Efficient Power Supply Contest 501
A reader writes: "In the June (paper) issue of Scientific American, there is a mini-article descibing the energy being wasted by power supplies in computers. Those things are only 60-70% efficient in converting line-voltage AC to low-voltage DC, and there are so many millions of them out there that a modest efficiency increase could trim $1billion or more from the annual energy costs of the USA. Well, various governmental agencies are seeking to get improved power-supply efficiency into the marketplace. The central "clearinghouse" site is at efficientpowersupplies.org, and details of their contest are in this PDF."
get it while its hot! (Score:3, Informative)
I'll give 2:1 odds its down before 10 comments are posted...
Please enjoy Google's version of the main page (efficientpowersupplies.org) [64.233.167.104]
Please enjoy Google's HTML Version of the PDF [64.233.167.104].
I promise no Karma Whoring, courtesy of your (sometimes) friendly AC :)
Re:get it while its hot! (Score:2, Insightful)
Re:get it while its hot! (Score:5, Insightful)
It is a popular Slashdot cliché that small, weakly administered sites use desktop PIII systems with IIS, with the Windows 2000 Server install disc titled in felt pen, on the corporate DSL line and in the same room as the Coke machine and copier.
To no small degree that cliché is based upon a grain of truth. I've seen those sites. It is also true that such sites are not the exclusively Microsoft. But the parent of your post knows his audience and isn't ashamed to go for the easy performance.
Power Supply Reviews (Score:5, Informative)
You can also check out power supply reviews on Silent PC Review [silentpcreview.com]. They concern themselves with efficiency since an efficient power supply can be quieter and produce less heat.
The site also has a lot of other good info.
Company Changes... (Score:4, Interesting)
Aj
GroupShares.com [groupshares.com] A free and interactive stock market community. It is just getting started so check it out!
Another lovely beancounter's story... (Score:4, Interesting)
*sigh*
Re:Another lovely beancounter's story... (Score:4, Informative)
Not totally unreasonable. (Score:5, Interesting)
Each worker needs a minimum amount of space to get their work done. My two old CRTs took up my entire desk, requiring me to have another desk in order to do any work that required paper. The new LCDs have freed enough space on my desk that I can use it for both purposes. This would allow them to mandate removal of my other desk and reduction in size of my cubbyhole.
If everyone's space needs can be reduced by a few square feet, we can pack in more people without the current occupants feeling more squished. Alternatively, we can improve the working environment for cramped people without actually investing in new office space.
Thus if I save 2 square feet at $200 per foot, I can actually justify spending $400 on a new monitor. I can spend more on monitors for workers in space limited work areas.
Re:Company Changes... (Score:4, Informative)
Re:Company Changes... (Score:5, Insightful)
The space savings are significant in the computer labs especially. Students now have room to put their books out in front of them, between themselves and the screen. (we had crowded labs before, the desks are narrow and close together.).
The power savings are good. Before, students would forget to turn off the monitors when class was done. It still happens, but when those LCD's go into powersave mode, they use almost nothing.
The rooms stay sooo much cooler. Our AC was always running in the computer labs before, with 30 17" CRT's going (and PC's). but the LCD's produce so little heat that the room stays nice and cool, and the AC is off more than it is on. (lots of energy savings there).
My back is very thankfull, and every time i have to move a CRT monitor across campus, I am reminded about how thankfull my back is.
Re:Company Changes... (Score:3, Informative)
CRTs can go into power-saving as well. Did you think about doing that? I have a "Kill-a-Watt" power meter, and I measured the power used by my NEC CRT monitor in power saving mode. When it first goes black, it drops from 70 watts down to like 10 watts. When it goes all the way into full power-saving mode where it turns off the tube, the
Re:Company Changes... (Score:3, Interesting)
Should use some of the "savings" to invest in a cart
On a side note, who around here is sick of having to justify savings every single year to management? I see no benefit in stating a $100,000 savings goal when it feels fake 'cause we spent 3 mil on a new phone switch...
