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how to boost microvolts to higher voltages?

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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.
 

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

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.
 

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

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
 

so how do i use meaningful resistor values?
 

Hi,

so how do i use meaningful resistor values?
It depends on a lot of things.
Power supply, power requirements, noise expectations, the chosen Opamp....

Often the datasheet and application notes gives hints.
For a more detailed selection there are dedicated application notes for each topic you want to focus on.

Often 10k is a good start, maybe a couple of 100uA...

Klaus
 

can you post links to the dedicated application notes for each topic you want to focus on?
 

Hi,

Every Opamp manufacturer provides such documents.
Start with the datasheet of the selected Opamp. Go to the manufacturer of the Opamp.. to the site of the selected Opamp. Usually there is a section, called "related documents", "technical documents", "application notes", "design notes" ... or similar.

And there are more informations in the internet. Please do an internet search on your own.
Don't let us fo the whole job for you.

Klaus
 

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