{"id":107,"date":"2024-08-26T10:40:52","date_gmt":"2024-08-26T14:40:52","guid":{"rendered":"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/?page_id=107"},"modified":"2024-09-19T14:38:31","modified_gmt":"2024-09-19T18:38:31","slug":"experiment-1-introduction","status":"publish","type":"page","link":"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/experiment-1-introduction\/","title":{"rendered":"Experiment #1 Introduction"},"content":{"rendered":"<h3>Objectives<\/h3>\n<ul>\n<li>To learn circuit simulation using LTSpice.<\/li>\n<li>To master the basic operations of lab equipment and tools.<\/li>\n<li>To understand how the lab equipment and tools work.<\/li>\n<\/ul>\n<h3>Equipment<\/h3>\n<ul>\n<li>Breadboard<\/li>\n<li>DC Power Supply<\/li>\n<li>Digital Multimeter (DMM)<\/li>\n<\/ul>\n<h3>Background<\/h3>\n<h4>I. Circuit Simulation<\/h4>\n<p>A circuit simulator is a software that provides emulation of the behavior of a real hardware circuit. Circuit analyses such as DC analysis, transient analysis, AC analysis, DC sweep analysis, etc. can be performed using circuit simulation. In this lab, the circuit simulator that will be used is <a href=\"https:\/\/www.analog.com\/en\/design-center\/design-tools-and-calculators\/ltspice-simulator.html\">LTspice<\/a>. An example of circuit simulation in LTspice is shown in Figure 1 &#8211; 1. Note that the current measurements I(R1) and I(R2) have opposite sign. This phenomenon is due to the different specified polarity for the two resistors, as shown in the Netlist. In LTspice, the 1st defined node is always referenced positive and the current through a component is always defined to flow from the positive terminal to the negative terminal.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-172 aligncenter\" src=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3123\/wp-content\/uploads\/2024\/01\/LTspice-Simulation.png\" alt=\"\" width=\"642\" height=\"310\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 1 &#8211; 1\u00a0 \u00a0A circuit simulation example in LTspice<\/strong><\/p>\n<p>There is an enormous amount of of LTspice tutorials on the internet and you are strongly encouraged to search and study them to meet your needs. Some notable examples are:<\/p>\n<ol>\n<li><a href=\"https:\/\/www.analog.com\/en\/education\/education-library\/videos\/video-series\/ltspice-getting-started-tutorial.html\">LTspice\u00ae Tutorial for Beginners by Analog Devices, Inc.<\/a><\/li>\n<li><a href=\"https:\/\/learn.sparkfun.com\/tutorials\/getting-started-with-ltspice\/all\">Getting Started with LTspice by Sparkfun<\/a><\/li>\n<li><a href=\"https:\/\/www.cxi1.co.uk\/ltspice\/dccircuits.htm\">LTSpice &#8211; DC Analysis by Andy Collinson<\/a><\/li>\n<\/ol>\n<h4>II. Breadboard<\/h4>\n<p>A breadboard, also called a solderless breadboard\/protoboard\/plugboard, is a simple device designed to let you create temporary circuits without the need for soldering. It is used for testing or building new circuits. Breadboards come in various sizes. Figure 1-2 shows the front and back of a breadboard that you will use in the lab.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-172 aligncenter\" src=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-content\/uploads\/2024\/08\/Breadboard.png\" alt=\"\" width=\"642\" height=\"310\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 1 &#8211; 2\u00a0 \u00a0Front and Back of a Breadboard<\/strong><\/p>\n<p>As seen in the left image of Figure 1 &#8211; 2, a breadboard has lots of holes. These holes are used for placing electrical components such as resistors, capacitors, inductors, diodes, transistors, etc. A breadboard has internal connections between its holes. These connections are created using metal strips connecting the holes, as seen in the right image of Figure 1 &#8211; 2.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-172 aligncenter\" src=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-content\/uploads\/2024\/08\/Breadboard-Region.png\" alt=\"\" width=\"642\" height=\"310\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 1 &#8211; 3\u00a0 \u00a0Regions of a Breadboard<\/strong><\/p>\n<p>Figure 1 &#8211; 3 shows the different regions of a breadboard. Usually, the regions highlighted in light green are used to connect electrical components while the regions highlighted in light orange are used for supply voltage connections and grounding. <\/p>\n<p>Based on the alignment of the metal strips shown in Figure 1 &#8211; 2, the following observations can be made.