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  1. #61
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    Re: how to boost microvolts to higher voltages?

    Your input and feedback resistor values are very low and your voltage divider resistor values are very high and are not matched. Then your circuit does not work properly like a circuit that has a plus and minus power supply or batteries or one with an opamp to produce a very low impedance for the voltage divider.



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    Re: how to boost microvolts to higher voltages?

    so the iput resistor and feedback resistor should be higher? why?



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    Re: how to boost microvolts to higher voltages?

    Quote Originally Posted by dl09 View Post
    so the iput resistor and feedback resistor should be higher? why?
    Because they are loading the opamp which affects the voltage divider voltage.
    But the NJM4558 dual opamp is too old to have a high resistance for the input and feedback resistors, and the impedance of your voltage divider is much too high without using two batteries or using a buffer for the voltage divider.



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    Re: how to boost microvolts to higher voltages?

    so this inverting amplifier will work if i use a buffer?



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    Re: how to boost microvolts to higher voltages?

    Hi,

    so this inverting amplifier will work if i use a buffer?
    Yes, with tye suitable combination of Opamp and buffer.

    But I call it stupid ... to add a buffer instead of using meaningful resistor values.
    An additional buffer may add stability problems.

    Klaus
    Please don´t contact me via PM, because there is no time to respond to them. No friend requests. Thank you.



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