simple interface board help needed

Discussion in 'The Projects Forum' started by max2help, Mar 18, 2012.

  1. max2help

    Thread Starter New Member

    Mar 18, 2012
    see attachment. i need help to convert the two mechanical switches into electrical switches.
    for one of the them the input voltage is 12vdc and the other is 12vac. i wanted a simple circuit that did the same job as the switches shown is middle left of the picture and with also provide isolation between each circuit.
    space is limited as i wanted to use relays, put they are big and bulks and my cause interference.

    thanks for the help in advance.
  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
    Do you have a datasheet of the EZ-TAG2?

    I don't see any 12V AC power. :confused:

    The two switches can be replaced with signal relays (don't have to be bulky) or optorelays.

    Both switches are referenced to the same ground potential so I don't see where the AC comes into play.
  3. max2help

    Thread Starter New Member

    Mar 18, 2012
    Hi praondevou

    i have attached the data sheet.
    the 12v ac singnal comes from the intercom system when you press the switch to open the door.

    the 12vdc signal comes from the fire alarm panel when it is activated via one of its relays.

    thats why i wanted some isolation as three systems are interfacing together and dont want one to damage the other if any thing does wrong.