Electronics Articles

Cheat Sheet / Updated 11-17-2022

Your iPhone can be so much more than a communication tool to talk into. Aside from making calls and creating your contacts, you should make yourself familiar with the many options available on the iPhone touchscreen. You'll also want to be able to handle troubleshooting when your Apple device acts strangely or stops working. When you need a bit of levity, check out our 10 ways to have fun with Siri. And finally, if you have an iPhone with Face ID, you’ll discover Face ID–specific tips for creating animoji and putting your iPhone into recovery mode.

Cheat Sheet / Updated 11-17-2022

One of the best things about your Android smartphone is that it is, well, yours. Android gives you a number of ways to customize not only the look and feel of your phone, but also the way it works for you. From adding widgets to your home screen, disabling notifications from apps of your choosing, and setting tap and zoom accessibility settings, you can add a little personality to your Android smartphone and turn it into a unique device for a truly unique user experience.

Cheat Sheet / Updated 11-14-2022

This cheat sheet gives you a rundown of some of the most useful features and apps so you can find what you need to customize your iPhone’s behavior. See how to get the most out of Siri (your iPhone’s virtual assistant), review some favorite apps for news and weather, and discover several of the most popular apps for multimedia.

Article / Updated 11-04-2022

Listen to the article:Download audio What is the Amazon Fire TV Stick? The Amazon Fire TV Stick is a device joining the ranks of home entertainment streaming technologies. The Fire Stick plugs into your TV’s HDMI port giving you access to your favorite TV shows, movies, subscription services, music, photos, and games. The Fire TV Stick houses all of your favorite content and is easily transportable, so you can take your media anywhere! What you get with the Fire TV Stick Imagine being able to take your TV with you when you go on vacation. That’s the functionality you get with the Fire TV Stick. The Fire TV Stick houses all of your content and is completely portable. Simply remove your device and take it with you when you travel. Plug it into any compatible TV to gain instant access to all of your favorite videos. If you are an Amazon Prime member, your Fire TV Stick comes pre-registered to your account. You have immediate access to all of your Amazon Prime content as soon as you plug your Fire TV Stick into your HDMI port. Being a Prime member also lets you choose from a cache of Amazon Originals that cannot be accessed by the average user. When you receive your box from Amazon, you will have everything you need to make the Fire TV Stick work. In the box you will find your new Fire TV Stick, the remote, a USB cable and power adapter, HDMI extender, 2 AAA batteries, and a guide to get you started. In addition, you get the following features: 1 GB of memory 8 GB of internal storage Optional voice support Dual-band, dual-antenna Wi-Fi A dedicated VideoCore4 GPU How the Fire TV Stick works The Amazon Fire TV Stick rivals other popular streaming devices like the Roku and Chromecast. How does the Amazon Fire TV Stick work? Your Fire Stick plugs into your HDMI TV via USB port, connects via Wi-Fi, and comes equipped with a Bluetooth remote. Simply plug your Fire Stick in and you will be directed through the setup process and prompted to sign into your Amazon account. The Fire Stick is a central repository for all your content. Once logged on, you will have access to any music and videos purchased through your Amazon account. In addition, you can view any pictures uploaded to your Amazon Cloud service. Using your device, you also have access to thousands of apps and games. For instance, you can use your Fire TV Stick to open the Netflix app and watch trending Netflix videos. Or, open YouTube and browse the latest uploads from your favorite vlogger. Other services like HBO Now, ESPN, and Hulu can also be accessed with your Fire TV Stick at a cost. However, even with the fee, you get the advantage of being able to choose your preferred services instead of being tied into a cable package. Games are also available. But, you will need a controller which is only available for purchase through Amazon. Fire TV Stick vs. Fire TV Amazon offers a Fire Stick and Fire TV. These products offer the same services and both come equipped with a Bluetooth remote. So, what's the difference? Size: The Fire TV Stick is far smaller than the Fire TV. The Fire Stick is about three inches long and plugs into your TV. Fire TV is a square console that, while sleek, is about four and half inches long on each side. If you prefer the minimalist look, the Fire TV Stick is the winner. Cost: You will find that the Fire Stick is the cheaper option. The Fire Stick costs $39.99 while the Fire TV will set you back $99. Speed: The Fire Stick will give you 1 GB of RAM, while the Fire TV offers 2 GB of RAM, making the Fire TV more responsive. If you're a serious gamer, you might want to go for the Fire TV to avoid lags and frustration in loading speeds. Additional ports and storage: With the Fire TV Stick, you won't have options for expansion. The Fire TV console has a USB port, Ethernet port, and microSD slot, making it easier to store and access content. Capabilities: The Fire TV stick can support your watching habits up to 1080p. Fire TV is enabled for 4K streaming. With the trend leaning toward 4K TVs, the Fire TV might be a better option if you are looking to upgrade or already have. Although, if you haven't (or don't plan) to go the 4K route anytime soon, the Fire TV's capabilities and portability factor make it a perfectly adequate choice for those just wanting to stream their favorite shows. Evaluate your needs and budget before determining which Fire TV option is right for you. Why you need the Fire TV Stick When people hear the phrase “streaming technology,” most groan and think about how they just want watching TV to be easy. Well, the Fire TV Stick makes it simple. Only now, instead of searching through those horizontal bars of endless TV shows, you can access what you want to see, when you want to see it. For easier searching, the Fire TV Stick offers voice control using Amazon's Alexa. You can get this capability two ways. Simply press the black button and speak your choice. If that extra cost doesn’t appeal to you, you can download the free Fire TV Remote app on your phone. Using your phone’s native voice prompts, you can speak your choice and your phone will relay your choice to the Fire Stick. Why else would you want the Fire TV Stick? Well, it learns. Or rather, it uses your preferences to make predictions about what you might like. Using ASAP (Advanced Streaming and Prediction), the Fire TV Stick offers you choices of related programming based on your previous watches.

