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  1. #1
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    opamp as comparator with waveform

    I'm using an OPAMP 741 as a comparator whose output is directly fed to a sqaure-wave inverter's transistor switches. As the magnitude of positive saturation voltage of 741 is not equal to that of the negative saturation voltage , there appears to be some unsymmetry in the output of the inverter voltage waveform.
    So, is there a way to make these two saturation voltages equal in magnitude ? Hopefully, this will produce a more symmetrical waveform .
    So, please help!!!

    •   Alt22nd November 2007, 05:40

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  2. #2
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    741 comparator

    use clippers....



    •   Alt22nd November 2007, 08:29

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    741 as a comparator

    Could u plz elaborate?
    The thing is i'm trying to raise the input voltages to +5V and -5V while my current voltage inputs are +4.15V and -3.15V for opamp 741 using +5V & -5V power supply.



    •   Alt22nd November 2007, 09:48

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  4. #4
    bas
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    op amp as a comparator

    hi
    usually the output voltage in saturation is vcc-1V
    so if you want to get a 5V output you should use a 6V power supply

    to make sure you jave the right voltage (5V), you can connect the output of your comparator to two 5V zener diodes to form a clipper on one condition use a 6V power supply

    this should do it
    and one more thing, don't forget to put a 1K ohm resistor at the base of your transistors

    feel free to send me an email if you still have any questions



  5. #5
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    clipper+op-amp

    This is not at all a problem, first of all.:D

    The best answer is to use clippers at the O/P.

    For eg. use Zener diodes in parallel for both the polarities.



  6. #6
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    op amp 741 saturation

    what is the output swing you are expecting... because if you are want equal swing with output level being less than |3.15| then using clipper would solve your problem...

    clipper is nothing but a zener at the output....



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