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Toroidal
inductors are often used in
passive filter and equalizer circuits.For
appreciable relative permeability’s
and moderate circuit selectivity’s,
stray magnetic fields are sparse. Coils
can be adjusted to desired inductance
by spreading or squeezing the turns
of the magnet wire winding. The design
of Toroidal inductors entails tradeoffs
between cost and factors such as desired
inductance value, physical size, unloaded
Q, power handling, adjustability, fragility,
and operating temperatures. For small
signal levels, small physical size,
and reasonable unloaded Q, Micrometals
powdered iron toroids with outer diameters
of 0.25 in. and 0.375 in. are commonly
used. |
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RF
transformers are widely used
in low-power electronic circuits for
impedance matching to achieve maximum
power transfer, for voltage step-up
or step-down, and for isolating DC from
two circuits while maintaining AC continuity.
They are also used for common mode rejection
and as baluns. Essentially, a RF transformer
consists of two windings linked by a
mutual magnetic field. When one Winding,
the primary has an AC voltage applied
to it, a varying flux is developed;
the amplitude of the Flux is dependent
on the applied voltage and number of
turns in the winding. Mutual flux linked
to the secondary winding induces a voltage
whose amplitude depends on the number
of turns in the secondary winding. By
designing the number of turns in the
primary and secondary windings, any
desired step-up or step-down voltage
ratio can be realized. Mutual coupling
is accomplished simply with an air core
but considerably more effective flux
linkage is obtained with the use of
a core of iron or ferromagnetic material
with higher permeability than air.
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Aircoil
Inductor are electric device
consisting of one or more turns of wire
and typically having two terminals.
An inductor is usually connected into
a circuit in order to raise the inductance
to a desired value. Since inductance
is a property that varies with frequency,
inductors range from a single loop in
a length of wire |
RF
chokes have high Q levels and
high-frequency performance characteristics
despite their size. This makes them
ideal for high-density applications
like telecom, computers and computer
peripherals, and electromagnetic-interference
(EMI) filters. They also suit VCRs,
DVD players, set-top boxes, auto navigation
systems, game consoles, and other consumer
electronics.
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Jumper is a mechanical switch
that is easily modified by hand. Essentially,
it's a circuit that has been broken
intentionally and a pin placed on each
end of the broken connection. Placing
a jumper across two pins connects them
electrically, completing the circuit;
removing a jumper from a set of pins
breaks the circuit. Hardware engineers
allow users to configure devices or
change their operation by creating different
sets of pins that implement different
functions depending on how the jumpers
are set. When power is applied to the
device it detects which circuits have
been closed or opened. |
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