{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Lab 0.9: Lab Equipment Overview\n", "\n", "### EECS 16A: Designing Information Devices and Systems I, Fall 2015" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "**Name 1**:\n", "\n", "**Login**: ee16a-\n", "\n", "\n", "**Name 2**:\n", "\n", "**Login**: ee16a-" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "\n", "## Table of Contents\n", "\n", "* [Instructions](#instructions)\n", "* [Lab Policies](#policies)\n", "* [Introduction](#intro)\n", "* [Lab Equipment](#equipment)\n", "* [Breadboaring](#breadboarding)\n", "* [Testing the Power Supply and Multimeter](#test1)\n", "* [Testing the Function Generator and Oscilloscope](#test2)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "\n", "##Instructions\n", "* Complete this lab by filling in all of the required sections, marked with `\"YOUR CODE HERE\"` or `\"YOUR COMMENTS HERE\"`.\n", "\n", "\n", "* When you finish notify your GSI to get get checked off for this lab. Be ready to answer a few questions to show your understanding of each section.\n", "\n", "\n", "* Labs will be graded based on completion for teams of 2 students\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "\n", "## Lab Policies\n", "* YOU MUST ATTEND THE LAB SECTION YOU ARE ENROLLED IN. If you anticipate missing a section please notify your GSI in advance.\n", "\n", "* You are required to return all parts checked out at the beginning of the lab section unless told otherwise.\n", "\n", "* ** Food and drinks are not allowed in the lab.**\n", "\n", "* **Clean up, turn off all equipment, and log off of computers before leaving.**" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "\n", "## Introduction\n", "Today we are going to get comfortable with the lab equipment at our stations by testing the functionality of the Power Supply, Multimeter, Function Generator, and Oscilloscope.\n", "\n", "

Lab Equipment

\n", "
\n", "Below is a brief introduction to the equipment that you will be using throughout the labs for this course.\n", "
\n", "\n", "\n", "####Power Supply\n", "Each lab station is equipped with an Agilent E3631A power supply, located on the bottom shelf. You can think of this device as a controllable battery that allows you to specify its voltage and current outputs (more on voltage and current later). \n", "\n", "
\n", "\n", "
\n", "\n", "Below is a brief summary of the steps you should take each time you use the power supply:\n", "
\n", "\n", "1. Set a current limit:\n", "This device allows you to limit the amount of current it outputs, which is very useful to prevent accidentally destroying parts when a circuit is connected incorrectly.\n", "

\n", "\n", "2. Select an output:\n", "This device is capable of outputting 3 different voltages with maximum values of 6V, 25V, and -25V respectively. Make sure to push the button for the output you would like to use.\n", "

\n", "\n", "3. Set the voltage:\n", "After selecting the correct output, set the voltage to the desired value. Do this by using the arrows to the right to select the digit and use the know to adjust the value of that digit. Make sure you are adjusting voltage and NOT current.\n", "

\n", "\n", "4. Turn the output on:\n", "By default the output of the device is turned off. For the device to actually output current, press the \"Output On/Off\" button.\n", "

\n", "\n", "\n", "\n", "####Multimeter\n", "There also exists devices capable of measuring voltages and currents. A multimeter is one such device that is capable of measuring voltage, current, resistance, and in our case even capacitance. The [Agilent 34405A](http://cp.literature.agilent.com/litweb/pdf/34405-91000.pdf) digital multimeter available at your station is very useful for \"debugging\" a circuit.\n", "
\n", "\n", "
\n", "\n", "Below is the series of steps one must follow to take a measurement with the multimeter.\n", "
\n", "\n", "1. Connect a black test lead to the black port on the device.\n", "

\n", "\n", "2. Connect a red test lead to one of the red ports on the device\n", "The ports are each labeled with what they should be used to measure. The top right port should be used to measure voltage, resistance, capacitance, etc. The other two ports should be used for current measurements and are capable of measuring up to a the marked maximum value.\n", "

