This material is based upon work supported by the U.S. Department of Homeland Security under Grant Award Number, 2013-PD-127-000001, Modification #2.
Materials List
Objectives
Notes
Teacher Notes:
• Elect13 PP Electromagnet Lab
• 1 or 2 C batteries per group
• Heavy duty copper wire, cut to 12” lengths and stripped to appx ½” from the ends
• Various ½” bolts, including Zinc, Galvanized, and Stainless
• Assorted ferrous and non-ferrous items to use to test the magnets; can include steel and plastic paper clips, brass tacks or document clips, etc.
• Conclude exploration into the flow of electrons
• Experiment with ferrous and non-ferrous objects
• Explore the properties of Stainless vs non-Stainless steel
• The presentation for this lab is primarily pictures, illustrating the interaction of electricity and magnetism.
• Slide 1
• Of all of the battery labs, this is definitely the most dangerous. By connecting the positive and negative ends of the battery to a single wire, we will actually be shorting out the circuit. If the circuit is connected too long, the wire has the capability to get extremely hot. Students should be encouraged to connect the circuit, test the magnetic ability, and disconnect the circuit.
• Slide 2
• This slide gives students an example to observe the flow of a magnetic field around a ferrous object like a bar magnet. This might simulate the bolt in the
coming experiment. This gives one the opportunity to discuss how the atomic structure of the materials in each of the bolts either permit restructuring or do not restructure. In all of the zinced or galvanized materials, the atoms allow for the magnetic moments to realign, turning the object into a temporary magnet, while the stainless steel does not realign.
• Slide4
• This slide illustrates the right hand rule. Namely, if your thumb of your right hand is used to indicate the direction of current, the fingers of your right hand, when curled around the wire, indicate the direction of magnetic flow.
• In the case of this experiment, you can show how the flow of current in the coil will combine with each layer of the coil to create a significant magnetic field into which we will place the bolts.
• Slide 5
• This slide begins to illustrate how a magnetic field forms around a coil of wire carrying current. The concept illustrated is the one discovered by Michael Faraday in 1821.
• One device he created helped to model electromagnetic rotation. Known as the homopolar motor, it caused a continuous circular motion that was engendered by the circular magnetic force around a wire that extended into a pool of mercury wherein was placed a magnet; the wire would then rotate around the magnet if supplied with current from a chemical battery.
• Slide 6
• This shows the actual coil, just like will be created in the lab. The induced magnetism is also shown, and students can get an idea of how significant the field is that will be created. Students should be encouraged to refer to this picture throughout the lab by checking the polarity of the battery and the direction of the wrap of the coil in order to identify the direction of the magnetic field.
• Slide 7
• This shows how the batteries, wire, and bolts are all connected. Please note, do not hold this circuit by the stripped wires at the batteries. You should only hold this by the insulated wire, similar to chopsticks. Use the rigidity of the wire to hold the battery in place, putting only light pressure on the battery but using just enough force to hold the contraption together.
• The Experiment
• Issue one of each bolt and a battery and coil to each group
• Encourage students to only hold the circuit together for a couple of seconds
• As the wire gets hot, they should disassemble the circuit and let everything cool
• Only when the wire has cooled, should they reassemble the circuit
• With each construction, they should try to pick up a variety of materials
• Towards the end, let them try to use the stainless bolt and have them explain their observations
• Observation
• During one run of this lab, a student inquired if the coil and current could make what would be considered a rail gun (http://en.wikipedia.org/wiki/Railgun).
• While the materials are not nearly strong enough to propel objects, it can suspend objects, like a screwdriver. If you have an object that is smaller than the inside of the coil (like a screwdriver), place the screwdriver in the coil, hold the assembly above a surface, and connect the source. If the voltage and current are strong enough, you may be able to let go of the screwdriver and it can be suspended by the charge in the coil. If at first it doesn’t work, try reversing the battery as that will affect the orientation of the magnetic field.
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Elect13 PP Electromagnet Lab
Electromagnet Lab This is a very dangerous lab. I will need your full attention throughout the circuit building process. You will not be allowed to participate in the lab if you are not paying attention. If you do not participate, you will receive a 0 for the lab.
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Electromagnet Lab
Electromagnet Lab
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Electromagnet Lab
Electromagnet Lab
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Electromagnet Lab
Credits Title: Elect13 PP Electromagnet Lab Author(s): Dr. Charles Gardner, NOMMA Cyber Science Coordinator Contributor(s): Dr. Krystal Corbett, NICERC Director of Curriculum Original Source: NOMMA (New Orleans Military and Maritime Academy) Published/Distributed by: NICERC (National Integrated Cyber Education Research Center) Additional Information: NICERC is a department within the Cyber Innovation Center that helps scholars, researchers, and teachers discover, use, and build upon curricular content that has been created through a trusted design process. For more information about NICERC, please contact [email protected]. Acknowledgement: This material is based upon work supported by the U.S. Department of Homeland Security under Grant Award Number DHS-13-NPPD-127-001. Disclaimer: The views and conclusions contained in this document are those of the authors and contributors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security.
This material is based upon work supported by the U.S. Department of Homeland Security under Grant Award Number, 2013-PD-127-000001, Modification #2.
Materials List
Objectives
Notes
Teacher Notes:
• Cyber07 PP Passwords
• Cyber07 WS Passwords
• Understand common shortfalls of passwords
• Evaluate alternatives to the standard password; describe what makes a password “strong”; suggest how to protect personal information online
• There isn’t much to this lesson other than the PowerPoint. The relevance for the lesson is it follows the network/malware lessons and precedes the cyber bullying lesson. Many times, cyber bullying can be triggered by an account hack due to easily guessed passwords. Students must be aware of the shortfalls of a simple password.
• The lesson begins with a few simple slides that explain the meaning of a password and a simple comic illustrating a poor choice in passwords. Students should understand that passwords are not solely for use with computers and digital technology. Passwords have been around for centuries, even millenia, protecting countries from attack.
• It wasn’t until 1961 when we saw passwords being used for computing purposes. In fact, it was at MIT where a student created a log for student access to the network, and that log provided usernames and passwords. So, why the care and concern about effective passwords? It was a needy student at MIT in the following year that found the password file on the network. Once he cracked the file, he found all the user passwords in plain text and had the ability to control the time on the system.
• Following the MIT example, we discuss the “Authentication” aspect of passwords and how the password ensures the user is the owner of the account. Students are asked to consider authentication systems and possible issues or problems with those systems.
Try to ensure students have ample time to consider the situations before you reveal the answers or analyses.
• At the halfway point, the presentation explains to students what a strong password is; how they should consider altering their current passwords to make them stronger; and in spite of a good, strong password, what are the potential issues they still face?
• The lesson delves back into malware a bit, but this time the material is related to passwords and password files.
• Finally, the original article as it appeared in Wired magazine has been provided for any students looking for additional information on the topic. As it is quite lengthy, it may not be assigned reading, but just something for the advanced student.
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Cyber07 PP Passwords
The End of the P@55W0rD – Do they really keep your stuff safe?
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Passwords What is a password? According to the dictionary, there are two definitions for password: 1. A secret word or phrase that must be used to gain admission to something. 2. A string of characters that allows access to a computer, interface, or system.
Passwords A Brief History of the Password "Passwords" or "watch words" were used before recorded history by men organized in groups to lookout for or guard a group. One example of the first "hacked" password occurred during the Peloponnesian War in 413 B.C. when the Athenians attacked the Syracusans in Sicily.
BypermissionofLeighRubinandCreatorsSyndicate,Inc.
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Passwords How do passwords work? The first computers to use passwords were part of MIT's Compatible Time-Sharing System developed in 1961. The purpose of this system was to limit the time any one user could access the system (a system of rationing usage). In 1962, a student located the file containing the passwords (all were in plain text) using a simple hack and could then login in as much as he wanted using other peoples' passwords.
Passwords How do passwords work? Passwords are meant to "authenticate" or verify that a user is who he/she says they are. Methods of Authentication: 1) direct authentication by sending a password directly to a server in plain text; the server then authenticates against a database problem: can be easily intercepted
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Passwords Methods of Authentication: 2. Passwords are sent through a 1-way hash function which converts the plain text password to a random-looking sequence which must then be converted by the server problem: can be intercepted and decoded 3. Challenge-response passwords - the server sends a challenge back to the user who must compute and respond to the challenge. Ticketmaster and online purchase sites use Challenge-response passwords.
Passwords Tips for Creating a Good, Strong Password 1. Choose a long password. Try to make sure that your password is not shorter than 12 characters. Use numbers and symbols. 2. Avoid words that can be found in the dictionary. 3. Avoid using obvious or weak passwords.
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Passwords Tips for Creating a Good, Strong Password 4. Don’t ever try to create passwords that identify yourself or relates to anything about you. 5. Maintain a habit of regularly changing your password. 6. If you’re having trouble creating a password that is difficult to crack, use a strong password generator.
Passwords Question: If we follow the guidelines for creating a good, strong password, why should we be worried? Passwords are no longer 100% safe! Some ways the criminals can get us: 1) brute force 2) guessed 3) stolen with a keylogger
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Passwords Some ways the criminals can get us: 4) lifted from a password dump 5) phishing 6) malware 7) resets by conning ISP's and customer service We can easily understand 1 & 2 and have talked about 3 ... let's concentrate on 4-7.
Passwords Lifted from a password dump A password dump is a place where hackers can list a number of passwords that have been hacked. Whole websites exist where passwords from companies like Yahoo!, Blizzard, and LinkedIn are listed. some of the most popular passwords ... password 123456
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Passwords Phishing phishing - the act of attempting to acquire information such as usernames, passwords, and credit card details (and sometimes, indirectly, money) by pretending to be a trustworthy entity in an electronic communication. This method can actually take you to a webpage that looks very real.
• The lesson begins with an introduction into InfraRed (IR) light and uses of IR signals.
• The material in the PowerPoint comes directly from the “Robotics with the BoeBot” Student Guide, version 3, by Parallax. While just about every piece of information from the first activity of Chapter 7 has been placed into this presentation, you may want to refer to the book for additional notes and assistance.
• Slides 9 and 10 try to give students an idea of what an IR signal looks like. If you have a remote and a cell phone camera in your classroom, this is an easy demonstration to replicate. Just make sure the remote is pointed away from its device. For example, don’t try to demonstrate the power button on your projector remote and then have the projector turn off on you!
• Slide 11 begins the assembly of the circuit by laying out the parts. The picture is a good tool here because it shows not only the parts diagram, but the schematic diagram for the IR LED and for the IR Receiver.
• Slide 12 illustrates the difference between a phototransistor (this piece comes with some BoeBot kits) and an IR LED. What makes them confusing is the fact that they both have clear cases. The LED is much bigger though, and is pretty hard to confuse.
• Slide 13 shows how the IR LED and the Shield Assembly work. The LED should snap into the base of the shield assembly. This is important for when students install the LED onto the breadboard that the LED doesn’t come out of the base of the assembly. The tape on the assembly is also important. While they mention clear tape in the instructions, you can also use masking tape here.
• Slide 14 indicates to students that there will be a schematic and a wiring diagram following on slides 15 and 16 respectively. They should be encouraged to build as much as possible from the schematic and when the wiring diagram comes up, they should use it to verify their build.
• Slide 17 begins the discussion on the code and the frequency that the IR LED must flash at to be recognized by the IR Receiver. Earlier in the discussion, the frequency 38,500 Hz was mentioned when discussing TV sets and their IR remotes. This is the same frequency we need the BoeBot’s IR LED to flash at. The command to accomplish this is FREQOUT, just like we used for the Piezo speaker.
• Slides 18, 19, and 20 briefly discuss the syntax of the FREQOUT command and the IN command that must follow.
• Slide 20 lays out the code to test the Left IR LED. Students are then tasked with realigning the code to test the Right LED.
• The final objective for the day should be to have students try to get both the left and right IR LED detectors providing information in the same DEBUG window. The key to this objective is to remember that the irDetectLeft line must come immediately
after the FREQOUT 8 line and that irDetectRight must come after FREQOUT 2.
Worksheet Notes
• The Worksheet for this lesson can be treated as a separate day’s event, depending on the time available. Regardless of when it is used, it is critical to collect this data before the BoeBot 15 lesson. The information from the sheet will be used to optimize the IR detection system for the final builds of the year.
• In order to process the worksheet, students will need at least one of each resistor. Care should be taken to explain that only the resistor on the LED circuit will be changed, not the resistor on the IR receiver circuit.
• Student teams should collect the resistors and a yard stick and use the basic “1-0” debug program that was first used to test the IR Circuit. All they are trying to do here is find out how “far” the BoeBot can see by holding their hand in front of the BoeBot and measuring at what distance the “0” becomes a “1” or vice-versa.
• The distance values should be recorded on the sheet’s top half, and average estimated for the left and right values, and the resulting averages sorted from farthest to nearest.
• The last question asks for some real world uses of IR circuits. Modern toilet facilities use IR circuits to determine when a toilet, sink, or paper towel dispenser is being used; parking garages sometimes use IR to determine how far a car is from approaching the gate; Wii, Xbox Kinect and other similar game consoles use IR with the controllers; and of course remotes for home TV and cable systems.
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BoeBot14 PP InfraRed Navigation
InfraRed Navigation The Boe-Bot can already use whiskers to get around objects it detects when it bumps into them, but wouldn’t it be better if the Boe-Bot could just “see” objects and then decide what to do about them? Well, that’s exactly what the Boe-Bot can do with infrared headlights and eyes like the ones on the next slide. The infrared headlight is an infrared LED inside a light shield that directs its light forward just like a flashlight. The infrared eye is an infrared receiver that sends the BASIC Stamp high/low signals to indicate whether it detects the infrared LED’s light reflected off an object.
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InfraRed Navigation
InfraRed Navigation INFRARED LIGHT Infrared is abbreviated IR and you can think about it as a form of light the human eye cannot detect. Devices like the IR LED introduced in this lesson emit infrared light, and detectors, known as infrared receivers, from this project detect infrared light.
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InfraRed Navigation Infra means below, so infrared means below red. The name refers to the fact that the frequency of infrared light waves is less than the frequency of red light waves. IR wavelengths and their uses: The wavelength our IR LED transmits is 980 nm, and that’s the same wavelength our IR receiver detects. This wavelength is in the near-infrared range. The far-infrared range is 2000 to 10,000 nm, and certain wavelengths in this range are used for night-vision goggles and IR temperature sensing.
InfraRed Navigation The infrared LED the Boe-Bot uses as a tiny flashlight is actually the same one you can find in just about any TV remote. The TV remote sends IR messages to your TV, and the microcontroller in your TV picks up those messages with an infrared receiver like the one your Boe-Bot will use to detect IR reflected off of objects.
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InfraRed Navigation Note that the TV remote sends messages describing which button you press by rapidly flashing its IR LED on/off at a rate in the 38 kHz neighborhood. That’s around 38,000 times per second. The IR receiver only responds to infrared if it’s flashing on/off at this rate. This prevents infrared from sources like the sun and incandescent lights from being misinterpreted as messages from the remote. So, to send signals the IR receiver can detect, your BASIC Stamp will have to send signals in the 38 kHz range too. The PBASIC language makes short work of that task, with just one line of code to transmit the signal, and a second line to check the IR receiver.
InfraRed Navigation The light color sensors inside most digital cameras, including cell phones and webcams, can all detect infrared light, which gives us a way to “see” it even if the eye cannot detect it. Figure 7-3 shows an example with a digital camera and a TV remote. When you press and hold a button on the remote and point its IR LED into the digital camera’s lens, it displays the infrared LED as a flashing, bright white light.
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InfraRed Navigation Activity: Building and Testing the IR Object Detectors Parts: (2) IR receivers (2) IR LEDs (clear case) (2) IR LED shield assemblies (2) Resistors, 220 Ω
(red-red-brown) (2) Resistors, 1 kΩ
(brown-black-red)
InfraRed Navigation Check the picture to make sure you have selected infrared LEDs and not phototransistors. The infrared LED has a taller and more rounded plastic dome, and is shown on the right side of the picture.
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InfraRed Navigation Activity: Building the IR Headlights • Insert the infrared LED into the LED standoff (the larger of the
two shield assembly pieces) as shown in Figure 7-6. • Make sure the IR LED snaps into the LED standoff. • Slip the LED shield (the smaller half of the LED shield assembly)
over the IR LED’s clear plastic case. The ring on one end of the LED shield should fit right into the LED standoff.
• Use a small piece of clear tape to make sure the two halves of the shield assembly don’t separate during use.
InfraRed Navigation Activity: IR Object Detection Circuit Figure 7-7 shows the IR object detection circuit schematic and Figure 7-8 shows a wiring diagram of the circuit. In the wiring diagram, one IR object detector (IR LED and receiver) is mounted on each corner of the breadboard closest to the very front of the Boe-Bot. • Disconnect power from your board and servos. • Build the circuit in the Figure 7-7 schematic using the
Figure 7-8 wiring diagram as a reference for parts placement.
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InfraRed Navigation Activity: IR Object Detection Circuit
InfraRed Navigation Activity: IR Object Detection Circuit Watch your IR LED anodes and cathodes! The anode lead is the longer lead on an IR LED by convention. The cathode lead is shorter and mounted in the plastic case closer to its flat spot. The same conventions applied to the red LEDs earlier. In this image, the anode lead of each IR LED connects to a 1 kΩ resistor. The cathode lead plugs into the same breadboard row as an IR detector’s center pin, and that row is connected to Vss with a jumper wire.
