posted Jun 10, 2010 2:51 AM by Anantha Narayan
[
updated Jun 10, 2010 4:04 AM
]
posted Jun 10, 2010 2:50 AM by Anantha Narayan
[
updated Jun 10, 2010 4:05 AM
]
The term Earth leakage circuit breaker (ELCB) is often incorrectly used to
describe its modern counterpart the Residual-current device (RCD). An earth leakage circuit
breaker (ELCB) is a device with two earth terminals used to directly detect
currents leaking to earth from an installation and cut the power. They were mainly
used on TT earthing systems before RCDs became common. They have been almost totally replaced by
RCDs (except in very old installations) due to a number of problems. |
posted Jun 10, 2010 2:49 AM by Anantha Narayan
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updated Jun 10, 2010 4:06 AM
]
shows the structure of a typical n-channel IGBT. All discussion here will
be concerned with the n-channel type but p-channel IGBT's can be considered in
just the same way. |
posted Jun 9, 2010 9:06 PM by Anantha Narayan
[
updated Jun 10, 2010 4:09 AM
]
posted Jun 9, 2010 9:05 PM by Anantha Narayan
[
updated Jun 10, 2010 4:10 AM
]
Equivalent Series Resistance, dc resistance of the inductor
or leakage Resistance in a cap.
The theoretical treatment of devices such as capacitors and
inductors
tends to assume they are ideal or "perfect" devices, contributing only
capacitance or inductance to the circuit. However, all physical devices are constructed of
materials with finite electrical resistance, which means that physical components
contain some resistance in addition to their other properties.
Q factor is
quoted in inductor data sheets, which is a more convenient way (than analyzing
ESR) to show the typical high-frequency deviations from the ideal in the
inductor magnetics and losses. |
posted Jun 9, 2010 9:03 PM by Anantha Narayan
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updated Jun 10, 2010 2:59 AM
]
Standard RYB Color Wheel
RYB also makes up the primary color triad in a standard color wheel.
The secondary colors VOG also make up another triad. Triads are formed by 3
equidistant colors on a particular color wheel. Other common color wheels
include the light model and the print
model.
A color
code is a system for displaying information by using different colors. Color codes
are often difficult or impossible for color
blind and blind people to understand. |
posted Jun 9, 2010 9:03 PM by Anantha Narayan
[
updated Jun 10, 2010 2:55 AM
]
Circuit
breaker -
A circuit breaker is an automatically-operated electrical switch designed to protect an electrical
circuit from damage caused by overload or short
circuit. Unlike a fuse, which operates once and then has to be replaced, a
circuit breaker can be reset (either manually or automatically) to resume normal
operation. Circuit breakers are made in varying sizes, from small devices that
protect an individual household appliance up to large switchgear
designed to protect high voltage circuits feeding an entire city. |
posted Jun 9, 2010 9:02 PM by Anantha Narayan
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updated Jun 10, 2010 2:53 AM
]
The American
National Standards Institute or ANSI is a private nonprofit organization
that oversees the development of voluntary consensus standards for products,
services, processes, systems, and personnel in the United States. The
organization also coordinates U.S.
standards with international standards so that American products can be used
worldwide. For example, standards make sure that people who own cameras can find
the film they need for them anywhere around the globe. |
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