WARNING: SHOCK HAZARD Never connect E-Blox® Circuit Blox™ to the electrical outlets in your home in any way! ! WARNING: Only use the battery holder with the cover securely in place. ! WARNING: CHOKING HAZARD Small parts. Not for children under 3 years. ! WARNING: MOVING PARTS Do not touch the fan while it is spinning. -1- WARNING: Always check your wiring before turning on a circuit. Never leave a circuit unattended while the batteries are installed.
! Batteries: l Use only 1.5V “AA” type, alkaline batteries (not included). l Do not mix alkaline, standard (carbon-zinc), or rechargeable (nickel-cadmium) batteries. l Insert batteries with correct polarity. l Remove batteries when they are used up. l Non-rechargeable recharged. batteries should not be l Rechargeable batteries should only be charged under adult supervision, and should not be recharged while in the product. l Do not mix old and new batteries.
About Electricity (Science) 1. What is Science? Q: What do we mean when we say “Science”? A: Science is defined as the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment. Early scientists were curious people that wondered what made lightning. They decided to experiment to see if they could understand lightning and even make their own somehow. 3.
About Electricity (Technology) 5. What is Technology? Q: What is technology and who used technology in the past? 6. Technical Terms Q: What terms do electrical technicians need to know? A: Technology is the application of scientific knowledge for practical purposes. Dating back to the 18th century, Benjamin Franklin (a famous American) proved that lightning was caused by electricity by performing an experiment in which an electrical conductor would be used to extract power from a thundercloud.
About Electricity (Engineering) 9. What is Engineering? Q: What is Engineering? What do engineers do? 10. Is Engineering only about Electronics? Q: Besides Electronics what else do Engineers do? A: Engineering is the application of Science, Technology, and Mathematics to make products that are useful to people. Engineers are skillful in using their knowledge to make products.
About Electricity (Mathematics) 13. Ohm’s Law 14. Switches and Power Ohms Law states that Voltage equals Current multiplied by Resistance. If V = Voltage, I = Current, and R = Resistance, then mathematically Ohms Law is V = I x R where “x” stands for “multiplied by”. Since the law starts with Voltage, we need a voltage source or a Power Supply. There are both DC (direct current) and AC (alternating current) power supplies. Batteries are also a source of DC voltage.
About Electricity (STEM) 17. Circuit Blox™ 18. Short Circuits in Circuit Blox™ For Circuit Blox™, the definition of an electrical circuit is: The complete path for an electric current flow, usually including the source of electric energy. The path shown in the circuit below is from the battery, through the blue 2-wire, through the motor under the fan, through the blue 4-wire, through the switch, through the blue 2-wire, and then back to the battery.
Parts List (colors and styles may vary) Symbols and Numbers Important: If any parts are missing or damaged, DO NOT RETURN TO RETAILER. Call toll-free (855) MY EBLOX (6932569) or e-mail us at: support@myeblox.com. Customer Service: 880 Asbury Dr., Buffalo Grove, IL 60089 U.S.A. Qty. Name 4 Symbol Part # Qty.
Qty. Name 1 Part # Qty. Name Spring Wire 6EB2X09 1 Photo Resistor 6EB2X68 1 Speaker 6EB2X93 1 Bi-directional LED 6EB2X71 1 100W Resistor 6EB2X41 1 Colorful LED 6EB2X72 1 1kW Resistor 6EB2X42 1 100mF Capacitor 6EB2X73 1 5.
Qty. Name 1 Buzzer 3 Fan Blade Symbol Part # Qty.
How to Use Your E-Blox® Circuit Blox™ Set E-Blox® Circuit Blox™ parts contain a PC board with connectors so you can build the different electrical and electronic circuits in the projects. Each block has a function: there are switch blocks, a light block, battery block, wire blocks, etc. These blocks are different colors and have numbers on them so that you can easily identify them. For Example: This is the press switch, it is green and has the marking 61 on it.
About Your E-Blox® Circuit Blox™ Parts (Part designs are subject to change without notice). The base grid functions like the printed circuit boards found in most electronic products. It is a platform for mounting parts and wire blocks (though the wires are usually “printed” on the board). The blue wire blocks are just wires used to connect other components, they are used to transport electricity and do not affect circuit performance.
About Your E-Blox® Circuit Blox™ Parts The blue level blocks (100 & 200) are non-conductive and just used as building blocks. A fiber optic tree (40) is used with the LED to enhance the light effects. The speaker (93) converts electricity into sound. It does this by using the energy of a changing electrical signal to create mechanical vibrations (using a coil and magnet similar to that in the motor). These vibrations create variations in air pressure which travel across the room.
DOs and DON’Ts of Building Circuits After building the circuits given in this booklet, you may wish to experiment on your own. Use the projects in this booklet as a guide, as many important design concepts are introduced throughout them. Every circuit will include a power source (the batteries), a resistance (which might be an LED, lamp, motor, integrated circuit, etc.), and wiring paths between them and back.
Examples of SHORT CIRCUITS – NEVER DO THIS! Placing a wire block directly across the battery holder is a SHORT CIRCUIT, indicated by a flashing LED in the battery holder. When the switch (S1) is turned on, this large circuit has a SHORT CIRCUIT path (as shown by the arrows). The short circuit prevents any other portions of the circuit from ever working.
Advanced Troubleshooting (adult supervision recommended) E-Blox® is not responsible for parts damaged due to incorrect wiring. If you suspect you have damaged parts, you can follow this procedure to systematically determine which ones need replacing: 1. Lamp (76), LEDs (69-72), Battery Holder (91): Place part directly across the battery holder as shown, it should light. If none work, then replace your batteries and repeat, if still bad then the battery holder is damaged.
Project Listings # Description 1. Closed Circuit 2. Magnetic Switch 3. The ‘Momentary’ Switch 4. Electrical to Mechanical Energy 5. Proximity Sensor 6. Newton’s First Law of Motion 7. Newton’s Second Law of Motion 8. Magnet-controlled Flying Saucer 9. Reversing the Motor 10. LEDs in Series 11. LEDs in Parallel 12. Disadvantage of Series Circuits 13. Advantage of Parallel Circuits 14. Fiber Optics 15. Fiber Optic Communication 16. The Bi-directional LED 17. Bi-directional LED Sensor 18.
Project Listings # Description 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 81. 82. 83. 84. 85. 86. 87. 88. 89. 90. 91. 92. 93. 94. 95. 96. 97. 98. 99.
Project Listings # Description 133. 134. 135. 136. 137. 138. 139. 140. 141. 142. 143. 144. 145. 146. 147. 148. 149. 150. 151. 152. 153. 154. 155. 156. 157. 158. 159. 160. 161. 162. 163. 164. 165. -19- Page # RC Time Constant Calculating RC Time Constant Relative RC Time Constant Intermittent Windshield Wipers Resistor Color Code Table 1kW Resistor 5.