Re:Company Changes... (Score:3, Informative)
The larger screens were great, except lugging them from a basement across the street to the other building, and then upstairs to the 2nd. floor got to be quite a chore. There was
Re:WTF? (Score:2)
I pay $0.21/kwh. Based on what my meter tells me about my PCs consumption, It costs me over $16/month to leave it on all the time, and that's without the monitor.
Re:WTF? (Score:3, Informative)
Re:WTF? (Score:2)
maybe the poster meant $2.5?
maybe that $ is actually chillean pesos?
Re:WTF? (Score:2, Interesting)
( 100 * 8) + (150 * 24) = 4400 Watts or 4.4 kw/h
4.4 kw *
I was way high.
Elegance (Score:4, Insightful)
Power supplies are a good example, as are cars (so much wasted energy -- hybrids are better in that regard, though, like in converting braking energy into electrical energy that can be re-used later to help the engine when it's at its most inefficient RPM levels).
snap! been thinking of this for a while (Score:5, Interesting)
i want an efficient AC to DC UPS which connects directly to a DC powersupply for my box(en).
that would rock.
don't get me started on an entire DC house running off of a fuel cell and/or wind/water generators. woot!
Re:snap! been thinking of this for a while (Score:2)
that would rock.
I too have thought about this recently, and yes it would rock. It would remove the heat from the power supply from being inside of the case of the computer, make the computer case smaller, and it would really rock in the sense of high density rackmount installations.
Powerstream (Score:3, Interesting)
48VDC (Score:2)
looks like 48VDC maybe a new standard? aren't cars moving toward 48v? or was that 42? no, that's life the universe and
i was prolly going to use 12v because the wind turbine i'm planning uses used car alternators. although i could put them in series to get 48V. sweet...
Wallwarts. (Score:2, Interesting)
If the power supply is plugged in... (Score:2)
but not connected to its device, the circuit is not complete and thus the PS is not drawing any power. (IANAEE but think I'm on reasonably solid ground here.)
Heh - 'ground'. I kill me.
When the PS and device are connected and plugged in, I think the efficiency depends on the quality and design of the PS. I've noticed the inexpensive 'universal' models seem to get warm, but the one for my Sony Clie does not. Better design (re: heat transfer)? Better quality? I'm guessing a little from column A and a
Re:If the power supply is plugged in... (Score:3, Informative)
When a wall-wart, or most any power supply is plugged into the wall, the first thing the power connects is a transformer, and then goes directly to the wall. It is 100% all the time connected to this transformer, and conducting current through it, even though the device on the other side of the transformer isn't picking up any juice. A transformer is just two coils spun together around a common axis. Both coils have inductance and resistance, and the "main" one is always powered as lon
Totally inefficient. (Score:5, Informative)
Actually, they're LESS efficient than normal. With no load, ALL the power they consume is wasted - efficience is 0%. B-)
Now the total AMOUNT of waste IS typically lower. But it's not trivial. Even the lowest tech wallwart burns power heating copper in the transformer and making up leakage in the capacitors. If it has a switching regulator it's also burning a bunch of power keeping that alive. And a voltage-flattening/capacitor-discharging resistor actually INCREASES the amount of power wasted in the wart when the load is gone (by eating some of the power that WOULD have gone into the load).
So why waste ANY by leaving the wart plugged in?
You can guesstimate the power by feeling the wart when it's been sitting there with no load for a while. The hotter, the more waste.
Power losses in switching power supplies (Score:5, Informative)
Switching supplies can approach 90% efficiency if they are carefully built. Such supplies will cost more, naturally, but an improvement from 60% to 90% efficiency will save you the extra cost over the course of a year or so. And, of course, you can feel better that you are contributing slightly less to carbon dioxide emissions.
Re:Power losses in switching power supplies - cost (Score:5, Insightful)
Doug Coulter, owner
C-Lab
http://clab.mystarband.net
A downside is thermal runaway. (Score:5, Informative)
A downside of high efficiency is that the energy lost to heating is a tiny fraction of the energy handled. When certain components start to fail they can increase their losses - and this increases the heating. The higher the overall efficiency, the greater the extra heating is as a percentage of the NORMAL heating.
