And the finger is now aimed at the incompetent Boston city officials. Expect many copies of these things to be made. They'll show up at people's homes and in cars. The whole city will be in a panic for months while the rest of the country laughs.
The terrorist's handbook is probably being re-written as you read this. Remember, their goal isn't actually to kill people so much as it is to create the panic that you might be killed. The ensuing panic causes far more economic damage than the loss of lives does. And incompetent government officials like those in Boston just play right into it. Now the terrorists know an all new way to create panic, thanks to the Boston Police.
If I lived in Boston, maybe I'd have already been aware of a long history of incompetence on the part of city officials there. If I was going to do something like this, it might help to know that the city overreacts to everything they see that blinks or has a wire. But normal people won't expect such stupidity. Remember, it was only in Boston that the overreaction happened. These things showed up in other cities without the effect.
I don't live in Boston and I find this both amusing and disgusting. But, if I did live in Boston I would have found it to be terribly embarassing. It's a shame on the city.
Turner, on the other hand may have something to answer for.
What makes you think Ted called this in?
I have heard from many colleagues who did not take these steps, and had their $5000 devices blown up by the bomb squad (again, this stuff was happening before 9/11).
So your city has a long history of overreaction and incompetence?
If Turner took these steps, and officials got their wires crossed, then yes the authorities obviously overreacted. But if the city wasn't informed, the city took all the right steps. Did you expect the authorities to just ignore the devices because they looked cute?
It's a frigging blinking sign! Thinking that is a bomb is just too far out there. Someone was just pissed that the sign was flipping the bird and chose to escalate it and made the false claim.
The only fine that is justified here is for the trespassing and vandalism. Nothing more than that should be paid. Let the idiots who decided this was a hoax (it was NOT a hoax) and the idiots that decided it was a bomb (it was NOT a bomb and didn't even look anywhere near like a bomb... as determined by officials in some other cities like Seattle) pay the fine. Or better yet, let them lose their jobs so people can come visit Boston some day in the future knowing that the city isn't going to overreact.
Sorry, but your city administrators are idiots. Plain and simple INCOMPETENT idiots. They cannot tell a light sign from a bomb and go off and panic at everything that blinks. These things showed up in other cities, including Seattle, and there was no such panic. It's a BOSTON issue, and maybe even a state-wide issue, too, given that your idiot governor is overreacting, too.
They showed one of these on TV (ABC) this morning. Anyone that thinks that is a bomb is just plain looney.
A crime here? Sure... trespassing... vandalism... nothing more than that.
But I sure as hell will avoid conducting business in Boston for the next couple years until you guys get this mess straighten out and get some people running the city that know WTF they are doing.
Even electronic ballast controlled (C)FL flicker at 120 Hz. This is because the voltage drops and crosses zero 120 times a second. The ballast is gating the circuit on and off at some rate, using either pulse width modulation or pulse density modulation. But at times (120 times a second) there's not enough voltage to make it light up. Hence you have flicker.
Of course you could add a bridge rectifier to isolate the polarity and some big capacitors to smooth it out enough. But this is $15 to $20 more cost. This kind can be had, but the market premium is more like $35. So in reality, most electronic ballasts are the cheap type that don't eliminate the flicker (but they do eliminate that annoying buzz).
Also, color index is not the only factor affecting color. That tells you if the primary components are in reasonable balance. But it doesn't tell you if the spectrum is continuous enough to enable non-stressful focus. This is hardly ever measured, anyway.
Fluorescent lights do make it easier to produce a uniform light coverage over a table. If you're not working there continuously (the time varies by person depending on various issues with their vision... about 30 minutes for me) they are fine. The color index is good. The color continuity sucks. And the flicker sucks. For me it's the color continuity that affects me before the flicker, though the flicker eventually will, anyway.
I'm all for saving energy. But there are a few places, basically longer term task lighted areas, that I do need the incandescent lights and will do whatever it takes make sure I have them. I do use (C)FL lights in a lot of places. But my workshop, kitchen, and the reading lamp in the living room... those stay incandescent (low voltage halogen is the way to go for these, which is a little more efficient than ordinary incandescent). Fluorescent simply doesn't cut it there (I do have FL in the kitchen, along with incandescent, but I just can't use the FL for very long).
BTW, I'm not super-human. Just don't assume that what you can't see can't be seen by anyone.
So, what will YOU do when you find that your hard drive dies, and you have to replace it... or maybe just have to upgrade the hard drive to a larger one because Vista is even more bloated than XP... and your old XP disk which you haven't had any need for in the few months since switching to Vista is now unreadable because it has too many scratches?
