pulse to constant X3 circuit

Discussion in 'The Projects Forum' started by firebird1, Jan 12, 2009.

  1. firebird1

    Thread Starter New Member

    Jan 12, 2009
    3
    0
    ok i thought this would be easy enough but i am having trouble figuring this out

    I need to control three 12v relays with the push of one momentary button.
    Example: If i push the button once while relay 1 is on it will turn off relay one and turn on relay 2. then i push it again and it will turn off relay 2 and turn on relay 3. Push it one more time and it will turn off relay 3 and go back to turning on relay 1.

    I did find a circuit that used two relays to activate/deactivate a relay on the12volt.com but i could not find a way for it to control three relays
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Use a decade counter IC, connect relay 1 on Q0, relay 2 on Q1 and relay 3 on Q2. Finally, connect Q3 to reset. In this way each time you press the button one relay will turn on (in sequence from relay 1 to 3). Note that, you have to use transistors on the outputs of the decade counter to drive the relays.
     
  3. firebird1

    Thread Starter New Member

    Jan 12, 2009
    3
    0
    i looked up using transistors a switches but i could not find any diagrams that used positive to activate the transistor. How would i go about using the decade couters positive out put to activate the transitor
     
  4. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Connect the transistor emitter to ground, the relay between the collector and positive supply voltage, and the base to the output of the decade counter via a 2K2 resistor. Also, put a diode in parallel with the relay coil with its anode facing the collector.
     
  5. jj_alukkas

    Well-Known Member

    Jan 8, 2009
    751
    5
    Use a decade counter like CD4017 with outputs to relay through driver transistors and input thu push buttons..
     
  6. firebird1

    Thread Starter New Member

    Jan 12, 2009
    3
    0
    here is a quick scematic i drew up.

    Does this look right?

    Also what kind of transister should i use?

    ( I have yet to include the diodes )

    [​IMG]
     
  7. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    The circuit looks fine. You can use BFY51 transistors.
     
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