If this is not taken into account in the design of the supply (and its cooling budget), the supply may be prone to thermal runaway and catastrophic failures as components age.
Re:A downside is thermal runaway. (Score:3, Interesting)
Depends how the design was handled. If the components were placed to handle 30W, then no, it's strictly better. The problem is that most people don't do a full thermal analysis on a design - they simply do it, then check its temperatures while running, and adjust things if it's too bad.
This means that most (cheap) designs are margin
Re:Power losses in switching power supplies (Score:2)
I only pollute with radioactive waste! They told me that nuclear energy was cleaner than burning fossil fuels.
How exactly am I supposed to ... (Score:5, Funny)
only the PSU for now (Score:2)
so fret not thyne egg fryer for your AMD powered stovetop shall still run hot!
$1 billion in energy savings.. (Score:5, Insightful)
It would be far better if government worked to reduce the amount of petroleum being consumed through initiatives to encourage telecommuting, locating companies in locations that don't require commuting in the first place, and research into fuel cells and hybrid vehicles.
Re:$1 billion in energy savings.. (Score:2, Insightful)
Re:$1 billion in energy savings.. (Score:3, Insightful)
Re:$1 billion in energy savings.. (Score:3, Insightful)
Guess what, government is already doing the former and latter of the three things you suggest in your second paragraph, plus many other things besides. These items are not mutually exclusive...
Re:$1 billion in energy savings.. (Score:3, Interesting)
That is true simply because there is no demand for them. Since most people don't know about power supply efficiency when buying PCs, the PC manufacturer gets the cheapest power supply, which is also likely to be inefficient. The inefficient power supplies become the most popular, and the high-quality ones start to cost more. In all likelihood, a high-quality power supply would cost about as much as a low-qualit
Re:$1 billion in energy savings.. (Score:3, Insightful)
The vast majority of the technological breaktrhoughs since 1940 were tax funded government research, it seems like a pretty darn good investment to me... I'm typing this using a BSD computer using this thing called the web that runs over the internet (hint: all three government funded).
Seems to me that you should double-check your ideology against reality every now and then to verify to what extent your aversion for the government is supported by the facts.
Re:$1 billion in energy savings.. (Score:5, Interesting)
This is where you are wrong. Some (I would not dare say "most") interesting innovation do not present an interesting business proposition. Take the Internet; I am not quite sure the telco would have waken one day and say "let's build a cooperative packet network where I will carry your client's traffic for free if you agree to carry mine". If it was not for ARPAnet, we would be using Compuserve and Prodigy today IMHO.
Just as governement-sponsored research is not systematically good, it's not systematically bad either. Don't throw the baby with the bathwater.
Re:$1 billion in energy savings.. (Score:3)
Hooray for inefficient power supplies! (Score:2, Funny)
For the inevitable (Score:2, Informative)
The Opportunity Power supplies are one of the crucial building blocks of a modern society, converting high-voltage alternating current (AC) into low-voltage direct current (DC) for use by the electronic circuits in office equipment, telecommunications, and consumer electronics. Over 2.5 billion AC/DC power supplies are currently in use in the United States alone. About 6 to 10 billion are in use worldwide.
While the best power supplies are more than 90% efficient, some are only 20 to 40% efficient, wasting
'Real' and 'Proposed' (Score:2)
A great concept to inspire a broad range of entries.
What about Mega Power Supplies (Score:5, Interesting)
What if the same idea where applied to computers. Right next to the standard wall outlet would be a world standardized jack with six or eight pins for each of the required voltages.
Low voltage computer mains would make UPS systems less complicated too.
I've even heard of vendors who make telco friendly rackmount PC's that take 48v DC mains.
Re:What about Mega Power Supplies (Score:5, Insightful)
You could provide a single higher voltage that gets regulated down as needed at the equipment, but you'd still have to deal with the current levels, just not as high.