Project Listings # Description 199. 200. 201. 202. 203. 204. 205. 206. 207. 208. 209. 210. 211. 212. 213. 214. 215. 216. 217. 218. 219. 220. 221. 222. 223. 224. 225. 226. 227. 228. 229. 230. 231.
Project Listings # Description 265. 266. 267. 268. 269. 270. 271. 272. 273. 274. 275. 276. 277. 278. 279. 280. 281. 282. 283. 284. 285. 286. 287. 288. 289. 290. 291. 292. 293. 294. 295. 296. 297.
Project Listings # Description 331. 332. 333. 334. 335. 336. 337. 338. 339. 340. 341. 342. 343. 344. 345. 346. 347. 348. 349. 350. 351. 352. 353. 354. 355. 356. 357. 358. 359. 360. 361. 362. 363.
1. Closed Circuit E-Blox® Circuit Blox™ uses electronic blocks that plug into a clear plastic grid to build different circuits. These blocks have different colors and numbers on them so that you can easily identify them. Build the circuit shown on the left by placing all the parts that plug into the first layer base. Then, assemble the parts that connect to the secondary layer. Install three (3) “AA” batteries (not included) into the battery holder (91). Secure the battery cover before using it.
Reminder: Remove the shaft cap (60A) before launching the flying saucer. 7. Newton’s Second Law of Motion Remove the cap (60A) that is on the fan blade (60). Hold the press switch (61) for ten seconds. Release the press switch (61) and the flying saucer should take off (Caution! Never let it fly near your face!). If the fan does not fly, make sure the batteries are fresh, the motor (95) is in the correct direction and give the fan a tap from underneath with the top of your fingernail.
+ 11. LEDs in Parallel Build the circuit on the left and turn on the switch (62). The heart LED (69) and the star LED (70) will both light, and this time they will both be bright. This is because these LED modules are in parallel in this circuit, which allows separate current paths to flow through each LED module. Thus, each current path in this circuit is only limited by the internal resistances of the LED module in that path (i.e.
13. Advantage of Parallel Circuits Build the circuit on the left, press the switch (62) and the fan blade (60) of the motor (95) will start running while the lamp (76) is on. Try disconnecting the lamp (76) from the circuit and notice that the motor (95) keeps spinning. This is one of the advantages of parallel circuits. Since there are separate current paths running through the lamp (76) and the motor (95), removing one of these components does not affect the current flowing through the other component.
16. The Bi-directional LED Build the circuit above, press the switch (62) and you will see the bidirectional LED (71) turn on red. Now install the bi-directional LED (71) in the reverse direction and when you press the switch (62) the bidirectional LED (71) will turn on blue. Bi-directional LEDs actually have two diodes in them in opposite directions so current can flow in both directions. But current is only flowing through one diode at a time, which determines which color LED lights. 17.
19. Resistors Build the circuit shown on the left, then turn on the switch (62) and you will see the heart LED (69) and the lamp (76) will be on at the same time. The heart LED (69) is a little dimmer than it was in project #11 due to the presence of the 100 Ohm (W) resistor (41) that is connected in series with the heart LED (69). Resistors get their name because they are designed to resist the flow of current.
22. LED, the Check Valve Light Build the circuit shown on the left making sure the heart LED (69) is in the correct direction. Press the switch (62) to turn it ON and OFF. Reverse the heart LED (69) and repeat. Notice that the heart LED (69) does not light when in the circuit in the reverse direction, demonstrating how LEDs only allow current to flow in one direction. 23. Alarm Switches Replace the switch (62) with the reed switch (83).
26. Electronic Efficiency Electronic Efficiency is defined as the Useful Power Output divided by the Total Power Input. Build the circuit shown on the left and press the switch (62). The star LED (70) will light, but the lamp (76) will not light brightly. There is resistance built into the star LED (70) to protect it (too much current could damage an LED), and this resistance is limiting the current in the circuit.
28. Ohm’s Law Using Ohm’s Law, the resistance of each part could be calculated. Build the circuit shown on the left. In this circuit the heart LED (69) and the lamp (76) are in series so they see the same current. If you had a voltmeter and measured the voltage drop across each component, you would see that the voltage drop across the heart LED (69) is much greater than the voltage drop across the lamp (76).
30. Light Emitting Diode Build the circuit shown on the left. Turn ON the switch (62) and the heart LED (69) will light. LED stands for Light Emitting Diode. The Diode is the component that only allows the current to flow in one direction, but an LED is a special type of diode that emits light whenever the current does flow in the designed direction. 31. Detecting Fluid Levels Replace the switch (62) with the reed switch (83).
. Red and Blue Light Wavelength Build the circuit shown on the left, press the switch (62) and the heart LED (69) will light and the bi-directional LED (71) will be red. Reverse the direction of the bi-directional LED (71) and it will be blue. LEDs produce different colors by transmitting light waves with different wavelengths. Light waves cycle up and down and a wavelength is the distance between successive crests of the wave.
37. Toy Lights Build the circuit shown on the left, press the switch (62) and the bidirectional LED (71) and star LED (70) will turn on. Press the switch (62) again and the LEDs will turn off. Circuits like this are used in lots of battery operated infant toys where lights go ON and OFF as the child presses the button. 38. Power Build the circuit shown on the left and the motor (95) will spin while the lamp (76) is on. Power is defined as voltage times current and is measured in Watts.
39. Light Power Build the circuit to the left, press the switch (62) and the star LED (70) will be bright but the lamp (76) will be very dim. Light power can be measured in Watts or Lumens. Watts refer to how much energy the bulb uses while Lumens are a measure of the bulb’s light output intensity. 40. Battery Power Build the circuit shown on the left, then turn on the switch (62) and you will see the star LED (70) is on.
42. Kirchhoff’s Voltage Law Build the circuit shown on the left and you will see the star LED (70) is on, but the lamp (76) is very dim and the and the motor (95) does not spin or spins very slowly. This is because the voltage across the lamp (76) and motor (95) is small compared to the voltage across the star LED (70). Kirchhoff’s voltage law states: The sum of the voltages around a closed network is zero.
43. Kirchhoff’s Current Law Build the circuit shown on the left, turn on the switch (62) and you will see that the Star LED (70) is on and the bi-directional LED (71) is blue. Kirchhoff’s current law states: At any node (junction) in an electrical circuit, the sum of currents flowing into that node is equal to the sum of currents flowing out of that node. Grid location C1 represents a node.
45. Motor Speed Build the circuit shown on the left and you will see the lamp (76) and the star LED (70) are on while the motor (95) does not spin or spins slowly. Because the motor (95) is in series with the star LED (70), and the star LED (70) has a large voltage drop of about 3.5V, the voltage across the motor (95) is small and thus it spins slowly. ! WARNING: Moving parts. Do not touch the motor during operation. Do not lean over the motor. 46.
