Transistor

“ Dick Earle shook his head. "Not particularly. The transistor is still a critical item in electronics and production isn't up to demand, especially for special designs. That means the stolen transistors can be sold fairly easily, once the proper channels to get them into the market are found."
"What kind of channels?" Rick asked.
Earle shrugged. "Anything to hide the fact that the transistors are stolen stock. The Earthman could make a deal with some jobber who handles electronic materials, and feed the transistors into regular trade channels through the jobber." ”

“ And even the larger domestic companies could suffer in the price ranges where computers were mere commodities; with flat displays and better memory chips, Nippon might again make us relive the transistor fiasco. I groped, poked, and wandered some more. And there in a dim corner I found the 1960s, too—in the form of a Nuvistor, another pygmy vacuum tube, another refinement of the obsolete. By the 1970s Heathkit was finally offering transistorized ham transmitters like the one I’d lend Eric. ”

“ One advanced notion is the “growing” of complex electronic circuitry, in which a completed amplifier, or array of amplifiers, is pulled from the crystal furnace much the way material for transistors is now grown. Pooh-poohed at first as ridiculous, the notion has been tried experimentally. Since a computer is basically a multiplicity of simple units, the idea is not far off at that. It is conceivable that crystal structure can be exploited to produce millions of molecules of the proper material properly aligned for the desired electronic action. ”

“ The computer uses power, far more than the brain. A single transistor, which forms only part of a neuron, may use a tenth of a watt; the brain is ahead on this score by a factor of millions to one.
Electronic switches have an advantage over the neuron in that they are much faster acting. So fast have they become that engineers have had to coin new terms like nanosecond and picosecond, for a billionth and a trillionth of a second. Thus, the computer’s individual elements are perhaps 100,000 times faster than those of the brain. ”

“ The next development to fire the imagination of scientists and engineers was the laser—an instrument that produces an enormously intense pencil-thin beam of light. Most of us have heard so much about this invention it seems hard to believe that the first one was built only a few years ago. We were told that the laser was going to have an even greater effect on our lives than the transistor. ”

“ After a week of intensive laboratory work, we had some pretty good evidence. The tests of individual transistors definitely showed that heavy radiation would cause them to deteriorate. Testing of the complete decoders also led to some failures, and, when we analyzed them, they turned out to be the kind that would be caused by faulty transistors. We also discovered that the most sensitive part of a decoder circuit was the zero gate, which recognizes the zeros in the one-and-zero code that commands the satellite. ”

“ To achieve such a great increase in speed requires faster electronic switches. Transistors have been improved, and more exotic devices such as tunnel diodes, thin-film cryotrons, magnetic thin-films, parametrons, and traveling-wave tubes are now coming into use. ”

“ There is no computer in existence with the equivalent of 10 billion neurons. One ambitious system of computers does use half a million transistors, plus many other parts, but even these relatively few would not fit under a size 7-1/2 hat. One advanced technique, using a “2-D” metal film circuitry immersed in liquid helium for supercooling, hopefully will yield a packaging density of about 3-1/2 million parts per cubic foot in comparison with the brain’s trillion-part density. ”

“ Figure 29 A miniature gas laser produces continuous output in visible red region.
The semiconductor laser is to solid and gas lasers what the transistor was to the vacuum tube; all the functions of the laser have been packed into a tiny semiconductor crystal. In this case, electrons and “holes” (vacancies in the crystal structure that act like positive charges) accomplish the job done by excited atoms in the other types. That is, when they are stimulated they fall from upper energy states to lower ones, and emit coherent radiation in the process. ”

“ The transmitter is an all transistorized unit, containing a push-pull output stage to obtain a minimum output of 200 milliwatts at a frequency of 246.3 mc. The transmitter frequency is derived by taking the basic frequency of an oscillator and multiplying it through a series of tripler and doubler stages.
The transmitter is powered by a de-de voltage regulator. The regulator is completely transistorized and supplies a regulated output voltage of 28 vdc. To reduce the probability of obtaining a spurious output signal, a band pass filter is placed in the output circuit. ”

“ Fabrication capability in these five critical areas will permit most other necessary components to be produced as well. For instance, an IC fabrication facility could manufacture at least some varieties of transistors, diodes (rectifiers, small-signal, and zener) , varactors, thyristors, silicon-controlled rectifiers (SCRs) , and others. ”

“ Each unit has a multipin audio and power connector, and a coaxial connector.
Electrical Characteristics: The uhf voice transmitter/receiver consists of a transmitter, receiver, and power supply.
The transmitter consists of a crystal controlled oscillator, two rf amplifiers, a driver, and a push-pull power amplifier. All stages except the driver and power amplifier are transistorized. The transmitter is fixed-tuned at 296.8 mc and is capable of producing an rf power output of 3.0 watts into a 50 ohm resistive load. The transmitter is amplitude modulated by a transistorized modulator stage. ”

“ From the secondary we obtain a higher voltage than we impress on the primary.
You can see one application of this rule at once. When we use an audion as an amplifier of an alternating current we send the current which is to be amplified through the primary of a transformer, as in Fig. 94. We use a transformer with many times more turns on the secondary than on the primary so as to apply a large e. m. f. to the grid of the amplifying tube. That will mean a large effect in the plate circuit of the amplifier. ”

“ A transformer is simply two coils of wire wound on an iron core. The simplest transformer is the form used by Faraday when he discovered electromagnetic induction. If instead of making and breaking a circuit that flows only in one direction as Faraday did, we cause an alternating current to flow through one of the coils, which we may call the primary, each time the current changes direction in the primary the magnetic field is reversed—that is, the end of the coil which was the north pole becomes the south pole. ”

