Electronics All-in-One For Dummies, 3rd Edition book cover

Electronics All-in-One For Dummies, 3rd Edition

By: Doug Lowe Published: 04-11-2022

If you know a breadboard from a breadbox but want to take your hobby electronics skills to the next level, this is the only reference you need. Electronics All-in-One For Dummies has done the legwork for you offering everything you need to enhance your experience as an electronics enthusiast in one convenient place. Written by electronics guru and veteran For Dummies author Doug Lowe, this down-to-earth guide makes it easy to grasp such important topics as circuits, schematics, voltage, and safety concerns.

Articles From Electronics All-in-One For Dummies, 3rd Edition

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28 results
Electronics All-in-One For Dummies Cheat Sheet

Cheat Sheet / Updated 02-24-2022

As you design and build with electronic circuits, you’ll invariably find yourself scratching your head trying to remember what color stripes are on a 470 Ω resistor or what pin on a 555 timer integrated circuit (IC) is the trigger input. Never fear! This handy Cheat Sheet will help you remember such mundane details so you can get on with the fun stuff.

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Alternating Current in Electronics: Hot, Neutral, and Ground Wires

Article / Updated 09-27-2021

Before you start working with line voltage in your electronic circuits, you need to understand a few details about how most residential and commercial buildings are wired. The following description applies only to the United States; if you’re in a different country, you’ll need to determine the standards for your country’s wiring. Standard line voltage wiring in the United States is done with plastic-sheathed cables, which usually have three conductors. This type of cable is technically called NMB cable, but most electricians refer to it using its most popular brand name, Romex. Three conductors inside electric cables Two of the conductors in NMB cable are covered with plastic insulation (one white, the other black). The third conductor is bare copper. These conductors are designated as follows: Hot: The black wire is the hot wire, which provides a 120 VAC current source. Neutral: The white wire is called the neutral wire. It provides the return path for the current provided by the hot wire. The neutral wire is connected to an earth ground. Ground: The bare wire is called the ground wire. Like the neutral wire, the ground wire is also connected to an earth ground. However, the neutral and ground wires serve two distinct purposes. The neutral wire forms a part of the live circuit along with the hot wire. In contrast, the ground wire is connected to any metal parts in an appliance, such as a microwave oven or coffee pot. This is a safety feature, in case the hot or neutral wires somehow come in contact with metal parts. Connecting the metal parts to earth ground eliminates the shock hazard in the event of a short circuit. Note that some circuits require a fourth conductor. When a fourth conductor is used, it's covered with red insulation and is also a hot wire. How they're connected to a standard outlet The three wires in a standard NMB cable are connected to the three prongs of a standard electrical outlet (properly called a receptacle). As you can see, the neutral and hot wires are connected to the two vertical prongs at the top of the receptacle (neutral on the left, hot on the right) and the ground wire is connected to the round prong at the bottom of the receptacle. You can plug a two-prong or three-prong plug into a standard three-prong receptacle. Two-prong plugs are designed for appliances that don't require grounding. Most nongrounded appliances are double-insulated, which means that there are two layers of insulation between any live wires and any metal parts within the appliance. The first layer is the insulation on the wire itself; the second is usually in the form of a plastic case that isolates the live wiring from other metal parts. Three-prong plugs Three-prong plugs are for appliances that require the ground connection for safety. Most appliances that use a metal chassis require a separate ground connection. There is only one way to insert a three-prong plug into a three-prong receptacle. But regular two-prong plugs, which lack the ground prong, can be connected with either prong on the hot side. To prevent that from happening, the receptacles are polarized, which means that the neutral prong is wider than the hot prong. Thus, there's only one way to plug a polarized plug into a polarized receptacle. That way, you can always keep track of which wire is hot and which is neutral. You should always place switches or fuses on the hot wire rather than on the neutral wire. That way, if the switch is open or the fuse blows, the current in the hot wire will be prevented from proceeding beyond the switch or fuse into your circuit. This minimizes any risk of shock that might occur if a wire comes loose within your project.

