As far as arcing in air goes, for 1MV at ~100kHz, there was a rule of thumb that for every foot of air corona could extend you'd need 500W of power on the primary (obviously varies with humidity, temp, pressure etc). For the primary and the spark gap on the line frequency side, the breakdown voltage rule was approximately 1kV per millimeter.
Most coilers start off with Neon sign transformers (10kV RMS, ~300W) which is fine for small coils. And yes, you can arc the secondary to yourself (well, to something metal you're holding, otherwise you get burns at the point of contact). You couldn't feel anything once the arc was established, but when it was just starting there was a definite tingle. Low frequency components introduced as the load was applied, perhaps.
Tesla coils have all sorts of hidden dangers anyway, such as getting an arc down to the primary (10kV @ 300W is still very likely to kill) and an arc to you - effectively creating an ionised path between the primary and yourself. Nasty - and why consciencious coilers put a grounded loop (with a little gap) just above the primary, to draw away any strikes that would otherwise hit the primary. The same goes for arcs down to mains.
From what I remember, the industrial microwave transformers were 2.4kV @ 1.2A (two for a total of just under 6kW). They were truely fearsome, and melted (well, vapourised) every spark gap design I came up with.
You're correct - they are both girls. Your comment suggests that this may not be, as I assumed, by chance. Please elaborate, I'm all ears (figuratively speaking).
Am I the only one that thinks he's an idiot for trying to construct ANY fusion device under his parent's house? Geez, what if he'd created a fusion reaction that was larger than he could contain?
You're the only one. I think you've been watching too much Star Trek. Fortunately, non-idiots, such as that lad, know that a Robert Hirsch type fusor only ever consumes more energy that it produces. It'll never "run away" as such.
Indeed, when I was a teen, I built Tesla coils. The spark gap alone peaked at ~14kV with a lot of energy. And they routinely produced > 1MV (calculated) from the top caps.
I did this in the back garden (hammering a steel pole into the lawn gives a good earth point). It seems the neighbours on one side didn't like or understand my odd looking machines, because they moved out shortly afterwards. Admittedly it interfered with every electric system in the neighbourhood, and there was a time whe I was experimenting with two industrial microwave transformers connected in antiphase (for the primary circuit, you understand), and powering them up would cause the lights to dim in every third house down the street, but hey...
Some people just fear science, I guess.:)
(And yes, I'm not dead, by some miricle, and I've had two kids since)
There is some evidence that nanoparticles can move into the brain along the olfactory nerve, so this is completely circumventing the blood-brain barrier.
You're forgetting - the reason Microsoft are so successful is because they're driven by profitability, not by being a technology leader. It just so happens that they're very good at taking other people's ideas and implementing them in a way that works and that people (in general) will want; they're also good at market research, it would seem.
Inventing new stuff is one thing - producing it in a mass-market easy-to-digest way is another. The latter is where the money is.
A true robot overlord wouldn't use a configurable design like that. It'd be hardwired to "evil" when it was built, to reduce the possibility of someone trying to hack it to run OpenWRT or other unauthorised software. No-one's going to brick my bots without a fight, dammit!
That's why if I ever build a world-dominating robot race, they'll have:
-Six legs
-Three brains in unassuming grey boxes mounted in different places
-A selection of disposable "false brains" with glowing eyes (to be held on sticks away from the main body when attacking an armed target)
-Painful diodes down one side
-Frickin' big lasers
Oh yeah, and they'll never make cute little bleeping noises, develop a conscience, or be enigmatic in any way.
I for one, welcome myself as your new robot-army-controlling overlord.
Foolhardy! Those of us that kite-landboard and rely on our bearings not to faceplant us into the sand at speed, know that WD-40 is a BAD PLAN for long term lubrication, as it dissolves the grease that bearings are usually packed with. Far better to use something like GT-80 - trust me on that one.:)
The demise of Commodore is a sad, sad story. Machines that everyone liked at home, that were well designed and straight forward to use, fell under the mighty axe of the corporate PC. Bad descisions were made.
I learnt to code in C on my A500. Guru Meditation was my friend... it will always have a special place in my heart.
