Electronics

“ The rapid evolution of computers and other high-speed switching devices has generated a need for higher speed equipment to supply input and output requirements. The changeover to electronics has realized minification, lighter weight, reduction of mechanical parts with a corresponding reduction in maintenance, quieter operation, and greater adaptability to code and language conversion. ”

“ Aluminum wire, spun basalt insulation, and aluminum base plates are provided from the bulk or parts fabrication system described in appendix 5F. After these parts are properly presented to the electronics assembly robots, these robots must assemble the components into major working electronics systems such as power supplies, camera systems, mini/microcomputers CPUs, computer I/O units, bulk memory devices, solar cell panels, etc. Electronics assembly appears to require a technology considerably beyond the state-of-the-art. ”

“ Some 60 countries are active members. Its mission is to develop and promote standardization among all nations in the technical specifications of electrical and electronic equipment. These technologies include electronics, magnetics, electromagnetics, electroacoustics, multimedia, telecommunications, electrical energy production and distribution, and associated fields such as terminology and symbology, compatibility, performance standards, safety, and environmental factors. ”

“ The composite consists of a high-speed general-purpose digital computer, an electronic analog computer, an analog-to-digital converter, a digital-to-analog and a suitable control for these two converters. The converters are called “transducers” and have the ability of changing the continuous analog signal into discrete pulses of energy, or vice versa.
Sometimes called digital differential analyzers, the hybrid computers feature the ease of programming of the analog, plus its speed, and the accuracy and much broader range of the digital machine. ”

“ A gear can have a finite number of teeth; when we deal with electrons flowing through a wire we leave the discrete and enter the continuous world. A tiny change in voltage or current, or magnetic flux, compounded several hundred times in a complex computer, can change the final result appreciably if the errors are cumulative, that is, if they are allowed to pile up. This is what happens in the analog computer using electrical and electronic components instead of precisely machined cams and gears. ”

“ And the mystery of the telephone grows no less the more one studies it. You speak against a tiny disc of sheet-iron, and the disc trembles. It has millions and millions of varieties of trembles, as many as there are sounds in the universe. A piece of copper wire, connected with an electric battery, stretches from the disc against which you have spoken to another disc [Pg 232] miles and miles away. The tremble of your disc sends an electric thrill along the wire to that other disc and makes it tremble exactly as yours did. ”

“ On left is an array of 16 analog computers; at right is a large digital data-processing system.
The facility can perform scientific and business tasks simultaneously.
The dictionary also gives us a good clue to the digital computer: “Digital.—Of the fingers or digits.” A digital machine deals in digits, or discrete units, in its calculations. For instance, if we ask it to multiply 2 times 2, it answers that the product is exactly 4. A slide rule, which we have said is an analog device, might yield an answer of 3.98 or 4.02, depending on the quality of its workmanship and our eyesight. ”

“ We have seen above that by this is determined the number of interruptions of the electric current of our apparatus by means of the membrane and the platinum strip. The iron wire must therefore give out the tone in the same height or depth as that which struck the membrane. Now since a very far leading of the electricity makes it suffer scarcely any weakening in proper apparatus, it is intelligible that one can make the tone which acts on the membrane at one place audible, by means of the iron rod, at any desired distance. ”

“ A radio tube of the audion or three electrode type consists of a bulb, within which a vacuum has been created, enclosing a filament, which is a negative electrode, or cathode; a plate, which is a positive electrode, or anode; and a third electrode, known as a grid, located between the filament and the plate. The grid is connected with an input circuit, over which electrical radio activity, actuated at the sending station, is gathered from the ether and passes to the grid. When the tube is used as an amplifier, the plate is connected in circuit with a telephone receiver or loud speaker. ”

“ For several years my attention was almost exclusively directed to the production of an instrument for making and breaking a voltaic circuit with extreme rapidity, to take the place of the transmitting tuning-fork used in Helmholtz’ researches. I will not trouble you with the description of all the various forms of apparatus that were devised, but will merely direct your attention to one of the best of them, shown in fig. 2. In the transmitting instrument T, a steel reed a is employed, which is kept in continuous vibration by the action of an electro-magnet e and local battery. ”

“ Every telephone receiver and transmitter has a mouth-and ear-piece to receive or throw out the sound, a thin round sheet of lacquered metal—called a diaphragm, and an electromagnet; together they reproduce human speech. An electric current from a battery or from the central station flows continuously through the wires wound round the electromagnet in receiving and transmitting instruments, so when you speak into the black mouthpiece of the wall or desk receiver the vibrations strike against the thin sheet-iron diaphragm at the small end of the mouthpiece ”

“ Where an electric current is used for some simple device a thorough knowledge of electricity may not be necessary but if your invention requires that a low voltage current be changed into high frequency oscillations which are in turn varied by the voice and these oscillations are sent out from an aerial wire, all of which is done in a wireless telephone, I should say that you ought to have a pretty fair understanding of the theory of electricity before you begin your experiments—that [13] is if you expect to develop your invention into an apparatus of utility and hence of worth. ”

“ When you take your receiver off the hook a tiny electric bulb glows opposite the brass-lined hole that is marked with your number on the switchboard of your central, and the telephone girl knows that you are ready to send in a call—the flash of the little light is a signal to her that you want to be connected with some other subscriber. Whereupon, she inserts in your connection a brass plug to which a flexible wire is attached, and then opens a little lever which connects her with your circuit. ”