Re:What about Mega Power Supplies (Score:2)
Since you obviouslly know much more about this than I do, at what length are such large diameters required? For these 2-3 meter runs I'm discussing would it be practicable to have some external power supply which would power 5-10 computers each?
Re:What about Mega Power Supplies (Score:4, Informative)
Re:What about Mega Power Supplies (Score:2)
Re:What about Mega Power Supplies (Score:2)
I hate having three to five PC's whirring away day & night. The noise adds up.
With one supply, I could put it in a noise-dampening box.
Re:What about Mega Power Supplies (Score:2)
You could have standardized connector shapes for different voltage/current combinations (12v 3a is a square, 5v 1a is a triangle, etc). If your external device needs more current than a single plug can provide, you bridge two of them (two 12v 3a square connectors gives you a single 12v 6a wire to run a large LCD monitor).
Chip H.
Wiring losses would eat any gain. (Score:3, Informative)
What if the same idea where applied to computers. Right next to the standard wall outlet would be a world standardized jack with six or eight pins for each of the required voltages.
Computer supply voltages are VERY LOW - and trending lower. That means, for a given amount of power, their currents are VERY HIGH.
Re:What about Mega Power Supplies (Score:3, Interesting)
Re:What about Mega Power Supplies (Score:3, Insightful)
One big problem is that you can't just put Gigabit Ethernet wires in the same cable as 120VAC because of the noise it will induce. Another is that you can't route 5V lines around a house because the resistive losses will eliminate any efficiency you gain from having a single 5V supply, and also because the 5V at the supply will only be 4.9V in one room, 4.6V in another room, etc. This obviously won't do for electronic equipment which requires tight regul
Switching Power Suppies (Score:4, Informative)
The power supply in my S-100 bus Z-80 computer weighed about 20 kg. Apple was one of the first microcomputer companies to use switching power supplies.
Low Power Boards and DC Power Supplies (Score:3, Interesting)
Most people would save more ... (Score:5, Informative)
I doubt you could achieve that kind of savings no matter how power efficient you made the PS.
Re:Most people would save more ... (Score:2)
Re:Most people would save more ... (Score:2)
Together they cost $800 (that is now - cost me way more back I when I got them). You can match those resolutions at $1000 for a 20" 1600x1200 and $600 for a 19" 1280x1024.
Other than the Apple/Sony/Sun widesc
Re:Most people would save more ... (Score:5, Informative)
0.1 KW * 24 hours * 365 days * $0.10/KWh = $88 / year
$88 saved per year if you compare both monitors constantly consuming max power. That doesn't cover the higher cost of the LCD monitor for at least 3 to 4 years. Run a power-saving mode, and you'll probably never recoup the initial cost difference in electricity savings.
And the national average for electricity is lower than that (~$0.085/KWh)
LCDs are great for several reasons, economics just isn't one of them.
Need a more efficient PSU for my Neverball Box (Score:2)
Bulbs, man... (Score:5, Insightful)
In short, there is almost NO reason to not use those fluorescent bulbs and it would result in a far greater amount of energy savings right now...
Re:Bulbs, man... (Score:4, Interesting)
White LED lights on the other hand are looking promising.
Re:Bulbs, man... (Score:3, Interesting)
I too doubt the eye damage thing. Less blinking? Is there something to back that up?
Re:Bulbs, man... (Score:3, Interesting)
Why always DC conversion? (Score:2, Interesting)
Every electronic doodad I can think of has an AC/DC adapter. It's not just an issue with computers.
And it would be nice to get rid of those bulky AC/DC power bricks too...
Carl
Re:Why always DC conversion? (Score:5, Informative)
1) Because the whole electronics industry has already been built up on electronics based on DC supplies, all chips, the circuits learned in EE class for common functions, etc.
2) The semiconductor technology that 98% of our electronics know-how is based on operates on low voltages, so you'd have to convert the higher 120-220-400 line and transmission voltages to low voltages anyways.
3) Most electronic active components in our current technology (semiconductors, even tubes), are asymmetric with regards to polarity and do not have "friendly" characteristics with truly bipolar (AC) signals and supplies.
