I went to the Popular Electronics website at;
http://www.gernsback.com/noframe/pe/PEindex.html
and their archives only go back to December 1996. You said
the 'negative transistor' article was in December 1975.
Do you or anyone else here happen to have that article handy
and could you either type it or send me a photocopy and I'll
type and scan it in?
I can go to the Dallas Library and look it up, but thats
about half a day to run down then, dig it out, copy and get
back....
I usually only go when I have several things to look up...
If anyone has this article, please at least type it up and
forward to my email address so it can be appended to the
discussion list and/or posted as a file.
THANKS!
------------------------
basic transistor operation with simple experiments;
http://www.pbs.org/transistor/teach/teacherguide_html/lesson4.html
------------------------
Also, I did a search for negative transistor and found;
tunneling and GUNN diodes;
http://www.patentec.com/data/class/defs/326/132.html
ccl/326/135 - class to search for at uspto.gov
------------------------
http://www.ecdl.hut.fi/~rka/research.htm
An active MMIC negative resistance can be realised as a
single transistor with appropriate feedback, or as a
differential pair with cross-coupled unity feedback. This
technique promises considerably lower noise and sensitivity
with low power consumption, but requires a passive inductor
as the resonating element and a varactor for frequency
tuning.
....These (negative resistance) circuits usually consist of a
single transistor with either inductive or capacitative
feedback to produce negative resistance at one of its
terminals.
....A negative resistance can also be realised with a
positive transconductance and unity feedback.
....The nodal impedances are low and the maximum possible
voltage swing can be obtained in the input.
------------------------
http://www.infosite.com/~jkeyzer/handy/1996/Apr-Jul/0067.html
BJTs (Bipolar Junction Transistors) are current based
devices, if you look
at the 'base' input to the transistor as a pipe, for NPN
devices there needs
to be current flowing "into" the base for them to turn on,
for PNP transistors
you need current flowing "out" of the base for them to turn
on. Given a typical
schematic like: NPN (PNP)
( NOTE THE FOLLOWING since Germanium is PNP, silicon is NPN
)
For an NPN transistor the Voltage at "Input" has to be
higher than the
voltage at "Base" for a current to flow "into" the
transistor. For a PNP
transistor the situation is reversed (Input at a lower
voltage than Base
to get a current flowing "out" of the transistor)
Mosfets work the same way except that they want a 'voltage'
on the
input (gate) rather than a current into the base. Thus to
use an Nchannel
mosfet the gate voltage must be *higher* than the motor
voltage. That
is what "high side" drivers do with charge pumps, create an
artifically
high voltage to turn on N-channel mosfets.
------------------------
Bearden says we need to get back to 'point contact'
transistors which have properties such as negative
resistance, this relates;
http://www.pbs.org/transistor/science/info/transmodern.html
Three years later, Brattain and Bardeen built the first
working transistor, the germanium point-contact transistor,
which was manufactured as the "A" series.
Shockley then designed the junction (sandwich) transistor,
which was manufactured for several years afterwards. But in
1960 Bell scientist John Atalla developed a new design based
on Shockley's original field-effect theories.
By the late 1960s, manufacturers converted from junction
type integrated circuits to field effect devices. Today,
most transistors are field-effect transistors.
You are using millions of them now.
Most of today's transistors are "MOS-FETs", or Metal Oxide
Semiconductor Field Effect Transistors.
Field-effect transistors are so named because a weak
electrical signal coming in through one electrode creates an
electrical field through the rest of the transistor.
This field flips from positive to negative when the incoming
signal does, and controls a second current traveling through
the rest of the transistor. The field modulates the second
current to mimic the first one -- but it can be
substantially larger.
-----------------------
details on the point contact transistor;
http://www.pbs.org/transistor/science/events/pointctrans.html
Before Brattain started, John Bardeen told him that they
would need two metal contacts within .002 inches of each
other -- about the thickness of a sheet of paper. But the
finest wires then were almost three times that width and
couldn't provide the kind of precision they needed.
Instead of bothering with tiny wires, Brattain attached a
single strip of gold foil over the point of a plastic
triangle. With a razor blade, he sliced through the gold
right at the tip of the triangle.
Voila: two gold contacts just a hair-width apart.
The whole triangle was then held over a crystal of germanium
on a spring, so that the contacts lightly touched the
surface. The germanium itself sat on a metal plate attached
to a voltage source.
This contraption was the very first semiconductor amplifier,
because when a bit of current came through one of the gold
contacts, another even stronger current came out the other
contact.