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Electronics Basics: What Is a Semiconductor?

Article / Updated 09-17-2021

Semiconductors are used extensively in electronic circuits. As its name implies, a semiconductor is a material that conducts current, but only partly. The conductivity of a semiconductor is somewhere between that of an insulator, which has almost no conductivity, and a conductor, which has almost full conductivity. Most semiconductors are crystals made of certain materials, most commonly silicon. To understand how semiconductors work, you must first understand a little about how electrons are organized in an atom. The electrons in an atom are organized in layers. These layers are called shells. The outermost shell is called the valence shell. The electrons in this shell are the ones that form bonds with neighboring atoms. Such bonds are called covalent bonds. Most conductors have just one electron in the valence shell. Semiconductors, on the other hand, typically have four electrons in their valence shell. Semiconductors are made of crystals If all the neighboring atoms are of the same type, it's possible for all the valence electrons to bind with valence electrons from other atoms. When that happens, the atoms arrange themselves into structures called crystals. Semiconductors are made out of such crystals, usually silicon crystals. Here, each circle represents a silicon atom, and the lines between the atoms represent the shared electrons. Each of the four valence electrons in each silicon atom is shared with one neighboring silicon atom. Thus, each silicon atom is bonded with four other silicon atoms. Pure silicon crystals are not all that useful electronically. But if you introduce small amounts of other elements into a crystal, the crystal starts to conduct in an interesting way. Two types of conductors The process of deliberately introducing other elements into a crystal is called doping. The element introduced by doping is called a dopant. By carefully controlling the doping process and the dopants that are used, silicon crystals can transform into one of two distinct types of conductors: N-type semiconductor: Created when the dopant is an element that has five electrons in its valence layer. Phosphorus is commonly used for this purpose. The phosphorus atoms join right in the crystal structure of the silicon, each one bonding with four adjacent silicon atoms just like a silicon atom would. Because the phosphorus atom has five electrons in its valence shell, but only four of them are bonded to adjacent atoms, the fifth valence electron is left hanging out with nothing to bond to. The extra valence electrons in the phosphorous atoms start to behave like the single valence electrons in a regular conductor such as copper. They are free to move about. Because this type of semiconductor has extra electrons, it's called an N-type semiconductor. P-type semiconductor: Happens when the dopant (such as boron) has only three electrons in the valence shell. When a small amount is incorporated into the crystal, the atom is able to bond with four silicon atoms, but since it has only three electrons to offer, a hole is created. The hole behaves like a positive charge, so semiconductors doped in this way are called P-type semiconductors. Like a positive charge, holes attract electrons. But when an electron moves into a hole, the electron leaves a new hole at its previous location. Thus, in a P-type semiconductor, holes are constantly moving around within the crystal as electrons constantly try to fill them up. When voltage is applied to either an N-type or a P-type semiconductor, current flows, for the same reason that it flows in a regular conductor: The negative side of the voltage pushes electrons, and the positive side pulls them. The result is that the random electron and hole movement that's always present in a semiconductor becomes organized in one direction, creating measurable electric current.

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How to Assemble a Color Organ Circuit

