convert circuit from single to dual supply

Discussion in 'General Electronics Chat' started by yardcat, Apr 24, 2009.

  1. yardcat

    Thread Starter New Member

    Nov 27, 2008
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    0
    I am very curious as to the how of converting a battery powered elec guitar effect to using a dual supply. The circuit, which I have attached, runs on a 9 volt battery. The supply is divided, +9v, +4.5v, and gnd. If I am using +9v,0v, and -9v, what do I need to do to adapt the circuit?

    There is a lot of information on converting to a single supply and none that I could find in converting to a dual supply. Any help would be appreciated. I am sure you can tell, my grasp of electrical engineering is weak. Thanks, yardcat
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Use only the +9V and ground wires, power the 9V lines directly (if the power supply is regulated) and use a voltage regulator (like LM317) to regulate the 9V to 4.5V.
     
  3. Wendy

    Moderator

    Mar 24, 2008
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  4. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    The "quick" conversion would be to wire two 9v batteries in series (one +/red lead to one -/black lead).

    Remove the portion of the circuit that's dividing the single 9v supply to 4.5v.

    Connect the common connection between the two batteries to what was the +4.5v supply, which will now be 0v/ground.

    Connect the + (red) lead of the two batteries to what was the +9v supply.

    Connect the - (black) lead of the two batteries to what was the ground, which will now be -9v.

    This doesn't address the shield connections; they would now be connected to -9v instead of the new 0v/ground. You're probably using 1/4" mono phono plugs/jacks. Those would need to be rewired.

    C9 should be replaced with a non-polarized capacitor.
     
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