Frequency to DC Converter

Discussion in 'The Projects Forum' started by yellowcloud, Jul 3, 2013.

  1. yellowcloud

    Thread Starter Member

    Jun 30, 2013
    32
    0
    I am trying to light up a led using the signal from Wi-Fi or Hot Spot in our house.. can anyone help me how to do it???

    here are the thing that i want to happen:
    1.power the led using wifi
    2.the circuit where my led is attach should not have any other supply.

    but the problem is i think i really need to use an active component. so it will require a supply. anyone please help. :)
     
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,999
    745
    You cant transmit electricty over the airwaves, your going to need a battery supply for your led wifi receiver to power it.
     
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  3. Logrod

    New Member

    Jun 28, 2013
    16
    2
    So how did crystal sets work? They're completely passive. The problem isn't that you can't transmit energy (what else is electromagnetic radiation?), more that the energy density might not be high enough for his application.
     
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  4. richard.cs

    Member

    Mar 3, 2012
    162
    31
    It's possible to light a torch bulb from a MW radio station, but only with a tuned loop antenna which has an effective size on the order of a wavelength irrespective of it's physical size.

    A standard wifi hotspot does radiate enough power to light an LED dimly, but you will only capture the tiniest fraction of this. If you really need wireless power you will have to construct a separate source and you should expect the efficiency to be dismal
     
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  5. wayneh

    Expert

    Sep 9, 2010
    12,151
    3,058
    The total output of a wi-fi router might be 100mW. That's barely enough for an LED even if you could capture all of it, and of course you can only get a tiny fraction at any distance.

    Not going to work. Look into a wi-fi sniffer. They're the size of a keychain fob and include a signal strength indication. But of course they contain a battery.
     
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  6. yellowcloud

    Thread Starter Member

    Jun 30, 2013
    32
    0

    this wifi sniffer is cool kind of stuff. i will make one of that. and i searched a good circuit about it.

    and sir. can you suggest any good project study? i want a project study that is simple but will make a big impact. im thinking about home automation using android phone but they are releasing stuff and theyre good. now i have to think another. >.<
     
  7. yellowcloud

    Thread Starter Member

    Jun 30, 2013
    32
    0
    Is that so. T_T that sucks. i really want to make that kind of project. what can you say about inductive charging sir?
     
  8. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,999
    745
    Inductive charging works like a transformer, they both have to be close to send/ pick up the impulses, move your phone away from the charge plate and it wont work.
     
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