APPLIE TEHNOLOGY & ENGINEERING Postcard Radio Project Name: ate: Grade: Section:
Postcard Radio Project ESIGN HALLENGE >> esign and build a simple radio that will receive an AM signal through the air without electricity riteria Your radio must have... A completed circuit board 8 meters of antenna wire An earpiece An attractive case or housing to hold all the parts Approved Materials circuit board earpiece 8 meters of wire metal tuning plate covers for front and rear of radio alligator clips Wood Paper clips Plastic NOTE: Keep track of and safeguard all materials. Points will be lost if replacement parts are needed. onstraints Your case must stay within these measurements: Maximum length: 0 cm (front to back) Maximum width: 8 cm (side to side) Maximum height: 0 cm (top to bottom) Key Points Electromagnetic (EM) radiation is pretty much all around us. When you listen to an AM or FM radio station, the sound that you hear is transmitted to your radio by the station using EM radiation as a carrier radio waves. rystal radios pick up AM radio without batteries or electricity. The broadcast station puts out enough power in the form of a radio signal. The c r y s t a l r a d i o a n t e n n a c a p t u r e s t h i s electromagnetic energy, and the signal then passes through the crystal detector and converts the signal back into sound using a diode. Key Terms Electromagnetic waves energy that can travel through air, solid materials and empty space. iode- an electronic part that allows current or waves to flow in one direction only. Wavelength- the distance between peaks of electromagnetic waves. Frequency- how often a wave peak goes by. Amplitude- the measure of something's size ecoder- separates the sound wave from the rest of the radio wave. Transmitter-an electronic device that broadcasts radio waves or signals lass ompetition Each radio will be rated as follows: No Signal: you can t hear any signal at all Inaudible Sound: you can barely hear a signal, but can t make out any words Weak Signal: you can hear a few words here and there, but nothing that makes sense Medium Signal: you can hear most words, but it still sounds scratchy 5 Strong Signal: you can clearly hear words or songs
RESEARH Transistor radios The transistor was invented in 97, at Bell Telephone Laboratories. It was smaller, used less electricity and operated more reliably than valves. The Regency TR- was the first transistor radio available in 95 costing around 0. The development of transistor radios changed the way music could be listened to. Transistors made radios smaller and as a result more portable and affordable. Young listeners began to buy the new transistor radios to listen to their own music. The transistor radio transformed the social use of radio. Sets were now inexpensive and highly portable. Radios were no longer a piece of furniture but a personal item that could be carried everywhere, and as a result the demand for radios increased. I based radios In 958 the integrated circuit was developed by Texas Instruments. It was now possible to place all the components of an electronic circuit on a small piece of silicon. The use of small Is has allowed the design of radios to change dramatically. The design of the case is no longer defined by the circuit it contains. This has allowed designers to develop a whole new range of novel and interesting shapes to contain radios. The development of I manufacturing has resulted in surface mounted Is and hip on board constructed radios that have allowed the size of radios to shrink even more. The diagram on the right shows a mini radio that sells for a few pounds and fits onto a key ring! Future of radio The st entury has seen the introduction of digital radio. Analogue radio signals frequently suffer from interference and distortion. igital radio signals do not suffer from interference. With digital radio all the transmitters use the same frequency. This means you do not have to re-tune as you move location. A digital signal can also carry several radio programmes and data simultaneously, allowing you to see text and pictures with your radio programme.
