Need to take 5v 1a step up to 12v 2a with only using the 5v power supply. Is this possible at all?

Discussion in 'General Electronics Chat' started by bytemedj, Aug 13, 2015.

  1. bytemedj

    Thread Starter New Member

    Aug 13, 2015
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    I am trying to take a 5v 1a current input and get an output of 12v 2a. Ive seen all kinds of step up modules mut amperage depletes. I want to boost the amperage along with the voltage. Is this possible and if so, how? I am very new to this so please dumb your answers down for me.

    I want to thank you ahead of time for taking your time to deal with an amateur for any assistance needed. Any help is greatly appreciated!
     
  2. paulktreg

    Distinguished Member

    Jun 2, 2008
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    You want 24W (12V x 2A) from a 5W (5V x 1A) source. Can't be done.

    The maximum you could get at 12V would be approx 300~400mA.
     
  3. JWHassler

    Member

    Sep 25, 2013
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    The 5v/1Amp supply is capable of delivering 5x1=5 watts of power.
    At 12V it would still deliver 5watts (less inefficiencies) for a current capability of 5/12 amps.
    It's physics.
     
  4. bytemedj

    Thread Starter New Member

    Aug 13, 2015
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    Thanks for the info, you guys are great! Youve saved me so much time.

    If I have a battery that puts out 5v2a power and I split that will that drop down to 5v1a per line? Im assuming when you split it you keep voltage but lose amperage. Can I also assume that whatever device is running off that power the amperage will drop only by what amperage is required to run the unit? So even if I run 3 items off of it and they drain under 2a, im fine, right?

    Thanks again, im sure ill have more questions later.
     
  5. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    1,103
    Provided the 3 devices are each rated for 5V and their total current draw is no more than 2A then fine. But what battery do you have that is 5V?
     
  6. dl324

    Distinguished Member

    Mar 30, 2015
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    Your power supply will supply 5W (P = IV = 1A * 5V = 5W).

    Step-up regulators can generate higher voltages, but they are never 100% efficient. At 100% efficiency, you would get 420mA (I = P/V = 5W/12V = 0.42A).

    Typical step-up regulator efficiency is 65-95%. Assuming something in the middle, you could get 0.8 * 420mA = 330mA
     
  7. dl324

    Distinguished Member

    Mar 30, 2015
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    Not necessarily. Each device is a load on the battery and each will try to get the current it requires.

    Batteries are rated in AH (Amp Hours). A 5V 2AH battery would provide about 2 Amps for an hour, 1A for 2 hours, 0.5A for 4 hours, etc (ignoring any self leakage and any other parasitics).
    You lose neither voltage or current.
    Each device will attempt to draw what it requires. As long as that's less than what the battery is rated for you're good to go.

    You can often draw more current from a battery for short periods. A 2AH battery might be able to provide 4A for half an hour...
     
  8. bytemedj

    Thread Starter New Member

    Aug 13, 2015
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    Thanks for all of the great information everyone!
     
  9. bytemedj

    Thread Starter New Member

    Aug 13, 2015
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    I'm using power banks with dual output. One is 5v2a and other is 5v1a.
     
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