? Best way to source 12 volt 1000 mA from car 12v aux port

Discussion in 'The Projects Forum' started by mrbluebottle, Feb 4, 2013.

  1. mrbluebottle

    Thread Starter New Member

    Feb 4, 2013
    2
    0
    Hey all just a quick question.

    I have an IR led array. It came with a wall transformer that outputs 12 v 1000ma DC.

    I want to power it with a car battery. But I think that just to hook it to the battery, it will be to much current.



    This will be used to illuminate my car from inside my car. I have some IR sensitive cameras that i used to watch my car in the apartment parking lot. But I have to park to far from my apartment for the IR LED's to reach the car. Even with CREE 5 and 15 watt IR LED's don't go far enough. I don't think i want to use an IR laser. But it does work the best.

    Thanks

    Thanks
     
  2. tshuck

    Well-Known Member

    Oct 18, 2012
    3,531
    675
    Your AC adapter doesn't regulate both 12V and 1A. The voltage is constant, the amount of Amps your circuit pulls is based off of the circuit attached. The AC adapter can supply 12V @ 1000mA, it doesn't have to supply 1000mA....

    As long as the new 12V source can supply the necessary current, you'll be fine...
     
  3. mrbluebottle

    Thread Starter New Member

    Feb 4, 2013
    2
    0
    Ok thanks , so I can just hook it to the car.
    Any ideas how long the car battery can power this.
     
  4. kubeek

    AAC Fanatic!

    Sep 20, 2005
    4,670
    804
    No, the fact that a car´s system is called 12V doesn´t mean that it actually is exactly 12V all the time. In fact it mostly is around 13.5V, but it drops under load and has nasty peaks of much higher voltage on some times.
    You will first need to find out if the old adapter is regulated or not, then what voltage can the LED light tolerate.
     
  5. cpqfe29

    New Member

    Jan 30, 2010
    26
    1

    That is impossible to know without some specs and even then.....

    Battery - what size in terms of amp-hours (or reserve capacity - so you can still start the vehicle)

    Battery - what is the state of battery? new? old? Low on fluid? and etc.

    Your LEDs.. What is the power consumption?

    ...And other factors like temperature and the such.

    Honestly… I wait for a weekend that you don’t need the car…. And do a field test. Make sure that you have jumper cables and an automotive battery charger on hand.
     
  6. tshuck

    Well-Known Member

    Oct 18, 2012
    3,531
    675
    Whoops, I just re-read my previous post, sorry... I posted that on my way out the door!

    Kubeek makes a valid point. If the 12V was regulated, you will probably need to regulate the input. If your circuit has a regulator, you should be fine.
     
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