Don't sever your connection. If you have any surplus energy, the supplier will pay you for it.
Ironically, the motivation that got me to start looking at solar, wind, and other off-grid power sources was specifically wanting to disconnect from the grid for reasons of safety. Did you know that the neutral of the primary circuit of the transformer feeding your home is connected to the neutral of the secondary circuit that is connected to your home? Did you know that there is a significant voltage drop between that transformer and the substation that feeds it (which is why they run at voltages of 7200 and higher so that the drop is not a significant portion and won't affect the final voltage very much)? Did you know that some of that neutral return current actually runs down through the neutral to your home, and through the ground rods? Did you know that most power companies do little or no maintenance on their own ground connections at each transformer, resulting in more of that return current going through your ground rod instead? Did you know that a break in the neutral wire along the primary distribution can go undetected, but result in your home being raised in voltage relative to the overall ground between there and the substation of hundreds, maybe even a few thousand, volts? You won't notice it much if it does happen because all the ground around your home would be raised in voltage as well. But it will do things like cause premature corrosion in your ground rods and any metal water piping. It can also cause voltage spikes in cable TV and telephone service, even if they are correctly grounded. You would notice it if you clamp an ampmeter around the ground wire going to the ground rod and see the current level, or disconnect the ground rod and see a spark.
In most cases these problems are not actually ongoing. They are somewhat rare. But when they do happen, the power company absolutely will deny it and do nothing at all on their end to fix it, even though in almost all cases it is their fault. If you want to find out more, Google for "stray current" or "stray voltage" and look closely at what various farm operators have found.
Getting off the grid means to me that I don't have to deal with their crap anymore. It's not about saving money or being "green". It's not about having power when the grid goes down (which is more likely to happen because the power companies are wasting millions of dollars investing in a doomed "broadband over power line" technology instead of in making a more reliable and better maintained grid). It's about cutting the umbilical from corporations that try to get away with anything and everything they can (and usually succeed).
That's not to say there aren't some well run utilities. I've heard of a small few that are. But most are not. You can find them easily: they are the big ones.
So I'll be looking at solar power, wind power, and even waterfall power, depending on where I end up when I finally get around to doing this. While being "green" is better, I'll also not exclude carbon based energy sources. Sure, I'll prefer more quickly renewable carbon energy sources over those that are not (e.g. burning tree corpses for heat is better than burning dinosaur grease for heat because the former makes way for replacements to suck carbon back out of the air in the near future). And I'll find ways to reduce energy needs so I can do this with a smaller system and hopefully even be entirely carbon-free. But it's more about the independence than about the money (though that being in short supply means I can't ignore it).
Anyone can publish any content on that type of media, in any format/resolution (extreme examples being video at 2160p60, or 32 bit audio at 384kHz sample rate). All players, recorders, software, or other devices, that can deal with that format/resolution shall do so whether DRM-ed or not. If not DRM-ed, then no copy restrictions exist. There also needs to be a way within the context of DRM to specify that no copy restrictions exist (which sounds kind of pointless but might have verification value).
The DRM must be designed so that an open source operating system (such as BSD or Linux) can act as a gateway between the recorded media or network feed source, and a device that integrates the DRM. For example, instead of having DRM in software, with all the headaches of protecting that software, the DRM could be put in the video card or the display monitor, or in the sound card, or in an external box. Then the software is doing little more than shuffling data between media/feed and the device. For this to be useful, the DRM-ed data stream must be structured so that the frame boundaries and index are NOT encrypted. This allows things like partial rewind in the software before any DRM decryption even needs to take place. An A/V program would be divided into chunks per frame or at least group of frames, with clear index headers as needed, and the rest of the content of that block encrypted. Then very basic software (not needing a bunch of codecs or plug-ins) is all you need since the device (video card, monitor, or external USB/Firewire/Ethernet connected device) can do the real work.
It's Wednesday. The link to the PDF is still dead (connection refused). Maybe this article should be titled "Slashdot may be considered harmful (to weak web servers)".
So what makes it high voltage conduit? Does it have "high voltage" stamped on it? Is there a particular color code for high voltage? Why didn't they just get low voltage conduit in the first place?
But that's going to require a disk with 100 to 300 GB of data. Well, for movies I'll settle for the frame rate being exactly what the original film was shot at and let my display up-scan it to some integral multiple over 60 Hz. of course this means I'm going to have to find a display that good at a decent price.
Sure, 720p and 1080i are a good notch above 480i. But it's not that good that I would be willing to buy into an HD media format for higher than what DVD costs today. When the HD media format gets down to this price, then why not. But until then, it's just not really worth it.
