HOW TO MAKE HOMEMADE WIFI ANTENNA IN ONE HOUR

HOW TO MAKE HOMEMADE WIFI ANTENNA IN ONE HOUR

How to Make Homemade WiFi Antennas


Wireless networking antennas can be manufactured at home using simple, everyday items and a minimum of knowledge about antenna physics. Two main types of antennas, the directional and omnidirectional, relate to the direction and intensity of the transmitted wave pattern. The average backyard engineer can construct a homemade Wi-Fi antenna in about an hour.

Things You'll Need

Large cookware pan lid
Soldering equipment

Wi-Fi cable
Wi-Fi antenna node

Instructions

Decide on a use for the antenna. The directional type can reflect signals a great distance, but has an angle of deflection that restricts the signal's width to about 30 degrees. This antenna would be used for long distance communication, but would not work well as a local access point's primary transmitter. Close range, widespread propagation can be sent by a "stick"--an upright antenna that throws its signal in all directions--or by an omnidirectional antenna.

Remove the handle on the back of the pan lid. This will probably expose one or two holes in the rear of the lid, which can be used to run antenna cable. If this hole is unavailable, drill one near the center.

Mount the Wi-Fi equipment's standard antenna (node) to the inside center of the pan lid. This will cause the wave form from the antenna to be concentrated and reflected in one direction. Many different reflectors have been used, such as metallic cans or pipes. The parabolic dish will be generally better for the amateur builder because it has a wider signal angle.

Mount the completed Wi-Fi dish at a receiver and test the signal. Some larger dishes have been known to throw a signal as far as nine miles under ideal conditions.

Tips & Warnings

Using a reflector for any antenna will concentrate and improve its signal.

Do not stand in front of the dish while it is active.

References

Antennas, Amplifiers and Propagation

HOW TO BUILD A HOMMADE BATTERY

HOW TO BUILD A HOMMADE BATTERY

How to Build a Homemade Battery
A battery is a device that contains materials that, when connected, trigger a chemical reaction that yields an electrical current, which is simply a stream of electrons. The transfer of electrons from one metal to another can be induced by putting them in the presence of an electrolyte solution. Commercial batteries contain highly corrosive acids, but it's possible to build a homemade battery with safer and easier to obtain materials.
Things You'll Need
10 copper pennies
Aluminum foil
Paper towel
Scissors
Electrical tape
Salt water or lime juice
Wires
Instructions
Prepare the anode. Aluminum loses electrons faster than copper, so it will be the source of our electric current, called an anode. To prepare the aluminum foil anode, cut 10 circles with the scissors to the exact size of a penny.
Cut the paper towel. The paper towel will hold the electrolyte solution, and act as the medium to bring it in contact with the cathode and anode. To prepare this, cut out 10 squares just large enough to circumscribe a penny.
Stack and tape. To make the battery requires stacking the pieces in the correct order. Begin with a penny, the cathode, and put a paper square on top of it. Then place an aluminum circle directly above that. This represents one simple battery cell. Continue stacking in the same order, with a penny followed by paper, foil then paper. When finished, there should be a penny at one end and aluminum foil on the other. Wrap once with electrical tape to hold together without completely sealing off the contents.
Dip into solution. The entire stack must be submerged in an electrolyte solution for it to soak into the paper towel squares. Salt water can be used, but lime juice, vinegar, diluted bleach or even cola will produce good results. Experiment with different stacks in different solutions if desired.
Connect wire to terminals. Using the electrical tape, connect one length of wire to the penny on one end and the other to the aluminum foil on the opposite side. These represent the positive and negative terminals of the battery. When the wires are connected to a conductive material to complete the circuit, a small electric charge is produced.
Tips & Warnings
Use a voltmeter to measure the strength of your homemade battery.
To increase the charge produced by the battery, increase the number of pennies and foil slips in the stack.
Once the paper towel is soaked and the wires are attached, the entire battery can be wrapped in electrical tape if desired, to improve appearance and reduce chance of a short circuit.
Even though the charge produced by your battery is small, it can still deliver an uncomfortable shock. Avoid touching both wires at the same time.