Cheat Sheet / Updated 10-21-2022

The TI-84 Plus CE graphing calculator is one of the most popular calculators in the world. Find out the important keystrokes you need to know to use the TI-84 Plus, and learn the math functions and constants that the TI-84 Plus CE makes available to you. Get to know the basics of graphing on your TI-84 Plus CE, as well as how to use the calculator’s zoom commands and special menus.

Article / Updated 10-19-2022

The letters STO may look like texting language, but the TI-84 Plus calculator's STO key is a handy feature to have around. If you plan to use the same number many times when evaluating arithmetic expressions, consider storing that number in a variable. To do so, follow these steps: If necessary, press [2nd][MODE] to enter the Home screen. Enter the number you want to store in a variable. You can store a number or an arithmetic expression. Press The result of this action is shown in the first screen. Press [ALPHA] and press the key corresponding to the letter of the variable in which you want to store the number. The letters used for storing variables are the letters of the alphabet and the Greek letter theta. Press [ENTER] to store the value. This is illustrated in the second screen. Insert your stored variable into an expression After you have stored a number in a variable, you can insert that number into an expression. To do so, place the cursor where you want the number to appear, press [ALPHA], and press the key corresponding to the letter of the variable in which the number is stored. See the third screen. The number you store in a variable remains stored in that variable until you or the calculator stores a new number in that variable. Because the calculator uses the letters X, T, and the Greek theta when graphing functions, parametric equations, and polar equations, it is possible that the calculator will change the value stored in these variables when the calculator is in graphing mode. For example, if you store a number in the variable X and ask the calculator to find the zero of the graphed function X2, the calculator will replace the number stored in X with 0, the zero of X2. So avoid storing values in these three variables if you want that value to remain stored in that variable after you have graphed functions, parametric equations, or polar equations.

Article / Updated 10-19-2022

Before you can graph a function on your TI-84 Plus calculator, you must enter it into the calculator. The calculator can handle up to ten functions at once, Y1 through Y9 and Y0. To enter functions in the calculator, perform the following steps: Press [MODE] and put the calculator in Function mode. To highlight an item in the Mode menu, use the keys to place the cursor on the item and then press [ENTER]. Highlight FUNCTION in the fourth line to put the calculator in Function mode. See the first screen. Press ! to access the Y= editor. See the second screen. Enter your function. If necessary, press [CLEAR] to erase a previous function entry. Then enter your function. Your math textbook may use a function notation like this: f(x)=2x+1. To graph a function in your calculator, you must realize f(x) is interchangeable with y, only the notation differs. See the third screen. When you’re defining functions, the only symbol the calculator allows for the independent variable is the letter X. Press to enter this letter in your function. As a timesaver, when entering functions in the Y= editor, you can reference another function. Use the shortcut Y-VAR menu to paste a function name in the function you’re entering in the Y= editor. Just press [ALPHA][TRACE] and choose the name of the function you want to insert in your equation. See the first screen. How does calling up the name of another function save you time? Well, say you’re trying to graph a circle in your calculator with the equation x2 + y2 = 36. Of course, you need to solve the equation for y to graph the circle equation in your calculator. Solving for y gives you: Notice, it takes two functions to graph a circle! No problem. In function Y1 enter Then, to save time, use the shortcut Y–VAR menu to enter Y2 = –Y1. See the second screen.