But a 25 GB optical disk would be nice to hold a kick ass Linux distribution and a whole lot of music.
20mw is wimpy ... more powerful are available ...
on
Blu-ray Laser Gadget
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When the extended family is gathering for holiday feasts, it is in fact quite typical to have every burner and every oven running, possibly longer than 3-4 hours. That and the microwave will be used to re-heat some things that were cooked at the earlier time frame. All this while a crock pot is running (current one is 1200 watts, but I've seen them up to 3000 watts).
These peak loads don't happen often... maybe 3 times a year. But they are important.
The system plans include a huge battery array. Power sources will include both photovoltaic and windmill, as the system grows and expands. If I can find a property with elevation change and a creek going downhill, I might even have some hydroelectric as well. Some power can be generated at night, sometimes. When none is, there's the batteries. I might even do hydrogen storage.
Certainly some things can use DC directly. My water heater has a mechanical thermostat with a two pole contact. It runs at 240 volts. Unless the contact can't break 18.75 amps of current at 240 volts of DC, it should work. But do keep in mind that contacts do need to be rated specifically for DC at that voltage to be safe. Apparently they will need at least 1cm of gap to break that much voltage, maybe more.
But I would aim to get hot water from the solar system, and finalize the heating in a big storage tank with less electric power used there, so a smaller water heater might make sense.
The cooking stove in the kitchen is probably the big thing. And they are not just heating elements. There is control circuitry and power supplies to drive it. Will they work on DC? Quite possibly not.
As for the power level. The solar panel array does not need to be as large as the peak load. The battery capacity needs to be able to at least deliver it, and hold it for a sufficient period of time under load. The solar array can be charging batteries all the time at their peak capability based on how much sun they are getting. I'm usually only cooking for an hour or two.
Most inverters want DC voltages other than 120 or 240 volts. For example the Xantrex 5500 watt inverters want 48 volts. To use DC directly means getting things designed specifically for 48 volts. I won't necessarily have the independent power system up when the new house can be moved in to, and it may be powered temporarily by a generator or the grid. I might need to start with 120/240 volt AC appliances.
Sure, using efficient appliances is always a good idea, either way. But I need to have a common voltage. If I'm going to run much directly on DC, it will need to be the same voltage as the AC, and I will thus need to configure the battery array that way, and run the inverters that way. Which shall it be? 48 volts? 96 volts? 120 volts? 192 volts? 240 volts?
The scenario is not insane at all. It is in fact quite realistic. The ideal inverter would operate on 240 volts DC and produce 120/240 volts AC, thus allowing me to configure the battery array as a 120/240 volt split system (that would make Thomas Edison smile). Then I can run a few things directly on DC.
Another option is to split the batteries into two different arrays, one at the voltage the inverters want, and the other at direct utilization voltage. That might even be practical with a cross-voltage charge converter than can charge one set from the other should one of them be overdrained. But otherwise it is capacity fragmentation.
As for running a stove on natural gas or propane... only if you know of a means to produce natural gas or propane directly from a renewable energy source. One of my goals in this project is to significantly reduce or better entirely eliminate use of fossil fuels. And that means even if I have a gas or oil deposit underneath my property, it won't be used.
That would be for a 120+120 split single phase system powering European 220-240 volt appliances. For the most part that is true about European appliances. But there are some exceptions. Some UPSes insist on a specific conductor being the grounded one, and will shut down safely if plugged in backwards. The instructions say to reverse the plug. Apparently the intent is that the output uses a polarized socket (e.g. for C13) that needs to have a grounded conductor specifically positioned for some reason (not sure why) and at least in bypass mode this can become an issue if the UPS is plugged in backwards. Given virtual no appliances (certainly no computers I've ever seen) have an issue with which conductor is grounded, or even if one is, I don't think UPSes should worry about it. But apparently some do.
So will a European 220-240 volt UPS work correctly and safely on then American 120+120 split 240 volt system? Try it and let me know.
DC has it's own issues. At 12 volts, you lose a lot in the wiring because the current is higher. At 120 volts you can run incandescent lights directly. But then you have the issue that DC arcs don't stop so easily in things like switch contacts. You have to be sure you have DC rated switches and circuit breakers (most circuit breakers can handle DC, but most light switches are not rated for DC above 12 or 24 volts).
Still, I plan to have some direct DC utilization. There are 48 volt DC power supplies for computers. Gotta power the penguin! And light bulbs are available at some other voltages.
