The embedded microprocessor came to the fore at the same time as the gadgets on the list, yet it gets no respect from PC Magazine. In particular, that embedded controller known as the "ECU" has caused dramatic improvements in automotive fuel consumption and tailpipe emissions, and automatically adapts to maintain that performance for years between tune-ups. That's an important innovation in my book.
Is PC Magazine more impressed by chrome than by what's under the hood?
Ability to use the same USB device with either a low power notebook computer or a desktop system is what USB is all about, and a strong case against powered USB. The deliberately low power limit is what makes USB universal: the peripherals work on any system, big or small, battery powered or cord connected.
There are also cable design issues with increased current levels. The wires must not over-heat or lose too much voltage from the conductor resistance. The USB cable connected to the system at my right has 28AWG and 30AWG conductors in it: 500mA is about all it's good for. Higher current means fatter wires, higher prices, and less flexibility (in more than one sense). That works against a big advantage of USB: the cables are much more manageable and more portable than the fat RS-232 and parallel printer cables they replaced. Shorting out a USB cable is not a significant fire hazard because the circuit protector will trip before much heat can be generated. 50W protection for "limited energy" circuits, though legal in most countries, is high enough that fire safety cannot be taken for granted. All of these problems are solvable, but all the solutions hurt the low cost, simplicity, and convenience that made USB so popular.
In other words, use the right tool for the job. Low power portable? USB. Medium power desktop? Firewire. Remote power for a network? Power over Ethernet. One size does not fit all.
That attitude from the IRS is irritating! The only way to use E-file is to pay one of the commercial outfits, sometimes in addition to their regular fee for tax software or tax preparation services. The the IRS sends nice reminders to "use e-File", which amounts to commercial advertising at public expense. I'll use a couple of stamps to file, not a credit card.
For an example of on-line filing designed for the taxpayer instead of the tax preparation industry, look here. Unlike e-File, this system is easy, fast, and free. If you pay Colorado taxes, there's no reason to pay for state tax software. A decent web browser is all you need!
Spread out the $12.5M and 4200 hours across all 1653 stations that they own, and it comes to less than $10,00 and three hours of air time each. It's a slap on the wrist, which is what usually happens with "We didn't do anything wrong, and promise we'll never do it again" consent decrees. It sounds like a lot until you consider the size of the companies involved here.
I used Kill-a-Watt power tester, which can test for a number of things - I used raw amps.
That added a hidden variable to the results, namely power factor (PF = Watts/(Volts*Amps)). Better grade power supplies often have better power factor as well as better efficiency, because they use a power factor correction stage at the input instead of the simple rectifier-capacitor input section found on cheaper models. Any PSU with a "CE" mark should have a decent power factor because it's required to comply with the EN61000-3-2 standard.
The excess current of a low PF power supply doesn't represent a total power loss in the computer, it's mostly harmonic distortion caused by the peak-charging diode-capacitor input section. That distortion does increase power loss in the wiring etc., but not as much as the Volts x Amps product suggests. You can use the W or kWhr function on your Kill-A-Watt meter to get more accurate results.
The author says he found voltage when measuring it with a multimeter: a high impedance tool, which barely loads the circuit. The results from different tests have been inconsistent. Grounding the adapter makes the voltage go away. All this suggests the available current is low, and there may be no genuine hazard from the power adapter.
The adapter is a switch-mode power supply, which doubles as a radio jammer unless care is taken to control the noise on the input and output wires. The first line of defense is bypass capacitors: some from input to ground, some from output to ground. The value of the capacitors is kept low enough that the power line leakage current is considered non-hazardous: 3500uA maximum if there is a reliable safety ground connection, or 500uA if there is not a reliable ground. Also, capacitors connected to the AC line are required to have special safety testing and approval for that application (a class "Y" safety capacitor). So, it is entirely possible to have detectable voltage and current on the laptop's side of the power adapter if there is no ground connection: from the AC line, through safety-rated capaciors, to an ungrounded RF "return" in the adapter, through the output RF bypass capacitors, and into the low voltage leads. Connecting a ground wire to the RF return provides a much lower impedance than the output bypass capacitors, which reduces the leakage current and capacitivly coupled current essentially to zero. But the adapter with no ground can still be safe, and comply with CSA/EN/UL standard 60950, provided the leakage current is low enough and appropriate safety-approved capacitors are installed (giving "double insulation" or "reinforced insulation" between the AC line and the DC output).
