Need help with electricity connection in vehicle !

Discussion in 'General Electronics Chat' started by arjch, Apr 22, 2014.

  1. arjch

    Thread Starter New Member

    Apr 22, 2014

    I am having some serious trouble with the devices placed in a vehicle, I am trying to add devices to it and get them powered during the start of the vehicle.

    Electricity Source: DC 12V { Battery }
    CONVERTER - [ DC -> AC ] 12V
    ADOPTER - 12V AC -> 6V AC

    Devices Power requirement->
    5V AC + 1.2 Amp [Device 1]
    WIFI Dongle dont know the power requirements it also requires 5V AC

    Graph is also added

    The devices circuits are failing due to fluctuating current from the battery, thus the reading of electricity is also different, can you help me achieve this, without increasing the price significantly !
    Thanks in advance.....

    - Arjch
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    During starting the starter motor is drawing a huge amount of current, and the battery voltage does drop significantly.

    It will take some work to create either a separate battery supply (with a diode so the started can't pull from it) or increase the range the DC-AC converter works, or add a switching pre-regulator in front of the DC-AC.
  3. t06afre

    AAC Fanatic!

    May 11, 2009
    I do not understand the purpose of the DC to AC conversion. Can you say more about why?
  4. JDT

    Well-Known Member

    Feb 12, 2009
    Also don't understand this.

    You need to isolate your equipment from the vehicle electrics and have a separate re-chargable battery. See diagram.
  5. Georacer


    Nov 25, 2009
    How are you connecting your devices to the car battery? Via the lighter plug or directly through a wire tapped on the battery or a fuse box?
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    5V "AC" ??? are you sure?

    A "wifi dongle" is powered by the USB port (5VDC)