HOW TO MAKE A SOLAR PANEL BATTERY CHARGER

HOW TO MAKE A SOLAR PANEL BATTERY CHARGER

How to Make a Solar Panel Battery Charger
With some basic equipment and a bit of wiring, build a solar panel battery charger that keeps small appliances going. The advent of solar energy has made small solar panels readily available in all sizes. Build a solar battery charger as a science fair project to demonstrate the simple process of solar power.
Things You'll Need
AA batteries
Battery holders
Terminal strip or soldering iron
Blocking diode
6-volt solar panel
Instructions
Put 4 AA batteries into the two battery holders.
Wire the holders together to make a series connection for the battery charger. Connect one positive wire from one holder to one negative wire of the other. Leave the other positive and negative wires alone for now.
Join the blocking diode and the battery charger. Use the ringed end. Connect this to the positive wire from the battery holder.
Connect the other end of the blocking diode to the solar panel.
Take the negative output of the solar panel, and connect it to the negative wire from the battery holders.
Charge the solar panel, and watch it charge the batteries.
Tips & Warnings
Use terminal strip instead of soldering for connections to make things quicker and easier.
Choose battery holders with the wire leads already attached. These are available at most hardware stores.
Select a solar panel with leads already attached.
Once you are confident, build a solar-powered panel battery charger by wiring smaller solar panels together in a series. Also build a larger version to serve as a solar-powered panel battery charger for the big utility batteries that power large flashlights and even small portable generators.

HOW TO MAKE A SOLAR PANEL FROM CD

HOW TO MAKE A SOLAR PANEL FROM CD

How to Make a Solar Panel From CDs
In the digital age,
many music-lovers have discarded CDs in favor of iTunes, MP3s and Windows Media Player. Portable music players are no larger than a silver dollar and easily connect to computers for music updates. This leaves music aficionados with blank and burned CDs they no longer need. You could simply toss or recycle them, but you could also take advantage of their reflective surfaces to create your own solar heating panel. The process is so simple, a teen could make one for her room in an afternoon.
Things You'll Need
Utility knife
Masking tape
Pencil
Super glue
Clear plastic drop cloth
Scissors
Awl
Measuring tape
Cardboard
CDs
Black spray paint
S-hooks
Instructions
Measure the length and width of your window and add 4 inches to both measurements. Cut out a piece of cardboard with your utility knife to match your expanded measurements. For instance, a window 24 inches wide by 36 inches long needs a cardboard rectangle 28 inches wide by 40 inches long.
Spray paint one side of your cardboard black. Let the paint dry overnight. If the cardboard needs more than one coat, let each coat dry for about an hour before applying the next one.
Cut a 4-inch square from each of the rectangle's corners. Bend the sides of the cardboard up so the corners meet, forming a box. The black part should be inside the box. Tape up the corners with masking tape.
Place your CDs in rows inside the box with the shiny side out. You’ll have some wiggle room since most CDs are about 5 inches across; that’s okay. Try to keep the rows as even as possible. The bottom row should touch the bottom side of the box and the top row should touch the top. This shows you how many CDs you’ll need. In this case, about five columns of seven CDs each.
Trace the center holes of the top and bottom rows of CDs with a pencil. Remove the CDs and cut these holes out with your utility knife. Glue CDs down over these holes with super glue. Glue down the rest of the CDs, leaving a small space above the bottom row and below the top. Leave space above and below the center row, also.
Cut four cardboard rectangles 4 inches wide and three-quarters as long as your box is wide -- 16 inches in this case. Glue them into your box on edge like maze walls. Place the first against the left side of the box above the bottom CD row, the second against the right side below the center row, the third against the left side above the center row and the last against the right side below the top row. Let the glue dry overnight.
Cut a piece of plastic drop cloth 3 inches longer and wider than your box. Stretch the drop cloth over the top of the box and glue it down over the sides, making the seal as airtight as possible. Let the glue dry overnight. Punch two holes in the upper corners of the box and slip an S-hook through each hole. Hang the panel in a south-facing window.