This is the same reason you may see a tiny spark or feel a tingle in your fingers when you hook up a TV set (most have no ground wire) to the TV cable (which must be grounded, per the electrical Code). If the author had measured excessive leakage current at the laptop, or showed that the adapter was not properly insulated, or that it lacked safety agency approval marks, or that it had defective safety insulation--then he would have a case, and should take it up with somebody who can do something about it: the CPSC and Dell.
That's a good point, and one that is likely to make these devices a market failure. They will have a hard time meeting the EPA's charger efficiency standards. Manufacturers are working hard to meet these levels without the additional loss in the split transformer. Failing to meet these "voluntary" standard locks you out of federal contracts, and the general market in places where efficiency standards are mandatory (California).
That's a bit unfair, as it's an extremely power-optimized system, but it shows what can be achieved.
I wouldn't call it unfair at all. The laptop power budget shows what can be achieved today, with affordable technology that meets the majority of PC users' needs. No, it's not enough performance for high-end gaming, 3D CAD modeling, FEA, or server duty (applications that always expand to the limits of available hardware). But it supports the browser, media player, email client, and office suite that meet the needs of most customers. Desktop systems can certainly be built with laptop technology to reduce their power usage. The question is whether people would buy more energy efficient desktop systems. Today's product offerings show that the major manufacturers don't see a market for more efficient desktop systems. Everybody sells high-powered SUVs, no major maker offers hybrid sedans.
Qualcomm's Eudora has had "mood watch" for a long time. The hotter the flame inside, the more chili peppers the message earns. This seems to be significant prior art.
The math isn't terribly hard. If both vehicles decelerate at the same rate, and are traveling at the same speed, then you must apply the brakes before the front of your vehicle reaches the point where the rear of the vehicle ahead was when its driver applied the brakes. Until you apply the brakes you continue at the original speed, and cover distance=velocity*time. That is where the fixed time gap rule comes from.
What does complicate the issue is whether the vehicle in front has better deceleration than you do. If you're in a big SUV with "light truck" tires, you have worse than average braking ability and need more than average following distance to avoid rear-end collisions.
Another complication is that brake lights don't tell you if the driver ahead is making a minor speed correction or is braking hard because of something you can't see. There's not just one reaction, but at least two: one to see the brake lights and put your foot on the brake pedal, and another to recognize the car ahead is braking aggressively and you need to push hard on the pedal. Leaving enough time for the first reaction but not another causes the "accordion effect" in a line of heavy traffic, where a slight tap on the brake becomes a panic stop for those following several cars behind.
Watching traffic beyond of the car in front of you helps you avoid this problem, but with the larger vehicles and dark tinted windows on the road these days it's becoming less and less practical as a defensive driving tactic. The accordion effect also makes flashing the brake lights for a tailgater a poor idea in heavy-but-moving traffic: you're causing more trouble for cars further back than for the tailgater behind you, as well as irritating the driver on your bumper. It's better to ease off the throttle just a little bit, encouraging them to go around you, and also giving you extra leeway so that both you and the tailgater can brake safely should the need arise.
Likewise, be careful when following a tailgater: they have to brake more abruptly than the car ahead, and you must avoid hitting them (without being hit by the car behind you). If you hit the rear of a tailgater who locked up the brakes, guess who's getting the traffic fine, license penalty points, and higher insurance premiums?
Aspirin is aspirin, for example, but there is Bayer who will sue the crap out of you if you don't pay them for making and distributing it.
A century ago that may have been true, but the patent on acetylsalicylic acid expired in 1917 and the trademark "Aspirin" was ruled to be a generic name a few years later. The history of aspirin, from Hippocrates' use of willow bark, through its chemical synthesis in the late 19th century, to the competing claims for that invention, shows that problems with prior art and and originality are nothing new!