Replicating Google's 200 petabytes of hard drive capacity would take less than one data center row and consume less than 10 megawatts, about the typical annual usage of a US household.
It's the old rate-of-energy-consumption vs energy-consumed misused once again.
An average household consuming 10 megawatt-hours in a year is pretty dull. An average household consuming 10 megawatts - now that'd be impressive! (Got to power all those gadgets, y'know!)
I think he means that the data center row would consume in an hour the same amount of energy that the average US household consumes in a year.
The trouble with Linux is inconsistency that comes about from multiple disparate groups of developers. Everything in Windows behaves the same, and the vast majority of apps of applications follow the same UI trends.
Take a look at Linux though, and you have a vast array of different widgets that perform the same functions, and different dialog layouts (down to which way around the "OK" and "Cancel" buttons are presented). This inconsistancy is just plain annoying. It's annoying on Windows too, when apps try and do something different (stupidly big buttons, for example, like in HJSplit).
If all the applications looked the same and behaved the same, then your average user at home might be happier to use them. Familiarity is the way forward.
Well, because the PVR you get is tied to the digital cable/satellite company, you don't really get to pick and choose your PVR in most cases. Because of this, they have no reason to offer features that may get them in trouble. However, if you buy your PVR on the free market, separate from your cable provider, I could see a lot more features being offered to try to woo buyers to buy one PVR over the other.
And there you hit the nail on the head.
IUTBASTBSWI (I Used To Be A Set Top Box SW Integrator). The big sat/cable broadcasters specify the functionality of the software to be provided by their PVR boxes. Of course they do this because the box OEMs and driver/silicon providers are paid directly by the broadcasters to supply and develop PVR boxes to the broadcasters specifications. And guess what - those specs specifically state the functionality of the video controls, so although the video drivers are always capable of skipping/fast playing any which way, the middleware layers that control the drivers just don't perform thse functions under certain circumstances. The broadcasters want you to watch the adverts so that they get paid by the advertisers, so they're going to make sure you watch them and can't just skip over them. Of course, third party PVRs will allow you to do this because they don't have the pressures of a broadcaster wanting advertising revenue, but then they also don't have the financial backing of the broadcasters (who really are rolling in it!) to fund nicely rounded and very stringently tested PVR boxes. So they may be of lesser quality. And of course, broadcasters usually don't want third party PVRs on their networks, so they make damn sure that only their boxes will work.
One thing is for sure, if people find ways to avoid watching the adverts, the broadcasters will put a lot of time and money into ensuring that it won't work in the future!
I believe they're more compressed - perhaps analysing the distortion characteristics of the sound could be helpful?
You are correct. In the industry it's flippantly referred to as CTF compression (as in "Compressed To F***"!) Television is one medium where good dynamic range is valued, especially for films, so in a film most of it may be quiet to allow for the odd very loud noise to go undistorted. Advertisers just want to use the upper few dBs of dynamic range to keep their adverts loud, so always use heavy compression on the audio (IE always in that very loud section). As such, it won't appear distorted (as in clipped), but you might be able to perform some analysis on dynamic range to determine if heavy compression is in use.
I presume by in-between-frame you mean VBI (Vertical Blanking Information). The vast majority of this is optional and depends on the broadcaster as to what is sent with the video, so there is unlikely to be anything reliable there to distinguish adverts from anything else. There may be a discontinuity in the time codes in the VBI, but more probably there won't. And you can guarantee that if the broadcasters find out that something in the VBI is being used to detect adverts then they'll stop broadcasting that information!
With hindsight, I probably should also have made sure that the AVO was set to measure AC current, not resistance, before commencing the experiment.
Believe me, it's better that than the other way around. I handed a meter set to measure current (10A max) to a colleague. Those things just have a bar in them that connect the terminals to measure high current. Anyway, he used it to test the voltage between two rails of a 1kW power amplifier, without moving the probes to the correct holes for voltage measurements. I heard a huge bang and saw him silhouetted against a sheet of sparks. The fat electrolytics in the amplifier power supply were more than a match for the multimeter, and melted the probe tips and a good deal of the tracks on the PCB. He was, fortunately, unharmed and is probably a good deal more careful these days.:)
Slashdot Mirror
True, it is all about power.
