Battery Voltage Sense Diff Amp

Thread Starter

pbishop

Joined Oct 23, 2023
3
Hi, Circuit is intended to measure a high voltage battery voltage and input it to an ADC to monitor the voltage.

Hoping someone can confirm that I am viewing this circuit appropriately, assuming ideal op amp rules apply. Trying to come up with an equation to relate the Input Voltage to the output voltage.
Actual Circuit
1698089178914.png
Circuit w/ Op Amp Converted to Ideal Components.
1698089186391.png

I'm thiking I need to solve a system of equations, just not sure how messy that is going to get?
 

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Ian0

Joined Aug 7, 2020
9,502
Delete Rb and Rd, then it's just Rc/Ra.
Is the battery voltage fully floating? If so, the common-mode voltage range of the op-amp may be a problem.
 

Thread Starter

pbishop

Joined Oct 23, 2023
3
Yes, the battery is floating. I'm inheritting this circuit so I don't have the luxury of making changes for now.
 

Thread Starter

pbishop

Joined Oct 23, 2023
3
My intention of having the "Vout" voltage source is to represent what the output voltage needs to be across the feedback resistor to drive the"Input Terminal Nodes" to the same voltage.
 
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