\n", "\n", "3. Select the quanitity you wish to measure (e.g. DC voltage, current, resistance, etc)\n", "Do this using the buttons on the machine: \"DC V\" for voltage, \"DC I\" for current, and \"Ω\" for resistance.\n", "

\n", "\n", "4. Connect the multimeter to your circuit.\n", "Measuring voltages requires that the test leads are connected to the circuit in parallel as shown for the $V$ measurement, while current measurements require the test leads to be connected in series as shown for the $A$ measurement. To measure resistance, connect the leads as if measuring a voltage. Use this diagram when you are ready to make a measurement.\n", "

\n", "
\n", "\n", "
\n", "\n", "\n", "####Oscilloscope\n", "The oscilloscope is another useful piece of test equipment that can be used to measure signals that vary over time. Unlike the multimeter which only shows the instantaneous voltage value, the oscilloscope shows a graph of a voltage versus time. This is particularly useful for measuring how devices like sensors respond to inputs. Although this instrument may appear complicated, half of the knobs are just to adjust the axes of the voltage plot. \n", "
\n", "\n", "
\n", "Below is a brief overview of how to use this oscilloscope:\n", "

\n", "1. Connect the probe to one of the 4 input channels\n", "

\n", "2. Make sure that the channel is on (indicated by a green light on the channel number).\n", "To turn on a channel, simply press one of the numbered buttons. To turn it off push the button twice.\n", "

\n", "3. Adjust the horizontal axis of the plot\n", "The knob at the top left controls the horizontal time axis and allows you to zoom in or out. The time increments represented by the tick marks on the plot are indicated at the top of the screen.\n", "4. Adjust the vertical scale\n", "The larger of the two knobs for each channel allows the vertical scale of the voltage graph to be adjusted. As with the horizontal scale, the number of volts per tick mark on the graph is marked at the top of the screen.\n", "

\n", "5. Adjust the offset\n", "In some cases signals will appear off screen; adjusting the smaller of the two knobs corresponding to each input will shift signals up or down on the plot.\n", "

\n", "6. Add measurements such as average voltage, amplitude, etc.\n", "Measurements can be added by pushing the \"Meas\" button and using the buttons at the bottom of the screen to select and add measurements.\n", "
\n", "\n", "####Function Generator\n", "The Function Generator is a device that enables us to output a voltage that varies with time (in contrast to the Power Supply which outputs a constant voltage). When an electric signal varies with time, it is labled \"AC\" for Alternating Current. When an electric signal is constant with time, it is labled \"DC\" for Direct Current. Here a simple graphic showing the difference.\n", "
\n", "\n", "
\n", "
\n", "\n", "
\n", "

\n", "Below is the series of steps to output an AC signal from the function generator:\n", "1. Turn on the machine (hold the power button for about 2 seconds).\n", "

\n", "2. The buttons on the right of the screen and bottom of the sreen follow the general pattern of menu buttons on the right, selection buttons on the bottom. Push the \"Waveform\" menu button and then use the bottom left selection button to select the desired waveform. \n", "

\n", "3. Use the \"Parameters\" menu buttonset specific properties of your output, such as amplitude, frequency, bias, etc. Just like the Power Supply, use the arrows to select a digit and the wheel to select a value.\n", "

\n", "4. When you are ready to output, connect your probe to channel 1. Push the channel 1 button above the probe connection and use the left selection button to set the output to ON.\n", "

\n", "\n", "

Circuit Symbols and Concepts

\n", "The table below shows two circuit symbols you will become very accustomed to over the next semester.\n", "
\n", "\n", "
\n", "
\n", "You will learn more formal definitions of resistance, voltage, and current in lecture, but here we will provide you of the water anology mentioned in lecture, which compares an electrical system or \"circuit\" of electrons and wires to a water system of water and pipes. In this comparison, electric current is akin to the flow rate of the water, voltage is the pressure forcing the water through the pipes, and resistance is the width of the pipes.\n", "
\n", "\n", "\n", "
\n", "In addition to these concepts, for the sake of verifying our measurements, we will introduce you to Ohm's law. Ohm's law describes the relationship between voltage, current, and resistance across a certain path, stating that $V = IR$. Again, Ohm's law will be taught formally in lecture, but in essence the equation states that voltage is directly porportional to current and resistance.\n", "\n", "\n", "