4) Much of electronics can be viewed as tasks in signal processing, particularly signals that vary in time. AC power is itself electrical power that varies in time (e.g. 50-60hz). Therefore using AC as a supply into circuit would inherent introduce a LARGE signal on top of any signals you were actually interested in.
5) Batteries are inherently DC sources, so making circuits that can run of both batteries and an AC power source would be more complicated if the circuit required AC to run (you'd have to build the equivalent of a DC->AC inverter which is considerably more difficult than a AC->DC power supply, and doing so would waste battery power (inefficiencies in conversion), which is much more precious in most applications than wasting power originating from an AC powerline source.
Re:Why always DC conversion? (Score:4, Informative)
AC, or Alternating Current, is like a sine wave. The voltage swings from a positive peak to a negative trough, and the current switches direction when the voltage changes polarity. If you apply current to the gate of a transistor the wrong way, it stops working and will probably break. Therefore, everything that uses transistors uses DC, or Direct Current, where the electricity flows one way, and at a consistent voltage.</SIMPLIFICATION>
That's because frequently those electronic doodads are computers, just not computers with a hard drive and a monitor. They have CPUs and RAM inside. Even if said electronic thingamajig is not a computer, it probably has transistors in it, hence the DC power.We use AC power instead of DC power because we use a centralized power grid. [ieee-virtual-museum.org]If the world moves to distributed power generation [distribute...ration.com], we'll likely abandon AC entirely. Of course, we'll never be completely free of power bricks, because our devices need different voltages. However, DC to DC conversion is much simpler than AC to DC conversion.
Space heaters.... (Score:2)
I wish there were a 5V/12V DC standard (Score:4, Insightful)
Re:I wish there were a 5V/12V DC standard (Score:2)
Consider existing wire. (Score:3, Informative)
Also: Heating. It's the CURRENT that heats the wire. The limit on wire size in a wall is keeping the heat down enough that it doesn't set the walls on fire.
Your house is wired with #14 for 15A circuits, #12 for 20A, #10 for 30A.
At 120 volts a puny 15 amp circuit can provide 1650 watts, enough to run a space heater with leftovers for a couple 75 watt bulbs, or all the lights in seve
power factor (Score:3, Interesting)
there are no energy savings (Score:3, Funny)
If you live in a cold place, efficiency is 100% (Score:5, Insightful)
Ultimately, most of the non-heat forms of energy loss get turned into heat in the surroundings when they get absorbed by something, like a wall.
So if you are trying to maintain your house at a higher temperature than it is outside, then all the lost energy from your computer goes to do useful work heating your surroundings. Hence a 100% power efficient computer.
Now if we could efficiently generate electricity, we might have an efficient total system. I don't see that happening soon.
Re:If you live in a cold place, efficiency is 100% (Score:3, Insightful)
Power company speak (Score:2)
As you can see gentlemen, with all these efficient switching power supplys RIPPING us off, we have to do something to stop this silly efficiency craze. Its costing us a billion dollars a year!
Power company exec 2.
Well, we could always raise the rates we charge, or bury some "switching supply" tax in the customers bill every month.
Power company exec 1. Dude! You're a genius!
This begs another question... home power meters? (Score:2, Interesting)
Anyone know of such a device? There are industrial ones out there, but I haven't seen a reasonable priced one for household use.
Hey, I am an
Most efficient power supply I have found (Score:3, Informative)
Also, use AMD 64-bit CPUs and set
The Mobile Athlon 64 3200+ (62W @ 1.4V max) is interesting if you really want to limit power consumption. I put one in my ASUS K8V Deluxe motherboard (Zalman CNPS7000A-AlCu heatsink, be VERY careful not to overtighten it and crack the unprotected core as there's no protective aluminum lid like on the desktop CPUs, not all heatsinks will fit). Drop 200MHz and get 46W, another 200MHz gets 34W, and at 800MHz a mere 13W. Given that the new Prescott-core Pentium 4's burns well north of 100W, this is pretty neat. Note that since AMD's transistors have a MUCH lower leakage level than Intel's (20% versus 50%) your idle power consumption at any clock rate is going to be pretty low. Things will get even better when the new 90nm chips come out in a few months.