<\/p>\n<ol>\n<li>Every column of 5 vertical holes in the component area are connected. An example is highlighted in orange. This connection means that <strong>all 5 vertical holes represent the same node in a circuit<\/strong>.<\/li>\n<li>Every row of 25 horizontal holes in the power supply area are connected. An example is highlighted in purple. This connection means that <strong>all 25 horizontal holes represent the same node in a circuit<\/strong>.<\/li>\n<\/ol>\n<p>The breadboard used in the lab has four binding posts (3 reds and 1 black) at the top. They are used for DC or AC power supply connections. To build a connection between a binding post and the breadboard, a wire with exposed conductor is inserted into the hole at the bottom of the post followed by tightening the plastic cap to ensure good connection. The other end of the wire is then plugged into one of the nodes on the breadboard.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-172 aligncenter\" src=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-content\/uploads\/2024\/08\/Component-Placement.png\" alt=\"\" width=\"642\" height=\"310\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 1 &#8211; 4\u00a0 \u00a0Placement of a Component<\/strong><\/p>\n<p>Figure 1 &#8211; 4 shows the proper placement of a resistor on a breadboard. A proper placement of any component requires both leads of the component to be placed in different nodes. A short circuit can occur when you make an improper connection. For example, if you place the two leads of a resistor in the same node (in any two of the vertical 5 holes), a short circuit will be created across the resistor. Short circuits can burn out components and cause damage. <strong>If you ever smell smoke, you need to turn off the power supply immediately.<\/strong><\/p>\n<h4>III. DC Power Supply<\/h4>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-172 aligncenter\" src=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-content\/uploads\/2024\/08\/DC-Power-Supply.png\" alt=\"\" width=\"642\" height=\"310\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 1 &#8211; 5\u00a0 \u00a0Rohde &#038; Schwarz NGE 100 DC Power Supply<\/strong><\/p>\n<p>A DC power supply is an equipment that supplies DC voltage and current to a circuit. The DC power supply used in the lab is Rohde &#038; Schwarz NGE 100, as seen in Figure 1 &#8211; 5. This unit offers three output channels. Each channel can be configured to produce a maximum of 32 volts and a maximum of 3 amperes, with an output power up to 33W. To create a connection between a DC power supply and a breadboard, an electrical cable with banana connectors at the two ends, as shown in Figure 1 &#8211; 6, can be used.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-172 aligncenter\" src=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-content\/uploads\/2024\/08\/Banana-Connector.png\" alt=\"\" width=\"482\" height=\"233\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 1 &#8211; 6\u00a0 \u00a0Banana Connectors<\/strong><\/p>\n<p>To configure a specific output voltage or current, perform the following steps.<\/p>\n<ol>\n<li>Press the power button to turn on the power supply.<\/li>\n<li>Press one of the 3 channel <strong>[Ch]<\/strong> buttons to select a channel.<\/li>\n<li>Press <strong>[Voltage]<\/strong> or <strong>[Current]<\/strong>.<\/li>\n<li>Use the rotary knob and arrows to set a specific value.<\/li>\n<li>Use the left\/right arrows to select a specific digit.<\/li>\n<li>Use the rotary knob and up\/down arrows to change value.<\/li>\n<li>Press <strong>[Enter]<\/strong> to confirm.<\/li>\n<li>Press <strong>[Output]<\/strong> to activate the supply. <strong>If the light on [Output] is not on, no power will be supplied by the unit even after the 1st step has been performed.<\/strong><\/li>\n<li>Output voltage and current values can be changed during operation using the knob and arrows.\n<\/ol>\n<p><!