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Posts Tagged ‘April 2010’

This 18-inch off-roader is made for play. But it packs an engine, starter and sensor system that are just like a real racecar’s—at a tenth of the size

Design Highlights on the R/C Car
Telemetry:The Ten-T is among the first R/C vehicles to come with a built-in telemetry system, similar to those in a pro racecar. Sensors on the car continuously beam data on speed, temperature and battery voltage to a display on the remote.

Fuel Tank: The 2.5-ounce tank includes a weighted pickup tube that follows the liquid as it sloshes around, ensuring that it can grab and deliver fuel even when the car drives up a steep hill. A full tank runs the engine for about 10 minutes (standard for high-power nitro cars), and it's refueled from a squeeze bottle.

Engine: The single-cylinder, 3.4cc engine provides 1.8 horsepower, enough to send the 6.2-pound car up to 45 mph in a few seconds.

Drivetrain: In the four-wheel-drive vehicle, the engine transmits power to the wheels by engaging a clutch and kicking off a series of gearsets that lets each wheel spin at a different speed. Dual disc brakes stop both the front and rear axles.

Suspension: The front and rear suspensions are adjustable to tackle many terrains. Shifting the control arm alters ride height, camber (the vertical angle of the wheels) and toe-in (the degree they point in or out). Turning a collar on the oil-filled shocks changes springiness.

Steering Servo: This small, high-torque electric motor moves the wheels' control arms. You can tweak its movement from the transmitter -- for instance, to alter the distance it turns with each command or limit the steering angle to speed over straight tracks.

See the world's deepest drill, the Taser shotgun, and more of How It Works

Bosch reinvents the common nailer, making a smaller tool with the nail-driving power of the big guns

Design Highlights on the Nail Gun
Self-Cleaning Filter: The pressurized air leaving the tool cleans this filter, which captures debris like sawdust and dirt, preventing it from clogging the cylinder.

Fitting: A connection to an air hose allows pressurized air to flow from an electric air compressor into the nailer, where it’s moved by valves controlled by the trigger.

Bump Firing: Like most nailers, the Bosch also has a semiautomatic mode called bump firing, in which you can hold down the trigger and fire a nail just by pressing the nose to the wood. A toggle switch on the trigger changes the position of a metal lever inside so that it touches the trigger-valve pin. At that point, depressing the nose pushes the metal lever into the pin, activating the trigger.

Depth of Drive: A dial lets you adjust the distance between the nose and the board, which changes how deeply the gun drives the nail.

Step By Step
1. A spring in the magazine feeds forward sleeves of 16-gauge nails one at a time, putting one directly under the driver blade.

2. Squeezing the trigger opens the nailer’s main valve, letting in air from a compressor that sets the 33-gram aluminum piston in motion.

3. The driver blade, a 5.3-inch steel rod attached to the bottom of the piston, smacks the nail, driving it into the wood.

4. Just behind the nose is a plastic vent that exhausts all the air as the piston descends in less than 0.1 second, so it meets with almost no resistance. A second burst of compressed air pushes the driver blade and the piston back up, ready for the next strike. In conventional nailers, a reservoir captures some of the air and rechannels it to push the piston back into position.

A massive floating laboratory is attempting to drill through four miles of seabed to take samples of the Earth’s mantle

Design Highlights of the Chikyu Research Vessel
Derrick: The main hoist winch and a system of elevators lifts 1,250 tons of pipes and machinery through the 72-
foot-wide opening in the bottom of the ship.

Riser Pipe: A four-foot-diameter steel pipe called a riser connects the ship to the borehole. Outside the riser are several hoses and smaller pipes for recirculating the synthetic mud and controlling the blowout preventer. The riser’s inner hollow core (a pipe within a pipe) is reserved for the drill string. At a 1.6-mile depth, the assembled riser weighs 1,000 tons.

Planned Upgrades
To drill in deeper waters, engineers will either replace the steel riser with one made from a lightweight material like carbon-fiber-reinforced plastic or they will use two pipes—one for the drill string and a second, small-diameter pipe to return the spent drilling mud back up to the ship for recycling.
For deeper ground penetration, where temperatures can exceed 500°F and corrosive chemicals reside, engineers will use a higher-tensile-strength steel to build the drill string. Also in development are new drilling muds that cool the drill bit during operation.