47. First Electric Motor Build the circuit shown on the left, turn on the switch (62) and you can see the motor (95) start spinning, and the two LEDs are turned on dimly at the same lime. Did you know that Michael Faraday made the first electric motor using a nail, a wire, a spindle, a magnet, and a battery? Can you figure out how he did it? ! WARNING: Moving parts. Do not touch the motor during operation. Do not lean over the motor. 48.
49. Uses of Motors Build the circuit shown on the left, turn on the switch (62) and the heart LED (69) and star LED (70) will light, but the motor (95) does not spin. The heart LED (69) in series with the motor (95) is limiting the current path through the motor (95) which is why it does not spin. If you look around your house you’ll see that motors are used for many things. Fans, blenders, and sink dispose-all are just a few. Can you think of more? 1st level 50.
51. Ohms Build the circuit and you will see the heart LED (69) and lamp (76) will light and the motor (95) spin at the same time. Because the lamp (76) and motor (95) are in parallel with the heart LED (69), the internal resistance of the heart LED (69) does not significantly limit the current path through the lamp (76) and motor (95). Recall from project #28 that Ohm’s law stated V=I*R. Solving for R yields R=V/I.
53. Calculating Equivalent Resistance Build the circuit shown on the left and you will see the motor (95) spin and the two LEDs turn on at the same time. It is interesting that the motor (95) spins in this circuit but does not spin or at least slows down if you remove the star LED (70) from the circuit. This is because the equivalent resistance of the two LEDs in parallel is less than the resistance of either one alone.
– 54. Polarity Tester Build the circuit shown on the left. If you connect the 4.5V terminal of the battery (91) to point A and the “–” terminal of the battery (91) to point B, you will see the heart LED (69) light. If you connect the “–” terminal of the battery (91) to point A and the 4.5V terminal of the battery (91) to point B (use the spring wire (9) to help you do this), then the star LED (70) will light.
56. Brushless Motors 1st level 1st level Build the circuit shown on the left, turn on the switch (62) and you will see the lamp (76) and the motor (95) spin at the same time. Now if you move the magnet (7) near the reed switch (83), you will see the lamp (76) go off while the motor (95) is running faster. Reed switches can actually be used to create what are called brushless motors. 57. Motor Speed Selection Circuit Replace the reed switch (83) with the press switch (61).
59. Internal Resistance of Heart LED Build the circuit shown on the left and put a 4-wire (4) across the points A and B. If you have a voltmeter, you can measure the voltage across the heart LED (69) and 100W resistor (41) (W is the symbol representing Ohms) and see that about 3.3V is across the heart LED (69) and only about 1.2V is across the 100W resistor (41).
61. Light Dimmer Build the circuit shown on the left, turn on the switch (62) and you will see the lamp (76) ON and the motor (95) spin at the same time. Now press the press switch (61) and the lamp (76) gets brighter while the motor turns OFF. Pressing the press switch (61) removes the internal resistance of the motor (95) from the circuit so that more current flows through the lamp (76) making it brighter. This concept is used in light dimmer circuits. 62.
64. Electronic ‘AND’ Gate Build the circuit shown on the left. Note that the lamp (76) only turns on when both the switch (62) and press switch (61) are ON. In digital electronics there are seven logic gates: AND, OR, XOR, NOT, NAND, NOR, and XNOR. This circuit represents an AND gate. If ON = True and OFF = False then an AND gate is best defined as: The output is TRUE only when both inputs are True.
66. Electronic ‘OR’ Gate Build the circuit shown on the left. The lamp (76) will light if either the switch (62) or the press switch (61) is pressed. This circuit represents an OR gate. If ON = True and OFF = False, then an OR gate is best defined as: The output is TRUE when any input is True and the output is False only when all the inputs are False.
+ 68. Safety Circuit Build the circuit shown on the left, turn on the switch (62) and press the press switch (61) and you will light up the LEDs at the same time. Sometimes, for safety reasons, it is required that two switches be ON before machinery will run. – + 69. Controlling Electrical Appliances Build the circuit shown on the left. If you want to turn on the LEDs you just need to turn on the switch (62) or press the press switch (61).
+ 70. Individually Controlled Electrical Appliances Build the circuit, turn on the switch (62) and you will see the heart LED (69) is on. If you press the press switch (61), you will see the star LED (70) is on. You might have a circuit in your family room like this where you have two switches on the wall where one switch turns on and off the lights in the room and one switch turns on and off the TV. – 1st level 71.
72. LEDs are less “Buggy” Build the circuit shown on the left, turn on the switch (62) or the press switch (61) and you can light up both LEDs at the same time. If you want to turn off the two LEDs, you must turn off both the switches. You may have noticed in the summertime at night, lots of bugs flying around your porch lights, especially if they are not LED lights but are incandescent lights. Try switching those incandescent lights to LED lights.
74. Triple Input ‘OR’ Gate Build the circuit shown on the left, making sure all switches are OFF. The lamp (76) should be OFF. Turn ON any one of the switches and the lamp (76) will be ON. To turn OFF the lamp (76), all of the switches must be OFF. Electronic OR Gates can have two or more inputs but the function is still the same. All inputs must be False (OFF) for output to be False (OFF). 75. Series-Parallel Circuit Paths (I) Build the circuit shown on the left.
76. Series-Parallel Circuit Paths (II) Build the circuit shown on the left. There are two ways to light the lamp (76) in this circuit. You can either press the switch (62) or place the magnet (7) next to the reed switch (83) and press the press switch (61). Using the hotel analogy from the last project, the reed switch (83) could represent the key card holder and the press switch (61) could be a switch for a light in the room. But this room now has a master key card holder that only the employees (e.g.
+ 78. Circuit Breakers – + In this circuit, if you want to turn on the two LEDs, you need to turn on all the switches at the same time. This circuit could represent your house circuitry. Think of the reed switch (83) like the circuit breaker in your house, the switch (62) like a wall switch, and the press switch (61) like the switch on an appliance plugged into the outlet controlled by the switch (62).
80. Reed Switches for Speed Sensors Build the circuit shown on the left. If you turn on any one of the switches, you can see the two LEDs are on at the same time. But if you want to turn off the LEDs, you need to turn off all the switches.
82. More AND/OR Gate Logic Build the circuit shown on the left and turn on the switch (62). Now touch the reed switch (83) with the magnet (7) or press the press switch (61) and you will light up both LEDs. If you want to turn off the LEDs, you can either turn off the switch (62) or turn off both the press switch (61) and the reed switch (83). Using the logical diagrams from project #81, you could represent the logic in this circuit as shown below. 1st level 83.
– + – 84. LED Efficiency Build the circuit shown on the left, then turn on the switch (62). If you touch the reed switch (83) or press the press switch (61), you will then light up the two LEDs at the same time. If you want to turn off the two LEDs, you can turn off the press switch (61) and the reed switch (83) or turn off the switch (62).
+ 86. Batteries Build the circuit to the left and you will see that the heart LED (69) is on. Now if you turn on any switch, you will see the star LED (70) is on too. 1st level 2nd level + – + – – Ever wonder how the batteries in your circuit work? Batteries have three parts, an anode (–), a cathode (+), and the electrolyte, as shown in the figure below.
88. Forward & Reverse Bias 1st level + – + 2nd level – Build the circuit shown on the left and you will see the heart LED (69) is on. If you want to turn on the star LED (70), you can turn on the switch (62), or you can press the press switch (61) and move the magnet (7) near the reed switch (83). Note that the LEDs must be in the circuit in the direction shown in the diagram. If they are put in backwards they will not light.
90. Measuring Current Build the circuit shown, turn on the switch (62) and you will see the heart LED (69) is on. If you want to turn on the star LED (70), you just need to press the press switch (61) or hold the magnet (7) near the reed switch (83). + + – 91. Calculating Internal Resistance of the LEDs – Build the circuit shown on the left, turn on the switch (62) and the reed switch (83) and you will see the heart LED (69) is on.
92. Revisiting Kirchhoff’s Current Law – Build the circuit shown on the left, turn on the switch (62) or press the press switch (61) and you will light up the heart LED (69). If you want to light up the star LED (70), then you also need to move the magnet (7) near the reed switch (83). + – The LEDs in this project are in parallel just like they were in project #91 so we would get the same ammeter measurements as discussed in project #91.
94. Measuring Voltage – 1st level + A Voltmeter is used to measure voltage. Since the LEDs in this circuit are in series, they each don’t see the full 4.5V from the battery (91). If you used a voltmeter you would see that when the switch (62) is on and the press switch (61) is off, then the voltage across the heart LED (69) is about 1.9V and the voltage across the star LED (70) is about 2.6V. Note that these voltages sum to 4.5V (Kirchhoff’s Voltage Law in action!).
96. Conservation of Energy + + – – – 2nd level – -63- 97. Different Color LED Turn On Voltages Build the circuit shown on the left, turn on the switch (62) and you will see the star LED (70) is on. Press the press switch (61) and touch the reed switch (83) with the magnet (7) and the heart LED (69) will be on too. In project #44 we saw that the frequency of red light is ~451 THz. The table below shows the frequency and wavelength of all light colors.
98. Fire Drill Alarm + Build the circuit shown on the left making sure the alarm (78) is in the correct direction. Press the switch (62) and you will hear the alarm (78) and see the lamp (76) light. This type of circuit could be used for fire drill tests where a switch is turned ON to set off the fire alarm for the fire drill and then turned OFF when the fire drill is over. – + – 99. Resistors in Parallel Build the circuit, turn on the switch (62) and you will see the heart LED (69) is on.
+ – 100. Sound Waves Build the circuit, turn on the switch (62) and you will hear the warning sounds from the alarm (78), but the lamp (76) is off. The internal resistance of the alarm (78) limits the current in this circuit preventing the lamp (76) from lighting. The alarm (78) makes sound by creating sound waves, much like light waves, but at much longer wavelengths and much lower frequencies. Frequency is the inverse of wavelength (frequency = 1/wavelength) and is measured in Hertz (Hz).
102. Sound Waves Build the circuit shown, press and release the press switch (61) several times and you will hear some clicks and pops from the speaker (93). In order to translate an electrical signal into an audible sound, speakers contain electromagnets made from a metal coil that creates a magnetic field when an electric current flows through it. The coil is designed such that reversing the direction of the current in the coil flips the polarity of the magnet.
+ – + 104. Charging the Capacitor Build the circuit shown on the left, press and hold the press switch (61). As the star LED (70) turns on and fades out, the 470mF capacitor (74) is being charged. Release the press switch (61) and the heart LED (69) will turn on and fade out. The reason the star LED (70) turns on for just a short time and fades out when you hold the press switch (61) can be explained by Kirchhoff’s Voltage Law.
107. NPN Transistor Basics Build the circuit to the left and you will see the lamp (76) light. The base of the NPN transistor (50) is connected to the 4.5V terminal from the battery through the 1kW resistor (42), enabling current to flow into the base of the NPN transistor (50), which turns on the NPN transistor (50) enabling current to flow through the lamp (76) into the collector and out of the emitter, which turns on the lamp (76).
+ 109. Electricity Storage Build the circuit shown on the left, then connect points A and B with the spring wire (9). The heart LED (69) will turn on and then fade out as the 470mF capacitor (74) is charging. Now remove the spring wire (9) from points A and B and connect the spring wire (9) between points B and C. The lamp (76) will turn on for a while and then fade out. This is because when the 470mF capacitor (74) is charged, it stores electrical energy.
111. Capacitor Basics Build the circuit shown on the left, connect points A and B with the spring wire (9), then turn on the switch (62). The heart LED (69) will light and then fade out as the 470mF capacitor (74) is charging. Remove the spring wire (9) from points A and B and place the spring wire (9) across points B and C. You will see the bi-directional LED (71) light red for a while and fade to be very dim as the 470mF capacitor (74) discharges.
+ + – – 113. Measure of Electric Charge - The Coulomb Build the circuit shown, connect points A and B with the spring wire (9), then turn on the switch (62). The heart LED (69) will light and then fade out as the 470mF capacitor (74) is charging. As discussed in the previous project, capacitors build up charge on their plates when a voltage source is placed across their leads. The amount of electric charge built up on the plates of a capacitor is measured in Coulombs.
116. Photoresistor Build the circuit to the left and turn on the switch (62). Whenever light shines on the photoresistor (68), the lamp (76) will be bright. Cover the photoresistor (68) with your finger and the lamp (76) will go off. A photoresistor (68) is designed to have low resistance when there is light shining on it, and high resistance when no light is shining on it. 117. Photoresistor Basics Build the circuit shown and turn on the switch (62).
+ – 119. Latency of a Photoresistor Build the circuit shown on the left and turn on the switch (62). Whenever light shines on the photoresistor (68), the colorful LED (72) will light the fiber tree (40). Cover the photoresistor (68) with your finger and the colorful LED (72) may get a little dimmer, but even the little current entering the Base of the NPN transistor (50) is enough to allow enough current to flow from the Collector to the Emitter to light the colorful LED (72).
121. Advantages of Photoresistors Build the circuit shown on the left and turn on the switch (62). Whenever light shines on the photoresistor (68), the bi-directional LED (71) will be bright red. Cover the photoresistor (68) with your finger and the bi-directional LED (71) may get a little dimmer, but even the little current entering the Base of the NPN transistor (50) is enough to allow enough current to flow from the Collector to the Emitter to light the bi-directional LED (71).
+ + – – 123. Reverse Control using Photoresistors Build the circuit shown and turn on the switch (62). Now, whenever light shines on the photoresistor (68), the heart LED (69) will be off. Cover the photoresistor (68) with your finger and the heart LED (69) will turn on. You may need to take your circuit into a dark room to see the heart LED (69) light. This circuit does the reverse of the circuit in project #116 by turning on the heart LED (69) in darkness and turning off the heart LED (69) in light.
+ 126. The Colorful LED – Build the circuit shown and turn on the switch (62). Whenever light shines on the photoresistor (68), the colorful LED (72) will be off. Cover the photoresistor (68) with your finger and the colorful LED (72) will turn on and light the fiber tree (40). The colorful LED (72) is made of three LEDs (one Red, one Green, and one Blue) connected to a tiny Integrated Circuit (IC) that varies the percentage of time each LED is “ON”.
129. Load on Emitter Build the circuit shown on the left and turn on the switch (62). Whenever light shines on the photoresistor (68), the lamp (76) will be off. Cover the photoresistor (68) with your finger and the lamp (76) will turn on.
134. Calculating RC Time Constant Build the circuit shown on the left and turn on the switch (62). Place the magnet (7) near the reed switch (83) and you will see the colorful LED (72) light the fiber tree (40). Move the magnet (7) away from the reed switch (83) and the colorful LED (72) will stay bright for a little while and then turn dim. As discussed in the previous project, the time constant of an RC circuit is R*C, which in this case is 1000*(470 x 10-6) = 0.47 second.
138. 1kW Resistor Build the circuit shown on the right and turn on the switch (62). Press the press switch (61) and you will see the heart LED (69) light. Release the press switch (61) and the heart LED (69) will stay bright briefly and then turn dim. + – The 1kW resistor (42) in this circuit would have the colors brown, black and red as the first three bands (10 x 102 = 1,000). 139. 5.1kW Resistor Replace the 1kW resistor (42) in project #138 with the 5.1kW resistor (43) and turn on the switch (62).
142. The Number e Build the circuit shown on the left and turn on the switch (62). Place the magnet (7) near the reed switch (83) and you will see the heart LED (69) light. Move the magnet (7) away from the reed switch (83) and the heart LED (69) will stay bright for a little while and then turn dim. As discussed in project #133, the voltage of the capacitor decays with a time constant of R*C.
146. t for 1kW Resistor and 100mF Capacitor Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the star LED (70) light. Release the press switch (61) and the star LED (70) will stay bright briefly and then turn dim. The t for this circuit is 1,000*100e-6 = 0.1 second. + 147. t for 5.1kW Resistor and 100mF Capacitor Replace the 1kW resistor (42) in project #146 with the 5.1kW resistor (43) and turn on the switch (62).
150. Transistor Gain b Build the circuit shown on the left and turn on the switch (62). Place the magnet (7) near the reed switch (83) and you will see the star LED (70) light. Move the magnet (7) away from the reed switch (83) and the star LED (70) will stay bright for a little while and then turn dim. Transistors like the NPN transistor (50) can be used as amplifiers where a small current into the Base can be “amplified” to produce a large current out of the Emitter.
154. RC Low Pass Filter Circuit Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the bi-directional LED (71) light red. Release the press switch (61) and the bi-directional LED (71) will stay bright briefly and then turn dim. One important application of RC circuits is that they can be used as filters to pass certain frequencies and reject certain frequencies. Consider the Input/Output of the RC circuit shown below.
156. Cutoff Frequency of 10kW Resistor and 100mF Capacitor RC Circuit Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the bi-directional LED (71) light red. Release the press switch (61) and the bi-directional LED (71) will stay bright for a while and then turn dim. If the 10kW resistor (44) and 100mF capacitor (73) in this project were used in an RC low pass filter, then the cutoff frequency would be 1/(2*3.14*10,000*100e-6) = 0.16 Hz.
158. Cutoff Frequency of 1kW Resistor and 470mF Capacitor RC Circuit Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the bi-directional LED (71) light blue. Release the press switch (61) and the bi-directional LED (71) will stay bright for a little while and then turn dim. If the 1kW resistor (42) and 470mF capacitor (74) in this project were used in an RC low pass filter, then the cutoff frequency would be 1/(2*3.14*1,000*470e-6) = 0.34 Hz.
162. Sine Wave Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will hear the alarm (78) sound. Release the press switch (61) and the alarm (78) will sound briefly and then go off. The sound you hear from the alarm (78) is a tone. A pure tone is produced by a sinusoidal wave (called a sine wave), which is shown in the figure below. 163. Formula for a Sine Wave Replace the 1kW resistor (42) in project #162 with the 5.
165. Frequency of Sine Wave Build the circuit shown on the left and turn on the switch (62). Turn on the switch (62) and hold the magnet (7) near the reed switch (83) and you will hear the alarm (78) sound. Move the magnet (7) away from the reed switch (83) and the alarm (78) will sound for a little while and then go off. fc was defined as the frequency of a sine wave in project #163. The frequency of a sine wave represents the number of cycles per second of the sine wave.
168. Resistor Tolerance + – Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the heart LED (69) and colorful LED (72) light. Release the press switch (61) and the heart LED (69) and colorful LED (72) will stay bright for a little while and then turn dim. In project #128 the 4-band resistor was discussed. The 4th band on the right represents the tolerance of the resistor.
172. 1kW Resistor Tolerance – Silver Band Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the heart LED (69) and colorful LED (72) light. Release the press switch (61) and the heart LED (69) and colorful LED (72) will stay bright briefly and then turn dim. If the 1kW resistor in this circuit had a 4th band that was silver, then the actual resistance of the resistor could be anywhere from 0.95*1,000 = 950W to 1.05*1,000 = 1050W. + + 173. 5.
176. 1kW Resistor Tolerance – Gold Band Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the star LED (70) and colorful LED (72) light. Release the press switch (61) and the star LED (70) and colorful LED (72) will stay bright for a little while and then turn dim. If the 1kW resistor (42) in this circuit had a 4th band that was gold, then the actual resistance of the resistor could be anywhere from 0.9*1,000 = 900W to 1.1*1,000 = 1100W.
180. High Accuracy Resistors + + – Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the star LED (70) and colorful LED (72) light. Release the press switch (61) and the star LED (70) and colorful LED (72) will stay bright briefly and then turn dim. Although most resistors use red, silver, or gold as the 4th band, there are other colors that may appear as the 4th band for higher accuracy resistors.
182. Resistor Temperature Effects + + – Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the star LED (70) and colorful LED (72) light. Release the press switch (61) and the star LED (70) and colorful LED (72) will stay bright for a while and then turn dim. Actual resistance of a resistors can vary based on temperature. At higher temperatures, electrons become more free to move around and this reduces resistance.
+ 184. Understanding PPM Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the bi-directional LED (71) and colorful LED (72) light. Release the press switch (61) and the bi-directional LED (71) and colorful LED (72) will stay bright briefly and then turn dim. Understanding how to calculate the effects of temperature on a resistor value can be confusing as it is specified in Parts Per Million (PPM).
188. Fiber Optic Communication Underwater Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the bi-directional LED (71) and colorful LED (72) light. Release the press switch (61) and the bi-directional LED (71) and colorful LED (72) will stay bright briefly and then turn dim. One of the benefits of fiber optic transmission is that fibers can be placed under water.
+ – 192. Capacitor Polarity Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the colorful LED (72) light and the alarm (78) will sound. Release the press switch (61) and the colorful LED (72) will stay bright for a while then turn dim and the alarm (78) will stay on for a while then turn off. The capacitors in your set have polarity, just like the LEDs.
194. Capacitor Tolerance Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the heart LED (69), star LED (70), and colorful LED (72) light. Release the press switch (61) and the heart LED (69), star LED (70), and colorful LED (72) will stay bright for a while and then turn dim. + + + Capacitor tolerances usually are not marked because most capacitors have a tolerance of ±20%.
197. Electrolytic Capacitor Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the heart LED (69), star LED (70), and colorful LED (72) light. Release the press switch (61) and the heart LED (69), star LED (70), and colorful LED (72) will stay bright briefly and then turn dim.
+ + – 200. Equalizer Build the circuit shown on the left and turn on the switch (62). Press the press switch (61) and you will see the bi-directional LED (71) and colorful LED (72) light and hear the alarm (78) sound. Release the press switch (61) and the bi-directional LED (71) and colorful LED (72) will stay bright for a while then turn dim and the alarm (78) will sound for a little while then turn off.
202. Relative Light Intensity Build the circuit, turn on the switch (62), and the lamp (76) and the colorful LED (72) will be turned on at the same time. Decibels can also be used to compare light intensity levels. For instance, if the colorful LED (72) was twice as bright as the lamp (76), the this would lead to a 10*log(2) = 3dB difference between the light intensity of the colorful LED (72) and the lamp (76). You can find the log function on your typical scientific calculator. 203.
206. IC Packaging Build the circuit shown on the left, connect the switch (62), and the three LEDs will be turned on all at the same time. Circuits like this (and much more complicated than this) often get put into ICs, which are then packaged in many different ways, but typically have pins of pads coming out of the packaging to connect the circuit to power and to provide inputs and outputs. + 207.
+ + Build the circuit, then turn on the switch (62); you will see the heart LED (69) is on and the colorful LED (72) is shining too. – + – -101- The fourth step in making an IC for a circuit like this or more complicated circuits is to perform doping. Doping is the process of heating the etched wafers with gases containing impurities to physically create the areas of n-type and p-type silicon. Steps 2 through 3 may be repeated a number of times to create layers of silicon for more complex circuits.
+ 212. Making ICs – Step 6 Build the circuit to the left, turn on the switch (62), and you will see all three LEDs will be on and also the alarm (78) will sound. The sixth step in making an IC for a circuit like this or more complicated circuits is to perform packaging. All the chips that pass the testing step are cut out of the wafer and packaged as discussed in project #206. + 213. Siren Build the circuit shown on the left. Press the switch (62) and you will hear the siren from the speaker (93).
218. Flickering Candle Replace the speaker (93) with the lamp (76) in project #213, then connect points C and D with a 4-wire (4). If you turn on the switch (62) you will see the lamp (76) is flashing quickly. You could put this circuit in your window at night and it would look like a candle in a gentle breeze. 219. Flashing Quick Sale Sign – Replace the speaker (93) with the bi-directional LED (71) in project #213, then connect points C and D with a 4-wire (4).
224. Moore’s Law Replace the switch (62) with the press switch (61) in project #213. Press the press switch (61) and you will hear the siren from the speaker (93). The 3-in-1 module (11) has an IC in it which is more complicated to provide various sounds. The complexity of what needs to go on ICs continues to grow every year. Fortunately, semiconductor technology has been able to advance at a fast rate too. Moore’s Law saws that microchips double in power every 18 to 24 months. 225.
229. Sampling Replace the switch (62) with the press switch (61) and replace the speaker (93) with the lamp (76) in project #213. Connect points C and D with a 4-wire (4), press the press switch (61) and you will see the lamp (76) is flashing quickly. Sampling is a method for digitally encoding sound signals including music.
233. Motion Detection Alarm Replace the switch (62) with the reed switch (83) in project #213. Hold the magnet (7) near the reed switch (83) and you will hear the siren from the speaker (93). This circuit simulates motion detection alarms that are in your house. 234. No Touch Special Effects Replace the switch (62) with the reed switch (83) in project #213. Place a 4-wire (4) across points C and D and when you hold the magnet (7) near the reed switch (83) you will hear a gun shot and machine gun sounds.
238. Geiger Counter Replace the switch (62) with the reed switch (83) and replace the speaker (93) with the lamp (76) in project #213. Connect points C and D with a 4-wire (4), hold the magnet (7) near the reed switch (83) and you will see the lamp (76) is flashing quickly. A Geiger Counter is a device for measuring radioactivity by detecting and counting ionizing particles. This circuit simulates a Geiger counter detecting radioactivity when the magnet (7) is near the reed switch (83). – 239.
242. Sound from Motor Build the circuit shown on the left, press the switch (62) and you will hear a faint siren from the motor (95). The motor (95) is actually acting as a speaker. As discussed in project #41, current through the motor (95) creates a force on the shaft. It turns out this force is also being applied to the shell of the motor (95) and the shell of the motor (95) is acting like a cone in a speaker, which is creating the sound you hear. 243.
247. Gears Replace the switch (62) with the press switch (61) in project #242, press the press switch (61) and you will hear a faint siren from the motor (95). A gear is a part having teeth, or cogs, which can mesh with another toothed part to transmit torque. By having different size parts, gears can change the speed, torque, and direction of a power source. 248.
252. Magnets and Photons Replace the switch (62) with the reed switch (83) in project #242, hold the magnet (7) near the reed switch (83) and you will hear a faint siren from the motor (95). Magnets attract to each other because they exchange photons, just like particles that make up light. But unlike the photons coming from a light source, these photons are virtual and you can’t see them. 253.
257. Siren & Red Light Warning Build the circuit shown on the left, then turn on the switch (62) and you will hear some low volume sounds of a police siren from the speaker (93). Also, you will see the heart LED (69) is flashing at the same time. The voltage changes at the speaker input SP2 are changing the voltage across the heart LED (69), causing it to flicker. 258.
262. Magnet-controlled Fire Siren with Red Light Warning Replace the switch (62) in project #257 with the reed switch (83), hold the magnet (7) near the reed switch (83) and you will hear some low volume sounds of a police siren from the speaker (93). Also, you will see the heart LED (69) is flashing at the same time. The reason the volume is low is because the heart LED (69) has resistance built into it which is limiting the current through the speaker (93). 263.
267. Distant Siren with Indicator Replace the switch (62) in project #257 with the press switch (61). Press and hold the press switch (61) and you will hear some low volume sounds of a police siren from the speaker (93). Also, you will see the heart LED (69) is flashing at the same time. In this circuit the heart LED (69) is in series with the speaker (93), so the voltage drop across the heart LED (69) reduces the voltage across the speaker (93) reducing the volume of the sound. 268.
