Circuits / 555 and op-amps
Non-inverting amplifier
Gain = 1 + R2/R1: the output is the input times 3, in phase
Tap a part to see its voltages and currents. It is a model, not a measurement.
What do you need?
- Integrated circuit LM358Search on Amazon
- Resistor 10 kΩSearch on Amazon
- Resistor 20 kΩSearch on Amazon
- Jumper wires × 4Search on Amazon
- BreadboardSearch on Amazon
How does a non-inverting op-amp amplifier work?
In a non-inverting amplifier the signal goes into V+, and a divider from the output back to V− sets the gain: G = 1 + R2 / R1. With R2 at 20 kΩ and R1 at 10 kΩ the gain is 3. The op-amp drives its output until V− matches V+, and since V− only sees a third of the output, the output has to be three times the input. Here the generator gives a sine of 0.5 V amplitude around 1 V, so the input goes from 0.5 V to 1.5 V. The output of the LM358 goes from 1.5 V to 4.5 V, three times larger and in phase: it rises when the input rises. The 1 V offset is there because the op-amp runs from a single 9 V supply and its output cannot go below ground.
Values from the Protoboard ISO simulation: a model, not a bench measurement.
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