If someone is touting Viagra, get in touch with the highest marketing authority you can at Pfizer.
Reality check time. Do you think the spammers are authorized distributors for Pfizer, that Pfizer deals with them and has some control over them? Or is it more likely the pills were stolen, or remanufactured with more filler and less active ingredient, if not outright fakes with no real medication at all? Are any watches sold via spam ever a genuine Rolex, not a cheesy Fauxlex? Spammers are unscrupulous, spammers are con artists, spammers are anything but legitimate businesses. That's why conventional controls don't work against them.
I'm with you on this! Most bike lanes seem to be designed by folks who think all bikes have training wheels and move slower than the average jogger. These glorified sidewalks have many dangerous "features":
-Limited or no visibility at driveways and alleys, where buildings and parked cars obstruct sight lines for both drivers and cyclists
-Narrow lanes that leave no room for steering errors, or to avoid litter, broken glass, and other obstacles
-Speed limits on straight, level pavement that require using a mountain-climbing "granny gear"
-Cyclists must pass to the inside of turning traffic, going from the driver's blind spot straight into the car's path
-Utility poles, garbage cans, decorative planters, news rack, mail boxes, and other fixed objects to collide with (all banished to the sidewalk because they would endanger drivers surrounded by a ton of steel!)
-Maintenance? What maintenance?
It's ironic that in most US cities bicycles are forbidden on sidewalks. But overnight, the city council can order a painted stripe and some "bikeway" signs forcing cyclists onto the same dangerous strip of concrete they were banned from the day before. It's a meaningless political gesture ("See what a bike-friendly city we are!") that wastes money while doing nothing for cycling safety. Unless, perhaps, discouraging cyclists is the goal of the safety program.
Batteries are far more than 10% efficient! Charge efficiency (Coulombs discharge / Coulombs recharge) is 80%-90%, and voltage efficiency (Volts discharge / Volts recharge) is about 90%. In round numbers, you get 70%-80% efficiency from the battery. Unless you leave it lying around so long that it self-discharges, which is unlikely for an EV.
It really needs to be operating on an ISM frequency. Otherwise, the power level would have to be extremely low to comply with the interference regulations.
Even ignoring the interference cap, coupling useful amounts of power at several meters separation means the Q of the resonators would have to be extremely high. With the EPA efficiency standards for rechargers, this seems to be a poor time to introduce any product that wastes even a little power.
Larimer County offered voters a choice between optically scanned paper ballots and Diebold touch-screen systems. Based on a small, highly unscientific sample (those present when and where I voted), signs point to a landslide victory for paper and ink. The twenty or so paper ballot booths were filled to capacity, but the handful of touchscreen booths were mostly vacant. This was likely influenced by the HBO documentary, as well as the touch screen booths having no privacy curtains so that the screens were in plain view to others.
Things did move reasonably smoothly, unlike the fiasco in Denver blamed on the consolidation of precincts into "vote centers", newly revised ID requirements for voters, new registration verification software, voting machine failures, and power failures. The voting machines were on UPS, but registration list PCs were not!
"Any time you have new technology you have challenges," Mayor John Hickenlooper said, at midday, just before the system began experiencing even wider outages. "We've got dozens of city employees out volunteering asking people if they want a lift to a vote center with a shorter line." Hickenlooper conceded the situation "is not good."
Low power intentional radiators are not tested by the FCC. They are "certificated" based on tests performed by the manufacturer or an independent test laboratory. Part 2 [pdf, 1.2MB] of the FCC regulations explains the procedure. The FCC accepts the manufacturers' test data unless they have good reason to doubt it, though the FCC can demand to inspect the equipment, test reports, etc. at any time. They aren't likely to do that unless there are interference complaints, and that's what NPR and NAB are doing: complaining the FM modulators have excessively high output and cause interference to licensed stations.
Another possibility you didn't mention is deliberate design changes in the FM modulators. With most consumer product manufacturing outsourced to the lowest bidder, there's a good chance that changes (cost reductions) will occur without the knowledge of the company whose name is on the label. But they're the ones ultimately responsible for compliance to the FCC rules and the ones who will pay the fines for any violations.