How to Reach the Mantle
1. Get in Position Using GPS and transponders on the ocean floor, the ship’s positioning system measures the forces acting on the craft, such as wind, wave and current direction and speed. Six computer-controlled propellers will keep the ship from drifting more than 15 feet in any direction.

2. Assemble Drill To break through the first layer of crust, the crew deploys a steel pipe with an 11-inch-wide drill bit at the bottom. The crew attaches new lengths of pipe one by one from the top until the “drill string” is long enough to hit the seafloor.

3. Start Drilling As the drill bit burrows through sediment and rock, a hose in the drill pipes in a synthetic mud to keep the drill cool and the borehole open under the crushing pressures found at those depths.

4. Collect Rocks Every few hundred feet, scientists collect rock samples for study. A narrow barrel with a razor-sharp edge (think of a very big apple corer) shoots down and pierces the undrilled layer of earth below. The 31-foot-long core samples are analyzed for their chemical and magnetic properties.

Shock bullet

And so goes the “capability gap,” one of the trickiest situations in law enforcement. For an officer in the field, this is a danger zone spanning 35 to 65 feet in which an assailant is beyond the range of Tasers and yet near enough to throw a deadly object, pushing an officer one step closer toward the use of deadly force. “Plain and simple, we need a less lethal option that works within throwing range,” says Sid Heal, a retired commander with the Los Angeles sheriff’s department and a consultant to the U.S. Department of Defense.

That’s where the Extended Range Electronic Projectile, or XREP, comes in. Unlike Taser’s conventional stun gun, which shoots tethered probes up to 35 feet to deliver an incapacitating jolt, the company’s new XREP is a 12-gauge wireless projectile that can be fired up to 100 feet from any pump-action shotgun. It sails through the air like a normal slug yet induces muscle paralysis on impact. “It takes everything that’s a Taser and puts it in a slug-like device,” Heal says.

Logistically, the biggest engineering challenge was miniaturization. With a Taser, two probes attach to the assailant, arcing up to 50,000 volts of electricity, enough to penetrate clothing. The XREP, on the other hand, uses just 500 volts to allow for smaller circuitry. Instead of arcing the current, it sends it directly into the body via barbed electrodes that pierce the skin. Lead XREP engineer Mark Hanchett says the key isn’t so much the voltage but the waveform. The current, shaped to mimic electrical signals in the body, jams the nervous system. “The waveform is the secret sauce,” he says.

Since its debut last year, the XREP has been fired successfully four times in the line of duty. Taser is now working on a grenade version for the Department of Defense that will be capable of launching up to 200 feet. That tricky capability gap? Consider it bridged.

Design Highlights on the Electronic Shotgun Slug

Nose: On impact, four electrified barbs on the nose of the projectile hook into the skin, delivering a small, localized shock across a six-inch area. This is merely a prelude to the bigger shock that will soon follow. The force of the impact breaks a series of pins that allow the projectile’s chassis to separate from the nose and dangle downward from a live copper wire.

Barbs: If the assailant fails to grab the wire to complete the circuit, six longer barbs on the projectile can also penetrate the skin. With the plastic sheathing removed on impact, the half-inch electrodes—called “chollas,” after a fierce cactus plant native to Arizona’s Sonoran Desert—pop out like spikes and swing into the body.

Hand Trap: The assailant’s natural instinct is to grab the dangling wire and rip out the barbs, but the wire is pulsing with current—touching it allows electricity to flow from the first set of electrodes in the nose of the projectile to the assailant’s hand, which contracts from the shock and squeezes tight around the wire so he can’t let go. Electricity now freely flows through his body, causing about 20 seconds of paralysis.

Fins: When the slug leaves the shotgun, three fins deploy from its tail, helping the projectile stay on track as it sails up to 100 feet toward its target.

Transformer: This converts energy from the battery to discharge 1.3 milliamps of current for 20 seconds. The power is relatively weak; in comparison, a wall outlet delivers about 20 amps. More important is the way the current propagates and interacts with electrical signals in the body. “If you get the waveform right, you can overwhelm the nervous system,” says Taser engineer Mark Hanchett.

Microprocessor: Once the circuit is complete, an onboard computer commands the voltage capacitor to fire, modulating the intensity, duration and shape of the current.

Power: Two lithium batteries power the microprocessor and electrical circuitry.