-- \n\n<h5>A. Series and Parallel Connection<\/h5>\n\n --><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-172 aligncenter\" src=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-content\/uploads\/2024\/08\/Series-and-Parallel-Connection.png\" alt=\"\" width=\"803\" height=\"388\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 1 &#8211; 7\u00a0 \u00a0Series and Parallel Connection<\/strong><\/p>\n<p>A series connection, as shown in the left image of Figure 1 &#8211; 7, can be used to produce a supply voltage higher than 32V. For example, the left image of Figure 1 &#8211; 7 shows a series connection of 3 channels that can supply up to 96V. On the other hand, parallel connections are used to produce a supply current higher than 3A. For example, the right image of Figure 1 &#8211; 7 shows a parallel connection of 3 channels that can supply up to 9A.<\/p>\n<p><!-- \n\n<h5>B. Constant Voltage and Constant Current Modes<\/h5>\n\n\n<img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-172 aligncenter\" src=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-content\/uploads\/2024\/08\/CV-and-CC-Modes.png\" alt=\"\" width=\"482\" height=\"233\" \/>\n\n\n<p style=\"text-align: center;\"><strong>Figure 1 - 8\u00a0 \u00a0Channels 1 and 2 in constant voltage mode (green display); channel 3 in constant current mode (red display).<\/strong><\/p>\n\n\n\nIn most cases, the power supply unit operates in the constant voltage mode. In this mode, the unit will output a constant voltage regardless of the load resistance value it sees. The output current is determined by Ohm\u2019s Law V = IR,  and depends on the resistance of the connected load. If the load resistance becomes really small, the load will draw a current that can be excessive and large enough to cause damage. To avoid this scenario, the power supply unit should be configured such that the output current is limited to a specific maximum value. This configuration can be performed using the [Current] function on the unit. When the power supply unit outputs a constant current regardless of the configured supply voltage value and the load resistance value, the unit is said to be operating in the constant current mode. Note that the mode of operation is determined by user-specified output current limit. There is no button or menu item to toggle between these two modes. --><\/p>\n<h4>IV. Digital Multimeter (DMM)<\/h4>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-172 aligncenter\" src=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-content\/uploads\/2024\/08\/DMM.png\" alt=\"\" width=\"642\" height=\"310\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 1 &#8211; 9\u00a0 \u00a0Rohde &#038; Schwarz HMC 8012 Digital Multimeter<\/strong><\/p>\n<p>A digital multimeter (DMM) is an electronic measuring instrument that can be used to measure quantities such as voltage, current, resistance, etc. The DMM used in the lab is the Rohde &#038; Schwarz HMC 8012 digital multimeter, as shown in Figure 1 &#8211; 9.<\/p>\n<h5>A. Voltage Measurement<\/h5>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-172 aligncenter\" src=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-content\/uploads\/2024\/08\/Voltage-Measurement.png\" alt=\"\" width=\"642\" height=\"310\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 1 &#8211; 10\u00a0 \u00a0Voltage Measurement<\/strong><\/p>\n<p>A voltage is measured by placing the DMM probes in <strong>parallel<\/strong> with the device under test (DUT), as shown in Figure 1 &#8211; 10. The DMM can be configured to take a DC or AC voltage measurement. To obtain a DC voltage measurement, press the <strong>[DC V]<\/strong> button on the front panel of the DMM; to obtain a AC voltage measurement, press the <strong>[AC V]<\/strong> button instead.<\/p>\n<p>The way in which the probes are connected to the DUT defines the polarity of the voltage measurement. In standard practice, the V-\u03a9 port represents the positive terminal while the COM (stands for &#8220;common&#8221;) port represents the ground or negative terminal. Preferably, the red probe should be placed at the node with higher potential. However, it is often very hard to figure out the node that is at higher potential, especially in a complex circuit. In any case, it is not necessary to do so. The simple reason is if a voltage reading ends up to be negative, it just means that the red probe is placed at the node with lower potential.