The Motor's Best Friend

Written by Thomas Yoon


The starting current of motor can become 3 to 6 timesrepparttar normal running current! That's normal for motors. The motor can experience this high current for a period ranging from 20 to 50 seconds.

A fuse will not be very useful in protecting a motor from this type of overload condition. A selected fuse large enough to permit passage ofrepparttar 133328 necessary starting current would give little or no protection against overheating ofrepparttar 133329 windings under normal running load conditions. The same case happens forrepparttar 133330 circuit breaker.

Overload relays offer protection of motors that is both compatible withrepparttar 133331 starting current ofrepparttar 133332 circuit, andrepparttar 133333 requirement of protection inrepparttar 133334 event of overload running condition. These conditions need to be adjustable. A particular motor requiring 56 seconds starting time under normal load will suffer serious damage ifrepparttar 133335 rotor locks andrepparttar 133336 motor is not tripped in 20 seconds. Another motor may be able to withstand 25 percent overload for 30 minutes. A hermetically sealed compressor motor may burn in 3 minutes at 25 percent overload!

Good protection against overheating ofrepparttar 133337 motor windings can be obtained from temperature monitoring protector devices that are embedded intorepparttar 133338 motor windings. These do not protectrepparttar 133339 motor itself, but act as sensors to trigger a temperature control circuit to stoprepparttar 133340 motor.

A thermal overload relay, however, uses a heating element to heat up a bimetallic strip so that it can trip a latch that will open repparttar 133341 motor control circuit. This action will disconnectrepparttar 133342 motor fromrepparttar 133343 line.

Wi-Fi Is Out There and Spreading Fast

Written by Anton Komarov


As this new wireless technology spreads to every corner ofrepparttar world, it's time that someone askrepparttar 133327 burning questions that are surely on everyone's mind: "How does Wi-Fi work, and can it mess uprepparttar 133328 molecular structure of my brain?" Experts say not to break outrepparttar 133329 aluminum hats quite yet. But I would keep them handy because no one's 100 percent surerepparttar 133330 low-intensity microwave radio waves aren't zapping our brains.

The chalkboard atrepparttar 133331 local Coffee Bean and Tea Leaf in Woodland Hills has sported a cryptic message in recent weeks. Under allrepparttar 133332 usual promos for double no-foam strawberry-mint Ice Blendeds was this: "Wi-Fi coming March 7."

Wilfred Finnegan, live in performance?

No. For those of you still clacking away on a Commodore 64, "Wi-Fi" stands for wireless Latest News about wireless fidelity. It'srepparttar 133333 technology that allows people to surfrepparttar 133334 Internet with no annoying plug-in phone lines - at much faster speeds.

There's a quiet Wi-Fi Latest News about Wi-Fi revolution going on in Los Angeles, and acrossrepparttar 133335 country. The only indication for those not inrepparttar 133336 know are these small signs popping up at coffeehouses, public libraries, universities, airports and hotel rooms and even open public spaces advertising "Wi-Fi available." You may even live in a private Wi-Fi zone, as I do, thanks to an unknowingly generous neighbor who hasn't secured his or her Wi-Fi network.

Evenrepparttar 133337 city is getting intorepparttar 133338 game with a six-month trial of a free Wi-Fi zone atrepparttar 133339 Van Nuys Civic Center aroundrepparttar 133340 Marvin Braude San Fernando Valley Constituent Services Center, orrepparttar 133341 MBSFVCSC, in conjunction with Woodland Hills company Aiirmesh Communications. More city-sponsoredhot spots Latest News about hot spot are planned downtown at Pershing Square and Little Tokyo.

Los Angeles itself may become one big hot spot one day soon. A panel of telecommunications experts is expected to report this spring onrepparttar 133342 feasibility ofrepparttar 133343 city leadingrepparttar 133344 creation of a citywide Wi-Fi community network that every citizen inrepparttar 133345 city could use for cheap or free.

It's already happening in Philadelphia, which is launchingrepparttar 133346 largest municipal hot spot in a few weeks, and Chicago is toying withrepparttar 133347 Wi-Fi network idea as well.

As this new wireless technology spreads to every corner ofrepparttar 133348 world, it's time that someone askrepparttar 133349 burning questions that are surely on everyone's mind: "How does Wi-Fi work, and can it mess uprepparttar 133350 molecular structure of my brain?"

Experts say not to break outrepparttar 133351 aluminum hats quite yet. But I would keep them handy because no one's 100 percent surerepparttar 133352 low-intensity microwave radio waves used by Wi-Fi networks aren't zapping our brains. Ifrepparttar 133353 Wi-Fi technology does turn out to scramble our memories or make us stupid, then we are already doomed. Most of us are surrounded every day by things that userepparttar 133354 same technology, most notablycell phones Latest News about cell phones, cordless phones and medical devices.

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