If you look at a radio you will see that there are usually two types of radio signal that it can receive, AM and FM. AM (amplitude modulated) FM (frequency modulated) Amplitude modulation (AM) AM is easier to transmit, but can be affected by electrical interference from devices like a switch. Tall buildings or hills also affect AM radio reception. Frequency modulation (FM) The FM wave is more difficult to transmit, but it does not suffer interference as much. FM carrier waves are higher in frequency than AM. How it works Guglielmo Marconi, was the first person to show that invisible radio waves could be used for communication between two places without wires. Radio waves are part of a wider spectrum of electromagnetic waves. Light is part of this spectrum. The difference between the two is the frequency at which they vibrate. Light has a higher frequency than radio waves. Radio, television and mobile phones, all use electromagnetic waves to transmit information. Each form of communication uses a different frequency to transmit the information. By using a different frequency for each we are able to separate them. Transmitting Radio At the transmitter, the signal from the microphone is first amplified. It is then combined with a radio carrier wave, this is called modulation. The modulated signal is then further amplified and transmitted from the aerial. Receiving Radio Since we are surrounded by many radio signals, the first task for the radio receiver is to select a particular station from all the others. This is done through the tuning section of the circuit. The tuner circuit is designed to respond to one particular frequency and ignore all others. By altering the value of the capacitor in the tuning circuit, you change the frequency the circuit responds to and thus change the radio station received. The tuner section of the circuit causes the radio to receive one of the many radio signals. Now the radio has to extract the voice or music from the carrier wave. This is done with part of the radio called a demodulator. emodulation removes the original sound wave from the carrier wave. Since the sound is very weak it needs amplification so that we can hear it. The final signal is then fed to a speaker where the original voice or music can be heard again.
ase design There are a variety of methods of containing your electronic products. The choice depends on your design requirements. Vacuum forming is an ideal method for creating cases to hold your electronic products. High impact Polystyrene or ABS make good case moulding material. The first stage is to design and make a mould. There are a number of important features that need to be included to make a good mould design: Vacuum forming process. The mould sides must be tapered to allow the mould to be removed.. Vent holes need to be drilled to help draw the plastic when the vacuum is created.. There should be no undercuts, which will prevent the moulding being removed from the mould.. The mould needs a high standard of finish. Any marks will appear on the surface of the moulding. The vacuum forming sheet is first clamped into position around its edge by an airtight seal. The sheet is then heated from above by the radiant heaters in the machine s hood. When the sheet becomes soft and pliable, between 50-70 the heating hood is removed. When the sheet is pliable and the heater has been removed, air is blown in under the sheet to stretch it. This is done to reduce the thinning on the moulding. The platen is now raised into the blown sheet. The air is then drawn from under the mould, creating a vacuum. The atmospheric air pressure above then forces the pliable sheet of plastic over the mould taking up its detailed shape. 5
IENTIFY THE PROBLEM In your own words... state what you ve been asked to do. I have been asked to that will Look at the rubric for this project on the last page and then answer the next two questions.. Which goal do you think will be the most challenging?. What s ONE strategy you can try to overcome it? EVELOP POSSIBLE SOLUTIONS In the boxes below, draw six (6) different versions of what your design might look like. It s very important to label the drawings to help me understand your thinking. Prototype # Prototype # Prototype # Prototype # Prototype #5 Prototype #6 6
