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Non-Inverting Operational Amplifier In this post we will explore how a  non-inverting operational amplifier is used when you want to increase the size of a voltage signal without changing its polarity . If the input goes up, the output goes up. If the input goes down, the output goes down. This makes it one of the most common and useful op-amp configurations. In a non-inverting amplifier: The input signal is connected to the non-inverting (+) input The output is fed back to the inverting (–) input using two resistors The feedback resistors control how much the signal is amplified The key idea is simple: The op-amp adjusts its output so that the voltage on the – input matches the voltage on the + input. Gain Formula Assumed knowledge: This section builds on the rules and formulas introduced in Part 1 (Op-Amp Basics) and Part 2 (Inverting Amplifier) . We assume you are already familiar with negative feedback, ideal op-amp assumptions, and how resistor ratios set gain. The voltage...

Inverting Operational Amplifier In this post we explore another important op-amp configuration: the inverting amplifier. Before building the circuit, we’ll look at the theory, understand the equations, and explain every term clearly. This circuit is perfect for learning how op-amps control current, how virtual ground works, and how gain is set using just two resistors. Inverting Op-Amp Theory of the Inverting Amplifier The inverting amplifier does two main things: It inverts the input signal. It scales that signal by a gain set by two resistors. The key concept is virtual ground . The non-inverting input (+) is connected to ground (0V) The op-amp adjusts its output so the inverting input (–) also sits at 0V, even though it isn't physically connected to it. Because the op-amp inputs draw almost no current: All current entering through the input resistor Rin must flow through the feedback resistor Rf. This gives us a simple and powerful relationship that leads to the ga...

Operational Amplifier Basics Operational amplifiers (“op-amps”) are one of the most important building blocks in electronics. They're used everywhere from audio circuits and sensors to filters, oscillators, and control systems. Before building more advanced circuits, we need a solid grounding in how an op-amp works and how to wire its simplest configuration: the voltage follower . The final setup can be seen in the picture below. Voltage Follower In this post you’ll learn: What an op-amp is The Golden Rules of op-amps Why negative feedback stabilises a circuit How to build a voltage follower using an LM358 How to generate a safe test signal using only a voltage divider How to verify the behaviour using a multimeter or oscilloscope This is the foundation for everything related to operational amplifiers. What Is an Operational Amplifier? An operational amplifier is a high-gain differential amplifier with: Two inputs Non-inverting (+) Inverting (–) One output Very l...