Article / Updated 05-09-2017

After you have gathered all the materials you'll need to build a color organ, you're ready to assemble the project. See What You Need to Build a Color Organ Circuit. You'll need the following tools: Soldering iron, preferably with both 20 and 40 W settings Solder Use thicker solder for the line-voltage wires and thin solder for assembling the MK110 kit. Magnifying goggles Phillips screwdriver Small flat-edge jewelers screwdriver Wire cutters Wire strippers Pliers Hobby vise Drill with 1/8-inch, 5/32-inch, 1/4-inch, 5/16-inch, 3/8-inch, and 3/4-inch bits Here are the steps for constructing a color organ: Assemble the Velleman MK110 kit. The kit comes with simple but accurate instructions. Basically, you just mount and solder all the components onto the circuit board. Pay special attention to the color codes for the resistors and the orientation of the diode. It's best to mount the circuit board in a good hobby vise and use an alligator clip or masking tape to hold the components in place while soldering. Drill all the mounting holes in the project box except the hole for the sensitivity control on the left side of the box. The figure shows the orientation of the approximate location of the mounting holes. Use the assembled circuit board to determine the exact drilling locations for the four holes that will mount the circuit board. The position of the other holes isn't critical, with the exception of the hole for the potentiometer knob. Don't drill that hole until Step 4. Mount the four standoffs in the four MK110 circuit board mounting holes. Use four of the machine screws that came with the standoffs. Drill the hole for the circuit board's potentiometer. Set the circuit board on top of the four standoffs to determine the exact location for this hole. Insert the two rubber grommets into the two 3/8-inch holes. The grommets are difficult to squeeze into the hole, but work at it and you'll get them in. If necessary, use the small edge of a flat screwdriver to push the rubber edges into the holes. In the steps that follow, you assemble all the parts into a box. Use the following figure as a guide for the proper placement of each of the parts. Cut the extension cord. First cut the outlet end of the extension cord, leaving about 12 inches of wire attached to the outlet. Then cut the plug end, leaving about 3 or 4 feet of wire attached to the plug. You'll have a few feet of wire left over; set this wire aside for later. Push the power cords through the grommets and tie a knot inside the box. It will be a tight squeeze, but the cords will fit. Pull about a foot of the cord with the plug attached through the hole nearest the switch. Then, tie it in a knot, cinch the knot down tight, and pull the plug so that the knot is snug against the grommet. The knot acts as a strain relief. Repeat the same process with the cord that's attached to the outlet, passing it through the other grommet, tying a tight knot, and pulling the knot up against the grommet. When both power cords are in place, separate the two wires of each cord inside the project box and strip about 3/8 inch of insulation from each wire. Cut two 1-1/2-inch lengths of extension cord wire and solder them to the switch terminals. You'll need to strip about 3/8 inch of insulation from each end of both wires. Put your soldering iron on its High setting and use thick solder. Set the switch aside when the solder sets. Cut two 1-1/2-inch lengths of extension cord wire and solder them to the terminals on the fuse holder. Again, you'll need to strip about 3/8 inch of insulation from each end of both wires and solder with high heat. Cut two 2-1/2-inch lengths of the hookup wire and strip 3/8 inch of insulation from the ends. Solder one of the hookup wires to the center terminal of the RCA-style phono jack and the other wire to the ground terminal. At this point, you're done with the soldering iron, so you can turn it off. Mount the RCA-style phono jack in the 1/4-inch hole in the project box. To mount the jack, you'll first have to remove the nut, the ground terminal, and the lock washer from the jack. Then, pass the wire connected to the center terminal of the phono jack through the 1/4-inch hole, and then insert the threaded end of the phono jack into the hole. Slip the lock washer, the ground terminal, and the nut over the wire connected to the center terminal, and then thread them onto the threaded part of the jack. Tighten with needle-nose pliers. In the next few steps, you attach wires to the MK110 circuit card. Do not mount the circuit board to the standoffs quite yet. You'll have an easier time connecting the wires if the circuit board is loose. After the wires are all connected, you mount the board. Connect the separated wires of the cord that's attached to the outlet to the two terminals marked Load on the back of the MK110 circuit board. Use a small, flat screwdriver to tighten the terminals. Make sure the wires are securely connected. Connect one of the wires attached to the fuse holder to one of the Mains terminals at the back of the MK110 circuit board. Connect one of the extension cord wires that's attached to the plug to the other Mains terminal at the back of the MK110 circuit board. Connect the two hook-up wires from the phono jack to the input terminals at the front of the MK110 circuit board. The input terminals are labeled LS on the board. You'll need a very small flat-blade screwdriver to tighten these terminals. Mount the MK110 circuit board on the standoffs. To mount the board, you'll need to tilt it a bit to slide the shaft of the potentiometer through the 5/16-inch hole. Once the shaft is through, set the board down on the standoffs and secure it with the remaining four machine screws that came with the standoffs. Use the 3/8-inch 4-40 machine screw and nut to mount the fuse holder. Slide the machine screw through the 5/32-inch hole in the bottom of the project box. Then pass the machine screw through the hole in the center of the fuse holder and attach the nut. Tighten with a screwdriver. Mount the switch. To mount the switch, first remove the plastic nut on the threaded end of the switch. Then, pass the wires and the threaded end of the switch through the 3/4-inch hole in the side of the project box. Finally, slip the nut over the wires and tighten it onto the switch. Connect the switch to the power cord and the fuse. Use one of the screw-on wire connectors to connect one of the switch wires to the unconnected wire on the fuse holder. Then, use the other wire connector to connect the other switch wire to the unconnected wire that leads to the power plug. Insert the fuse in the fuse holder. Guess what — you're almost done! The figure shows the project with all the parts assembled. Attach the knob to the potentiometer shaft protruding from the box. Use a small, flat screwdriver to tighten the set screw on the knob. Place the lid over the project box and secure it with the provided screws. Now you really are done!

