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Component 1: Operational Amplifiers

3 dot points across 3 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How does negative feedback set the gain of inverting and non-inverting op-amp amplifiers?

Inverting and non-inverting amplifiers: negative feedback, the virtual earth, the closed-loop gain equations, and the voltage follower (buffer).
A focused answer to WJEC A-Level Electronics inverting and non-inverting op-amp amplifiers, covering negative feedback, the virtual earth concept, the closed-loop gain equations for both configurations, and the voltage follower used as a buffer.
12 min answer →

What are the properties of an ideal op-amp, and how does it work as a comparator and Schmitt trigger?

Operational amplifier properties and the comparator: the ideal op-amp, open-loop gain, the comparator with and without hysteresis, and the Schmitt trigger.
A focused answer to WJEC A-Level Electronics operational amplifier properties and the comparator, covering the ideal op-amp model, open-loop gain, the inverting and non-inverting comparator, hysteresis, and the Schmitt trigger.
12 min answer →

How do summing, difference and instrumentation amplifiers combine or compare several signals?

Summing, difference and instrumentation amplifiers: the summing (mixer) amplifier, the difference amplifier, and the instrumentation amplifier for small differential signals.
A focused answer to WJEC A-Level Electronics summing, difference and instrumentation amplifiers, covering the summing (mixer) amplifier at a virtual earth, the difference amplifier that amplifies the difference of two inputs, and the instrumentation amplifier for small differential sensor signals.
12 min answer →