Article / Updated 10-19-2022

After you have entered functions into the TI-84 Plus calculator and formatted your graph, you’re almost ready to start your graphing fun. Once you get the hang of graphing, you won’t need to go through all these steps. Turning off Stat Plots (if necessary) The top line in the Y= editor tells you the graphing status of the Stat Plots. If Plot1, Plot2, or Plot3 is highlighted, then that Stat Plot will be graphed along with the graph of your functions. If it’s not highlighted, it won’t be graphed. In the first screen, Plot1 is highlighted and will be graphed along with the functions in the Y= editor. To turn off a highlighted Stat Plot in the Y= editor, use the keys to place the cursor on the highlighted Stat Plot and then press [ENTER]. See the second screen. The same process is used to highlight the Stat Plot again in order to graph it at a later time. When you’re graphing functions, Stat Plots can be a nuisance if they’re turned on when you don’t really want them to be graphed. The most common symptom of this problem is the ERROR: INVALID DIMENSION error message — which by itself gives you almost no insight into what’s causing the problem. So if you aren’t planning to graph a Stat Plot along with your functions, make sure all Stat Plots are turned off! Selecting and deselecting a function on the TI-84 Plus Deselect (turn off) Y1 and Y2 by removing the highlight from their equal signs. This is done in the Y= editor by using the keys to place the cursor on the equal sign and then pressing [ENTER] to toggle the equal sign between highlighted and not highlighted. The calculator graphs a function only when its equal sign is highlighted! Do you see the difference between the two screens? Adjusting the TI-84 Plus graph window When you graph a function, you usually can’t see the whole graph. You are limited to viewing the graphing window, which typically shows only a small portion of the function. There are four values that determine the portion of the coordinate plane you can see: Xmin, Xmax, Ymin, and Ymax. Press [WINDOW] to display the current window variables. It takes practice to find a good viewing window for the function you’re graphing. Here are the steps needed to set the window of your graph: Press [WINDOW] to access the Window editor. After each of the window variables, enter a numerical value that is appropriate for the functions you’re graphing. Press e after entering each number. Entering a new window value automatically clears the old value. Make sure your (Xmin < Xmax) and (Ymin < Ymax) or you’ll get the ERROR: WINDOW RANGE error message. Editing your Window variables is a good place to start as you search for a good viewing window. In addition, using the Zoom features may be necessary to perfect your graphing window. The following gives an explanation of the variables you must set to adjust the graphing window: Xmin and Xmax: These are, respectively, the smallest and largest values of x in view on the x-axis. If you don’t know what values your graph will need for Xmin and Xmax, press [ZOOM][6] to invoke the ZStandard command. This command automatically graphs your functions in the Standard viewing window. Xscl: This is the distance between tick marks on the x-axis. (Go easy on the tick marks; using too many makes the axis look like a railroad track. Twenty or fewer tick marks makes for a nice looking x-axis.) If you want to turn off tick marks altogether, set Xscl=0 and Yscl=0. Ymin and Ymax: These are, respectively, the smallest and largest values of y that will be placed on the y-axis. If you have assigned values to Xmin and Xmax but don’t know what values to assign to Ymin and Ymax, press [ZOOM][0] to invoke the ZoomFit command. This command uses the Xmin and Xmax settings to determine the appropriate settings for Ymin and Ymax, and then automatically draws the graph. Yscl: This is the distance between tick marks on the y-axis. (As with the x-axis, too many tick marks make the axis look like a railroad track. Fifteen or fewer tick marks is a nice number for the y-axis.) Xres: This setting determines the resolution of the graph. It can be set to any of the integers 1 through 8. When Xres is set equal to 1, the calculator evaluates the function at each of the 133 pixels on the x-axis and graphs the result. If Xres is set equal to 8, the function is evaluated and graphed at every eighth pixel. Xres is usually set equal to 1. If you’re graphing a lot of functions, it may take the calculator a while to graph them at this resolution. If you change Xres to a higher number, your function will graph quicker, but you may not get as accurate of a graph. TraceStep and These two variables are linked together, and TraceStep is always twice as big as value, which determines how your cursor moves on a graph screen in “free trace.” TraceStep controls the X-value jump when you are tracing a function on a graph screen. Press [GRAPH] to graph the functions. Stopping or pausing your TI-84 Plus graph After pressing [GRAPH], there’s usually a small delay before you begin to see your function plotting on the graph from left to right. If it’s taking a long time for the calculator to graph your functions (maybe your Xres setting is too small), press [ON] to terminate the graphing process. Simply press [ENTER] to pause the plotting of your graph and then press [ENTER] again to resume graphing. See the following two screens. Notice, the elliptical busy indicator in the top right corner of the screen indicating that your calculator is working hard.