:)
As far as arcing in air goes, for 1MV at ~100kHz, there was a rule of thumb that for every foot of air corona could extend you'd need 500W of power on the primary (obviously varies with humidity, temp, pressure etc). For the primary and the spark gap on the line frequency side, the breakdown voltage rule was approximately 1kV per millimeter.
Most coilers start off with Neon sign transformers (10kV RMS, ~300W) which is fine for small coils. And yes, you can arc the secondary to yourself (well, to something metal you're holding, otherwise you get burns at the point of contact). You couldn't feel anything once the arc was established, but when it was just starting there was a definite tingle. Low frequency components introduced as the load was applied, perhaps.
Tesla coils have all sorts of hidden dangers anyway, such as getting an arc down to the primary (10kV @ 300W is still very likely to kill) and an arc to you - effectively creating an ionised path between the primary and yourself. Nasty - and why consciencious coilers put a grounded loop (with a little gap) just above the primary, to draw away any strikes that would otherwise hit the primary. The same goes for arcs down to mains.
From what I remember, the industrial microwave transformers were 2.4kV @ 1.2A (two for a total of just under 6kW). They were truely fearsome, and melted (well, vapourised) every spark gap design I came up with.
A very interesting hobby for geeks anyway.
Suggested reading for you:
http://en.wikipedia.org/wiki/Fusor#Robert_Hirsch
Indeed, when I was a teen, I built Tesla coils. The spark gap alone peaked at ~14kV with a lot of energy. And they routinely produced > 1MV (calculated) from the top caps.
:)
I did this in the back garden (hammering a steel pole into the lawn gives a good earth point). It seems the neighbours on one side didn't like or understand my odd looking machines, because they moved out shortly afterwards. Admittedly it interfered with every electric system in the neighbourhood, and there was a time whe I was experimenting with two industrial microwave transformers connected in antiphase (for the primary circuit, you understand), and powering them up would cause the lights to dim in every third house down the street, but hey...
Some people just fear science, I guess.
(And yes, I'm not dead, by some miricle, and I've had two kids since)
Even Carmageddon had road markings...
It will happen, you know it.
Who thought up "bionic hornet"? Seriously, it sounds like the perfect title for a cheap B-movie. How about, "Bionic Hornet 2:The Spawning"?
You're forgetting - the reason Microsoft are so successful is because they're driven by profitability, not by being a technology leader. It just so happens that they're very good at taking other people's ideas and implementing them in a way that works and that people (in general) will want; they're also good at market research, it would seem.
Inventing new stuff is one thing - producing it in a mass-market easy-to-digest way is another. The latter is where the money is.
A true robot overlord wouldn't use a configurable design like that. It'd be hardwired to "evil" when it was built, to reduce the possibility of someone trying to hack it to run OpenWRT or other unauthorised software.
No-one's going to brick my bots without a fight, dammit!
Microsoft infringes on our patience sometimes, as well.
That's why if I ever build a world-dominating robot race, they'll have:
-Six legs
-Three brains in unassuming grey boxes mounted in different places
-A selection of disposable "false brains" with glowing eyes (to be held on sticks away from the main body when attacking an armed target)
-Painful diodes down one side
-Frickin' big lasers
Oh yeah, and they'll never make cute little bleeping noises, develop a conscience, or be enigmatic in any way.
I for one, welcome myself as your new robot-army-controlling overlord.
Ahem.
That'd be the worst USB powered Christmas gadget ever - a mini-robot that screams in pain from the moment it gets plugged in.
:)
I think you've found a gap (albeit a small one) in the market there.
Foolhardy! Those of us that kite-landboard and rely on our bearings not to faceplant us into the sand at speed, know that WD-40 is a BAD PLAN for long term lubrication, as it dissolves the grease that bearings are usually packed with. Far better to use something like GT-80 - trust me on that one. :)
Small Boy Pulls Four Legs off Robot. Robot says, "It's only a fleshwound, I've had worse!" and rolls about a bit.