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What You Need to Build a Color Organ Circuit

Article / Updated 05-09-2017

Other than the Velleman kit itself, most of the materials you need to build a color organ circuit can be purchased at your local RadioShack store or any other supplier of electronic components. The table lists all the materials you'll need. Quantity Description 1 Velleman MK110 Simple Onee Channel Light Organ kit 1 2-x-3-x-6-inch project box (RadioShack part 2701805) 1 20 mm PC board standoffs (package of 4, RadioShack part 2760195) 1 RCA-style phono jack (RadioShack part 2740346) 1 3/4-inch control knob (RadioShack part 274415) 1 Chassis-type fuse holder for 1-1/4-x-1/4-inch fuses (RadioShack part 2700739) 1 1 A, 250 V, fast-acting 1-1/4-x-1/4-inch fuse (RadioShack part 2701005) 1 3/8-inch 4-40 machine screw and nut (for mounting the fuse holder) 1 SPST rocker switch (RadioShack part 2750694) 2 3/8-inch grommets (RadioShack part 6403025) 2 Screw-on wire connectors (RadioShack part 6403057) 5 inches 20-gauge stranded hook-up wire 1 Indoor extension cord

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How a Color Organ Works

Article / Updated 05-09-2017

There are several different ways to design a color organ circuit. Most of them rely on a special type of electronic component called a triac, which is essentially a transistor that's designed to work with alternating current. It has three terminals. Two are anodes, called A1 and A2, and the third is a gate. A voltage at the gate — either positive or negative — allows the anodes to conduct. The anodes are connected to the line load, and the gate voltage is derived from the audio input. The audio input isn't connected directly to the triac gate, however. Instead, most color organs use one of two techniques to isolate the audio input from the line-voltage side of the circuit. One method is to use a transformer. The other is to use an optoisolator, which is a single component that consists of an infrared LED and a photodiode or other light-sensitive semiconductor. Voltage on the LED causes the LED to emit light, which is detected by the photodiode and passed on to the output circuit. The Velleman MK110 kit uses an optoisolator triac, in which the photosensitive semiconductor is actually a triac whose gate is stimulated by light rather than by voltage. The optoisolator is an integrated circuit in a 6-pin DIP package. The figure shows a simplified schematic diagram for the circuit used by the Velleman MK110 kit. As you can see, the audio input is applied to the LED side of the optoisolator, controlled by a potentiometer, which lets you adjust the sensitivity of the circuit. The output from the optoisolator is applied to the gate of the triac, whose anodes are connected across the line voltage circuit. Thus, the volume of the audio input directly controls the voltage of the output circuit.

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What is a Color Organ Circuit?