Shell: The circuitry is potted inside shock-absorbing plastic to ensure that it survives the force of the shotgun blast and collision with the target.

To take advantage of the strong winds that blow over the ocean, this gearless turbine uses a giant ring of magnets and 176-foot blades

GE created lightweight 176-foot blades—about 40 percent longer than the average—with a more aerodynamic shape. The blades will attach to a drivetrain that does away with many of the moving parts, including the gearbox, that are prone to breakage and energy loss. A direct-drive mechanism replaces gears, and permanent magnets replace the electromagnets that require starter brushes, coils and power from the grid every time they fire up. The blades are now being tested in the Netherlands, and the drivetrain in Norway. Combining the two should result in a turbine that captures 25 percent more wind power than conventional models, so it can operate more often at its full four-megawatt potential—enough to power 1,000 homes.

Design Highlights on the Windmill
Generator: The 90-ton generator consists of a nearly 20-foot ring of magnets that spins to produce current. Its large diameter lets it create a lot of power when turning slowly, at the same 8 to 20 rpm as the blades, so it doesn’t need a gearbox to speed it up to the thousands of rpm most megawatt generators require. “Get rid of the gearbox, and now you don’t have to change the oil,” says GE engineer Gary Mercer.

Electrical Circuitry: Converters stabilize the current’s varying frequencies. Transformers boost voltage from 690 volts to more than 22,000, so current travels efficiently over long-distance lines.

Pitch Controller: To maximize lift as the wind speed changes, a controller can automatically rotate each blade anywhere from a fraction of a degree to multiple degrees per second. It can also turn the blades away from dangerously high winds to avoid power overloads or hardware damage.

Blades: Light, stiff carbon fiber replaces fiberglass at critical points in the blades, so they lose pounds and gain strength. A flat (rather than tapered) edge gives them a shape that increases lift.

How to Spin Power
1. Position the Blades
Based on data from wind-direction sensors, a yaw-drive motor turns the nacelle to face the wind. A pitch controller rotates each blade around a bearing, setting it to the best angle for the wind speed.

2. Capture the Wind
The three-bladed rotor spins in winds from 7 to 70 mph, sweeping twice the area of a football field. A 23-foot-long steel rotor shaft and two roller bearings transfer the mechanical energy to the generator.

3. Turn it into Electricity
The shaft spins the generator’s neodymium magnets inside stationary copper coils, inducing current in the coils. Circuitry adjusts the frequencies and voltage of the current and sends it off to the grid.

Click here for more How It Works

Say you want to open a file you downloaded from a questionable source, kick the tires on a new operating system like Linux, or even run an older OS from the familiar environment of your main desktop. If anything goes awry in your virtual machine, you can reset it to a previous state or just delete it altogether, with no harm to your system. You could even run a separate operating system as a virtual machine just to use that one killer app that’s not available on your OS of choice.

Free applications like Microsoft’s Windows Virtual PC (micro soft.com), VMware Player (vmware.com) and the open-source app VirtualBox (virtualbox.org) are great for getting your feet wet. Setting them up is a similar process to installing a regular operating system. Once you’ve done it, it will seem like you’ve got a real, separate computer living inside your system.

Despite the grid’s numerous built-in safeguards, if enough transformers go down, they could take large chunks of the grid with them. The only way to get it running again would be to replace all the damaged gear. CMEs aren’t usually disastrous, but the two largest blasts on record, which took place in 1859 and 1921, could each knock out the Northeast power grid if they happened today. On the bright side, although CMEs have been known to put satellites out of commission, our atmosphere deflects most of the energy, so the radiation is too diffuse by the time it reaches your electronics to destroy them.

A man-made EMP poses a greater threat. If one goes off in your neighborhood, there’s a significant risk that the concentrated pulse will induce extra voltage in the circuit-board components, frying them for good. The best bet for protecting your electronics is to store them in a Faraday cage: a cube of interweaving metals, preferably copper and quarter-inch-thick steel, which together can act as an electromagnetic shield. Like in a lightning rod, the copper attracts electricity while the steel absorbs magnetic pulses. A cage big enough to hold all your favorite gadgets—your cellphone, TV, computer, and so on—runs in the neighborhood of $15,000. An EMP could also crash the power grid, so you might want to spring for an extra cage to protect your generator too.

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