You can also significantly reduce the AC hum while still having AC by using what is called balanced power. Basically that means having two line wires at opposite phases (180 degrees... 120 degrees won't do it). If you have true split single phase in North America (or a few other countries like Japan and Taiwan) at 120/240 volts or similar (100/200 for Japan), you can use the higher voltage directly have not have anywhere near the hum because the grounded neutral won't be carrying current. That does mean you need to run things at 240 volts. Most computers can. Some other things can. For those things that cannot, you could use a 60+60 volt split phase system as long as you be sure that things are not wired to connect the neutral wire to the chassis. You can see some equipment designed to provide that here.
Hey, if you can find a more efficient heating element that can deliver an extra 25% more heat for the same amount of power, I've love to know about it.
My electric hot water heater is inside a closet with extra insulation on the walls of that closet. Yet the closet is hardly any warmer than the rest of the house (maybe 2 degrees at times). The heater's own insulation is keeping the heat in better. One area I could improve this is the long run hot water pipe to the kitchen. My new house design will have a separate hot water tank specifically for the kitchen right behind the sink location. And these will be pre-heated from solar concentrated water heating in the future.
Probably the most efficient way to cook is induction heaters that heat the pan directly. While not much heat is wasted the way I cook now, the residual heat when I'm done certainly is. That's not much concern in the winter when it just adds to the whole house heat. But in the summer, it matters.
Still, I'm aiming for a full power inverter system. One critical reason is to ensure correct circuit breaker operation, and the occaisional peak demands during a family gathering or big party. It just all depends on how much property I can end up getting. And my goal is to be entirely off-grid... no buy, no sell.
I've checked out more than a dozen companies for inverters. The problem with the Outback models is they don't work in series beyond just 2 units. Otherwise it takes a transformer to get the correct voltage system (120/240 split phase) that everything else is designed for. The European models for Europeans works out better because it delivers the exact voltage needed, and can be paralleled to several units. Oddly, it might actually work out better to go with the 230 volt 50 Hz units and just buy 50 Hz stuff where the frequency is important. Another disadvantage of these is they use a lower battery voltage.
Do you know of an inverter that can take 120 volts or 240 volts DC input and produce a split single phase 120/240 volt 60 Hz sine wave AC output with a 30 kW / 40 kVA (power factor 0.75) rating?
The "box" is more about a means to describe the construction. Perhaps no real box would be used. Or someone can just experiement with it using a cardboard box. Personally, I'd go with the linear collector with a combination of solar cells in front and water to be heated behind. That would let me avoid changing tilt during the day. In northern climates, they can probably leave it permanently tilted at the optimum winter elevation (low) to maximize power for heating systems. In southern climates, they can probably leave it permanently tilted at the optimum summer elevation (high) to maximum power for cooling systems. Otherwise seasonal tilt adjustments might be all that is needed.
The water heat collector is for those who are doing direct heating of water anyway. If you'd rather heat your water from an electric tank heater indoors, and expand the photovoltaic collectors to accomodate that extra load, by my guest.
These concentrating lenses do not need to be very complex at all. In fact they don't even need spherical curvature at all. What they need are angles. That effectively makes a crude, but adequate, Fresnel lens. With flat surfaces, they are also cheaper to make.
The original Fresnel lens design for lighthouses needed to work with a very small focal point, the light source, and beam that light very straight. Thus it needed that spherical curvature. Even in its varies steps or layers, that sperical curvature still exists. Solar cells, however, do not need this.
Suppose you have a small solar cell module that measures 10cm x 10cm. Place it at the center of the back of a larger 50cm x 50cm box with the front aimed directly at the sun. Over the front of the box place a 5x5 grid of 25 openings, each the size of the solar cell. In the center, only a flat piece of plastic is needed. Outward from the center, a piece of plastic that is angled like a thin prism would be placed to bend the light at the necessary angle to hit the solar cell at the back. You'll have to figure out the right angle based on how deep the box is. But you will only need to have just a few different kinds of angles to complete the construction and concentrate almost 25 times the light onto the solar cell. Solar cells even operate more efficiently on concentrated light levels.
The box will need to track the sun to keep the various angled beams focused on the solar cell.
An alternative design is a box that is wider in one dimension and has open sides in the other. Stack multiple boxes with the wider dimension vertical so their open sides mate with each other. Tilt the stack to the angle of the sun's path and aim it for about the noon sun position. Then the morning and afternoon sun will be at an angle that lens light from one of these narrow boxes go through the mated openings and hit the solar cells of the adjacent box. You only lose what would be at the ends but you don't have to set up a steering mechanism.
Variations of these designs use mirrors instead of lenses to concentrate light. I personally favor the mirror designs using non-imaging reflective topologies. The same methods are also used for water heating.