Breadboarding

\n", "Throughout this semester we will be using a [breadboard](https://learn.sparkfun.com/tutorials/how-to-use-a-breadboard) to construct our circuits. Breadboards are very useful for prototyping circuits as they provide a convenient way to connect components.\n", "
\n", "\n", "
\n", "Top of the breadboard (left), bottom of the breadboard (right)\n", "
\n", "
\n", "As shown above, each of the holes in horizontal rows until the gap in the middle are electrically connected by a strip of metal on the back side of the board. Rather than just touching wires together or soldering them to a printed circuit board, you can connect two components together by pushing the wires into the same row of a breadboard. The two long vertical strips on either side of the board connect all of the holes in that vertical column together. These are very useful for components with many connections such as power and ]ground] of a voltage source.\n", "

\n", "\n", "

Practical Tips


\n", "We highly recommend placing components on the board in some kind of organized and systematic way as shown in the image on the left.\n", "
\n", "\n", "
\n", "It's both easier to translate a circuit diagram to a logical pattern on a breadboard, and easier to figure out problems after building the circuit. \n", "\n", "There are plenty of resources online if you are interested in more information about breadboards. This [video](https://www.youtube.com/watch?v=spw0IrA85ks) gives a nice introduction and [this tutorial]( https://learn.sparkfun.com/tutorials/how-to-use-a-breadboard) has a more detailed explanation including some interesting historical notes.\n", "

" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "\n", "

Testing the Power Supply and Multimeter

\n", "Follow these steps to test the Power Supply and Multimeter:\n", "
\n", "1. Grab one resistor from the component drawer on the TA desk, with a value less than 3000 Ohms (3k Ω). Go to the back wall of the lab and grab one red Power Supply lead, one black Power Supply lead, one red Multimeter lead, and one black Multimeter lead.\n", "

\n", "2. Follow the steps mentioned in the Power Supply section to set the voltage to +5V (use the 6V terminals).\n", "

\n", "3. Follow the steps mentioned in the Multimeter section to measure and record the voltage across the resistor. See image below for hookup details. Try to maintain wire color, but the circuit will still work properly otherwise; it just helps with debugging.\n", "
\n", "\n", "
\n", "

\n", "4. Follow the steps mentioned in the Multimeter section to measure and record the current flowing through the resistor. See image below for hookup details.\n", "
\n", "\n", "
\n", "

\n", "5. Use Ohm's law, $V = IR$, to determine the theoretical value of the resistor.\n", "

\n", "6. Use the Multimeter to measure and record the actual value of the resistor. See image below for hookup details.\n", "
\n", "\n", "
" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "**Are there any discrepencies in the theoretical value of the resistor and the actual measured value? Why or why not?**\n", "\n", "YOUR COMMENTS HERE\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "\n", "

Testing the Oscilloscope and Function Generator

\n", "Follow these steps to test the Oscilloscope and Function Generator:\n", "
\n", "1. Grab one Oscilloscope probe and one Function Generator probe from the back wall of the lab.\n", "

\n", "2. Hookup the Oscilloscope to the Function Generator using the image below as a reference.\n", "
\n", "\n", "
\n", "

\n", "3. Follow the steps above to have the Function Generator output a 10kHz sinewave with an apmlitude between 1-10V (make sure you set \"Output = On\").\n", "

\n", "4. Follow the steps above to display this sinewave on the Oscilloscope. Don't forget to Autoscale.\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "**Is this an AC or DC signal? Why or why not?**\n", "\n", "YOUR COMMENTS HERE" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Congrats, you're finished! Please have a GSI or AI come by to check you off. Make sure to put everything away before you leave!" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [] } ], "metadata": { "kernelspec": { "display_name": "Python 3", "language": "python", "name": "python3" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.4.3" } }, "nbformat": 4, "nbformat_minor": 0 }