DOC PREVIEW
Berkeley ELENG 100 - LAB 1 Solar Power Supply

This preview shows page 1-2 out of 6 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 6 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 6 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 6 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

LAB1after.pdfprelab1.pdfUC Berkeley, EECS 100 LabB. BoserLaboratory Organizationfor all labs. These instructions serve dual purpose as pre-lab instructions and lab guide. Here is what you have to do:1. Preparation (“pre-lab”): Download the instructions and read them to be ready for the laboratory. For manylabs you will be asked to analyze and design the circuits you will be building. Complete all these assignmentsbefore the lab and make sure to enter all your results into a printed copy of the lab instructions or on separatesheets appended to the instructions. Please get help in office hours before the lab if you have questions.2. Prelab submission: Answers to numerical and textual pre-lab questions boxes are submitted at the beginningof the lab period. Copy your answers to the prelab questions (in the blue boxes) to the Prelab Summary pageat the end of the lab document.3. Laboratory: Follow the instructions and perform all required measurements. Ask the lab GSI for help if you haveproblems with equipment, parts, or your circuits. The instructions also ask for the GSI to verify certain measurements.Demonstrate your working circuit and ask the GSI to acknowledge its correct operation in the box provided.4. Report: Collect your measurement results, interpretations, etc. on the printed lab instructions and addadditional sheets as needed. Turn in the completed instructions with all questions answered to the lab GSI.You can do this at the end of the laboratory, or up to one week after the lab.Power Supply LaboratoryElectronic equipment needs power to operate. Most systems require a specific supply voltage. For example, the“power brick” of my laptop supplies 20 V to my computer to operate. Check the labels of supplies you own forthe voltages used by different electronic devices.In this laboratory we first familiarize ourselves with the programmable laboratory supply (E3631A) and thendesign a solar powered supply. We will also learn how to use the digital multimeter (DVM, 34401A). Downloadthe instructions for these instruments from the EE 40 website (section manuals).DVM and Laboratory Power SupplyThe DVM measures voltage or current and is indispensable in the lab. Most can also be set to measure resistance.We use the DVM not only to check the output of circuits we design, but also to verify our setup. Does the voltagesupplied to the circuit have the correct value? Is the supply current in the expected range? When set to measureresistance the DVM can be used to check wiring. Are two components properly wired to one another? Did Iinadvertently short the supply? Such simple checks can save hours debugging.To try out the DVM, program the laboratory supply to 5 V and set the maximum current to 20 mA. In this as infuture labs, always set a current maximum when using the laboratory supply, typically about 50 percent above thecurrent you expect your circuit to draw. This prevents your design from going up in smoke if you inadvertentlymake a wrong connection. Veri fy the output voltage of the supply with the DVM. Can you make the DVM displaya negative voltage?1February 4, 2009 LAB1 v1251NAME 2:The document you are looking at are the instructions for the first laboratory in EE 100. You will use similar instructionsSID:SID:NAME 1:LAB1: Solar Power SupplyFigure 1 A resistor with value 680Ωand 5 % tolerance (colors blue-grey-brown-gold).Next we need to verify that the output voltage stays constant independent of the current flowing (up to the setmaximum). We do this by connecting a resistor across the output terminals of the supply. Figure 1 shows apicture of resistors like those we use in the lab. The colored rings encode the value of the resistor. You canfind that code e.g. on Wikipedia under “electronic color code” or “resistor”. Use the Ohmmeter (multimeter setto measure resistance) if you are not sure about the value of a resistor. You will find that only certain resistorvalues are available. Most resistor types are only made with values 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82and decimal multiples or fractions thereof. In many situations the closest value can be substituted (e.g. 4.7 kΩ for5 kΩ). Alternatively it is possible to combine two or more resistors in series and/or parallel to synthesize a desiredvalue (e.g. two 10 kΩ resistors connected in parallel produce exactly 5 kΩ). When you design a circuit you needto round calculated component values to available ones and decide if the rounding error is acceptable or a moreprecise value must be synthesized from several parts.What is the value of the resistors shown in Figure 2? Include the unit in your answer, e.g. mV, MW, kOhm. Useproper capitalization, and include the correct unit even if the result is zero (e.g. 0 V).1 pt.0Figure 2 Color coded resistors (colors orange-orange-red-gold).Assume a kΩ resistor is connected across the supply.What is the the value of the current flowing?1 pt.1What is the power dissipated in the resistor?1 pt.2As the value of the resistor connected to the supply decreases, the current increases up to the maximum pro-grammed into the supply. For lower resistance values, the maximum current flows and the supply voltage dropsbelow the programmed value. With the laboratory supply programmed as indicated above, what is the minimumresistance value below which voltage drops?1 pt.3Assume a Ω resistor is connected across the supply.What is the value of the current flowing?1 pt.4What is the voltage across the resistor?1 pt.5Draw a circuit diagram showing how to connect volt- and ampere-meters to measure the voltage and currentsimultaneously. Include the laboratory supply and load resistor RLin your diagram. Use standard electroniccircuit symbols for these devices, not “pictures”.2February 4, 2009 LAB1 v12512.7852 pts.6Connect different resistors RLwith values as indicated below to the supply and calculate and measure the voltageVsacross the resistor and current Isflowing.Fill in the table below and compare calculated and measured results. Explain differences.measured calculatedVsfor RL= 1.8 kΩ1 pt.61 pt.6Isfor RL= 1.8 kΩ1 pt.71 pt.7Vsfor RL= 120 Ω1 pt.81 pt.8Isfor RL= 120 Ω1 pt.91 pt.9Solar Power SupplyOur objective is to design solar power supply for a small appliance such as a cell phone. One of the questions weneed to investigate is the size of the panel that is required. To answer this question we need to better understandthe characteristics of the solar cell. It’s


View Full Document

Berkeley ELENG 100 - LAB 1 Solar Power Supply

Documents in this Course
Lecture

Lecture

75 pages

Load more
Download LAB 1 Solar Power Supply
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view LAB 1 Solar Power Supply and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view LAB 1 Solar Power Supply 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?