Also consider using a water heat collector behind the solar cells. They do get hot (they aren't 100% efficient, so the energy is wasted somewhere).
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And the finger is now aimed at the incompetent Boston city officials. Expect many copies of these things to be made. They'll show up at people's homes and in cars. The whole city will be in a panic for months while the rest of the country laughs.
The terrorist's handbook is probably being re-written as you read this. Remember, their goal isn't actually to kill people so much as it is to create the panic that you might be killed. The ensuing panic causes far more economic damage than the loss of lives does. And incompetent government officials like those in Boston just play right into it. Now the terrorists know an all new way to create panic, thanks to the Boston Police.
If I lived in Boston, maybe I'd have already been aware of a long history of incompetence on the part of city officials there. If I was going to do something like this, it might help to know that the city overreacts to everything they see that blinks or has a wire. But normal people won't expect such stupidity. Remember, it was only in Boston that the overreaction happened. These things showed up in other cities without the effect.
I don't live in Boston and I find this both amusing and disgusting. But, if I did live in Boston I would have found it to be terribly embarassing. It's a shame on the city.
What makes you think Ted called this in?
So your city has a long history of overreaction and incompetence?
It's a frigging blinking sign! Thinking that is a bomb is just too far out there. Someone was just pissed that the sign was flipping the bird and chose to escalate it and made the false claim.
The only fine that is justified here is for the trespassing and vandalism. Nothing more than that should be paid. Let the idiots who decided this was a hoax (it was NOT a hoax) and the idiots that decided it was a bomb (it was NOT a bomb and didn't even look anywhere near like a bomb ... as determined by officials in some other cities like Seattle) pay the fine. Or better yet, let them lose their jobs so people can come visit Boston some day in the future knowing that the city isn't going to overreact.
Sorry, but your city administrators are idiots. Plain and simple INCOMPETENT idiots. They cannot tell a light sign from a bomb and go off and panic at everything that blinks. These things showed up in other cities, including Seattle, and there was no such panic. It's a BOSTON issue, and maybe even a state-wide issue, too, given that your idiot governor is overreacting, too.
They showed one of these on TV (ABC) this morning. Anyone that thinks that is a bomb is just plain looney.
A crime here? Sure ... trespassing ... vandalism ... nothing more than that.
But I sure as hell will avoid conducting business in Boston for the next couple years until you guys get this mess straighten out and get some people running the city that know WTF they are doing.
Even electronic ballast controlled (C)FL flicker at 120 Hz. This is because the voltage drops and crosses zero 120 times a second. The ballast is gating the circuit on and off at some rate, using either pulse width modulation or pulse density modulation. But at times (120 times a second) there's not enough voltage to make it light up. Hence you have flicker.
Of course you could add a bridge rectifier to isolate the polarity and some big capacitors to smooth it out enough. But this is $15 to $20 more cost. This kind can be had, but the market premium is more like $35. So in reality, most electronic ballasts are the cheap type that don't eliminate the flicker (but they do eliminate that annoying buzz).
Also, color index is not the only factor affecting color. That tells you if the primary components are in reasonable balance. But it doesn't tell you if the spectrum is continuous enough to enable non-stressful focus. This is hardly ever measured, anyway.
Fluorescent lights do make it easier to produce a uniform light coverage over a table. If you're not working there continuously (the time varies by person depending on various issues with their vision ... about 30 minutes for me) they are fine. The color index is good. The color continuity sucks. And the flicker sucks. For me it's the color continuity that affects me before the flicker, though the flicker eventually will, anyway.
I'm all for saving energy. But there are a few places, basically longer term task lighted areas, that I do need the incandescent lights and will do whatever it takes make sure I have them. I do use (C)FL lights in a lot of places. But my workshop, kitchen, and the reading lamp in the living room ... those stay incandescent (low voltage halogen is the way to go for these, which is a little more efficient than ordinary incandescent). Fluorescent simply doesn't cut it there (I do have FL in the kitchen, along with incandescent, but I just can't use the FL for very long).
BTW, I'm not super-human. Just don't assume that what you can't see can't be seen by anyone.
So, what will YOU do when you find that your hard drive dies, and you have to replace it ... or maybe just have to upgrade the hard drive to a larger one because Vista is even more bloated than XP ... and your old XP disk which you haven't had any need for in the few months since switching to Vista is now unreadable because it has too many scratches?