A point that's been missing is how the sellers of fake equipment take advantage of legitimate buyers and sellers. Here I'm talking about those who sell counterfeits as the real thing, at normal prices--not shady too-good-to-be-true deals.
They don't provide any customer support.
They don't cover the warranty returns.
The buyer of the fake model calls the legitimate supplier, and one of two things happens. The customer may get support from them, because either the supplier doesn't know the item is fake or wants to maintain customer goodwill. Here the counterfeiter has passed on a substantial business cost to the legimate supplier. The other case is when the supplier recognizes the fakes as such and refuses to support them. This time the bogus supplier has robbed the customers of the support and warranty coverage they paid for. This is no trivial matter: for high-volume items production costs are a fraction of the wholesale price.
With discounts for off-peak electricity, this sort of system could pay for itself while providing backup generator services as a side effect. Then again, so would...a bunch of batteries.
It takes a big peak-power premium to offset the price of the batteries and system losses. For example, consider a 12V 100 Ahr deep-cycle, flooded cell lead acid battery (the most economical choice, so we'll accept its maintenance requirements, weight, etc.). You can get perhaps 400 deep cycles out of it, or about 1000 cycles to 50% discharge. 12V x 100Ahr x 50% x 1000 cycles = 600kWhr lifetime energy capacity. With a 95% efficient charge and discharge system and 85% efficiency for the battery itself you'll pay for an extra 140kWhr over the life of the battery, so at $0.07/kWhr (off peak) add another $10.00 to the purchase price. If you can get a good battery for $60, that's $70 extra you paid for the 600 kWhr: close to $0.12 per kWhr premium. If the utility's peak price premium is less than that, you're losing money even before amortizing all the other equipment you'll need. Store power for emergency backup, store power when it's not available from the utility--but don't expect to save money in the process. It's the same as electric car economics: it's not the cost of the electricity, the challenges lie in storing it in a portable, affordable, safe way.
What good is a UPS going to do in the case the machine powers off because of a problem with the power unit, a motherboard short circuit, and so on?
The UPS covers the power line problems, which are the leading cause of system outages. To protect against the less frequent hardware failures you need properly engineered redundancy for every critical component. That's why "enterprise-class" data storage costs so much more per GB than the disk drives on sale at retail store. An alternative is to not use any write-behind caching. The performance loss varies, depending on the write/read ratio. The average desktop system doesn't gain much performance from write caching, because the most time consuming disk activity is loading multi-megabyte executables and existing data files, not writing and updating files. That also means they're at less risk in any case, because there is less unwritten data in the cache to cause problems. An online transaction system, on the other hand, does continuous file updates and little application loading. These need professional quality hardware (and software!) to deliver the expected level of reliability.
Estimate storage system voltage = 600 Vdc (optimistic, 400 Vdc is more likely)
Charging current: 982kW / 600 V = 1.64 kA (that's one serious cord and connector!)
Assume 480V three phase power
Assume an ideal charger: 100% efficiency and 1.00 power factor
982 kW / 480 Vac / sqrt(3) = 1.18 kA per phase input current
If you add a "two pump" recharge island at each filling station in town, that's a huge impact on the power grid. We aren't talking about off-peak usage here, this is day time demand that strains generation capacity. It's an interesting technology, but has the same shortcomings as any extreme-rate recharge scheme. Adding large, variable loading to the power grid at peak hours won't help establish a viable EV market. As high density energy storage for a hybrid car--there it has potential. As storage for an overnight-recharge EV--there too it holds promise, if it performs as well as they claim. But with 500 mile range, there's little benefit compared to the high costs of extreme rate charging.
There will be an ascent Saturday in Northern Colorado. This one is planned to reach "only" 70,000 feet (21km); others by this group have reached over 100,000. Listen for it if you're in UHF radio range.
The problem with "Johnny can't code" is elsewhere. Johny does not have the stimulus to code. At all. In most households he is introduced at an early age to the computer as a toy and treats it as a toy...