STEP WidTH WidTH LENGTH WITH Front View HOOSE A SOLUTION STEP STEP WidTH WidTH You need to create clear, specific and labeled drawings (using rulers WidTH and other drawing instruments) WidTH from three different views A (front, LENGTH top and WITH side). raw the designs in centimeters and label the dimensions. You Front View LENGTH WITH Front View will not be able to begin construction until this drawing is completed. Teacher s initial are required for approval. Follow the examples A below. A B A- HEAT Transfer the height of the shape to the side view by drawing dotted lines B - raw in the object line representing the overall width ( ½ inches or 0 blocks) Front View B - raw in the object line representing the overall height (inches or 8 blocks, you Top also have View a dot that represents B the height) - Finish drawing the object lines A- HEAT that represent Transfer the the outside A- height HEAT edges of the of shape the Transfer shape to the the side height view of by the drawing shape to dotted the side lines view by drawing dotted lines B - raw in the object line Side B representing - raw the object overall line width representing ( ½ inches the or overall 0 blocks) width ( ½ inches or 0 blocks) - raw in the object line representing - raw the object overall line height representing (inches the or 8 overall blocks, height you also (inches have or a dot 8 blocks, that represents you also the have height) a dot that represents View the height) - Finish drawing the object STEP - lines Finish that drawing represent the the object outside lines edges that represent of the shape the outside edges of the shape HEAT LENGTH Front View HEAT / HEAT / / STEP STEP Length WidTH Top View Length Length WidTH WidTH LENGTH LENGTH Top View Top /" View Front View Front View /" /" /" /" /" A - imension the overall length (either the front or top view) A - imension the overall length (either the front or top view) A - imension the overall length B - imension the overall height (either the front or side view) B -(either imension the front the overall or top height view) (either the front or side view) - imension the overall width (either the top or side view) B - imension the overall height -(either imension the front the overall or side width view) - imension (either the any top other or side edges, view) cut-outs, slants, holes, etc. (don t over dimension, it only makes the drawing look messy) - imension the overall width (either - imension the top any or other side view) edges, cut-outs, slants, holes, etc. (don t over dimension, it only makes the drawing look messy) - imension Production any other edges, cut-outs, slants, rawings holes, etc. (don t over dimension, it only makes the drawing look messy) STEP 5 STEP 5 STEP 5 Sketch 5 B Front View Sketch Sketch B Sketch B Sketch Sketch Sketch A- raw the side view of the shape in the bottom right corner of the sketch box (over one up one) B - Starting at point #, draw a diagonal line up to the left 5 intersections. (take your time and hit each diagonal intersection) - Repeat step B for points,,, and 5. - Now simply connect all 5 dots and your isometric view will be complete. Sketch Sketch 5 5 5 5 A5 A5 A A A A- raw the side view of the shape in the bottom right corner of the sketch box (over one up one) B - Starting at point #, draw a diagonal line up to the A- raw the side view of the shape the bottom right corner of the sketch box (over left one 5 intersections. up one) (take your time and hit each diagonal intersection) B - Starting at point #, draw 5- Repeat a diagonal step line B for up points to the, left, 5, intersections. and 5. (take your 5 time and hit each diagonal intersection) - Repeat step B for points, - Now,, simply and 5. connect all 5 dots and your isometric view will be complete. A - Now simply connect all 5 dots and your isometric Aview will be complete. A Materials Needed Tools Needed A Top View 7
HOOSE A SOLUTION Identify which prototype you ve chosen to make and explain why. If you really can t describe it to me and tell me why this prototype is insanely great, you shouldn t be building it. A paragraph has a beginning a middle and an end. The beginning, or the topic sentence, states what the paragraph is about. The middle develops the idea in detail by giving specific support & details for it (usually - 5). The end (conclusion) restates the main idea in the topic sentence. 8
ENGINEERING YOUR PROTOTYPE G'.,)%(#!HI#J;.(K.;%(.( 9(*)#*&$)#('#:(0"$6""#(&(!)&/$(;&%.(+&$%)'(0)&$(&#.($/(0&/"(/$&$)#(/( /)6#(0"')68( ( <"(0)&$(/"/($"(/&$"''$"($)(*)#*&$"($/(+)/$)#($)($"(0&/"(/$&$)#8( # &8 =>+'&#($"(+%+)/"()?(&(."*)."%(#(&(*)#*&$)#(/@/$"8( 08 -."#$?@(%(.()?($"(."*)."%/(#($/(/@/$"(&#.(."/*%0"()6($(/(/".8( *8 =>+'&#($"(+%+)/"()?(&($%&#/$$"%(#(&(*)#*&$)#(/@/$"8(.8 -."#$?@(%(.()?($"(">&+'"/()?(&($%&#/$$"%(#($/(/@/$"8(A)%($"( $%&#/$$"%(@)(&B"(."#$?".7(">+'&#($/(/+"*?*(%)'"8( 9