The demise of Commodore is a sad, sad story. Machines that everyone liked at home, that were well designed and straight forward to use, fell under the mighty axe of the corporate PC. Bad descisions were made.
I learnt to code in C on my A500. Guru Meditation was my friend... it will always have a special place in my heart.
*sniff*
Is Slashdot the people equivalent of Google?
It's the old rate-of-energy-consumption vs energy-consumed misused once again.
An average household consuming 10 megawatt-hours in a year is pretty dull. An average household consuming 10 megawatts - now that'd be impressive! (Got to power all those gadgets, y'know!)
I think he means that the data center row would consume in an hour the same amount of energy that the average US household consumes in a year.
The trouble with Linux is inconsistency that comes about from multiple disparate groups of developers. Everything in Windows behaves the same, and the vast majority of apps of applications follow the same UI trends.
Take a look at Linux though, and you have a vast array of different widgets that perform the same functions, and different dialog layouts (down to which way around the "OK" and "Cancel" buttons are presented). This inconsistancy is just plain annoying. It's annoying on Windows too, when apps try and do something different (stupidly big buttons, for example, like in HJSplit).
If all the applications looked the same and behaved the same, then your average user at home might be happier to use them. Familiarity is the way forward.
OK, so who clicked the "unwittingly downloaded a keylogger program" link in the article without having second thoughts?
;)
A double whammy for the phishers if it linked to the keylogger infected file in question.
And there you hit the nail on the head.
IUTBASTBSWI (I Used To Be A Set Top Box SW Integrator). The big sat/cable broadcasters specify the functionality of the software to be provided by their PVR boxes. Of course they do this because the box OEMs and driver/silicon providers are paid directly by the broadcasters to supply and develop PVR boxes to the broadcasters specifications. And guess what - those specs specifically state the functionality of the video controls, so although the video drivers are always capable of skipping/fast playing any which way, the middleware layers that control the drivers just don't perform thse functions under certain circumstances. The broadcasters want you to watch the adverts so that they get paid by the advertisers, so they're going to make sure you watch them and can't just skip over them. Of course, third party PVRs will allow you to do this because they don't have the pressures of a broadcaster wanting advertising revenue, but then they also don't have the financial backing of the broadcasters (who really are rolling in it!) to fund nicely rounded and very stringently tested PVR boxes. So they may be of lesser quality. And of course, broadcasters usually don't want third party PVRs on their networks, so they make damn sure that only their boxes will work.
One thing is for sure, if people find ways to avoid watching the adverts, the broadcasters will put a lot of time and money into ensuring that it won't work in the future!
You are correct. In the industry it's flippantly referred to as CTF compression (as in "Compressed To F***"!) Television is one medium where good dynamic range is valued, especially for films, so in a film most of it may be quiet to allow for the odd very loud noise to go undistorted. Advertisers just want to use the upper few dBs of dynamic range to keep their adverts loud, so always use heavy compression on the audio (IE always in that very loud section). As such, it won't appear distorted (as in clipped), but you might be able to perform some analysis on dynamic range to determine if heavy compression is in use.
I presume by in-between-frame you mean VBI (Vertical Blanking Information). The vast majority of this is optional and depends on the broadcaster as to what is sent with the video, so there is unlikely to be anything reliable there to distinguish adverts from anything else. There may be a discontinuity in the time codes in the VBI, but more probably there won't. And you can guarantee that if the broadcasters find out that something in the VBI is being used to detect adverts then they'll stop broadcasting that information!
Believe me, it's better that than the other way around. I handed a meter set to measure current (10A max) to a colleague. Those things just have a bar in them that connect the terminals to measure high current. Anyway, he used it to test the voltage between two rails of a 1kW power amplifier, without moving the probes to the correct holes for voltage measurements. I heard a huge bang and saw him silhouetted against a sheet of sparks. The fat electrolytics in the amplifier power supply were more than a match for the multimeter, and melted the probe tips and a good deal of the tracks on the PCB. He was, fortunately, unharmed and is probably a good deal more careful these days.