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Displays Power

Monitor Draws Zero Power In Standby 405

fifthace writes "A new range of Fujitsu Siemens monitors don't draw power during standby. The technology uses capacitors and relays to avoid drawing power when no video signal is present. With political parties all over Europe calling for a ban on standby, this small development could end up as one of the most significant advances in recent times. The British Government estimates eight percent of all domestic electricity is consumed by devices in standby."
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Monitor Draws Zero Power In Standby

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  • Re:power isnt free (Score:5, Informative)

    by CaptainPatent ( 1087643 ) on Thursday November 08, 2007 @10:49PM (#21289839) Journal

    Then it just draws EXTRA power while running, to charge the capacitors. Electricity can't be produced from nothing.
    Yes, but it only draws enough electricity to fill the capacitors instead of constantly drawing enough power to bring the monitor out of standby.

    Sure you're going to use some extra electricity to come out of standby, but this does cut down on that amount in a vast manner.
  • Re:power isnt free (Score:2, Informative)

    by amccaf1 ( 813772 ) on Thursday November 08, 2007 @10:51PM (#21289849)

    A more useful version would be one that used solar cells on the top of the LCD to absorb the already expended energy of ambient lighting.
    Looks like it does... From TFA:

    Solar panels provide enough power to maintain zero consumption mode for up to five days, after which you have to press a regular power button to bring the machine out of standby.
  • Re:power isnt free (Score:2, Informative)

    by Gothmolly ( 148874 ) on Thursday November 08, 2007 @10:54PM (#21289887)
    Dude... the total energy consumption remains constant. Think about it. For the capacitors to run the monitor that long, they MUST HAVE DRAWN THE POWER IN THE FIRST PLACE.
  • by Spy der Mann ( 805235 ) <`moc.liamg' `ta' `todhsals.nnamredyps'> on Thursday November 08, 2007 @10:55PM (#21289895) Homepage Journal
    A more useful version would be one that used solar cells

    *AHEM* From TFA:

    A relay cuts off the mains power whenever the video stream stops; capacitors store enough charge to flick the relay back when the signal returns. Solar panels provide enough power to maintain zero consumption mode for up to five days, after which you have to press a regular power button to bring the machine out of standby.


  • by EmbeddedJanitor ( 597831 ) on Thursday November 08, 2007 @11:00PM (#21289935)
    Most use some sort of supervisory micro or other electronics to sense you pressing the power switch etc. It might draw very little power, but it isn't nothing.
  • Not necessarily. If the two polarizers are in parallel, then, yes, it has to twist the light as it goes through to block it. But if the two polarizers are perpendicular, then black is the "default state", and light is blocked unless the liquid crystal twists it to let it through the second polarizer. (My Sony CLIE (SL-10) was like this -- it turned black when the device was off. It looked nice.)

  • Re:power isnt free (Score:4, Informative)

    by Zekasu ( 1059298 ) on Thursday November 08, 2007 @11:02PM (#21289965)

    A relay cuts off the mains power whenever the video stream stops; capacitors store enough charge to flick the relay back when the signal returns. Solar panels provide enough power to maintain zero consumption mode for up to five days, after which you have to press a regular power button to bring the machine out of standby.

    There's a difference here, and that is that this new monitor will draw enough power to wake itself out of standby, and then not draw anymore power. Normal monitors generally go into standby, and then continue consuming power, which is less wpoer than an idle screen, but still more than just enough to charge some capacitors.

    I don't see it as winning a prize for groundbreaking-innovation, though.
  • Re:power isnt free (Score:2, Informative)

    by amccaf1 ( 813772 ) on Thursday November 08, 2007 @11:02PM (#21289969)

    Dude... the total energy consumption remains constant. Think about it. For the capacitors to run the monitor that long, they MUST HAVE DRAWN THE POWER IN THE FIRST PLACE.
    According to the article:

    Fujitsu Siemens showed two 22in widescreen test monitors with power meters attached at a press event in Augsburg, Germany. The display drew 0.6-0.9W when the monitor was switched off using its standby button and with an active video signal from a VGA cable present. When the display signal was switchedc off the monitor drew zero power even though the standby/power button was not pressed
    This technology would appear to charge the capacitors with a one time burst as it goes into it's standby mode (and the charge is kept up via solar power). Ordinarily monitors are drawing 0.6 - 0.9W constantly while they are on (for minutes... or hours... or weeks.) The article doesn't state how much power is used to initially charge the capacitors, but I can't imagine that it would take more (or as much) power to charge them once than it would to let the monitor constantly bleed 0.6 - 0.9W over five days...
  • by EmbeddedJanitor ( 597831 ) on Thursday November 08, 2007 @11:04PM (#21289987)
    You don't need much power to run a very small 8-bit micro, enough to wake a sleeping monitor. We're talking about nano Amps here. A cheap capacitor can keep that going for months.

    The biggest wastage in taditional designs is that they use switch mode power supplies designed to run at full power. They don't operate very efficiently at very low (standby) power. It is far better to completely turn off the power supply and just use a local capacitor to keep the micro going.

  • by DAldredge ( 2353 ) <SlashdotEmail@GMail.Com> on Thursday November 08, 2007 @11:09PM (#21290019) Journal
    CRT != LCD...
  • Re:power isnt free (Score:2, Informative)

    by slazzy ( 864185 ) on Thursday November 08, 2007 @11:15PM (#21290073) Homepage Journal
    I think you've got it there - the transformer AKA power supply uses a lot of power when the monitor is doing nothing at all - IE in stanby mode. The relay will disconnect the power supply, and store the tiny amount of power needed to turn back on the relay in a capacitor - seems like a good idea to me.
  • by iminplaya ( 723125 ) on Thursday November 08, 2007 @11:29PM (#21290203) Journal
    Well, he was talking about CRTs. And you are wrong on both counts. On a CRT more current flows to make the screen white. For an LCD, just remove the signal or power from the screen, but not the light and the pixels go "black". However...transmitting black over air takes more energy. And the sync pulse, even more.
  • Re:power isnt free (Score:2, Informative)

    by arodland ( 127775 ) on Thursday November 08, 2007 @11:44PM (#21290299)

    There's a difference here, and that is that this new monitor will draw enough power to wake itself out of standby, and then not draw anymore power.
    Except of course that that's not really possible since it needs to draw power to know when to come out of standby. That's where the constant draw comes from. The key to this is the solar panels they mention, which keep the caps topped off against leakage current. Without them, the design seems worthless to me, but with them you have an "alternative energy" monitor that puts photovoltaics to a use where, amazingly enough, they actually work.
  • Re:Annoying LEDs? (Score:3, Informative)

    by TurboStar ( 712836 ) on Friday November 09, 2007 @12:20AM (#21290535)
    How'd that get modded funny? I tape over mine too. Some blue LEDs literally hurt even glancing at them in a dark room. Then you have the night vision loss.
  • by SeaFox ( 739806 ) on Friday November 09, 2007 @12:28AM (#21290595)

    Between displaying 100% white at the highest brightness and the blackest black at the lowest brightness, there is only a 5-10% difference depending on resolution and refresh rates.

    Blackle [blackle.com] seems to say differently. And people have done the math [blogspot.com].
  • Re:power isnt free (Score:3, Informative)

    by JonathanR ( 852748 ) on Friday November 09, 2007 @03:14AM (#21291651)

    After months or years, the spring will lose tension strength and wait a longer time (if nothing trips it) and it will eventually be all the way back to it's beginning.
    This is not true. Your symptoms might occur after repeated cycles of energising/de-energising the spring, but at normal ambient temperatures, creep does not occur (in metallic materials).

    Capacitors (to return to the monitor standby topic) will lose their charge over time, which is presumably what the solar cells are to mitigate in this application.
  • by Zaffle ( 13798 ) on Friday November 09, 2007 @03:28AM (#21291721) Homepage Journal

    "As for Fujitsu's 0W-standby monitor, they conveniently omit the fact that this extra relay's coil and related components will be drawing an extra 1W or so while the monitor/TV is on."


    1 Watt??? I built a circuit that used a relay for precisely this. I just called it from the other point of view, it turned itself off. There is no way you need 1 Watt of power to hold anything but the largest relays.