“ There are some twenty-two thousand electron tubes in each one, you know, and so we devised a gadget that went down the aisles and replaced them one after another automatically. Now, the machine must have started from that crude affair and by using its cable-clamps, worked on another machine capable of more complex action. Sort of like a lobster fashioning a hammer out of a rock with its claws. Then the more complex machine must have rebuilt the repair-gadgets, making them even more facile—and so on until we have the completely capable machine. ”

“ An apparatus for dispelling fogs by electricity, television, or transmitting sight by electricity, cheap electric lights, see Fig. 113, a simple telautograph, or writing telegraph, a means for directing wireless telegraph and telephone messages, automatic block signals which [192] operate in the engine driver’s cab and are positive in action, transmitting pictures by wireless and a cheap and powerful generator of sustained electric oscillations by a battery or other low voltage current, all these needs show that there is still plenty of room for improvement. ”

“ Small machines using a few electronic tubes—much like a radio set, for example—and containing spools of magnetic wire or magnetic tape will doubtless be available to us. We shall be able to use them to keep addresses and telephone numbers, to figure out the income tax we should pay, to help us keep accounts and make ends meet, to remember many things we need to know, and perhaps even to give us more information. For there are a great many things that all of us could do much better if we could only apply what the wisest of us knows. ”

“ More than 1,000 variables are controlled, and 200 analog signals and 100 digital computer-generated signals are used in the process. The steel sheets are shot out of the rolls at some 45 miles an hour, or about 66 feet a second! A human supervisor would have a difficult job just watching the several hundred signals related to thickness, temperature, quality, and so on, much less trying to think what to do if he noticed something out of specifications. ”

“ 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. ”

“ High-speed analog storage permits the machine to make sequential calculations, a job once reserved for the digital computer. But even these advances cannot offset the basic limitations the analog computer is heir to.
84Fewer analog machines are being built now, and many in existence do not enjoy the busy schedule of the digital machines. As the mountains of data pile up, created incidentally by computers in the first place, more computers are needed to handle and make sense of them. It is easier to interpret, store, and transmit digital information than analog ”

“ After a few weeks of trial the use of metal blocks or types to [Pg 251] regulate the recording marks was abandoned, and although the construction of the handle, called the manipulator, for regulating the transmission at intervals of sufficient electricity to produce the marks, was a later improvement, he ever afterwards declared that his first rude instrument had the leading features that characterised the more perfect apparatus of later years; or to use his own appropriate words, “It lisped its first accents and automatically recorded them in New York. ”

“ Never satisfied, computer designers pondered the problem of all the lost time entailed in laboriously preparing cards or tapes for the ravenous electronic machine. The results of this brain-searching are interesting, and they are evident in computers that actually read man-talk. Computers used in the post office and elsewhere can optically read addresses as well as stamps; banks have computers that electrically read the coded magnetic ink numbers on our checks and process thousands of times as many as human workers once did. ”

“ Bell Telephone uses the computer approach in circuit analysis, and Westinghouse in the design of radar circuitry. It is interesting that as we move up the design scale, closer to what the engineer once considered the domain of human creativity, the computer still is of great value. ”

“ The Theory of the Electric Current and Circuit, Electro-Chemistry, Primary Batteries, Storage Batteries, Generation and Utilization of Electric Powers, Alternating Current, Armature Winding, Dynamos and Motors, Motor Generators, Operation of the Central Station Switchboards, Safety Appliances, Distribution of Electric Light and Power, Street Mains, Transformers, Arc and Incandescent Lighting, Electric Measurements, Photometry, Electric Railways, Telephony, Bell-Wiring, Electro-Plating, Electric Heating, Wireless Telegraphy, etc. It contains no useless theory; everything is to the point. ”

“ A Boston mechanic expressed the general ignorance when he stoutly maintained that in his opinion there must be “a hole through the middle of the wire.” [Pg 231] And the telephone is still to most people a mystery, far more so than the telegraph or the incandescent light or the other uses to which electricity has been put. It is one thing to send a message by the mechanical process of dots and dashes made by breaking and joining a current. ”

“ The most accurate and reliable analog computers are mechanical in nature. We can cut gears and turn shafts and wheels to great accuracy and operate them in controlled temperature and humidity. Paradoxically, this is because mechanical components are nearer to digital presentations than are electrical switches, magnets, and electronic components. ”

“ It can also “learn” to play a mediocre game of chess.
If we investigate the workings of a digital computer, we find much to remind us of the human brain. First is the obvious similarity of on-off, yes-no operation. This implies a power source, usually electrical, and a number of two-position switches. The over-all configuration of the classic computer resembles, in principal if not physical appearance, that of the human brain and its accessories.
As we have learned, the electronic computer has an input section, a control, an arithmetic (or logic) section, a memory, and an output. ”

“ A fertile field for the analog computer from the start was that of industrial process control. Chemical plants, petroleum refineries, power generating stations, and some manufacturing processes lend themselves to control by analog computers. ”

“ In the instrument-room the bands are connected with ordinary steam machinery, by which they are drawn in regular order with the utmost rapidity between the charged poles of an electrical machine in such a manner that, during the moment of each pin’s passing, it forms electrical communication between the instrument and the telegraph, and a signal is transmitted to the other end of the wire, where the spark perforates a paper and records the message. ”