## Negative Resistance Definitions.

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• negative resistance In electrical circuits, static resistance is the ratio of the voltage across a circuit element to the current through it. However, the
Message 1 of 1 , Jun 19, 2005
negative resistance
In electrical circuits, static resistance is the ratio
of the voltage across a circuit element to the current
through it. However, the ratio of the voltage to the
current may vary with either voltage or current. The
ratio of the change in voltage to the change in
current is known as dynamic resistance.

Circuit elements composed of certain materials exhibit
the property that, over certain voltage ranges,
current is a decreasing function of the voltage. This
range of voltages is known as a negative resistance
region.

It may be more correct to say that a circuit element
has a negative differential resistance region than to
say that it exhibits negative resistance because even
in this region the static resistance of the circuit
element is positive, while it is more precisely the
slope of the resistance curve which is negative.

[HDN/ well it takes awhile to think about that one,
but acccording to the slope definition, we plot V vs
R, but with SrFe heating the resistance goes down with
the impressed voltage; With the additional
complication that when lower resistances of the load
are reached with the highest heats; that low ohmic
load will also drop the output voltage of the source
powering it; according to maximum power transfer laws:
similar to action of that load being placed as an
interphasal resonant one, where impedance matching
then becomes possible.]

An example of an electronic component exhibiting the
negative differential resistance region is the tunnel
diode. Such a device, when biased into its negative
differential resistance region, will act as an
amplifier.

In conformance with the known law of conservation of
energy, a plot of the negative differential resistance
region of a component cannot normally pass through the
origin.

Some work by Professor Deborah Chung at the University
of Buffalo has discovered a composite configuration of
carbon nanotubes which appears to exhibit anomalous
results which resemble a static negative resistor.
However, the physical interpretation of this
observation is still controversial.

Gabriel Kron, while a scientist for General
Electric,[1]
(http://www.quantum-chemistry-history.com/Kron_Dat/KronGabriel1.htm)
is thought to have built a negative resistor for the
US Navy's "Network Analyser" (probably an analogue
computer) in the 1930s; but as it was a military
project no details have ever come to the public.[2]
(http://www.cheniere.org/misc/kron.htm) One of his
papers does contain a blasÃ© "Although negative
resistances are available for use with a network
analyzer..."[3]
(http://www.quantum-chemistry-history.com/Kron_Dat/Kron-1945/Kron-PR-1945/Kron-PR-1945.htm)

Another concept of negative resistance exists in the
domain of radio frequency antenna design. This is also
known as negative impedance. It is not uncommon for an
antenna containing multiple driven elements to exhibit
apparent negative impedance in one or more of the
driven elements.

HDN/ To further delve into this concept of negative
impedance; we further classify the meaning of positive
impedance; which is simply the sum effects of both the
inductance and the resistance upon the currents of the
load. A positive impedance then means that the
currents will be less then what would exist if the
inductance were not present where Ohms Law V=IR then
applies. What a negative impedance may appear to do;
dependent on how we measure the circuit conditions; is
to provide for a measurement whereby instead of the
impedance detracting from the possible current
delivery by ohms law amount; we find current above and
not below that amount.

This happens when three adjacent spirals of high
mutual induction are attached to the alternator three
phase/ and wired in WYE, where the currents of each
phase must return on another phase. The voltage
mesurement of each WYE section is actually a delusion
brought upon by mutual induction; and when measuring
the V/I ratio for each wye segment, the measurement
shows a conduction above that possible by ohms law.

However when the Delta voltage measurements are
in three phase does not yeild a negative impedance
measurment when wired in Delta. But what does occur is
impedance cancellation by three magnetic fields all
simultaneously summing to zero at any instant of time;
a sort of three phase scalar magnetic compression.
Each of these magnetic fields induces currents on its
neighbors; and those currents are in the same
direction as the currents made from its line
connections. However APPARENTLY even though both of
these sources of emf make currents in the same
direction, the inductive source appears to have an emf
opposite to that of the line connected source, so that
when the net difference is noted by that voltage
mesurement of the segment in WYE, we find that the
inside voltage measurements are much smaller then
would should exist by mesurements on the outside delta
voltage sources; where this is normally a 1.7 ratio,
but now this has been formed into a higher ratio.

The further idiosychasies involved here is that a
single wind of these segments is only 1/4 of the
amount used for maximum energy transfer, therefore