Article / Updated 05-09-2017

Simply put, a color organ converts the volume of an audio input into an output voltage that gets higher as the sound source gets louder. If you connect a light to the output, the light will glow brighter when the audio input is louder and dimmer when the input is quieter. One of the great things about Disneyland is that sometimes the long line you have to wait in to go on a particular ride is almost as good as the ride itself. One of the best examples of this is the famous Indiana Jones Adventure: Temple of the Forbidden Eye. Just outside of an ancient temple, you pass by a rickety steam-powered generator that is barely running. The clickity-clickity sound of the generator alternately grows louder and softer as the generator sputters and threatens. Once inside the temple, you pass through narrow tunnels and creepy caverns that are lit overhead by lights that appear to be powered by the rickety generator. The lights flicker and dim, then grow brighter for a moment, then flicker and dim again in sync with the laboring generator. A color organ is an electronic circuit you can use to create this creepy lighting effect, including lighting the narrow passageways in haunted house (or tomb) at Halloween or to create a thunderstorm in your front yard to add the right ambiance to your haunted Halloween graveyard. And the same circuit creates a spooky red heartbeat in the chest of a plastic skeleton that stands watch over the scene. This circuit requires that you work with line-level voltages (120 VAC), so it's potentially dangerous. The circuit is designed with safeguards, but you must be careful to not bypass them. You should inspect any color organ project every time you use it to make sure none of the wiring has come loose or frayed, and you must never work on a circuit while it's plugged in.

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How to Use a Color Organ Circuit

Article / Updated 05-09-2017

To put a color organ circuit to use making interesting sound and lighting effects, you'll have to connect both lights and a sound system to the color organ. The procedure for actually using the color organ is quite simple: Connect a light to the color organ's female extension cord connector. Connect a speaker-level audio input to the RCA connector. Plug the male extension cord connector into a power outlet. Turn on the color organ. Play the sound. Turn the knob on the color organ to adjust the sensitivity. If the light never comes on, try increasing the output volume on the stereo. The color organ can handle just 120 W on the output circuit, so you need to be careful not to overload the circuit. You can use a single 100 W flood light or a couple of 60 W lamps. Or you can use a few strings of Christmas lights or other low-wattage lights. The easiest way to connect the color organ to the sound system is to simply replace one of the speakers with the color organ. The type of cable you'll need to do that depends on how the speakers connect to the sound system. If the speakers connect with simple post connectors, you'll need a cable with bare wire on one end and an RCA plug on the other end. If the speakers connect with RCA connectors, you'll need a cable with RCA plugs on both ends. When you use the color organ in this way, it's important to realize that the color organ will respond to one channel of the stereo recording while the speaker plays the other channel. In most cases, you won't notice much difference. However, in some recordings, the sound on the left channel is very different from the sound on the right channel. This can affect the quality of the sound, and it can also prevent the light from flashing in perfect sync with the sound, since the light is responding to a different sound source from the one heard through the speakers. In some cases, you can use this to improve the effect you're trying to achieve with the color organ. For example, in an actual thunderstorm, the lightning flashes well before the thunder is heard. To reproduce this effect, all you need is a sound recording of a thunderstorm in which the thunder is heard on the left channel before it's heard on the right channel. Then, if you connect the color organ to the left channel and the speaker to the right channel, the light will flash before the sound is heard. Have fun with your color organ!

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Introducing the ShowTime PC Controller

