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Stand by saver help

  1. Dec 8, 2009 #1
    im trying to understand the concept of how a stand by saver works, What components and how it is put together. any suggestions???
     
  2. jcsd
  3. Dec 8, 2009 #2

    berkeman

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    Could you please describe it in a little more detail, and maybe post a link to what you are talking about? The term "stand by saver" doesn't exactly correspond to things I'm familiar with. Do you mean a screensaver for a computer monitor? Or a UPS power supply backup for a computer, or some other device?

    Welcome to the PF, BTW.
     
  4. Dec 8, 2009 #3
    http://www.standby-saver.co.uk/ . . . this is basically the most popular devices available. Its used to prevent standby power consumption. i'd like to know what components are used to automatically turn the applications off when switched to standby.

    Thanks for your reply :) nd for the welcomin :)
     
  5. Dec 8, 2009 #4

    berkeman

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    Ah, a power strip with the ability to turn ofn and on power to the sockets. Looks small enough that they are most likely using solid state relays (SSRs). There will be a small microcontroller (uC) that is monitoring the IR or USB signals, and it controls the SSRs. The ironic thing is that this circuit itslef takes power, but probably less than the standby power of your TV and associated equipment.
     
  6. Dec 8, 2009 #5
    thank you :). . .but could you remove the microcontroller and replace it with another component that can acknowledge a voltage drop within the circuit and then divert it to the SSRs??
     
  7. Dec 8, 2009 #6

    berkeman

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    You could put in a current sense circuit per socket, and have that socket's SSR shut off when the current dropped low enough to be recognized as standby current. But then how do you let the appliance turn back on? With power shut off to it, it has no way to tell the socket to turn back on for it. That's why the link you showed has the IR and USB controls -- to make it convenient to turn the appliance back on.
     
  8. Dec 8, 2009 #7
    ye the IR controls make sense for convience but installing simple switch to the socket could reactivate its supply aswell, couldn it?
     
  9. Dec 8, 2009 #8

    berkeman

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    Yup, absollutely. A simple switch-per-socket power strip would do the same thing, be cheaper, and more energy efficient. Just a little less convenient, depending on where the power strip is located, and how well it's labelled.
     
  10. Dec 8, 2009 #9
    ah thats good :). . .another thing, can metal oxide varistors be used, i seen that they are used in surge protectors to divert excess current to ground but coud they be used to let a constant current pass while an application is being used and then prevent any current passing when the application is on standby?
     
  11. Dec 8, 2009 #10

    berkeman

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    No, sorry. MOVs are totally different devices than SSRs. They are basically over-voltage clamps that short when the voltage across them gets too high. They are used as you say, to divert the current from large voltage transients to Earth Ground, away from sensitive circuitry.
     
  12. Dec 9, 2009 #11
    awh ok, just abit of a risky thought :rofl: . . .regarding the current sense circuit, In this case, would a Low side circuit be used?
     
  13. Dec 9, 2009 #12

    berkeman

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    No, not in general for an AC mains circuit. A current-sense transformer would be the more standard way to do it, I believe.
     
  14. Feb 2, 2010 #13
    hey hey. me again....probably wrecking ur head at dis stage...but back on this topic, i was wondering is it possible and easier to use a UVLO to cut the power from a socket to an application consuming standby energy??? wb plz
     
  15. Feb 2, 2010 #14

    berkeman

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    Not sure what you mean by undervoltage lockout in this context. UVLO is generally a feature on some power supplies where they sense the rectified DC input voltage, and disable the power supply when the input voltage is below spec. I'm not familiar with a stand-alone UVLO circuit or module, which it sounds like you are asking about.

    Also, what does "wb" stand for?
     
  16. Feb 2, 2010 #15
    oh ok, i wasn to sure, i was jus came across it when researching a current sense transformer and thought it would be suitable.
    im still not to sure how it works and how it would work in this situation. i have very basic knowledge on electronics :(

    and it stands for write back :)
     
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