EC Directive on Waste Electrical and Electronic Equipment (WEEE)

The Waste Electrical and Electronic Equipment Directive (WEEE Directive) aims to minimise the impact of electrical and electronic goods on the environment, by increasing re-use and recycling and reducing the amount of WEEE going to landfill. It seeks to achieve this by making producers responsible for financing the collection, treatment, and recovery of waste electrical equipment, and by obliging distributors to allow consumers to return their waste equipment free of charge.

Electrical standards worldwide

ANSI - American National Standards Institute
AS - Australian Standards
BS - British Standard
CE - European Conformity Marking
CENELEC - European Committe for Electrotechnical Standardization
CSA - Canandian Standards Association
DIN - German Industrial Standards
IEC - International Electrotechnical Commision
ISO - International Standards Organization
JIS - Japanese Industrial Standards
NEMA - National Electrical Manufacturers Association
UL - Underwriter's Laboratories, Inc.
VDE - Association of German Electrical Engineers

RESIDUAL CURRENT CIRCUIT BREAKERS

I am new to the term RCCB. I found what it is.. Residual current circuit breakers(RCCB) are used for protection against indirect touching of parts under voltage, for prevention of lasting voltage on earthed parts because of a defect in electrical installation and for protection against direct contact of parts under voltage where the residual current is greater than 30ma. Residual current circuit breakers can be used in all systems where neutral and protective conductor are separated.

Walking robot offers clues to human movement

A walking robot that adapts to different terrain is helping scientists understand how humans move and could one day lead to improved treatment for spinal cord and other injuries, German researchers said on Friday.
Previously, RunBot the robot's inventors said the 30-centimeter-tall machine could only walk forward on flat surfaces and would topple over when encountering a slope.
But using an infrared eye, the robot can now detect an incline in its path and adjust its gait after four or five attempts to navigate up the slope, researchers said.
The machine, which simply falls over until it learns to walk uphill, takes 3-4 stride lengths per second, a touch faster than the normal human gait of about 1.5 to 2.5 stride lengths per second.
"It is trial and error learning," said Florentin Woergoetter, a researcher at the University of Goettingen who helped design RunBot.
"It needs about four or five falls to learn this."
Woergoetter, who published his findings in the journal Computational Biology, compared the process with the way a child learns to walk. He said just like humans, RunBot leans forward slightly and uses shorter steps to navigate uphill.
A key is the robot's "brain" in this case the infrared eye connected to the control circuits—which directs the machine to change its gait when needed.
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Contactors

When a relay is used to switch a large amount of electrical power through its contacts, it is designated by a special name: contactor. Contactors typically have multiple contacts, and those contacts are usually (but not always) normally-open, so that power to the load is shut off when the coil is de-energized. Perhaps the most common industrial use for contactors is the control of electric motors........>>>>>

Types of Circuit breakers

There are many different technologies used in circuit breakers and they do not always fall into distinct categories. Types that are common in domestic, commercial and light industrial applications at low voltage (less than 1000 V) include:
MCB (Miniature Circuit Breaker)—rated current not more than 100 A. Trip characteristics normally not adjustable. Thermal or thermal-magnetic operation. Breakers illustrated above are in this category.
MCCB (Moulded Case Circuit Breaker)—rated current up to 1000 A. Thermal or thermal-magnetic operation. Trip current may be adjustable.
Electric power systems require the breaking of higher currents at higher voltages. Examples of high-voltage AC circuit breakers are:
Vacuum circuit breaker—With rated current up to 3000 A, these breakers interrupt the current by creating and extinguishing the arc in a vacuum container. These can only be practically applied for voltages up to about 35,000 V, which corresponds roughly to the medium-voltage range of power systems. Vacuum circuit breakers tend to have longer life expectancies between overhaul than do air circuit breakers.
Air circuit breaker—Rated current up to 10,000 A. Trip characteristics are often fully adjustable including configurable trip thresholds and delays. Usually electronically controlled, though some models are microprocessor controlled via an integral electronic trip unit. Often used for main power distribution in large industrial plant, where the breakers are arranged in draw-out enclosures for ease of maintenance.