7v-9v DC Step up to 12v DC Regulator

Discussion in 'General Electronics Chat' started by Omni, May 22, 2016.

  1. Omni

    Thread Starter New Member

    May 22, 2016
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    Hello all,

    I would like to make a regular that will take 7v to 9v DC and to then regulate it to 12v DC. I would also like the circuit to shutdown at below 7v DC.

    Any ideas if there is anything out there that can already achieve this, or is there a way I can make this?

    Thanks all

    Title should say regulator. Sorry. I can't ammending it on my phone.
     
    Last edited by a moderator: May 22, 2016
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    What you're looking for is a "DC-DC boost converter". Plenty advertised online. Cheaper to buy than build.
     
    Roderick Young likes this.
  3. ronv

    AAC Fanatic!

    Nov 12, 2008
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    How much current?
     
  4. Omni

    Thread Starter New Member

    May 22, 2016
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    Under 1A. I am awaiting the exact mA at the mo.

    Is there a way I can use this: http://www.robotshop.com/uk/12v-step-up-voltage-regulator-u3v12f12.html with 3 x CR123A batteries but add something that when VIN drops below say 6V the circuit shuts down?

    I am trying to ensure the reg will not get to hot and also to ensure that it remains above 80 percent efficiency.

    Any thoughts?

    Thanks guys :)
     
  5. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    To get 1A out at 12V would need 12/9 = 1.33A input at 9v, assuming 100% efficiency. Factor in the 80% efficiency and you'd need 1.66A. That exceeds the rated 1.4A for the switching device in the linked converter :(.
     
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  6. Omni

    Thread Starter New Member

    May 22, 2016
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    Thanks for the info.

    I waiting for the official figures so hopefully it is under 1A.

    My gut says it will be near 600mA but I need the to tell me. Lol
     
  7. ronv

    AAC Fanatic!

    Nov 12, 2008
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    You can use a boost regulator to get there, but if you look at the battery it is a little marginal.
    [​IMG]
     
    Last edited: May 23, 2016
  8. Omni

    Thread Starter New Member

    May 22, 2016
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    Cheers ronv.

    Any idea what I can do to shut the circuit down bellow 6v?
     
  9. ronv

    AAC Fanatic!

    Nov 12, 2008
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    This is the easiest one I know of.
     
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