Ironically, the motivation that got me to start looking at solar, wind, and other off-grid power sources was specifically wanting to disconnect from the grid for reasons of safety. Did you know that the neutral of the primary circuit of the transformer feeding your home is connected to the neutral of the secondary circuit that is connected to your home? Did you know that there is a significant voltage drop between that transformer and the substation that feeds it (which is why they run at voltages of 7200 and higher so that the drop is not a significant portion and won't affect the final voltage very much)? Did you know that some of that neutral return current actually runs down through the neutral to your home, and through the ground rods? Did you know that most power companies do little or no maintenance on their own ground connections at each transformer, resulting in more of that return current going through your ground rod instead? Did you know that a break in the neutral wire along the primary distribution can go undetected, but result in your home being raised in voltage relative to the overall ground between there and the substation of hundreds, maybe even a few thousand, volts? You won't notice it much if it does happen because all the ground around your home would be raised in voltage as well. But it will do things like cause premature corrosion in your ground rods and any metal water piping. It can also cause voltage spikes in cable TV and telephone service, even if they are correctly grounded. You would notice it if you clamp an ampmeter around the ground wire going to the ground rod and see the current level, or disconnect the ground rod and see a spark.
In most cases these problems are not actually ongoing. They are somewhat rare. But when they do happen, the power company absolutely will deny it and do nothing at all on their end to fix it, even though in almost all cases it is their fault. If you want to find out more, Google for "stray current" or "stray voltage" and look closely at what various farm operators have found.
Getting off the grid means to me that I don't have to deal with their crap anymore. It's not about saving money or being "green". It's not about having power when the grid goes down (which is more likely to happen because the power companies are wasting millions of dollars investing in a doomed "broadband over power line" technology instead of in making a more reliable and better maintained grid). It's about cutting the umbilical from corporations that try to get away with anything and everything they can (and usually succeed).
That's not to say there aren't some well run utilities. I've heard of a small few that are. But most are not. You can find them easily: they are the big ones.
So I'll be looking at solar power, wind power, and even waterfall power, depending on where I end up when I finally get around to doing this. While being "green" is better, I'll also not exclude carbon based energy sources. Sure, I'll prefer more quickly renewable carbon energy sources over those that are not (e.g. burning tree corpses for heat is better than burning dinosaur grease for heat because the former makes way for replacements to suck carbon back out of the air in the near future). And I'll find ways to reduce energy needs so I can do this with a smaller system and hopefully even be entirely carbon-free. But it's more about the independence than about the money (though that being in short supply means I can't ignore it).
They should just implement some kind of gun control. Yeah, that's the ticket; keep guns out of the hands of kids. Oh wait ...
How about including in this design the single voltage power supply design that Google wants? You can read the original Slashdot discussion here.
DRM would need to allow:
Anyone can publish any content on that type of media, in any format/resolution (extreme examples being video at 2160p60, or 32 bit audio at 384kHz sample rate). All players, recorders, software, or other devices, that can deal with that format/resolution shall do so whether DRM-ed or not. If not DRM-ed, then no copy restrictions exist. There also needs to be a way within the context of DRM to specify that no copy restrictions exist (which sounds kind of pointless but might have verification value).
The DRM must be designed so that an open source operating system (such as BSD or Linux) can act as a gateway between the recorded media or network feed source, and a device that integrates the DRM. For example, instead of having DRM in software, with all the headaches of protecting that software, the DRM could be put in the video card or the display monitor, or in the sound card, or in an external box. Then the software is doing little more than shuffling data between media/feed and the device. For this to be useful, the DRM-ed data stream must be structured so that the frame boundaries and index are NOT encrypted. This allows things like partial rewind in the software before any DRM decryption even needs to take place. An A/V program would be divided into chunks per frame or at least group of frames, with clear index headers as needed, and the rest of the content of that block encrypted. Then very basic software (not needing a bunch of codecs or plug-ins) is all you need since the device (video card, monitor, or external USB/Firewire/Ethernet connected device) can do the real work.
It's Wednesday. The link to the PDF is still dead (connection refused). Maybe this article should be titled "Slashdot may be considered harmful (to weak web servers)".
So what makes it high voltage conduit? Does it have "high voltage" stamped on it? Is there a particular color code for high voltage? Why didn't they just get low voltage conduit in the first place?
But that's going to require a disk with 100 to 300 GB of data. Well, for movies I'll settle for the frame rate being exactly what the original film was shot at and let my display up-scan it to some integral multiple over 60 Hz. of course this means I'm going to have to find a display that good at a decent price.
Sure, 720p and 1080i are a good notch above 480i. But it's not that good that I would be willing to buy into an HD media format for higher than what DVD costs today. When the HD media format gets down to this price, then why not. But until then, it's just not really worth it.
But a 25 GB optical disk would be nice to hold a kick ass Linux distribution and a whole lot of music.
... here.