Quite right! So what should we do about it? Do your kids see you programming? If so, do you tell them what you're doing, and try to explain how it works in words they can understand? Did you help them get through their first void main () { puts ("Hello, world!\n");/* We don't say "big ***s" around little tykes! */ exit (); } ? Show your children that computers are more than a fancy DVD player/video game/net connection. If you don't, who will?
Grinding gears, running on fumes: automotive analogies, how appropriate! Vista is XP with restyled tail fins, more chrome, and some new hardware under the hood. Most people can get along just fine with their old model, but others simply must have the lastest version before the Jones buy it. If you're in the market for a new PC you really have no choice: the dealers don't carry last year's model any more. Oh yes, the price went up again.
Planned obsolesence: it's how to keep the revenue flowing in a saturated market.
"because they can't make as many assumptions as a programmer who knows what's going on..." That's true. Of course, the next developer/maintainer who works on that code, or needs it to interface with it, or (heaven forbid!) re-uses it in another project won't know about all your assumptions, either. Whether you're engineering hardware or software, there's such as thing as trying to be too clever. It may seem easy today, but someday somebody will curse you while trying to find what has gone wrong. Think about how you feel when you find that long-gone developers not only made assumptions, but didn't describe exactly what they were, why they made them, and what's necessary for them to be valid.// and/* are your best allies when the new wears off the project!
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The embedded microprocessor came to the fore at the same time as the gadgets on the list, yet it gets no respect from PC Magazine. In particular, that embedded controller known as the "ECU" has caused dramatic improvements in automotive fuel consumption and tailpipe emissions, and automatically adapts to maintain that performance for years between tune-ups. That's an important innovation in my book.
Is PC Magazine more impressed by chrome than by what's under the hood?
Ability to use the same USB device with either a low power notebook computer or a desktop system is what USB is all about, and a strong case against powered USB. The deliberately low power limit is what makes USB universal: the peripherals work on any system, big or small, battery powered or cord connected.
There are also cable design issues with increased current levels. The wires must not over-heat or lose too much voltage from the conductor resistance. The USB cable connected to the system at my right has 28AWG and 30AWG conductors in it: 500mA is about all it's good for. Higher current means fatter wires, higher prices, and less flexibility (in more than one sense). That works against a big advantage of USB: the cables are much more manageable and more portable than the fat RS-232 and parallel printer cables they replaced. Shorting out a USB cable is not a significant fire hazard because the circuit protector will trip before much heat can be generated. 50W protection for "limited energy" circuits, though legal in most countries, is high enough that fire safety cannot be taken for granted. All of these problems are solvable, but all the solutions hurt the low cost, simplicity, and convenience that made USB so popular.
In other words, use the right tool for the job. Low power portable? USB. Medium power desktop? Firewire. Remote power for a network? Power over Ethernet. One size does not fit all.
That attitude from the IRS is irritating! The only way to use E-file is to pay one of the commercial outfits, sometimes in addition to their regular fee for tax software or tax preparation services. The the IRS sends nice reminders to "use e-File", which amounts to commercial advertising at public expense. I'll use a couple of stamps to file, not a credit card.
For an example of on-line filing designed for the taxpayer instead of the tax preparation industry, look here. Unlike e-File, this system is easy, fast, and free. If you pay Colorado taxes, there's no reason to pay for state tax software. A decent web browser is all you need!
Spread out the $12.5M and 4200 hours across all 1653 stations that they own, and it comes to less than $10,00 and three hours of air time each. It's a slap on the wrist, which is what usually happens with "We didn't do anything wrong, and promise we'll never do it again" consent decrees. It sounds like a lot until you consider the size of the companies involved here.
I used Kill-a-Watt power tester, which can test for a number of things - I used raw amps.
That added a hidden variable to the results, namely power factor (PF = Watts/(Volts*Amps)). Better grade power supplies often have better power factor as well as better efficiency, because they use a power factor correction stage at the input instead of the simple rectifier-capacitor input section found on cheaper models. Any PSU with a "CE" mark should have a decent power factor because it's required to comply with the EN61000-3-2 standard.