Here's why it worked: Germanium is a semiconductor and, if
properly treated, can either let lots of current through or
let none through. This germanium had an excess of electrons,
but when an electric signal traveled in through the gold
foil, it injected holes (the opposite of electrons) into the
surface. This created a thin layer along the top of the
germanium with too few electrons.
Semiconductors with too many electrons are known as N-type
and semiconductors with too few electrons are known as
P-type.
A small current in through one contact changes the nature of
the semiconductor so that a larger, separate current starts
flowing across the germanium and out the second contact. A
little current can alter the flow of a much bigger one,
effectively amplifying it.
------------------------
http://ourworld.compuserve.com/homepages/Andrew_Wylie/pointcon.htm
The first transistor was a point-contact transistor. This
device used a wafer of N-type germanium as the base block,
into which were pushed two phosphor-bronze wires, similar to
the 'cats whisker' of a radio crystal set. Short
high-current pulses were used to fuse the wires to the
germanium, a technique called 'electrical forming'. This
caused some phosphorus to diffuse from the wires into the
germanium, creating P-type regions around the points. If
forming was done correctly, a PNP structure with a narrow N
region was created: the conditions needed for transistor
action.
Point-contact transistors were only manufactured for a few
years before being superseded by the junction transistor.
They are rarely mentioned in modern electronics books, and
if they are, they are written off as some inferior early
aberration. This is unfair to a device which was never fully
understood, but which operated completely differently from
the junction transistor.
In particular, they had a common-base current gain ('alpha')
well in excess of one, and they also exhibited negative
resistance, useful in oscillators and switches. Junction
transistors always have alpha less than one: this shows that
the base current flowed in the opposite direction in the
point-contact device.
------------------------
Crystal Triode point contact picture and info;
http://ourworld.compuserve.com/homepages/Andrew_Wylie/ls737.htm
------------------------
http://www.antiqueradio.com/ward_history_12-98.html
....the point contacts were erratic, mechanically unstable
and yielded wide ranges of performance.
-----------------------
http://acomp.stanford.edu/siliconhistory/Usselman/Gersi2.html
There is very little historical research on the important
changeover from
germanium to silicon.
BTL's historians present no explanation or interpretation of
what the replacement of germanium by silicon meant to
semiconductor manufacturers and their computer customers.
Historians often ascribe the demise of the germanium
semiconductor to the influence of the Defense Department.
Aggregate research funding by the Defense Department favored
silicon devices, but it was germanium that the military
purchased for high-volume logic requirements.
Even at BTL, a hotbed of silicon research, practically all
semiconductors manufactured through 1958 used germanium as
the basic or starting material.
Scientists and engineers selected germanium and silicon for
military research because they were elemental semiconductors
with an orderley atomic structure.
Germanium and silicon crystallize in a diamond lattice,
consisting entirely of one type of atom.
D. K. Wilson, a BTL development engineer, observed that a
pulse or series of pulses in the forward direction improved
dramatically the electrical properties of n-type germanium
point-contact transistors and diodes. It appeared that these
electrical pulses heated the immediate area under the metal
contact to form a p-type region resulting in a p-n junction
[Wilson, June 1955: 227-231].
A high-purity single crystal has an intrinsic electrical
conductivity, affected only by variations in temperature.
This electrical conductivity can be manipulated by the
controlled introduction of impurities. The impurities rather
than temperature then control the resistivity of the
material until a certain
temperature level is reached. At that point, temperature
becomes the predominant factor. Operation of the
semiconductor beyond this temperature level results in
device failure.
Computer designers preferred the germanium junction diode
for their logic circuits because of its high-speed switching
capability. Diodes designed for switching allow practically
no current to pass until a threshold voltage is reached.
At that point, a large current is allowed to pass,
energizing the circuit. Diode resistance drops sharply and
becomes relatively independent of the voltage across the
device. The diode functions as an electronic switch, faster
and longer lasting than any mechanical or electromechanical
switch. Germanium switching diodes also exhibited a lower
threshold voltage than silicon devices when turned on, a
useful property for logic designers trying to minimize
voltage drops.
------------------------
http://fox.rollins.edu/~tlairson/$h$ightech/TRANSECON.HTML
The cat’s whisker
Although transistors come in many shapes and sizes, they all
operate on a similar principle. A voltage applied to a
contact controls the current flowing through the rest of the
device, much as a tap (faucet) controls the flow of water
through a pipe.
But the central point about both taps and transistors is
that they allow a small
signal—the twist of a hand or the increase of a voltage—to
control a much larger one—the rush of water or of electrical
current. In other words, the small signal is amplified.