Seasonic PSUs (Score:4, Informative)
I measured the before and after current draw of my PCs and found that the Seasonic Super Tornado PSUs were not only much quieter than the PSUs I replaced, but also reduced current draw out of the wall about 15%. Additionally, they have a PF that I measured at
The Seasonic PSUs are the most efficient that SilentPCReview has reviewed at about 80%. It makes sense that if you are building a new PC or need to replace a failed unit to spend the money on the Seasonic units. They are even competitively priced compared to other name brand PSUs as well.
No problem, but it costs, (Score:3, Interesting)
The cheapo power supplies used in PCs cost less than a tenth of that. Many of them don't have protection circuitry and forged UL certifications are common. Most won't deliver their rated load, and many, if loaded up to their rated load, will burn out, or worse, catch fire.
The real problem is to get to 90-95% efficiency at $0.10/watt.
Re:a small step (Score:5, Insightful)
Now that you have a smaller PS, you might could drop a fan or two. This now decreases your power load on your new 400W.
Savings on effeciency == savings everywhere
Re:a small step (Score:4, Informative)
Re:a small step (Score:5, Informative)
Re:a small step (Score:2)
I am the stupid
Re:a small step --NOT stupid (Score:5, Informative)
WarriorPoet42 got it right the second time around - but this did not make your question "stupid."
BY THE WAY: Just because you have a 400W power supply in your PC does NOT mean you are consuming 400W of power from the AC outlet. If you put an older (slower) CPU/mobo with no expansion cards, and run, say, a modern low-power hard drive, etc., the LOAD presented to the 400W power supply will be much lower. Think about it. Small form factor PCs are often built with 150W power supplies. This means that the components NEVER consume more than 150W, and probably seldom if ever hit that peak.
A side-effect of this is that the power supply efficiency does not necessarily always *waste* its ratedpower-minus-(1-minus-efficiency).
(whaatt??) Let's say:
R is the power supply's rated power.
E is its efficiency expressed as a fraction of 1 (i.e. 90% efficiency is expressed as 0.9)
So, a 400W (R=400) power supply with 80% (E=0.8) efficiency will *waste* 400*(1.0 - 0.8) 80 watts of power. But ONLY if the LOAD is drawing the full 400 watts of power!
Now let's say we have a 400W power supply with 80% efficiency, but the computer components only draw 180W of power. Let's use C to represent the power draw of the computer, so C=180. Now, just substitute C for R and you get:
C*(1-E) = 180*(1.0 - 0.8) = 36W. This is what you are REALLY losing due to power supply inefficiency.
Note: A switching power supply will have some minimal losses even if there is NO load attached to it. These are small compared to the efficiency losses in normal operation, so for practical purposes may be ignored. You could add a constant (say, K) to the equations above to account for this static power loss in the power supply, but K would be small, when compared to C, so has little effect on the math....
Re:a small step (Score:4, Insightful)
That being said, even currently all PSU's are not created equal. A decent 400W will power most computers very nicely, with closer to the rated output. A cheap PSU will die, or cause anomalies, or just not do the job as well.
While it's not always true that heavier=better... if your PSU is quite light then chances are it's a cheapy, and you aren't going to often get near the "max" rated output.
I wonder though, if the better PSU's are also more efficient in this manner as per the draw from household current?
Re:a small step (Score:3, Interesting)
Well, Yes.
But to produce that full output of 400 watts at 60% (0.60) per cent efficiency it will consume 666.666 watts, dumping 266.666 watts as waste heat.
More important, *Please note also* that the power supply reaches maximum efficiency at rated output, I.E. at outputs less than rated, the efficiency can be a LOT LOWER than you think.
Re:What's the point? (Score:2)
But perhaps the difference in terms of carbon dioxide emissions will be felt. The issue shouldn't be about saving money, it should be about being environmentally responsible.
