph on this observation, the first phonograph used a cylinder instead of a disk to record sound.
Many have commented on how Edison 'stole' the idea of the electric lamp from others. What Edison did was to take their primative ideas and make two simple but essencial changes to the design, which made the difference between success and failure. Until Edison all previous attempts at an electric lamp used a heavy low resistance element heated to incandecance by a low voltage electrical current. The element was operated in air either in the open, or protected by a glass cover. Sometimes a thermal regulator was used to allow the element to operate close to its melting point to produce as much light as possible. Edison's lamp used a thin high resistance element operating at high voltage. Since such a thin element would burn up quickly Edison sealed it inside a blown glass bulb in a high vacuum. Edison was lucky in that a brand new type of vacuum pump that used the flow of mecury to trap air had just been invented. He bought the first production model available for his experiments. He hired professional glass blowers to produce the sealed bulbs for his lamps. He experimented with various metals to find one that had the same rate of thermal expansion and contraction as glass for use as the lead in wires for the lamp (Edison used platinum). He spend years expermenting to perfect what seems today like such a simple idea. It wasn't so simple at the time. Any complaints about Edison stealing the idea of the electric lamp from someone else is simply sour grapes.
Actually most of Edison's ideas WERE his own. He didn't do much of the actual work of constructing prototypes or models, his hired "technicians" did this work. Edison did supervise the most interesting projects but his employees were simply given some guidelines and did the work themselves in most cases. Comparing him with Bill Gates would be correct, Mr. Gates was very involved with most of Microsoft's technical direction and he contributed to much of the technology they developed, at least in the early days.
On very interesting fact is that Edison almost invented electronics. He was working on improving the telephone (he did invent the carbon button microphone) at the same time that he was working on improvements to the electric lamp. One problem that plagued the early production carbon filament lamps was a gradual darkening of the inside of the bulb (due to evaportation of the carbon filament). Edison noted that one side of the bulb (the side connected to the positive end of the filament) darkened more than the negative side AND that a shadow appeared behind the positive end where no carbon was deposited. This was partly do to the bulb not having a perfect vacuum. Edison added a free wire into the bulb to which he connected a sensitive ammeter. When the meter was connected between this free wire and the positive end of the filament a current flowed. When it was connected to the negative end of the filament there was no current. This was the "Edison Effect", or thermionic emission, the principle upon which the vacuum tube depends on. If Edison was aware of atomic theories of electricity (IE: that electricity is the flow of negative atomic particles) is unknown. If he had been just a bit more curious he might have inserted a THIRD element into the bulb between the filament and his first electrode and experimented with the effects of both positive and negative charges on it. If he had he would have been able to notice that there was a ratio between the current change on the outer element and the voltage change on the inner, IE: amplification that could have been used as a repeater element for telephone circuits. Edison was just a small step away from inventing the Triode Vacuum tube about 30 years early! He was working on two projects that could have been connected to do this. However it didn't happen. I wonder how the world might have changed if Edison had made this leap of discovery.
That's what the scientists thought in the "Blackjack 21" anime. They created a virius that could produce electricity to run an artifical heart. They ended up creating the incurable Phoenix disease. Dr. Blackjack found the cure just in time.
It takes AT LEAST 20 seconds for the wife and kids to finish in the bathroom after I've put the disk into the player to show up in the family room when we are starting a movie. I can skip though the 'comming attractions' on the disk (though we actually find SOME of them interesting). BTW IIRC the Oppo-video DVD players do have some button press combo that will actually skip all this shit (including the FBI logo) and jump to the main menu. (They also can be hacked via a few button presses to become regionless ... it's all in undocumented 'back door' codes in the firmware).
My guess is that Heath was already deep in red ink when they decided to re-enter the kit market. They probably wanted to ride the current maker movement. Maybe if their creditors had given them enough time they could have saved the company with new kit products. Just look at Adafruit.com, Evilmadscience.com, or Sparkfun.com and you will see that there IS a demand for kits. No one ever did kits better than Heath. I'm sorry to be the reporter of the bad news. RIP Heathkit.
The name VAX is actually an acroname. It stands for Virtual Address eXtendion. The VAX is an extention of the PDP-11 instruction set, and extends the word and address size from 16 to 32 bits. Same thing Intel later did to the 80286 microprocessor with the 80386. The VAX was one of the few mini computers with THREE address instructions. (IE: ADD A,B,C) or "add a with b and store the result in c." Most computers have only one or two address instructions (few have even TWO address instructions), the destination and usually one of the operands is a register (usually the SAME register).
For many years as IBM introduced newer and faster computers the instruction sets of the older machines were emulated by the newer ones so that customers code would not be obsoleted. Eventually you might have had several layers of emulation going on.
DEC's vax emulated the PDP-11 instruction set and would run RSX-11 (their most poplular PDP-11 OS) under the VAX OS as a sub task so that customers could migrate from the PDP-11 to the VAX. And DEC's Alpha machines would emulate VAX, PDP-11, and 386 instruction sets (in software). Nothing new here.
This kind of thinking, laws that favor society as a whole over the individual reminds me of the zeroth law of robotics.
For me the problem is using the bulbs with a dimmer. CFL's DO NOT DIM. Period! Even the so called dimable ones simply drop in output maybe 30-40% then flicker and go out. If you have a multi bulb fixture the CFL's don't dim together and usually go out at different settings. In the rooms of my house that require dimable fixtures I have to use incandecents. If the LED bulbs will dim with standard dimmers (I use X10 switches than can be remote controlled) I would consider switching to them. At some point I will try the 75watt LED bulbs in the bedroom or maybe the 60w ones in the family room and see if they work with dimmers. (If they don't they will go back to HomeDepot for a refund!). The LED bulbs should also be more vibration proof than CFL's so they can be used in ceiling fan fixtures.
The word "hacker" has suffered the same fate as the word "gay". Just as you can no longer say you are 'happy' by using the 'g' word (least you admit you are something else), one can no longer use the word hacker to mean a computer wiz without getting 'cuffed'. GD 5th estate!
Looks like the giant robot spider build by Loveless in the Wild Wild West movie.
Well Intel won't mess with AMD over this because THEY took the AMD-64 instruction set and added it to THEIR processors. So both companies have a bit of each other's copyright in their products.
Albert Einstein, who had a deep belief in god.
"God would not play dice with the universe!"
We toured the MIT campus a few weeks ago during a trip to Boston to visit several schools that my daughters might attend. (My daughter that applied there didn't get admitted though.) Anyway we saw the Green building and the tour guides (some junior and senior students) told us the history of the hacks. (My favorite hack is still the smoot marks on the bridge). They mentioned that the lights in that building are ALWAYS on and if there was a time at night that the building was completely dark it would be a sign of the coming of the end of the world. So I suggested that a good hack would be to black out the building on "Mayan Long count Calendar rollover day". I was told that maybe I should not have said that! (Future hack?)
Too bad their sponsor is one of the worst things that has ever happened to this country. The family involved is worse than the KKK in it's anti american John Birch attitudes. They don't believe in global warming and the environment. FS should tell them to take their money and stuff it where the sun don't shine.
More fuel to the fire that FSU is a better school than FS. 'Noles rock! Gators SUCK!
2MW is about 2700HP. That's somewhere between the output of a locomotive and a battleship.
That's about 550HP, about one locomotives worth.