SOLAR ENERGY KIT MODEL SK-40 Elenco® Electronics, Inc. 150 Carpenter Avenue Wheeling, IL 60090 (847) 541-3800 Website: www.elenco.com e-mail: elenco@elenco.com Elenco Electronics, Inc. ® Copyright © 2008 by Elenco® Electronics, Inc. All rights reserved. 753149 No part of this book shall be reproduced by any means; electronic, photocopying, or otherwise without written permission from the publisher. Parts List Solar Cell Angle Stand Other Uses Angle Stand Base Motor Fan Cardboard Figures Plastic Discs SK-40-P12 SK-40-P17 SK-40-P1 SK-40-P2 Motor Holder Motor Holder Base SK-40-P3 Music Box SK-40-P4 Light Bulb SK-40-P5 Jumper Wires SK-40-P14 SK-40-P7 Wrench SK-40-P6 SK-40-P8 SK-40-P13 SK-40-P9 SK-40-P10 SK-40-P11 SK-40-P18 SK-40-P15 SK-40-P19 SK-40-P16 SK-40-P20 Ë » Radio Calculator The Solar World Solar power: With energy costs and pollution rising, the limitless supply of pollutionfree solar energy will have an ever-increasing role in meeting our world’s energy needs. Since the sun will always be bright, solar energy will always be available. Solar panels are quiet, clean, and will last for years since they don’t have any moving parts that can wear out. Although electricity produced from solar panels is still several times as expensive as electricity produced by normal energy sources, that is changing as solar panels become less expensive and more efficient. Scientists are constantly experimenting with new ways to capture the energy radiated from our sun. More and more products are being developed that use solar panels as their power source. Sun power: The sun produces heat and light on an immense scale, by transforming Hydrogen gas into Helium gas. This “transformation” is a thermonuclear reaction, similar to the explosion of a Hydrogen bomb. The earth is protected from most of this heat and radiation by being so far away, and by its atmosphere. But even here the sun still has power, since it can spin the motor on your kit and give you sunburn on a hot day. + – – + 9 Battery Charger Cassette Player ® Another Elenco Kit to Build Elenco® Snap Circuits® Jr. Model SC-100 with over 100 projects Models SC-100 and SC-100R contain over 30 parts to introduce students at the elementary level to the world of electricity and electronics. Build over 100 projects from the easy-to-follow color manual by simply snapping all the parts in place. No tools needed. The student will learn about resistors, capacitors, motors, batteries, series/parallel circuits, and much more. Figure 1 Requires two (2) “AA” batteries. -1- -10- Spinning Disc There are four disc sizes along with some cardboard figures. Cut the figures out and attach them to the discs using double-sided tape. Connect the disc to the motor then place the solar panel facing the sunlight directly. You can vary the speed by adjusting the amount of sunlight hitting the solar panel. Disc Birds Disc Fan Planes -9- Nearly all of the energy in any form on the surface of the earth originally came from the sun. Plants get energy for growth from the sun using a process called photosynthesis. People and animals get energy for growth by eating plants (and other animals). Fossil fuels such as oil and coal that power most of our society are the decayed remains of plants from long ago. These fuels exist in large but limited quantity, and are rapidly being consumed. Born in the space program: The solar panel is a photovoltaic cell, with photo meaning light and voltaic meaning that it produces electricity. Photovoltaic cells were first developed for the space program, to recharge batteries and power various systems in spacecraft and satellites. Although they were expensive, they saved money because heavier batteries or other fuel sources did not have to be launched into earth’s orbit on very expensive rockets. The sun’s brightness is reduced when it passes through the earth’s atmosphere, so solar cells are more efficient in space. Solar cells are used to power most satellites because they are lightweight and never wear out (sending a serviceman to do maintenance on a satellite is extremely expensive). Over the years manufacturing processes for photovoltaic cells have improved and reduced costs, and now they are used in many common products on earth such as calculators, and often charge batteries in industrial applications. It is likely that a large portion of America’s electricity will be produced from solar cells by the end of this century. -2- Figure 2 Solar Cell on a Satellite Figure 3 How your solar panel works: Your solar panel is made from silicon, like the transistors and microprocessor used throughout the electronics industry. Silicon is easy to find, since ordinary sand contains mostly silicon. The silicon is refined into two layers of very pure crystal, but tiny amounts of different minerals (such as Boron and Phosphorus) are added to give one side a positive electrical charge and the other side a negative charge. These opposite charges cancel each other out, producing a neutral cell. However when sunlight shines on the silicon crystal, charged particles in the light unbalance the cell and create an electrical charge across it (called a voltage). By connecting wires to the positive and negative layers this voltage will make a flow of electrical charge, called an electric current. Solar Motor Power requirement: 1.5V @ 300mA. Each row of cells are 1.5V 100mA, so 3 rows of cells are needed to be connected in parallel. Formula: I total = 3 rows of cells x 100mA = 300mA. To assemble your Solar Motor, follow these steps: Step 1 Step 2 1 2 3 Insert motor into motor holder Screw & nut Negative Silicon Current Flow Direction Sunlight (photons) 1. Attach jumper wires across terminals #1 - #3 & #2 - #4. 