The excess current of a low PF power supply doesn't represent a total power loss in the computer, it's mostly harmonic distortion caused by the peak-charging diode-capacitor input section. That distortion does increase power loss in the wiring etc., but not as much as the Volts x Amps product suggests. You can use the W or kWhr function on your Kill-A-Watt meter to get more accurate results.
Thanks for posting your results!
The author says he found voltage when measuring it with a multimeter: a high impedance tool, which barely loads the circuit. The results from different tests have been inconsistent. Grounding the adapter makes the voltage go away. All this suggests the available current is low, and there may be no genuine hazard from the power adapter.
The adapter is a switch-mode power supply, which doubles as a radio jammer unless care is taken to control the noise on the input and output wires. The first line of defense is bypass capacitors: some from input to ground, some from output to ground. The value of the capacitors is kept low enough that the power line leakage current is considered non-hazardous: 3500uA maximum if there is a reliable safety ground connection, or 500uA if there is not a reliable ground. Also, capacitors connected to the AC line are required to have special safety testing and approval for that application (a class "Y" safety capacitor). So, it is entirely possible to have detectable voltage and current on the laptop's side of the power adapter if there is no ground connection: from the AC line, through safety-rated capaciors, to an ungrounded RF "return" in the adapter, through the output RF bypass capacitors, and into the low voltage leads. Connecting a ground wire to the RF return provides a much lower impedance than the output bypass capacitors, which reduces the leakage current and capacitivly coupled current essentially to zero. But the adapter with no ground can still be safe, and comply with CSA/EN/UL standard 60950, provided the leakage current is low enough and appropriate safety-approved capacitors are installed (giving "double insulation" or "reinforced insulation" between the AC line and the DC output).
This is the same reason you may see a tiny spark or feel a tingle in your fingers when you hook up a TV set (most have no ground wire) to the TV cable (which must be grounded, per the electrical Code). If the author had measured excessive leakage current at the laptop, or showed that the adapter was not properly insulated, or that it lacked safety agency approval marks, or that it had defective safety insulation--then he would have a case, and should take it up with somebody who can do something about it: the CPSC and Dell.
That's a good point, and one that is likely to make these devices a market failure. They will have a hard time meeting the EPA's charger efficiency standards. Manufacturers are working hard to meet these levels without the additional loss in the split transformer. Failing to meet these "voluntary" standard locks you out of federal contracts, and the general market in places where efficiency standards are mandatory (California).
That's a bit unfair, as it's an extremely power-optimized system, but it shows what can be achieved.
I wouldn't call it unfair at all. The laptop power budget shows what can be achieved today, with affordable technology that meets the majority of PC users' needs. No, it's not enough performance for high-end gaming, 3D CAD modeling, FEA, or server duty (applications that always expand to the limits of available hardware). But it supports the browser, media player, email client, and office suite that meet the needs of most customers. Desktop systems can certainly be built with laptop technology to reduce their power usage. The question is whether people would buy more energy efficient desktop systems. Today's product offerings show that the major manufacturers don't see a market for more efficient desktop systems. Everybody sells high-powered SUVs, no major maker offers hybrid sedans.
Qualcomm's Eudora has had "mood watch" for a long time. The hotter the flame inside, the more chili peppers the message earns. This seems to be significant prior art.
What does complicate the issue is whether the vehicle in front has better deceleration than you do. If you're in a big SUV with "light truck" tires, you have worse than average braking ability and need more than average following distance to avoid rear-end collisions.
Another complication is that brake lights don't tell you if the driver ahead is making a minor speed correction or is braking hard because of something you can't see. There's not just one reaction, but at least two: one to see the brake lights and put your foot on the brake pedal, and another to recognize the car ahead is braking aggressively and you need to push hard on the pedal. Leaving enough time for the first reaction but not another causes the "accordion effect" in a line of heavy traffic, where a slight tap on the brake becomes a panic stop for those following several cars behind.