The oldest ancestor of the point-contact transistor was the
crystal detector, used in early wireless sets. This
device—patented by a German scientist, Ferdinand Braun, in
1899—was made of a single metal wire, fondly called a cat’s
whisker, touching against a semiconductor crystal.
The result was a “rectifying diode”, which lets current
through easily one way, but hinders flow the other way.
Diodes are essential in radios to turn rapidly oscillating
radio waves into a smoother direct-current signal that can
power a speaker.
Rectifying a signal sounds like an altogether humbler task
than amplifying it. But to an electronics engineer, an
amplifier is really just two diodes connected face to face.
The result is a “triode”, because it has three terminals,
the two free ends of the diodes and their common junction. A
voltage applied to the junction controls a current flowing
through the other two terminals. To create the point-contact
transistor,
Shockley’s team modified the cat’s whisker by placing two
fine metal wires close together on the surface of a
germanium crystal, turning it from a diode into a
triode.
Germanium oxide is, alas, soluble in water.
------------------------
enlightening interview showing rewrite of history to favor
Bell;
http://www.ieee.org/organizations/history_center/oral_histories/transcripts/holonyak.html
------------------------
Lillienfeld was the original inventor of the transistor;
http://www.luminet.net/~wenonah/history/edpart5.htm
Actually, the team only "rediscovered" the transistor
concept, for back in 1929 an engineer named Julius
Lillienfeld patented what today would be called a
metal–oxide field–effect transistor.
His discovery faded away in a short time since the materials
required to build the device just couldn't be made pure
enough, and worse, the money needed for further development
wasn't available because the U.S. was just entering the
Great
Depression and venture capital for research projects just
was not around.
-----------------------
Its interesting that Bill Fogals Charge Barrier
'superconducting transistor' are each hand made on a kitchen
table. They correlate to this negative resistance phenomenon
by using a capacitor on the emitter to create the 'charge
barrier'.
Bill showed them to us when we had drinks and dinner at a
conference a few years back. We were amazed that someone
could DO that with just a soldering iron and the right
materials.
article by Fogal and Bearden plus two patents;
http://www.eskimo.com/~ghawk/fogal_device/
-----------------------
more weird stuff about Fogal transistor;
http://www.newphys.se/elektromagnum/physics/USENET-news/RoomTemperatureSuperconductor
Fogal is not claiming he has invented a room temperature
superconductor. What he has invented is either completely
fatuous or it is astounding in that it strikes at the very
core theoretical underpinnings of electromechanics.
Fogal told SN that his device grew out of his efforts to fix
a broken car radio in the mid 1970s. As he got past the
wiring and the circuits and into the semiconductors actually
running the radio, he made changes that greatly improved the
audio quality.
Fogal says his charged barrier semiconductor device allows
electrons to flow without resistance (i.e., as in
superconductors) at room temperature.
He claims the device demonstrates a very high AC voltage and
AC current gain. His charged barrier device is on a bipolar
design that can be incorporated in (MOS) metal oxide
semiconductor designs, as well as multiple gate devices.
It operates on a hall effect electromagnetic field internal
device. The hall effect magnetic field forces electron flow
and angular spin of the electrons
in the same direction to the top of the conduction bands in
the crystal lattice on semiconductor devices, unlike (SOI)
silicon on insulator devices that force electron flow to the
surface of the semiconductor lattice.
"Unlike superconductors which generate an external field, my
semiconductor creates a self-regulating magnetic field
internal to the device," Fogal said.
It is important to note that the device does not violate the
rules of thermodynamics involving the conservation of
energy. It does not make energy from nothing. One end of a
Fogal circuit would provide electricity for work such as
running a light bulb or a computer, and the other end will
draw energy from the environment and get quite cold in the
process.
------------------------
Marcelo Puhl wrote:
>
> >
> > With negative resistance transistors...there is a fellow who
> > remains very secretive but says they have mapped the
> > necessary characteristics that must be combined to produce a
> > free energy device....I asked him if I had his circuit,
> > COULD I build it from off the shelf parts and duplicate his
> > free energy self running results....
> >
>
> About the "Negistor", a negative-resistance transistor, see Popular
> Electronics, Dec 1975, pages 69-70.
>
> Basically a NPN transistor reverse biased.
>
> Marcelo Puhl
> mark@plug-in.com.br
> -------------------------------------------
> Get paid to surf the WEB !
> Ganhe dinheiro enquanto surfa na Internet !
> http://alladvantage.com/go.asp?refid=DTJ608
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