“ Let O be the nominal value of the full secondary output of the transformer in watts, V1 and V2 the terminal voltages on the primary and secondary side, N1 and N2 the number of turns, and A1 and A2 the currents for the two circuits;, then O/V2 is the full load secondary current measured in amperes, and N2N1 multiplied by O/V2 is to a sufficient approximation the value of the corresponding primary current. Hence O2R2/V22 is the watts lost in the secondary circuit due to copper resistance, and O2R1N22/V22N12 is the corresponding loss in the primary circuit. ”

“ The transmitter on long and high resistance lines worked better by joining, in the manner shown in fig. 7, the microphone, a battery and the primary of an induction coil in a local circuit, and putting the line in circuit with the secondary of the induction coil, which acted as the transmitter. The resistance of the microphone can thus be made a large fraction of the total resistance of the circuit in which it is placed; hence by using considerable currents, small variations in its resistance can be made to induce somewhat powerful currents in the line wire. ”

“ He reactivated the servo and went on to M-19.
"If you think it's so great, why don't you volunteer?" countered Sokolski, a trifle sourly. "Incidentally, it's a good thing we came in, Joe. There's half a dozen units here working on reserve transistors."
Their sporadic conversation lapsed; it was exacting work and they could remain for only a limited time under that lethal radiation. Then, almost sadly, Gaines said, "Looks like the end of the road for M-75."
"Oh?" Sokolski came over beside him and peered through the violet haze of his viewing glass. "He's an old timer." ”

“ The current on a long-distance line is alternating in character, and it passes readily through a repeating-coil. The only effect it has on the transmission is slightly reducing the volume. The current passes into the repeating-coil, then divides and passes through the two line wires. At the other end the halves balance, so to speak. Thus, currents passing over a phantom circuit don't set up currents in the terminal apparatus of the side circuits. ”

“ But if we connect these wires to the coils of the induction apparatus and then take hold of the two ends of the secondary coil and break and close the primary circuit we should feel a painful shock at each break and close, although the actual amount of current flowing through the secondary wire is not as great as that which flows through the primary; but the voltage (or electromotive force) is higher, and thus is able to drive what current there is through a conductor of higher resistance, such as the human body. ”

“ Every time that the circuit is made the primary coil creates a field and every time it is broken it is destroyed. A direct current is a current which passes in one direction only. It may be represented by a straight line as A in Fig. 40. Its voltage is usually very constant and does not vary greatly. In the case of electric lighting circuits the normal voltage is usually 110. If an interrupter is included in the circuit the current may be represented by a broken line, the spaces corresponding to the periods when the current is "broken" and the lines to the periods it is flowing. ”

“ Inductance increases with the frequency of the current in a conductor, and in each of the three systems just considered the frequency is sixty cycles per second.
The use of one circuit of larger wire instead of two circuits of smaller wire has the obvious advantage of greater mechanical strength in each conductor, saves the cost of one pole line and of the erection of the second circuit. With voltages above 40,000 to 50,000 on long transmission lines there is a large loss of energy by leakage directly through the air from wire to wire. ”

“ When an alternating current is set up in the circuit containing the cathode, anode, and secondary of the transformer, the electronic discharge from the cathode closes the circuit and permits a continuous flow of electricity through it when the phase of the current is such than the anode is positively charged, while preventing any flow of current through the tube when the anode is negatively charged. ”

“ On most, if not all, transmission lines the guard wire or wires, if used at all, are placed either above or on a level with the highest power conductors. With one conductor of a three-phase circuit mounted on a pin set in the top of a pole, and the two remaining conductors on a two-pin cross-arm beneath, in the method most frequently adopted for transmission lines of very high voltage, it is obviously impracticable to put guard wires either above or on a level with the power circuits. ”

“ As shown in the diagram, the instrument embodies the principle of a short circuited transformer, consisting of a primary or exciting coil A, a secondary or closed coil B, linked in inductive relation to the primary by a laminated iron core C, constructed to give a completely closed magnetic circuit, that is, without air gap. The secondary is so mounted with respect to the primary as to have a movement under the influence of their mutual repulsion when the primary is traversed by an alternating current. ”

“ Electromagnetic conversion efficiency. The delay line may best be considered as forming an electrical network of the kind usually (rather misleadingly) described as ‘four-pole’, i.e. a network which has one input current and one input voltage which together determine an output voltage and current. Such a network is described by three complex numbers at each frequency. In the case where there is little coupling between the output and input, which will apply to our problem, we may take these quantities to be the input and output admittances and the ‘transfer admittance’. ”

“ The circuit A is connected to the line L and in series with it is a primary P, which may have its free end connected to an insulated plate P1, such connection being indicated by the dotted lines. The other motor circuit B is connected to the secondary s which is in inductive relation to the primary P. When the transformer terminal T1 is alternately electrified, currents traverse the open line L and also circuit A and primary P. The currents through the latter induce secondary currents in the circuit S, which pass through the energizing coil B of the motor. ”

“ The shunt-circuit extends from the place through a galvanometer to the filament. His specifications disclose that the vacuous space within the globe is a conductor of current between the plate anode and the filament; that the strength of the current in the filament-to-plate circuit through the vacuum depends upon the degree of incandescence at the filament; and that the plate anode is preferably connected to the positive side of the current supply. The claims of the patent are for the combination of the filament, plate and interconnecting circuit, including the galvanometer. ”