That seems like a real possibility. Maybe a flywheel ride-through system on top of the inverters could do it.
When the extended family is gathering for holiday feasts, it is in fact quite typical to have every burner and every oven running, possibly longer than 3-4 hours. That and the microwave will be used to re-heat some things that were cooked at the earlier time frame. All this while a crock pot is running (current one is 1200 watts, but I've seen them up to 3000 watts).
These peak loads don't happen often ... maybe 3 times a year. But they are important.
The system plans include a huge battery array. Power sources will include both photovoltaic and windmill, as the system grows and expands. If I can find a property with elevation change and a creek going downhill, I might even have some hydroelectric as well. Some power can be generated at night, sometimes. When none is, there's the batteries. I might even do hydrogen storage.
Certainly some things can use DC directly. My water heater has a mechanical thermostat with a two pole contact. It runs at 240 volts. Unless the contact can't break 18.75 amps of current at 240 volts of DC, it should work. But do keep in mind that contacts do need to be rated specifically for DC at that voltage to be safe. Apparently they will need at least 1cm of gap to break that much voltage, maybe more.
But I would aim to get hot water from the solar system, and finalize the heating in a big storage tank with less electric power used there, so a smaller water heater might make sense.
The cooking stove in the kitchen is probably the big thing. And they are not just heating elements. There is control circuitry and power supplies to drive it. Will they work on DC? Quite possibly not.
As for the power level. The solar panel array does not need to be as large as the peak load. The battery capacity needs to be able to at least deliver it, and hold it for a sufficient period of time under load. The solar array can be charging batteries all the time at their peak capability based on how much sun they are getting. I'm usually only cooking for an hour or two.
Most inverters want DC voltages other than 120 or 240 volts. For example the Xantrex 5500 watt inverters want 48 volts. To use DC directly means getting things designed specifically for 48 volts. I won't necessarily have the independent power system up when the new house can be moved in to, and it may be powered temporarily by a generator or the grid. I might need to start with 120/240 volt AC appliances.
Sure, using efficient appliances is always a good idea, either way. But I need to have a common voltage. If I'm going to run much directly on DC, it will need to be the same voltage as the AC, and I will thus need to configure the battery array that way, and run the inverters that way. Which shall it be? 48 volts? 96 volts? 120 volts? 192 volts? 240 volts?
The scenario is not insane at all. It is in fact quite realistic. The ideal inverter would operate on 240 volts DC and produce 120/240 volts AC, thus allowing me to configure the battery array as a 120/240 volt split system (that would make Thomas Edison smile). Then I can run a few things directly on DC.
Another option is to split the batteries into two different arrays, one at the voltage the inverters want, and the other at direct utilization voltage. That might even be practical with a cross-voltage charge converter than can charge one set from the other should one of them be overdrained. But otherwise it is capacity fragmentation.
As for running a stove on natural gas or propane ... only if you know of a means to produce natural gas or propane directly from a renewable energy source. One of my goals in this project is to significantly reduce or better entirely eliminate use of fossil fuels. And that means even if I have a gas or oil deposit underneath my property, it won't be used.
That would be for a 120+120 split single phase system powering European 220-240 volt appliances. For the most part that is true about European appliances. But there are some exceptions. Some UPSes insist on a specific conductor being the grounded one, and will shut down safely if plugged in backwards. The instructions say to reverse the plug. Apparently the intent is that the output uses a polarized socket (e.g. for C13) that needs to have a grounded conductor specifically positioned for some reason (not sure why) and at least in bypass mode this can become an issue if the UPS is plugged in backwards. Given virtual no appliances (certainly no computers I've ever seen) have an issue with which conductor is grounded, or even if one is, I don't think UPSes should worry about it. But apparently some do.
So will a European 220-240 volt UPS work correctly and safely on then American 120+120 split 240 volt system? Try it and let me know.
DC has it's own issues. At 12 volts, you lose a lot in the wiring because the current is higher. At 120 volts you can run incandescent lights directly. But then you have the issue that DC arcs don't stop so easily in things like switch contacts. You have to be sure you have DC rated switches and circuit breakers (most circuit breakers can handle DC, but most light switches are not rated for DC above 12 or 24 volts).
Still, I plan to have some direct DC utilization. There are 48 volt DC power supplies for computers. Gotta power the penguin! And light bulbs are available at some other voltages.