    Btw - this 0W standby only works when its a relatively simple thing to monitor for to come out of standby, a line level. Try making a TV that is 0W standby, yet I can boot it with just my remote. Actually, its quite simple, you use a rechargeable battery to power a IR monitoring circuit, but thats cheating :)
  • by Chaos Incarnate ( 772793 ) on Friday November 09, 2007 @04:42AM (#21292033) Homepage
    If you read the link, you would see that it allows the machine to bypass normal Sleep and go directly to "Safe Sleep" aka Hibernation. (The default—Sleep then Safe Sleep—would be akin to the Hybrid Sleep mode. But it can be configured otherwise.)
  • by Alioth ( 221270 ) <no@spam> on Friday November 09, 2007 @04:51AM (#21292069) Journal
    No, it can be saving power and this is why.

    If you power your standby circuit off the line power, you need a transformer or switch mode supply to isolate it from line power and provide the low voltage (probably not 5v, probably 3.3v for most modern devices). The power supply itself unloaded will consume several watts - at very low loads, the power supply is probably less than 1% efficient, so it's just wasting 99% of the energy.

    If you charge a capacitor instead, when the supply is under load and operating efficiently, then while you've just shunted energy around - the incremental energy cost of charging that capacitor while the device is on is tiny, and you don't have to keep that big lump of iron running when the device is in standby. Hence instead of consuming 6 or 7 watts (mostly due to the unloaded power supply), you can truly use microwatts to run the standby circuitry because you're using the power transformer or SMPS much more intelligently.
  • by nmg196 ( 184961 ) * on Friday November 09, 2007 @06:13AM (#21292501)
    > As for Fujitsu's 0W-standby monitor, they conveniently omit the fact that this extra relay's coil
    > and related components will be drawing an extra 1W or so while the monitor/TV is on

    Can you please post a link to the datasheet or page where you read that. I strongly suspect that you made that up because I've never come across a relay that requires 1 *WATT* to work. A relay only requires a few milliamps to work. A 1 watt relay would be a brick sized device that might be used to turn on some stadium lights or or several miles of highway lighting or something - not an LCD screen sat on your desk.

    I doubt it adds any significant power consumption wattsoever (geddit?).
  • by Anonymous Coward on Friday November 09, 2007 @08:55AM (#21293297)
    Well, nothing prevents plugging it in, but these nifty devices called circuit breakers stop someone from overloading it. And running to the furnace room to reset the breaker serves as a deterrent, so they won't do it too often.
    As for separate power and lighting circuits, ?!?!? Don't lights require power? It's not like all the wall outlets are on one circuit, and all the lights on another, if that's what you mean. Circuits tend to be divided by room/rooms they serve, and the entire circuit is wired for 15 or 20 amp, so you can plug anything in that doesn't blow a breaker anywhere it fits. High loads, like an electric stove, furnace, or water heater, are usually 220V anyway, but if 110, are still on their own circuit, and couldn't plug in to a low amp circuit.
  • Re:instead (Score:3, Informative)

    by russotto ( 537200 ) on Friday November 09, 2007 @11:20AM (#21294647) Journal
    Look up "inrush current". Wear and damage due to switching devices on and off all the time is not limited to mechanical devices. You can get high voltages when turning a device off, as well.

    Old TVs certainly did have standby. It was called "instant on".

    Modern devices barely last five years before needing replacing.

    Generally because of obselescence, not failure. Or because of a failure that, in an older device in former times, would have been worth repairing. Those old TVs and radios and VCRs were not maintenance free, as the repairman for my parent's 1969 color TV could attest. My current CRT TVs are all 10 years are older (and the large ones have instant-on), but I don't use them much any more because I've replaced the main one with an LCD TV.
  • get a power meter (Score:2, Informative)

    by Coop ( 9778 ) on Friday November 09, 2007 @12:43PM (#21296197)
    A power consumption meter is essential to monitor the ghost loads of stuff around the house. The makers of the KillAWatt meter have a new model out so the old ones are just $16. Check out what your TV and DVD player are up to -- they waste just as much power as a monitor. When I found out how much, I put them on a power strip so I could switch them off -- *really* off -- easily when I go out of town.

    http://www.newegg.com/Product/Product.aspx?Item=N82E16882715001 [newegg.com]

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