Watching traffic beyond of the car in front of you helps you avoid this problem, but with the larger vehicles and dark tinted windows on the road these days it's becoming less and less practical as a defensive driving tactic. The accordion effect also makes flashing the brake lights for a tailgater a poor idea in heavy-but-moving traffic: you're causing more trouble for cars further back than for the tailgater behind you, as well as irritating the driver on your bumper. It's better to ease off the throttle just a little bit, encouraging them to go around you, and also giving you extra leeway so that both you and the tailgater can brake safely should the need arise.
Likewise, be careful when following a tailgater: they have to brake more abruptly than the car ahead, and you must avoid hitting them (without being hit by the car behind you). If you hit the rear of a tailgater who locked up the brakes, guess who's getting the traffic fine, license penalty points, and higher insurance premiums?
A century ago that may have been true, but the patent on acetylsalicylic acid expired in 1917 and the trademark "Aspirin" was ruled to be a generic name a few years later. The history of aspirin, from Hippocrates' use of willow bark, through its chemical synthesis in the late 19th century, to the competing claims for that invention, shows that problems with prior art and and originality are nothing new!
Reality check time. Do you think the spammers are authorized distributors for Pfizer, that Pfizer deals with them and has some control over them? Or is it more likely the pills were stolen, or remanufactured with more filler and less active ingredient, if not outright fakes with no real medication at all? Are any watches sold via spam ever a genuine Rolex, not a cheesy Fauxlex? Spammers are unscrupulous, spammers are con artists, spammers are anything but legitimate businesses. That's why conventional controls don't work against them.
-Limited or no visibility at driveways and alleys, where buildings and parked cars obstruct sight lines for both drivers and cyclists
-Narrow lanes that leave no room for steering errors, or to avoid litter, broken glass, and other obstacles
-Speed limits on straight, level pavement that require using a mountain-climbing "granny gear"
-Pedestrians, dogs, roller skaters and other unpredicable living things (all legal at this California web-cam location, but risky never the less)
-Cyclists must pass to the inside of turning traffic, going from the driver's blind spot straight into the car's path
-Utility poles, garbage cans, decorative planters, news rack, mail boxes, and other fixed objects to collide with (all banished to the sidewalk because they would endanger drivers surrounded by a ton of steel!)
-Maintenance? What maintenance?
It's ironic that in most US cities bicycles are forbidden on sidewalks. But overnight, the city council can order a painted stripe and some "bikeway" signs forcing cyclists onto the same dangerous strip of concrete they were banned from the day before. It's a meaningless political gesture ("See what a bike-friendly city we are!") that wastes money while doing nothing for cycling safety. Unless, perhaps, discouraging cyclists is the goal of the safety program.
Batteries are far more than 10% efficient! Charge efficiency (Coulombs discharge / Coulombs recharge) is 80%-90%, and voltage efficiency (Volts discharge / Volts recharge) is about 90%. In round numbers, you get 70%-80% efficiency from the battery. Unless you leave it lying around so long that it self-discharges, which is unlikely for an EV.
Even ignoring the interference cap, coupling useful amounts of power at several meters separation means the Q of the resonators would have to be extremely high. With the EPA efficiency standards for rechargers, this seems to be a poor time to introduce any product that wastes even a little power.
Things did move reasonably smoothly, unlike the fiasco in Denver blamed on the consolidation of precincts into "vote centers", newly revised ID requirements for voters, new registration verification software, voting machine failures, and power failures. The voting machines were on UPS, but registration list PCs were not!
You Denver folks have my sympathy!
Another possibility you didn't mention is deliberate design changes in the FM modulators. With most consumer product manufacturing outsourced to the lowest bidder, there's a good chance that changes (cost reductions) will occur without the knowledge of the company whose name is on the label. But they're the ones ultimately responsible for compliance to the FCC rules and the ones who will pay the fines for any violations.
They don't provide any customer support.
They don't cover the warranty returns.