You can also significantly reduce the AC hum while still having AC by using what is called balanced power. Basically that means having two line wires at opposite phases (180 degrees ... 120 degrees won't do it). If you have true split single phase in North America (or a few other countries like Japan and Taiwan) at 120/240 volts or similar (100/200 for Japan), you can use the higher voltage directly have not have anywhere near the hum because the grounded neutral won't be carrying current. That does mean you need to run things at 240 volts. Most computers can. Some other things can. For those things that cannot, you could use a 60+60 volt split phase system as long as you be sure that things are not wired to connect the neutral wire to the chassis. You can see some equipment designed to provide that here.
Hey, if you can find a more efficient heating element that can deliver an extra 25% more heat for the same amount of power, I've love to know about it.
My electric hot water heater is inside a closet with extra insulation on the walls of that closet. Yet the closet is hardly any warmer than the rest of the house (maybe 2 degrees at times). The heater's own insulation is keeping the heat in better. One area I could improve this is the long run hot water pipe to the kitchen. My new house design will have a separate hot water tank specifically for the kitchen right behind the sink location. And these will be pre-heated from solar concentrated water heating in the future.
Probably the most efficient way to cook is induction heaters that heat the pan directly. While not much heat is wasted the way I cook now, the residual heat when I'm done certainly is. That's not much concern in the winter when it just adds to the whole house heat. But in the summer, it matters.
Still, I'm aiming for a full power inverter system. One critical reason is to ensure correct circuit breaker operation, and the occaisional peak demands during a family gathering or big party. It just all depends on how much property I can end up getting. And my goal is to be entirely off-grid ... no buy, no sell.
I've checked out more than a dozen companies for inverters. The problem with the Outback models is they don't work in series beyond just 2 units. Otherwise it takes a transformer to get the correct voltage system (120/240 split phase) that everything else is designed for. The European models for Europeans works out better because it delivers the exact voltage needed, and can be paralleled to several units. Oddly, it might actually work out better to go with the 230 volt 50 Hz units and just buy 50 Hz stuff where the frequency is important. Another disadvantage of these is they use a lower battery voltage.
Do you know of an inverter that can take 120 volts or 240 volts DC input and produce a split single phase 120/240 volt 60 Hz sine wave AC output with a 30 kW / 40 kVA (power factor 0.75) rating?
The "box" is more about a means to describe the construction. Perhaps no real box would be used. Or someone can just experiement with it using a cardboard box. Personally, I'd go with the linear collector with a combination of solar cells in front and water to be heated behind. That would let me avoid changing tilt during the day. In northern climates, they can probably leave it permanently tilted at the optimum winter elevation (low) to maximize power for heating systems. In southern climates, they can probably leave it permanently tilted at the optimum summer elevation (high) to maximum power for cooling systems. Otherwise seasonal tilt adjustments might be all that is needed.
The water heat collector is for those who are doing direct heating of water anyway. If you'd rather heat your water from an electric tank heater indoors, and expand the photovoltaic collectors to accomodate that extra load, by my guest.
These concentrating lenses do not need to be very complex at all. In fact they don't even need spherical curvature at all. What they need are angles. That effectively makes a crude, but adequate, Fresnel lens. With flat surfaces, they are also cheaper to make.
The original Fresnel lens design for lighthouses needed to work with a very small focal point, the light source, and beam that light very straight. Thus it needed that spherical curvature. Even in its varies steps or layers, that sperical curvature still exists. Solar cells, however, do not need this.
Suppose you have a small solar cell module that measures 10cm x 10cm. Place it at the center of the back of a larger 50cm x 50cm box with the front aimed directly at the sun. Over the front of the box place a 5x5 grid of 25 openings, each the size of the solar cell. In the center, only a flat piece of plastic is needed. Outward from the center, a piece of plastic that is angled like a thin prism would be placed to bend the light at the necessary angle to hit the solar cell at the back. You'll have to figure out the right angle based on how deep the box is. But you will only need to have just a few different kinds of angles to complete the construction and concentrate almost 25 times the light onto the solar cell. Solar cells even operate more efficiently on concentrated light levels.
The box will need to track the sun to keep the various angled beams focused on the solar cell.
An alternative design is a box that is wider in one dimension and has open sides in the other. Stack multiple boxes with the wider dimension vertical so their open sides mate with each other. Tilt the stack to the angle of the sun's path and aim it for about the noon sun position. Then the morning and afternoon sun will be at an angle that lens light from one of these narrow boxes go through the mated openings and hit the solar cells of the adjacent box. You only lose what would be at the ends but you don't have to set up a steering mechanism.
Variations of these designs use mirrors instead of lenses to concentrate light. I personally favor the mirror designs using non-imaging reflective topologies. The same methods are also used for water heating.
Also consider using a water heat collector behind the solar cells. They do get hot (they aren't 100% efficient, so the energy is wasted somewhere).