ME2345 Intro to Mechatronics
Laboratory Experiment 4
Introduction to Op Amps
2.1 Objectives
In this laboratory exercise, you will use operational amplifiers to build common circuits for mechatronic
applications. You will also use the function generator to create constant, sinusoidal, and ramp input signals,
and the oscilloscope to measure the circuits' outputs.
2.2 Introduction
We will use the Analog System Lab Kit, which uses the Texas Instruments TL082 OP-Amps:
TL082 is a dual op amp in an 8-pin Dual In-line Package (DIP). This is a standard electronic component
housing featuring two parallel rows of four pins each. This package is widely used for integrated circuits (ICs)
like timers and operational amplifiers because its 0.1-inch pin spacing and 0.3-inch row spacing make it
compatible with breadboards and easy to solder by hand. Pins are numbered counterclockwise starting from
the top-left, typically identified by a small notch or dot at one end of the chip.
Supply voltage:
±2.25V to ±20V
Closed-loop gain vs. frequency
2
8
A
3
1
4
Figure 4.1 Texas Instruments TL082 Operational
amplifier packaging, pin-out, and main electrical
characteristics.
2.3 Laboratory Procedure / Summary Sheet
Group:
Names:
(1) Construct an inverting amplifier circuit in the lower left corner of the board. Use 𝑅𝑅𝐹𝐹 = 𝑅𝑅14 = 4.7 𝑘𝑘Ω,
and 𝑅𝑅 = 𝑅𝑅11 = 1 𝑘𝑘Ω. What is the gain of the amplifier: Gi =_______________
Figure 4.1 Inverting amplifier
First, apply a 1 Vpp 1kHz sinusoidal signal from the function generator and measure both the input and
the output on the oscilloscope. Sketch the input and output signals in different colors:
Determine the maximum output swing voltage by increasing the amplitude of the input in small steps and
noting where the sinusoidal output is first distorted. What is the maximum peak-to-peak voltage of the
output:___________.
Why:______________________________________________________________________________
Change the input to a Square function with a 1 Vpp and a frequency of 50kHz. Magnify the oscilloscope
time scale and observe the shape of the output (rise time).
(2) Construct a noninverting amplifier circuit on the lower mid-section of the board. Use 𝑅𝑅𝐹𝐹 = 𝑅𝑅34 =
2 𝑘𝑘Ω, and 𝑅𝑅 = 𝑅𝑅31 = 1 𝑘𝑘Ω. What is the gain of the amplifier: Gn = _______________
Figure 4.2 Noninverting amplifier
Apply a 1 Vpp 1kHz Ramp signal from the function generator and measure both the input and the
output on the oscilloscope. What is the output’s Vpp_=_________.
Sketch the input and output signals in different colors:
(3) Construct the difference amplifier used to subtract analog signals. Use R1 = R31 = 1kΩ, RF =R35 = 1kΩ,
and R2 = R38 = 2 kΩ.
Figure 4.3 Difference amplifier
What is the relationship between Vout, V1, and V2:
Attach a 1Vpp 1kHz sine wave to both inputs and explain what you would expect and note any
discrepancies with the measured signal:
Sketch the inputs and output signals in different colors: