Operational Amplifiers Lab 7 Overview Operational Amplifiers

What are Op-amps for? Op-amps have many, many uses amplifiers in general are used to change the amplitude of voltage signals A typical application of op-amps is in audio systems Video from Jonathan Hull’s Lab 7 Step 7 Audio Amp Extra Credit Demo Sp16 Our hardware has changed a bit since this version, and the speaker is much more robust! Video from Jonathan’s Lab 7 Step 8 Audio Mixer Extra Credit Demo

How to wire a real op-amp circuit? Inverting Amplifier Test Circuit

Amplifiers make more sense with AC signals… EveryCircuit Demo of Inverting Op-Amp Notice the way the output voltage is flipped Notice the effects of saturation (output sinewave is flattened at high amplitude) …but we will start the lab with DC signals to really understand how they work Constructing dual +12V and -12V supply Using a potentiometer to get a variable voltage source Measuring voltage at the different pins of the op-amp Calculating gain, plotting Vout vs Vin, observing saturation

How our circuit looks in Circuits.IO Circuits.io simulation of Inverting Op-Amp

The Inverting Op-Amp Transfer function We will measure and plot Gain is the slope of the line Saturation at limits

Saturation When the output voltage doesn’t leave enough room for transistors in op-amp to work properly An intentional effect for heavy metal guitar amps

Other stuff Repeat with a Non-inverting Op-Amp Extra Credit Audio Amplifier and Audio Mixer circuits