HOW TO MAKE HOMEMADE SOUND SYSTEM

HOW TO MAKE HOMEMADE SOUND SYSTEM

How to Make a Homemade Sound System

Most surround sound systems come with everything required to set it up, including the speakers, receiver and wires. But if you want to build your own surround sound system you can use any combination of speakers and surround sound receiver to get the surround effect. This is helpful if you already have speakers available at home or want to customize your own equipment.
Things You'll Need
5 speakers
1 subwoofer
Surround sound receiver
Instructions
Place the single subwoofer on the floor near the receiver. The actual placement of the receiver or subwoofer doesn't matter, unlike the rest of the speakers. Plug the cable running from the subwoofer into the subwoofer "line out" port on the receiver.
Position two of your five speakers to the left and right of the television. You can use old stereo speakers or speakers you purchased individually. Connect the wires from the two speakers into the "front left" and "front right" ports on the receiver.
Place a single speaker directly under the TV. This will act as the center channel. Typically the center channel speaker is positioned on its side -- otherwise it looks a bit out of place as a single, tall speaker in the middle of your entertainment center. Connect the wires from the speaker into the "center" speaker port on the receiver.
Place the remaining speakers behind your main seating area, one to the left and the other to the right. Connect the wires to the "back left" and "back right" ports.
References
The Home Cinema Guide: Install Surround Sound System

HOW TO MAKE A UNIVERSAL CELL PHONE BATTERY CHARGER

HOW TO MAKE A UNIVERSAL CELL PHONE BATTERY CHARGER

How to Make a Universal Cell Phone Battery Charger

Everyone has found themselves in a situation where their cell phone battery is dying and they are without their charger. Even worse is having a access to a charger that doesn't fit your phone and can be especially troublesome in an emergency. However, you can actually make your own universal cell phone charger with just a few items even if there is no wall outlet in sight. This should charge most phones, except for the iPhone.

Things You'll Need
3 to 4 AA batteries
4-AA battery tray
Metal paper clip
2 alligator clips
Batteries and Voltage
Take the battery out of the phone to check the voltage. This tells you how many AA batteries will be needed. Most cell phones are 3.7 volts and AA batteries are 1.5 volts. So three batteries, for a total of 4.5 volts, are needed to charge most cell phones.
Put the three batteries in the four-battery tray. If the phone only requires the three batteries for voltage, then the paper clip will be needed in the fourth tray for the circuit to be completed.
Unfold the paper clip and hook one end through the metal spring in the negative end of the empty slot. Bend the other end so it touches the metal contact on the outside of the tray at the positive end of the same slot. This turns the charger on. Move one end of the paper clip away from one of the contacts to turn it off.
Connecting Power
Solder or crimp a red alligator clip to the red wire that is running from the tray. This wire carries a current from the positive battery terminal.
Solder or crimp a black alligator clip to the black wire that is running from the tray. This wire carries a current to the battery's negative terminal.
Examine the phone battery and make note of the small metal contacts that absorb electricity. One should have a positive (+) sign next to it and the other a negative (-) sign next it. Only reference these two contacts. And if they don't have positive or negative markings, use a voltmeter to distinguish between the two.
Clasp the red alligator clamp to the side of the battery so that the metal jaws touch the positive metal contact and the black clamp to the side of the battery so that it's touching the negative. Ensure that the two clamps do not touch each other. The battery should now be charging.
Tips & Warnings
While this should charge most phones, it will not work for the iPhone series. Also, keep the charger and/or materials somewhere accessible to you in case of an emergency.
Keep a finger on the battery as it charges to make sure it does not overheat while it is charging. There is no built-in way to limit the current, so monitoring the battery's temperature will be key in preventing it from overheating. Also, using the homemade charger may invalidate your phone's warranty.
References
Popular Mechanics: How to Make Your Own Battery-Powered Gadget Chargers