Help with 741 opamp

Discussion in 'General Electronics Chat' started by stevejnr, Sep 21, 2011.

  1. stevejnr

    Thread Starter New Member

    Sep 8, 2011
    3
    0
    Hi folks

    I'm trying to create a voltage increase circuit using the 741 op amp in a non inverted configuration. This is the first curcuit I've ever made so I'm a complete novice...

    So, I've got a small question. When I hook the op amp up to the supply, using a 12v dc computer supply with the GND/-12v?? connected to pin 4 and the +12v to pin 6 the volatage going in to pin 6 is 12.15V. However there is an output voltage on pin 6 of 11.53. Is this the correct characteristics of the opamp? How would I make the output 0, so that only the voltage I'm trying to increase is on the output?
     
  2. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
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    Can you make a drawing of your setup. Need that to say what is wrong.
     
  3. MrChips

    Moderator

    Oct 2, 2009
    12,447
    3,362
    You need a dual power supply, +12V and -12V.
    Or replace the 741 opamp with one that will work on single supply, try LM324.
     
  4. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Hi stevejnr,

    Sounds like you have the pins confused Pin 7 is the V+ supply, and pin 4 is the V- supply.

    Here's an example circuit that is a "voltage follower"; basically, you get out what you put in:
    [​IMG]

    If you want to increase the amplitude of the input signal, you use divided feedback with resistors. This is explained in our E-book, here:
    http://www.allaboutcircuits.com/vol_3/chpt_8/5.html
     
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