Article / Updated 05-09-2017

Light-O-Rama's most popular lighting controller for residential use is called the ShowTime PC controller, shown in the figure. Several companies sell lighting controllers for holiday displays. From Light-O-Rama, you can purchase preassembled lighting controllers, or you can purchase kits and assemble the controllers yourself. So if you're handy with a soldering iron, you can save a few hundred dollars on a basic sequencer by building the circuit yourself. For complete information about Light-O-Rama and its products, point your browser to www.lightorama.com. Light-O-Rama controllers are useful for much more than just holiday displays; they're also useful for school events, carnivals, amusement parks, store and museum displays, theatrical productions, malls and shopping centers, and so on. The ShowTime PC controller (model number CTB16PC) offers the following basic features: Sixteen separate channels of light: Each channel is a separate 120 VAC circuit that can power up to 8 amps of lights. The power cords dangling from the bottom of the unit are where you plug the lights in; each cord connects the lights for one of the 16 channels. (The total current load for the controller should not exceed 30 amps.) In most cases, you won't plug your lights directly into the power cords dangling from the bottom of the lighting controller. Instead, you'll use extension cords to reach from the lighting cords to where the lights are actually placed. If you plan on making a holiday lighting display, you'll need a lot of extension cords. Sixteen channels is enough to get started with Light-O-Rama displays, but once you've set up your first show, you'll wish you had additional channels. Most Light-O-Rama setups include two, three, or four controllers for a total of 32, 48, or 64 channels. The ability to turn the lights on and off, separate for each channel: The controller also has a few other special effects, such as fade up, fade down, different intensity levels, twinkling, and shimmering. These special effects are what make the Light-O-Rama controller special. You can find much less expensive ways to simply turn lights on and off. For example, two Kit-74 relay controllers connected to a computer can turn 16 channels of lights on and off for less than half the price of a ShowTime PC controller. However, the Kit-74 can't fade the lights up or down, and the ability to gradually fade the lights adds a lot to the impact of the light show. Computer control of the light show: You simply connect the ShowTime PC controller to the computer via a special USB adapter cable. Then, you run special software available from Light-O-Rama to control the show. Although the ShowTime PC controller is mounted in a weatherproof container, your computer isn't. As a result, you'll want to place the computer inside your house or garage, then use a long cable to reach the ShowTime PC controller. Light show control without a computer: If you don't want to drive the show from a computer, you can purchase a special device called an MP3 Director that lets you control the show without a computer. Expandability: You can connect as many as 240 ShowTime PC controllers together to create a massive show with as many as 3,840 separate light circuits. You'd need a small nuclear reactor to power it all, but it's possible. If you want to get started with Light-O-Rama, purchase one of its starter kits. You can purchase a completely preassembled kit including a 16-channel ShowTime PC controller, USB adapter, and software for under $400, or you can purchase built-it-yourself kits for considerably less. These kits require you to solder the components to the board, but assembling the board yourself will give you the satisfaction of knowing you built it yourself.

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A Basic Light-O-Rama Setup for Holiday Light Displays

Article / Updated 05-09-2017

The figure shows a basic setup for using a single, 16-channel ShowTime PC controller to control up to 16 separate strands of lights. Although you can design the circuitry to control light shows from scratch, the easiest way to build a light show is to buy an inexpensive lighting controller. The following paragraphs describe each of the elements in this setup: ShowTime PC controller: Usually located outside, close to where your lights are. It comes with a weatherproof enclosure so you can place it outside. Although it isn't shown in the figure, the ShowTime PC controller requires a source of AC power. As a result, you should locate the controller near an electrical outlet. The controller has two electrical plugs; each provides power to half of the 16 light channels. If you plug both of these cords into the same electrical outlet, the total lighting capacity of the controller will be limited by the maximum amperage rating of the outlet you plug the cords into (typically 15 A). However, you can plug the two cords into separate outlets to double the lighting capacity of the controller to 30 A, provided that the two outlets you plug the controller into are located on separate electrical circuits. Lights: Connected to the 16 power cords that hang from the bottom of the controller. Computer: Runs the ShowTime software that controls the lights. You'll want to place the computer in a secure location that isn't exposed to weather. Unfortunately, Light-O-Rama's software isn't free. If you purchase one of Light-O-Rama's starter kits, the software is included in the purchase price, but if you purchase a do-it-yourself kit and assemble the circuit board yourself, you'll have to buy the software separately. (The cost is under $50.) USB adapter: Required to connect the computer to the ShowTime PC controller. Sound system: Plays or broadcasts the sound that is synchronized to the lights. The sound system connects to the computer's headphone output and either amplifies it for speakers or broadcasts it so it can be heard on an FM radio. If you want to play the sound through speakers, you can use any amplifier that has an input jack and is powerful enough to play the sound at the volume you desire. If you want to broadcast the music so that people can listen to it on their car radios as they drive by your house, you can purchase a low-power FM broadcaster from many sources on the Internet. Light-O-Rama sells one for about $125.

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