I know the math kinda sorts itself out when you calculate the closed loop gain using control systems techniques and such, but I’m looking to understand how it physically happens
I look at it this way: when you first apply your input (suppose it’s a non inverting configuration), your output is still 0 so there is no feedback path yet, which means the output is exactly your input. How does it then proceed to make the difference between the two inputs of the op amps small enough so that the output doesn’t derail given the op amp’s very high internal gain ? and how comes it knows exactly this point of equilibrium where the difference is just enough?
In: Engineering
If the + (non-inverting) input is higher than the – (inverting) input, the voltage on the output rises, and will keep rising until the voltage on the inputs is equal. if the – is higher than the +, the voltage on the output will decrease until the voltage on the inputs is equal. It doesn’t know beforehand how much it needs to adjust the output, it’s just constantly getting new information as the voltage on its inputs changes.
Yes, opamps can overshoot, causing an oscillation. It’s up to the person using an opamp in their circuit design to account for this.
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