Controlling 24VDC coil based on DC voltage reading...

Discussion in 'The Projects Forum' started by Andreas1989, Feb 26, 2016.

  1. Andreas1989

    Thread Starter New Member

    Feb 26, 2016
    3
    0
    Hi all,

    So I have solar energy at home consisting out of panels, batteries and inverter/charger. Thing is I am running my house on this 24/7 with a way too small battery bank ( don't tell me upgrade the battery bank!) resulting in the need to charge from time to time.

    I have a 48VDC battery bank, that can be charged by a 220VAC charger, I have a 220VAC contactor controlled by a 24VDC coil that should(this is where you come in) be connected to my Arduino. It should be able to measure the battery bank voltage ( doesn't matter if it is measuring 48VDC 24 VDC or 12VDC) and switch the coil when a certain voltage is reached which in turn switches the contactor that starts the charge, it should then charge for 3hours and switch the charge off. Can you help please?
     
  2. crutschow

    Expert

    Mar 14, 2008
    12,974
    3,220
    Is all you want to know is how to drive the contactor coil from the Arduino?
    What is the coil resistance?
     
  3. #12

    Expert

    Nov 30, 2010
    16,247
    6,744
    There are a few ways to do this.
     
  4. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,965
    743
  5. Andreas1989

    Thread Starter New Member

    Feb 26, 2016
    3
    0
    Thanks guys, @ crutschow yes but it must only be activated once a certain voltage is reached.
     
  6. Andreas1989

    Thread Starter New Member

    Feb 26, 2016
    3
    0
    Dave can you give me code to your ideas?
     
  7. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,965
    743
    What code? I dont do Arduino only pic programmes.. soz

    As a guide use the A2D converter read the battery voltage using a resistor divider, and set an upper and lower level to compare it with, then use that to put the relay on/off.
     
Loading...