Experiment1: Introduction to laboratory equipment and basic components.

Transcription

1 Experiment1: Introduction to laboratory equipment and basic components. 1 OBJECTIVES. This experiment will provide exposure to the various test equipment to be used in subsequent experiments. A primary purpose of this lab course is for you to master the use of electronic test equipment. The devices we will be using include DC power supplies, breadboards, digital multi-meters DMM, oscilloscope and a function generator, as well as some resistors, capacitors and inductors, so we can have something to measure on. By the end of this experiment you should be able to tell how to use the equipment to measure voltage, current resistance, inductance, capacitance, frequency, period, rms voltage, peak-peak voltage, phase, as well as knowing how to generate waveforms using the function generator. NOTE: THIS LAB AND THE APPENDICES SERVE AS INTRODUCTIONS TO THE TEST EQUIP- MENT. IF YOU ARE IN DOUBT ABOUT HOW TO USE A DEVICE IN A SAFE AND APPROPRIATE MANNER, ASK YOUR LAB INSTRUCTOR, OR BETTER YET, READ THE MANUAL. ALTHOUGH IT IS UNLIKELY THAT YOU WOULD INJURE YOURSELF WITH THE EQUIPMENT IN THIS LAB, YOU MIGHT DAMAGE THE EQUIPMENT. ALSO, YOU MAY SOMEDAY USE EQUIPMENT THAT COULD INJURE OR KILL YOU IF USED IMPROPERLY. 2 INTRODUCTION AND TEST CIRCUITS. The purpose of this experiment is to learn to use the test equipment, in order to do that we need a source of measurements. So we need to build some circuits using resistors and a power supply or the function generator. In this lab we will be measuring voltages (peak-peak, avg(dc), rms(ac)), current(dc), frequency, period, phase. 3 PREPARATION. Be sure to read over the appropriate appendices in your lab manual. These will introduce you to the breadboard you will use to construct your circuits, to reading component values off of the components themselves, and to the equipment to be used. 4 PROCEDURE. 4.1 Recognition of basic components Here we are going to get aquainted to some of the basic components used in electronics such as the resistors, capacitors and inductors. We will learn how to read the values using the codes as well as how to measure them using the LRC bridge and the ohmmeter in the case of resistance. 1

2 4.1.1 Resistors You will be given some resistors, use the color code as well as instruments to find their values and fill out the table Capacitors You will be given some capacitors, use the numeric code as well as instruments to find their values and fill out the table Inductors You will be given some inductors, use the color code as well as instruments to find their values and fill out the table Measurement of s and s DC Before you start make sure you read and understand how to use the breadboard, the power supply, the function generator, the digital multimeters and the oscilloscope. Keep in mind you will be needing to connect in series the amp-meter in different places to make the measurements required, so think of a good way to place the resistors on the breadboard. Build the circuit on fig 1-1, make the measurements required to fill the table 1-4. Build the circuit on fig 1-2, make the measurements required to fill the table AC Before you start make sure you read and understand how to use the breadboard, the power supply, the function generator, the digital multimeters and the oscilloscope. Keep in mind you will be needing to connect in series the amp-meter in different places to make the measurements required, so think of a good way to place the resistors on the breadboard. Build the circuit on fig 1-3, make the measurements required to fill the table 1-6. Build the circuit on fig 1-4, make the measurements required to fill the table Other AC measurements Build the circuit in fig 1-5. you will use this circuit for the rest of the lab. 2

3 4.3.1 Peak-Peak voltage Definition: The peak-peak voltage is defined as the difference between the maximum and the minimum voltages of a waveform. Use the to measure the peak-peak voltages required to fill the table Frequency Definition: The times a signal crosses the same point over a period of time divided by that period of time. Use the oscilloscope and the DMM to measure the frequency and fill the table 1-9 with the readouts Period Definition:The time a waveform takes to reach the same point again. Use the oscilloscope and the DMM to make the measurements needed to fill out the table Phase Definition:The delay, in degrees, between two signals. Use the oscilloscope to measure the phase between the signal in the component and the function generator.use the signal from the function generator as the reference. Fill the table hint: To measure the phase in the resistor place the oscilloscope ground lead in the node where the function generator and the resistor are joined. Connect the channel 1 lead to the other resistor terminal and the channel 2 lead to the other function generator terminal and disconnect the external trigger connection cable. To measure the phase in the capacitor place the oscilloscope ground lead in the node where the function generator and the capacitor are joined. Connect the channel 1 lead to the other capcitor terminal and the channel 2 lead to the other function generator terminal and disconnect the external trigger connection cable. 5 Analysis Be sure to fill out all the tables in the procedure section. In your write up include also an analysis of the accuracy of your measurements, i.e. How accurate you expect your measurments to be. Just as example think on the color code of the resistors, they have a tolerance value band, so if a resistor has a 5% tolerance its actual value is expected to be in the range of its nominal value ± 5%. Consult the instruments manual so you can figure out the accuracy of your measurements. Explain the results obtained in table

4 Resistor 1 Resistor 2 nominal measured color code Ohm meter LCR bridge Table 1-1: Comparison between nominal and measured values. Capacitor 1 Capacitor 2 nominal numeric code measured LCR bridge Table 1-2: Comparison between nominal and measured values. Inductor 1 Inductor 2 nominal color code measured LCR bridge Table 1-3: Comparison between nominal and measured values. Table 1-4: Measurements on a basic serial circuit. Table 1-5: Measurements on a basic parallel circuit. Table 1-6: Measurements on a basic serial circuit. Table 1-7: Measurements on a basic parallel circuit. 4

5 Resistor Capacitor Function generator Table 1-8: Peak-peak voltage measurements. DMM Resistor Capacitor Function generator Table 1-9: Frequency measurements. DMM Resistor Capacitor Function generator Table 1-10: Period measurements. Resistor Capacitor Table 1-11: Phase measurements. Figure 1-1: DC serial circuit 5

6 Figure 1-2: DC parallel circuit. Figure 1-3: AC serial circuit Figure 1-4: AC parallel circuit. 6

7 Figure 1-5: Basic AC circuit 7