Download Op Amp Circuits Lab: Inverting, Noninverting Amplifiers - Georgia Southern Univ. - Prof. M and more Lab Reports Engineering in PDF only on Docsity! TMAE 5132G Essentials of Applied Electrical Engineering Laboratory Laboratory # 4 Op Amp Circuits Spring 2009 Mechanical and Electrical Engineering Technology Georgia Southern University Page 1 of 4 Name: _____________________ PRE-LAB Before going to the lab do the following: a) Read Sections 5.1 to 5. 4 of the textbook (Fundamentals of Electric Circuits by Alexander) b) Using MultiSim, simulate the circuits given in figures 2 to 6. The simulation will help you to understand what you should obtain in the experiment. Introduction The operational amplifier of op amp is a high performance linear amplifier with an amazing variety of uses. The op amp has two inputs, inverting ( – ) and non-inverting (+), and one output as shown in figure 1. The polarity of a signal applied to the inverting input is reversed at the output. A signal applied to the non- inverting input retains its polarity at the output. The gain (degree of amplification) of an op amp is determined by a feedback resistor that feeds some of the amplified signals from the output to the inverting input. This reduces the amplitude of the output signal, hence the gain. The smaller the feedback resistor, the lower the gain. This lab introduces the operational amplifier. The op amp circuit is already constructed for you on a single IC (integrated circuit) and in this lab we will use the IC in several of its most popular configurations. For an introduction to op amps, refer to Chapter 5 of the Alexander. The pinout diagram for the LM741 op amp IC is shown in figure 1. Use this to construct the op amp circuits in this experiment. Figure 1. Pinout for the 741 op amp 1.- Inverting Amplifier ( Sec. 5.4 in Alexander) A basic inverting amplifier is shown in figure 2. Construct this circuit in your breadboard. At first, use R1 = 1kΩ and R2 = 33kΩ. Derive the gain formula: Av = – R2/ R1 and experimentally verify the gain for a 100mV, 100Hz, sine wave. Also calculate and measure the gain with R1 = 10kΩ and R2 = 100kΩ. For your lab report, give your derivation and compare the two calculated and measured gains. Why is this called an inverting amp? TMAE 5132G Essentials of Applied Electrical Engineering Laboratory Laboratory # 4 Op Amp Circuits Spring 2009 Mechanical and Electrical Engineering Technology Georgia Southern University Page 2 of 4 Figure 2. The inverting amplifier 2.- Noninverting Amplifier ( Sec. 5.5 in Alexander) Construct the noninverting amplifier shown in figure 3. At first, use R1 = 1kΩ and R2 = 33kΩ. For your report, derive the gain formula: Av = 1+ R2/ R1 and experimentally verify the gain for a 100mv, 100Hz, sine wave. Also calculate and measure the gain with R1 = 10kΩ and R2 = 100kΩ. Figure 3. The noninverting amplifier