Article / Updated 10-19-2022

The functions housed in the Angle menu on your TI-84 Plus calculator enable you to convert between degrees and radians or convert between rectangular and polar coordinates. To convert degrees to radians, follow these steps: Put the calculator in Radian mode. Press [MODE], use the arrow keys to highlight RADIAN, and then press [ENTER]. If necessary, press [2nd][MODE] to access the Home screen. Enter the number of degrees. Press [2nd][APPS][1] to paste in the degree function. Press [ENTER] to convert the degree measure to radians. This is illustrated in the first screen. If you’re a purist who likes to see radian measures expressed as a fractional multiple of pi whenever possible, continuing with the following steps accomplishes this goal if it’s mathematically possible. To divide the radian measure by pi, press This is illustrated in the second screen. Press [MATH][ENTER][ENTER] to convert the result to a fraction, if possible. This is illustrated in the third screen. If the calculator can’t convert the decimal obtained in Step 6 to a fraction, it says so by returning the decimal in Step 7. To convert radians to degrees: Put the calculator in Degree mode. Press [MODE], use the arrow keys to highlight DEGREE, and then press [ENTER]. If necessary, press [2nd][MODE] to access the Home screen. Enter the radian measure. If the radian measure is entered as an arithmetic expression, surround that expression with parentheses. Press [2nd][APPS][3] to paste in the r function. Press [ENTER] to convert the radian measure to degrees. This is illustrated in the first screen. The TI-84 Plus is a complicated tool and it's easy to make mistakes on it. For more help, check out 10 Common Errors When Using the TI-84 Plus Calculator.

Article / Updated 09-19-2022

Using the Laplace transform as part of your circuit analysis provides you with a prediction of circuit response. Analyze the poles of the Laplace transform to get a general idea of output behavior. Real poles, for instance, indicate exponential output behavior. Follow these basic steps to analyze a circuit using Laplace techniques: Develop the differential equation in the time-domain using Kirchhoff’s laws and element equations. Apply the Laplace transformation of the differential equation to put the equation in the s-domain. Algebraically solve for the solution, or response transform. Apply the inverse Laplace transformation to produce the solution to the original differential equation described in the time-domain. To get comfortable with this process, you simply need to practice applying it to different types of circuits such as an RC (resistor-capacitor) circuit, an RL (resistor-inductor) circuit, and an RLC (resistor-inductor-capacitor) circuit. Here you can see an RLC circuit in which the switch has been open for a long time. The switch is closed at time t = 0. In this circuit, you have the following KVL equation: vR(t) + vL(t) + v(t) = 0 Next, formulate the element equation (or i-v characteristic) for each device. Ohm’s law describes the voltage across the resistor (noting that i(t) = iL(t) because the circuit is connected in series, where I(s) = IL(s) are the Laplace transforms): vR(t) = i(t)R The inductor’s element equation is given by And the capacitor’s element equation is Here, vC(0) = V0 is the initial condition, and it’s equal to 5 volts. Substituting the element equations, vR(t), vC(t), and vL(t), into the KVL equation gives you the following equation (with a fancy name: the integro-differential equation): The next step is to apply the Laplace transform to the preceding equation to find an I(s) that satisfies the integro-differential equation for a given set of initial conditions: The preceding equation uses the linearity property allowing you to take the Laplace transform of each term. For the first term on the left side of the equation, you use the differentiation property to get the following transform: This equation uses IL(s) = ℒ[i(t)], and I0 is the initial current flowing through the inductor. Because the switch is open for a long time, the initial condition I0 is equal to zero. For the second term of the KVL equation dealing with resistor R, the Laplace transform is simply ℒ[i(t)R] = I(s)R For the third term in the KVL expression dealing with capacitor C, you have The Laplace transform of the integro-differential equation becomes Rearrange the equation and solve for I(s): To get the time-domain solution i(t), use the following table, and notice that the preceding equation has the form of a damping sinusoid. Now, you plug in I0 = 0 and some numbers from this figure: Now you’ve got this equation: You wind up with the following solution: i(t) = [-0.01e-400t sin500t]u(t) For this RLC circuit, you have a damping sinusoid. The oscillations will die out after a long period of time. For this example, the time constant is 1/400 and will die out after 5/400 = 1/80 seconds.