Re:What's the point? (Score:2)
P.S. If you don't want your $3.18 savings, can I have it?
Re:What's the point? (Score:5, Insightful)
You're way off. In 1994, the U.S. alone produced over 1.3 billions tons [cnie.org] of carbon (not CO2, just carbon; the CO2 weighs even more than that).
while about 500 million tons were produced by natural causes.
Natural causes do not "produce" CO2. They merely recycle carbon. The CO2 emissions of living organisms have no net effect on the global carbon balance, because all they are doing is moving it around, from the atmosphere into the biosphere and back again.
It is true that methane emissions from cows are an issue. This is because methane is many, many times more effective than CO2 at trapping heat. But the net amount of carbon still remains the same.
Re:What's the point? (Score:3, Informative)
Maybe you need a refresher on how to divide numbers. In 1994, as I've already shown, the U.S. alone emitted about 1.3 billion tons. The paper the parent poster linked to shows CO2 emissions from the biggest volcanic sources. They add to about 1 billion tons.
So in fact, the U.S. is emitting about 30% more CO2 per year than all the most active volcanic and geothermal ar
Re:Awards? (Score:2)
-Jesse
-5 you're digging too far (Score:2)
You'd better move then (Score:3, Insightful)
The official model of the US, put in place by the Founding Fathers, is "E Pluribus Unum" or "Out of many, one". The founders did not share the philosophical view of Ayn Rand, and creating a state was exactly what they were committed to.
Besides, energy efficiency is a national security interest. Over-dependence on oil imports means the US is more likely to engage in foreign wars.
Try again (Score:3, Insightful)
Out of many (states), one (nation). Basically this statement refers to the representative government (republic) that was established, not a pure democracy.
It has nothing to do with the role of the citizen, let alone imply any obligation of citizens to a collective.
Though we do agree that energy efficiency is indeed a national security issue.
Re:-1, Communist (Score:4, Insightful)
Three cheers for liberals and a centralized federal government, then! Without them, the city streets wouldn't have lamps--let alone the power to run 'em--and we'd all be walking down long, dark...
Um...
Re:-1, Communist (Score:4, Insightful)
Bravo.
Pointing out the "central planning" aspect of the press release highlights its futility.
If the central planners had been thinking more clearly, they'd have been lobbying for power-supply efficiency labeling, ala the energy-usage labels on major appliances such as furnaces, water heaters, refrigerators, and the like.
(Disclosure to the individual purchasers of the information necessary to make informed choices, in a standardized format, puts the market forces to work constructively for all concerned. It's an intervention that even minarchists can often find it in their hearts and ideologies to forgive. B-) And a case where even an inadequate standard can be better than none.)
But of course the liberals don't think that way...
Mod me down, and I will become more powerful than you can possibly imagine.
Having already commented elsewhere in this thread, and reviewed your recent postings on other topics (which often bring up insights others have missed), I've decided to mod you "friend" for a while. B-) (Let's debate Godwin's Law some time. IMHO it's all too convenient for neo-NAZIs.)
Re:This hits the nail on the head. (Score:3, Informative)
No, sorry, it is NOT simpler to convert DC to DC than AC to DC or DC to AC, particularly if you want to maintain good efficiency as well as simplicity.
In fact, to efficiently do DC->DC, most circuits actually do DC->AC->DC, again using
Re:Can someone tell me.. (Score:4, Informative)
Aside from the inefficiency of the linear regulation, the other big problems with this kind of supply are size/weight (because of the huge transformer), losses in the transformer itself, and the need to have a large heatsink on the regulator.
Lastly, transformers don't make computer power supplies inefficient or heavy, because they don't have them. Computer PSs use switching power supplies, which have capacitors, inductors, and transistors (operated in the highly efficient saturation (full-on) mode), and are much more efficient than the linear power supplies you referred to. However, the efficiency of switchers can vary greatly, which is what this article is all about. Well-designed switchers can be extremely efficient (like over 90%), but commonplace PC power supplies are much less efficient due to poor design and construction, which is no surprise since most people and companies buy the cheapest stuff they can.