<\/p>\n<h5>B. Current Measurement<\/h5>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-172 aligncenter\" src=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-content\/uploads\/2024\/08\/Current-Measurement.png\" alt=\"\" width=\"642\" height=\"310\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 1 &#8211; 11\u00a0 \u00a0Current Measurement<\/strong><\/p>\n<p>A current is measured by inserting the DMM into the circuit such that the current being measured flows through the DMM, as shown in Figure 1 &#8211; 11. In other words, to measure a current through a DUT, the DMM is connected in <strong>series<\/strong> with the DUT. The DMM can be configured to take a DC or AC current measurement. To obtain a DC current measurement, press the <strong>[DC I]<\/strong> button on the front panel of the DMM; to obtain a AC current measurement, press the <strong>[AC I]<\/strong> button instead.<\/p>\n<p>To take a current measurement, connect the red probe to the blue 10A port and the black probe to the COM port. Preferably, the connection with the DUT should be made in a way such that current flows into the DMM through the 10A port and flows out through the COM port. However, it is often very hard to figure out the current direction, especially in a complex circuit. In any case, it is not necessary to do so. The simple reason is if a current reading ends up to be negative, it just means that the measured current flows in the direction that is opposite to the presumed direction. <\/p>\n<h3>Hand Analysis<\/h3>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-172 aligncenter\" src=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-content\/uploads\/2024\/08\/Exp1.png\" alt=\"\" width=\"321\" height=\"155\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 1 &#8211; 12\u00a0 \u00a0DC Circuit<\/strong><\/p>\n<p>For the circuit in Figure 1 &#8211; 12, use V<sub>S<\/sub> = 10V as the input voltage and choose any resistor values within the range of 1 k\u2126 to 10 k\u2126 unless specified otherwise. Assign the same value to all resistors with the same name and different values to those with different names. Perform the following steps.<\/p>\n<ol>\n<li>Calculate I<sub>X<\/sub> and I<sub>Y<\/sub>.<\/li>\n<li>Compare the magnitudes and signs of both I<sub>X<\/sub> and I<sub>Y<\/sub>. Do the comparisons make sense? Explain your reasoning in detail.<\/li>\n<li>Calculate V<sub>1<\/sub> and V<sub>2<\/sub>.<\/li>\n<li>Compare the magnitudes and signs of both V<sub>1<\/sub> and V<sub>2<\/sub>. Do the comparisons make sense? Explain your reasoning in detail.<\/li>\n<\/ol>\n<h3>Simulation<\/h3>\n<p>Simulate the circuit in Figure 1 &#8211; 12 using a circuit simulator. Determine the values for I<sub>X<\/sub>, I<sub>Y<\/sub>, V<sub>1<\/sub> and V<sub>2<\/sub>. Compare all the simulation results with those determined in Hand Analysis.<\/p>\n<h3>Hands-on Experiment<\/h3>\n<p>Construct the circuit in Figure 1 &#8211; 12 using the necessary equipment and tools. Measure the values for I<sub>X<\/sub>, I<sub>Y<\/sub>, V<sub>1<\/sub> and V<sub>2<\/sub> using a DMM. Compare all the measured values with those determined in Hand Analysis and Simulation.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Objectives To learn circuit simulation using LTSpice. To master the basic operations of lab equipment and tools. To understand how &hellip; <a href=\"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/experiment-1-introduction\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Experiment #1 Introduction<\/span><\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-107","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-json\/wp\/v2\/pages\/107","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-json\/wp\/v2\/comments?post=107"}],"version-history":[{"count":60,"href":"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-json\/wp\/v2\/pages\/107\/revisions"}],"predecessor-version":[{"id":336,"href":"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-json\/wp\/v2\/pages\/107\/revisions\/336"}],"wp:attachment":[{"href":"https:\/\/www.ece.ucf.edu\/labs\/EEL3004\/wp-json\/wp\/v2\/media?parent=107"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}