272. Nearby Siren Build the circuit to the left, then turn on the switch (62) and you will hear some medium volume sounds of a police siren from the speaker (93). Also, you will see the lamp (76) is flashing at the same time. The resistance in the lamp (76) is lower than that in the heart LED (69), allowing more current to flow through the speaker (93) and thus the volume is higher. 273.
278. Loudest Sound Connect points C and D with a 4-wire (4) in project #277. Press and hold the press switch (61) and you will hear gun shots in medium volume and the lamp (76) with flash at the same time. Did you know that the loudest natural sound on Earth is that of an erupting volcano? 279. Animal Hearing [ 278 - 281 ] Connect points A and B with a 4-wire (4) in project #277. Press and hold the press switch (61) and you will hear a fire siren in medium volume and the lamp (76) will flash.
282. Flies and Sound Replace the switch (62) with the reed switch (83) in project #272. Hold the magnet (7) near the reed switch (83) and you will hear some medium volume sounds of a police siren from the speaker (93). Also, you will see the lamp (76) is flashing at the same time. Did you know that flies cannot hear sound? So don’t worry about being quiet when you are trying to catch that fly! 283. Dolphins Hearing Underwater [ 282 - 286 ] Connect points C and D with a 4-wire (4) in project #282.
287. Motor and Speaker in Parallel Build the circuit shown on the left, then turn on the switch (62) and you will hear sounds of a police siren from the speaker (93). Also, you will see the motor (95) is spinning at the same time. The motor (95) and speaker (93) are in parallel in this circuit so they both get enough current to operate. 288.
293. High Impedance Input Connect points C and D with a 4-wire (4) in project #292. Hold the magnet (7) near the reed switch (83) and you will hear gun shots and the motor (95) will spin at the same time. [ 293 - 296 ] Note that this circuit places a 100W resistor between the T2 input and ground when you place the 4-wire (4) across points C and D. This is because T2 is a high impedance input. Impedance is a measure of the opposition of a circuit or input to current flow.
297. Floating Inputs Replace the switch (62) with the press switch (61) in project #287. Press and hold the press switch (61) and you will hear sounds of a police siren from the speaker (93). Also, you will see the motor (95) is spinning at the same time. A floating input is one that is not connected to anything. While this circuit has not connected the T1, T2, I/O1 and I/O2 inputs to anything external to the 3-in-1 (11), internally it’s possible the 3-in-1 has tied these inputs to ground or 4.
302. Norton’s Theorem Build the circuit shown on the left, then turn on the switch (62) and you will hear some medium volume sounds of a police siren from the speaker (93). Also, you will see the star LED (70) is flashing at the same time. Norton’s Theorem states that any linear electrical network consisting entirely of voltage and current sources and resistances can be replaced by an equivalent current source in parallel with an equivalent resistance. Norton’s Theorem is the inverse of Thevinin’s Theorem.
307. Susceptance Replace the switch (62) with the press switch (61) in project #302. Press and hold the press switch (61) and you will hear some medium volume sounds of a police siren from the speaker (93). Also, you will see the star LED (70) is flashing at the same time. Susceptance is the measure of how easily (or susceptible) a circuit or input is to the flow of AC current due to inductance or capacitance. 308.
312. Linear Circuit Components Replace the switch (62) with the reed switch (83) in project #302. Hold the magnet (7) near the reed switch (83) and you will hear some medium volume sounds of a police siren from the speaker (93). Also, you will see the star LED (70) is flashing at the same time. A circuit will be linear if it consists entirely of ideal resistors, capacitors, inductors or other linear circuit elements. 313. Nonlinear Circuits Connect points C and D with a 4-wire (4) in project #312.
317. Orientation of IC Build the circuit shown, turn on the switch (62) and you will hear the sounds of a police siren from the speaker (93). Also, you will see the heart LED (69) is flashing at the same time. If you ever looked at an IC you would see that there is a dot or notch on them. Since many ICs are symmetrical in shape (e.g. rectangular or square), the notch or dot is use to represent the orientation of the IC relative to the pin locations of the IC. 318.
322. Work Replace the switch (62) with the reed switch (83) in project #317. Hold the magnet (7) near the reed switch (83) and you will hear the sounds of a police siren from the speaker (93). Also, you will see the heart LED (69) is flashing at the same time. In physics, work is done when a force moves an object. 323. Formula for Work Connect points C and D with a 4-wire (4) in project #322.
327. Weight Replace the switch (62) with the press switch (61) in project #317. Press the press switch (61) and you will hear the sounds of a police siren from the speaker (93). Also, you will see the heart LED (69) is flashing at the same time. Weight is different than mass. Weight is based on the gravitational pull on an object. Mathematically, weight and mass are related through the formula Weight = mass*g, where g is the gravitational acceleration due to the Earth. 328.
332. Siren is Breaking up and Fading Out Build the circuit shown and turn on the switch (62). Press the press switch (61) for a while and you will hear the siren. Release the press switch (61) and wait for a while. You will eventually hear the siren start breaking up and fading out.
335. Power Connect points E and F with a 4-wire (4) in project #332. Press the press switch (61) for a while and you will hear space battle sounds. Release the press switch (61) and wait for a while. You will eventually hear the space battle sounds start breaking up and fading out. Power is the rate of doing work, or the energy transferred per unit of time. Mathematically, Power = Work/Time. 336. Watts Connect points G and H with a 4-wire (4) in project #332.
339. Transformers Connect points A and B with the 4-wire (4) in project #337. Hold the magnet (7) near the reed switch (83) for a while and you will hear the fire siren. Move the magnet (7) away from the reed switch (83) and wait for a while. You will eventually hear the fire siren start breaking up and fading out. A transformer transfers electrical energy between two or more circuits through electromagnetic induction.
343. Monolithic IC Connect points C and D with the 1kW resistor (42) in project #342. Press the press switch (61) for a while and you will hear gun shots. Release the press switch (61) and wait for a while. You will eventually hear the gun shots start breaking up and fading out. The IC in the 3-in-1 (11) is a monolithic IC, which means all the circuitry for producing the sounds is contained in a single silicon chip. 344. Hybrid ICs Connect points A and B with the 4-wire (4) in project #342.
347. Shorter Siren Fade Out Build the circuit shown and turn on the switch (62). Press the press switch (61) for a while and you will hear the siren in soft volume. This is because the 100W resistor (41) limits the current through the speaker (93). Release the press switch (61) and wait for a while. You will eventually hear the siren start breaking up and fading out. Since there is a 5.
350. Quantization and Encoding Connect points E and F with a 4-wire (4) in project #347. Press the press switch (61) for a while and you will hear space battle sounds in soft volume. This is because the 100W resistor (41) limits the current through the speaker (93). Release the press switch (61) and wait for a while. You will eventually hear the space battle sounds start breaking up and fading out.
352. ADC Converter Replace the switch (62) with the reed switch (83) in project #347. Hold the magnet (7) near the reed switch (83) for a while and you will hear the siren in soft volume. This is because the 100W resistor (41) limits the current through the speaker (93). Move the magnet (7) away from the reed switch (83) and wait for a while. You will eventually hear the siren start breaking up and fading out.