The buyer of the fake model calls the legitimate supplier, and one of two things happens. The customer may get support from them, because either the supplier doesn't know the item is fake or wants to maintain customer goodwill. Here the counterfeiter has passed on a substantial business cost to the legimate supplier. The other case is when the supplier recognizes the fakes as such and refuses to support them. This time the bogus supplier has robbed the customers of the support and warranty coverage they paid for. This is no trivial matter: for high-volume items production costs are a fraction of the wholesale price.It takes a big peak-power premium to offset the price of the batteries and system losses. For example, consider a 12V 100 Ahr deep-cycle, flooded cell lead acid battery (the most economical choice, so we'll accept its maintenance requirements, weight, etc.). You can get perhaps 400 deep cycles out of it, or about 1000 cycles to 50% discharge. 12V x 100Ahr x 50% x 1000 cycles = 600kWhr lifetime energy capacity. With a 95% efficient charge and discharge system and 85% efficiency for the battery itself you'll pay for an extra 140kWhr over the life of the battery, so at $0.07/kWhr (off peak) add another $10.00 to the purchase price. If you can get a good battery for $60, that's $70 extra you paid for the 600 kWhr: close to $0.12 per kWhr premium. If the utility's peak price premium is less than that, you're losing money even before amortizing all the other equipment you'll need. Store power for emergency backup, store power when it's not available from the utility--but don't expect to save money in the process. It's the same as electric car economics: it's not the cost of the electricity, the challenges lie in storing it in a portable, affordable, safe way.
The UPS covers the power line problems, which are the leading cause of system outages. To protect against the less frequent hardware failures you need properly engineered redundancy for every critical component. That's why "enterprise-class" data storage costs so much more per GB than the disk drives on sale at retail store. An alternative is to not use any write-behind caching. The performance loss varies, depending on the write/read ratio. The average desktop system doesn't gain much performance from write caching, because the most time consuming disk activity is loading multi-megabyte executables and existing data files, not writing and updating files. That also means they're at less risk in any case, because there is less unwritten data in the cache to cause problems. An online transaction system, on the other hand, does continuous file updates and little application loading. These need professional quality hardware (and software!) to deliver the expected level of reliability.
%9.00 power at $0.11 per kWhr, 81.8 kWhr
81.8 kWhr x 60 min/hr / 5 min = 982 kW
Estimate storage system voltage = 600 Vdc (optimistic, 400 Vdc is more likely)
Charging current: 982kW / 600 V = 1.64 kA (that's one serious cord and connector!)
Assume 480V three phase power
Assume an ideal charger: 100% efficiency and 1.00 power factor
982 kW / 480 Vac / sqrt(3) = 1.18 kA per phase input current
If you add a "two pump" recharge island at each filling station in town, that's a huge impact on the power grid. We aren't talking about off-peak usage here, this is day time demand that strains generation capacity. It's an interesting technology, but has the same shortcomings as any extreme-rate recharge scheme. Adding large, variable loading to the power grid at peak hours won't help establish a viable EV market. As high density energy storage for a hybrid car--there it has potential. As storage for an overnight-recharge EV--there too it holds promise, if it performs as well as they claim. But with 500 mile range, there's little benefit compared to the high costs of extreme rate charging.
There will be an ascent Saturday in Northern Colorado. This one is planned to reach "only" 70,000 feet (21km); others by this group have reached over 100,000. Listen for it if you're in UHF radio range.
Quite right! So what should we do about it? Do your kids see you programming? If so, do you tell them what you're doing, and try to explain how it works in words they can understand? Did you help them get through their first void main () { puts ("Hello, world!\n"); /* We don't say "big ***s" around little tykes! */ exit (); } ? Show your children that computers are more than a fancy DVD player/video game/net connection. If you don't, who will?
Planned obsolesence: it's how to keep the revenue flowing in a saturated market.
"because they can't make as many assumptions as a programmer who knows what's going on..." That's true. Of course, the next developer/maintainer who works on that code, or needs it to interface with it, or (heaven forbid!) re-uses it in another project won't know about all your assumptions, either. Whether you're engineering hardware or software, there's such as thing as trying to be too clever. It may seem easy today, but someday somebody will curse you while trying to find what has gone wrong. Think about how you feel when you find that long-gone developers not only made assumptions, but didn't describe exactly what they were, why they made them, and what's necessary for them to be valid. // and /* are your best allies when the new wears off the project!