2. Attach jumper wires across terminals #3 - #5 & #4 - #6. 3. Attach the motor wires to terminals #1 & #2 and Loosen screw on the motor holder, insert the motor tighten the nuts. and then tighten the screw. Negative Contact Positive Contact Step 3 Step 4 Press the motor shaft into the hole on the fan. Insert the the plastic post into the base key hole and tighten by twisting it 90 degrees. Barrier Layer Positive Silicon Electrons Figure 4 Solar cells operate best when bright sunlight is available at all times. Unfortunately, most areas of the United States only get about 4-5 hours of sunlight per day on average. The electricity needs of people vary throughout the day, whether or not the sun is shining. Because of this, most solar cell arrays are used to charge rechargeable batteries. The batteries provide for people’s electricity needs throughout the day, and are recharged whenever the sun shines. Solar power is often used in remote desert areas, because it is too expensive to build electricity distribution networks to them. Place the solar panel facing the sunlight directly and the fan will spin. To reverse the rotation, switch the position of the motor wire connections to the solar panel. -3- -8- If there is no sunlight, place the panels approximately five inches from a 100W light. Caution; not more than three minutes as the heat may melt the plastic frame. Solar Music Player Using Solar Electricity Power requirement: 4.5V @ 100mA There is no limit to the amount electricity you can produce from sunlight. The more cells you use, the more power you get. Formula: 4.5V = 3 rows of cells Each row of cell 1.5V To increase the voltage, connect the cells in series from the negative side to the positive side as shown in Figures 6-11. Although the voltage (E) increases the current (Ι) remains constant. To assemble your Solar Music Player, follow these steps: The formula for cells in series is as follows: Step 2 Step 1 E Total = E1+E2+E3 e.g: (E1)1.5V+(E2) 1.5V+(E3)1.5V = 4.5V 1 2 3 4 5 6 I Total = I1+I2+I3 current (I) remains constant = 100mA Angle stand Slide into place in direction of arrow 1. Attach jumper wires across terminals 2-3 & 4-5. Base 2. Attach the music player’s negative wire to terminal #1 and the positive lead (+) lead to #6. Slide the angle stand onto the base as shown. Step 3 Step 4 Tighten the two screws enough so you can adjust Slide the stand into the slot on the solar panel. To the angle position if necessary. release the stand, pull up the locking tab as shown. Place the solar panel facing the sunlight directly and the music should play. If there is no sunlight, place the panels approximately five inches from a 100W light. Caution: No more than three minutes as the heat may melt the plastic frame. -7- Figure 5 Figure 6 Figure 7 Figure 8 E1 E2 (E1 + E2) E3 (E1 + E2 + E3) 1.5V 100mA connection (Figure 6). 3V 100mA series circuit. 4.5V 100mA series circuit. Figure 10 Figure 11 Figure 9 Terminals #1 & #2 are the output. Terminal #2 connected to #3. Terminals #1 & #4 are the output. -4- Terminal #2 connected to #3, terminal #4 connected to #5. Terminals #1 & #6 are the output. To increase the current (I), connect the cells in parallel, connecting the positive point to the positive point, negative point connected to the negative point as shown. Although the current (I) increases, the voltage (V) remains constant. The formula for cells in parallel is as follows: I Total = I1+I2+I3 e.g: (I1)100mA+ (I2) 100mA + (I3)100mA = 300mA E Total = E1+E2+E3 – The voltage (E) remains constant at 1.5V Caring for your solar panel: Your solar panel will never wear out and could spin the motor forever if sunlight were always shining on it. But the motor itself would wear out, since it has moving parts that rub against each other. The solar panel may break if you drop or smash it. Use a soft cloth and glass cleaner to keep dust off the panel, since dust would reduce the brightness of light shining on it. Future of solar power: We at Elenco® Electronics believe solar power will have an important role in meeting America’s electricity needs of the 21st century. We think it is important to educate everyone about the environmental advantages of solar energy instead of pollution-causing fuels like oil and uranium. We hope you enjoyed building this kit, please contact us if you have any questions about it. Light Bulb Power requirement: 1.5V @ 300mA Each row of cells are 1.5V 100mA, so 3 rows of cells are needed to be connected in parallel. Formula: I total = 3 rows of cells x 100mA = 300mA. To assemble your Light Bulb, follow these steps: Figure 12 Figure 13 Figure 14 I1 I2 (I1 + I2) I3 (I1 + I2 + I3) 1.5V 100mA connection. 1.5V 200mA parallel circuit. 1.5V 300mA parallel circuit. Step 1 1. Attach jumper wires across terminals #1 - #3 & #2 - #4. 1 2 3 4 5 6 2. Attach jumper wires across terminals #3 - #5 & #4 - #6. 3. Attach the light bulb to terminal #1 & #6 and tighten the nuts. Figure 15 Terminals #1 & #2 are the output. Figure 16 Figure 17 Terminal #2 connected to #4, #1 connected to #3. Terminals #1 & #4 are the output. Terminal #2 connected to #4, #1 connected to #3, #4 connected to #6, #3 connected to #5. Terminals #1 & #4 are the output. -5- It’s best to do this project using a lamp instead of the sun. Place the panels approximately five inches from a 100W light and the bulb lights. Caution: No more than three minutes as the heat may melt the plastic frame. -6-