355. Digital Signal Processing Connect points E and F with a 4-wire (4) in project #352. Hold the magnet (7) near the reed switch (83) for a while and you will hear space battle sounds in soft volume. This is because the 100W resistor (41) limits the current through the speaker (93). Move the magnet (7) away from the reed switch (83) and wait for a while. You will eventually hear the space battle sounds start breaking up and fading out.
358. BJT and FET Connect points C and D with the 1kW resistor (42) in project #357. Press the press switch (61) for a while and you will hear gun shots in soft volume. This is because the 100W resistor (41) limits the current through the speaker (93). Release the press switch (61) and wait for a while. You will eventually hear the gun shots start breaking up and fading out.
361. MOSFET Connect points G and H with a 4-wire (4) in project #347. Press the press switch (61) for a while and you will hear music in soft volume. This is because the 100W resistor (41) limits the current through the speaker (93). Release the press switch (61) and wait for a while. You will eventually hear the music start breaking up and fading out. The makeup of a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) is shown in the figure below.
364. Distortion Connect points A and B with the 4-wire (4) in project #362. Turn on the switch (62) and you will hear very loud fire siren. Turn off the switch (62) and the fire siren will go off. You may notice that the fire siren is so loud in this circuit that it sounds distorted. This is happening because fire siren waveform coming out of the 3-in-1 (11) is not just being amplified by the amplifier (14) but the waveform is being changed in some other way (i.e.
367. Low Volume Siren Build the circuit to the left, turn on the switch (62) and you will hear a low volume siren and the colorful LED (72) will light the fiber tree (40). Turn off the switch (62) and the siren will go off. In this circuit, the speaker (93) is in series with the 100W resistor (41). The 100W resistor (41) limits the current through the speaker which is why the volume is lower. 368.
372. Siren Fading In and Out + – [ 372 - 374 ] – + Build the circuit to the left, turn on the switch (62), and you will hear a low volume siren with the heart LED (69) and colorful LED (72) flashing. Listen as the colors change on the colorful LED (72). Can you detect a pattern? Turn off the switch (62) and the siren and LEDs will go off. In this circuit you may have noticed that the siren fades out as the colorful LED (72) turns green and blue but then the siren comes back when the LED turns red.
375. Battery Power When Red [ 375 - 376 ] – + Connect points E and F with a 4-wire (4) in project #372. Turn on the switch (62) and you will hear low volume space battle sounds with the heart LED (69) and colorful LED (72) flashing. Turn off the switch (62) and the sounds will go off. Project #38 discussed that Power is calculated as V*I. In this circuit, when the colorful LED (72) is red the power drawn from the battery module (91) is 4.5V*60mA = 0.27 Watt. 376.
378. OR Gate Revisited Build the circuit shown on the left. Note that the heart LED (69) turns on when either the switch (62) or the press switch (61) are on. This was discussed as an OR Gate logic in Project #66. OR gates can also be purchased in ICs. Below is a picture of the pinout for one example IC that provides four OR gates. + 1st level 2nd level – 2nd level 2nd level + 379. NOT Gate Build the circuit shown on the left.
380. NOT Gate Applications Build the circuit shown on the left. Note that the lamp (76) is on when the press switch (61) is off and the lamp (76) is off when the press switch (61) is on. You might have a circuit like this in your car, where the light in your car stays on while the door is open, but when you close the door, it’s like pressing the press switch (61) and the light goes out. 381. NAND Gate Build the circuit from project #380 but add the switch (62) in series with the press switch (61).
383. AND Gate Applications Build the circuit shown. Note that the siren sounds only when both the switch (62) and the press switch (61) are on. One of the most common applications of AND gates are as enabling circuits like this. So for instance, the press switch (61) in the circuit could represent a stream of digital date going into your computer and the switch (62) is the ON-OFF switch on your computer.
385. More NOT Gate Applications Build the circuit to the left. The lamp (76) lights and you will hear the sound of a siren. Note that the siren sounds while the press switch (61) is off, but when you press the press switch (61) the siren goes off. This type of circuit could act like a mute button for the sound on your TV. 386. FM Radio Build the circuit to the left, turn on the switch (62), and move the magnet (7) near the reed switch (83) and you will hear some FM radio stations from the speaker (93).
387. FM Technology Build the circuit to the left, turn on the switch (62) or press the press switch (61) and you will hear some FM radio stations from the speaker (93). You may have to press the press switch (61) connected to CH+ to get the FM receiver to scan for a channel. For best FM reception, hold the open end of the spring wire (9) in the air.
389. FM Radio Channels Build the circuit to the left, turn on the switch (62) and press the press switch (61), and you will hear some FM radio stations from the speaker (93). You may have to press the press switch (61) connected to CH– to get the FM receiver to scan for a channel. For best FM reception, hold the open end of the spring wire (9) in the air. FM radio channels are spaced 200 kHz apart. This means that theoretically there could be about 100 FM channels in a given city/ area.
391. FM Radio Audio Range + – + Build the circuit to the left, turn on the switch (62) and you will hear some FM radio stations from the speaker (93) and the heart LED (69) will flash with the sounds. You may have to press the press switch (61) connected to CH– to get the FM receiver to scan for a channel. For best FM reception, hold the open end of the spring wire (9) in the air.
394. Pathloss Calculation Build the circuit above, put the reed switch (83) across points A and B and turn on the switch (62). You won’t hear any radio stations from the speaker (93) until you place the magnet (7) near the reed switch (83). You may have to press the press switch (61) connected to CH– to get the FM receiver to scan for a channel. For best FM reception, hold the open end of the spring wire (9) in the air.
+ – 395. FM Transmission Power Build the circuit above, turn on the switch (62) and you will hear some FM radio stations from the speaker (93) and the colorful LED (72) will light. You may have to press one of the press switches (61) to get the FM receiver to scan for a channel. For best FM reception, hold the open end of the spring wire (9) in the air. As discussed in the previous project, over-the-air propagation losses are huge even at relatively low frequencies like 88-108MHz.
Other E-Blox® Products More sets available! Visit www.myeblox.
Other E-Blox® Products More sets available! Visit www.myeblox.com TM Builds Deluxe Builds Plus Contains over 100 parts, including 8 LEDs. Contains over 70 parts, including 6 LEDs. Compatible other toy sets. Compatible with other toy brick sets. with brick Flashing Frenzy Starter Contains 25 patented parts, including 6 LEDs. Compatible other toy sets. with brick Contains over 125 patented parts, including 50 LEDs. Online instructions available for three models.
Other E-Blox® Products TM Story Blox™ include a storybook with QR codes that create an interactive learning environment using online resources. Eight models are built one at time in several parts of the story using a fully illustrated and easy-to-follow assembly manual, further enhancing the learning experience. Seymour E. Blox and his robot Robyn investigate a mysterious light in the distant ocean horizon.
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