BUIL YOUR PROTOTYPE EXAMPLE escribe what you did today. Mention any problems you had, design changes or questions. Make a labeled sketch that shows what you did. LOG # ate: YES I used complete sentences to describe my progress YES My description is neatly written and legible YES I used key terms when possible YES My drawing is large enough and centered in the space YES My line quality is sharp and precise (no smudges) YES Labels and dimensions are OUTSIE the drawing 0
escribe what you did today. Mention any problems you had, design changes or questions. Make a labeled sketch that shows what you did. LOG # ate: YES I used complete sentences to describe my progress YES My description is neatly written and legible YES I used key terms when possible YES My drawing is large enough and centered in the space YES My line quality is sharp and precise (no smudges) YES Labels and dimensions are OUTSIE the drawing escribe what you did today. Mention any problems you had, design changes or questions. Make a labeled sketch that shows what you did. LOG # ate: YES I used complete sentences to describe my progress YES My description is neatly written and legible YES I used key terms when possible YES My drawing is large enough and centered in the space YES My line quality is sharp and precise (no smudges) YES Labels and dimensions are OUTSIE the drawing
escribe what you did today. Mention any problems you had, design changes or questions. Make a labeled sketch that shows what you did. LOG # ate: YES I used complete sentences to describe my progress YES My description is neatly written and legible YES I used key terms when possible YES My drawing is large enough and centered in the space YES My line quality is sharp and precise (no smudges) YES Labels and dimensions are OUTSIE the drawing escribe what you did today. Mention any problems you had, design changes or questions.. Make a labeled sketch that shows what you did. LOG #5 ate: YES I used complete sentences to describe my progress YES My description is neatly written and legible YES I used key terms when possible YES My drawing is large enough and centered in the space YES My line quality is sharp and precise (no smudges) YES Labels and dimensions are OUTSIE the drawing
TEST & EVALUATE THE SOLUTION Trial 5 Antenna length (m) Signal strength (-5) Location number Signal Strength : No Signal: you can t hear anything. : Inaudible Sound: you can barely hear a signal, but can t make out any words. : Weak Signal: you can hear a few words here and there, but nothing that makes sense. : Medium Signal: you can hear most words, but it still sounds scratchy. 5: Strong Signal: you can clearly hear words or songs. Things that worked or went well... Things that did not work or go well... Things that I redesigned (changed)... What the changes did... Things I d do differently next time... What these might do...
APPLIE TEHNOLOGY & ENGINEERING Postcard Radio Project GOAL #: I AN use and follow the engineering design process in my design brief to solve problems about communication technology. This is how I ll do it... a. I will make a collection of concept drawings that shows different ways to solve a communication problem. 0 b. I will make three-view drawings of my best idea with measurements & labels that others can follow. 0 c. I will have an explanation for my best idea with specific reasons and supporting details. 0 d. I will create a written response to an open response question about communication technology. 0 e. I will keep track of my progress and design changes by completing engineering logs during the project. Engineering Log # 0 Engineering Log # 0 Engineering Log # 0 Engineering Log # 0 Engineering Log #5 0 f. I will collect and display data about my prototype and use it to evaluate how well it worked. 0 GOAL#: I AN choose, use and keep track of tools and materials and have good reasons for using them. This is how I ll do it... a. I will wear safety goggles and follow all safety procedures in the workshop. 0 b. I ll keep track of my materials and not need any replacement parts. 0 c. I will clean up my work space and put tools and materials back where they belong. 0 Final Score GOAL#: I AN use tools and materials to build a prototype that works. This is how I ll do it... a. I will follow my building guide and instructions and make a radio that will receive an AM signal through the air without electricity 0 b. I will build a prototype that looks like a finished product without any loose parts, damaged or rough surfaces, dents, gouges or globs of glue. 0 c. I will build, test and demonstrate a prototype that is sturdy, holds together and doesn t need repairs between multiple uses. 0 omments: Final Score Final Score