Electrical connection

“ Form a communication by a chain from the coating to the cushion, and the phial will charge.
For the globe then draws the electrical fire out of the outside surface of the phial, and forces it, through the prime conductor and wire of the phial, into the inside surface. ”

“ In the ordinary construction of transmission lines on land the tensile strength of wire is secondary in importance to its electrical conductivity, because supports can be spaced according to the strength of the conductor used. ”

“ The term wiring is commonly understood to mean the methods employed in laying the conductors used for the transmission and distribution of electrical energy for lighting, power, and other purposes. Interior wiring, comprises the various methods of installing the conductors from the entrance devices in the walls or other parts of the buildings to the lamps, motors, and other electrical apparatus within the buildings. ”

“ You must remember, to begin with, that in referring to wire used on magnets and armatures and for carrying the electricity away to the lamps, we always mean wire that is covered or insulated. In electric lighting, insulated wire is always used, except at the points where it is connected with, the dynamo, the lamps, a switch, or any point where we make what is called a "connection." ”

“ Just here we may refer to the fact—for it is a fact—that the electrical energy transmitted over a line, which may be many miles in length, really does not travel by the wire connecting the two points. It travels in the ether surrounding the wire. The wire itself is, in fact, the guiding core of the disturbances in the ether which proceed outward in all directions to unlimited distances. The guiding core or conducting wire is needed to focalize or direct the delivery of the energy. ”

“ Fig. 22 shows the form of apparatus that I was then employing for producing undulatory currents of electricity for the purposes of multiple telegraphy. A steel reed A was clamped firmly by one extremity to the uncovered leg h of an electro-magnet E, and the free end of the reed projected above the covered leg. When the reed A was vibrated in any mechanical way, the battery current was thrown into waves, and electrical undulations traversed the circuit B E W E ́, throwing into vibration the corresponding reed A ́ at the other end of the circuit. ”

“ Now (if the power be sufficient) it does not signify what length of wire there may be between the two ends of this arrangement or “battery,” whether the ends be connected by a few feet of wire, or as many hundred miles—the electricity passes instantaneously from one end to the other; and furthermore, it has been found in practice, that this electrical influence can be transmitted through the earth in one direction if sent by a wire in the other; for instance, if a wire from one end of the battery be carried on from London to Liverpool ”

“ When the center of distribution is at a considerable distance from the supply circuit, and it becomes advisable to divide the wiring into two distinct elements—a feeder and one or more mains, the junction of the feeder and the mains should be located at the electrical center of the mains whenever possible. ”

“ All wires and current carrying parts should be kept far enough apart at all points to prevent accidental contact or the jumping across of the 428 current where there is a great difference of voltage. Such wires should be also kept at a sufficient distance from screw heads, metal brackets, gas pipes, water pipes, and other conducting bodies, in order to prevent accidental grounds or short circuits. ”

“ The alternating current will operate incandescent lamps, arc lamps, electric heating apparatus, alternating current motors. It will flow through a straight wire with slightly increased retarding effect, but if the wire be wound on an iron bar its strength is greatly reduced. ”

“ The field for relays is more extensive for alternating current than for direct current power circuits, the latter being generally confined to much smaller and simpler systems and areas of distribution, and generally sufficient selective action can be obtained by the use of fuses or circuit breakers arranged with instantaneous trip. ”

“ The facility with which alternating current can be transformed from one voltage to another, thus permitting high pressure transmission of electric energy to long distances through small wires, and low pressure distribution for the operation of lighting systems and motors, gives a far greater variety of systems of transmission and distribution than is possible with direct current. ”

“ It is very easy to detect the electric lines which radiate from every part of such a wire when a spark jumps between the terminals S of the coil. All that is necessary to do is to pass the wire through a sensitive film and to develop the film. The accompanying photograph (Fig. 3) was taken at the top of such a wire, by means of a very powerful apparatus at my command. When the photograph is examined with a microscope the arborescent electric lines radiating from the wire, like the rays of light Fig. 2a represents a more complete electrical arrangement of the receiver circuit. ”

“ Every one knows that when by means of an ordinary electrical machine electricity has been generated in sufficient quantity and under suitable conditions to prevent its dispersion, a spark of intense brilliancy and greater or less length, according to the amount of electricity thus collected, can be obtained when some body, not similarly electrified, is brought near to what is called the conductor of the machine. ”

“ It is known since a long time that electric currents may be propagated through the earth, and this knowledge has been utilized in many ways in the transmission of signals and the operation of a variety of receiving devices remote from the source of energy, mainly with the object of dispensing with a return conducting-wire. ”

“ A TELEGRAPHIC CIRCUIT WITH RELAY AND SOUNDER
In the telegraphic circuit only one connecting wire is [133] needed. The earth, being a good conductor of electricity, is used as part of the circuit. It is necessary, therefore, to make a ground connection at each end of the line, the instruments being connected between the line wire and the earth. For long-distance telegraphy a current from a dynamo is used instead of a battery current. Fig. 64 shows a simple telegraphic circuit. ”

“ Electrical energy may be transmitted around the world if the line voltage is unlimited. This follows from the law that a given power may be transmitted to any distance with constant efficiency and a fixed weight of conductors, provided the voltage is increased directly with the distance.
The physical limits of electric-power transmission are thus fixed by the practicable voltage that may be employed. The effects of the voltage of transmission must be met in the apparatus at generating and receiving stations on the one hand, and along the line on the other. ”

“ Having described the electrical machine, we are now to consider some of the phenomena attending its operation. When the prime conductor receives electricity from the cylinder, it is said to be electrified by communication, and it then acts in every respect like the cylinder itself, except that the latter, when touched by a conductor communicating with the earth, gives a considerable number of sparks before it is discharged; whereas the conductor discharges itself by a single spark. ”

“ The energy of the currents and the quality of the wire also affect the speed. Until lately it was supposed that the wire acts only as a conductor of electricity, and that a long wire must produce a weaker effect than a short one, on account of the consequent attenuation of the electrical influence; but it is now known that, the cable being a reservoir as well as a conductor, its electrical supply is increased in proportion to its length. ”

“ In discharging electrical jars, the electricity goes in the greatest quantity through the best conductors, and by the shortest passage. Thus if a chain and a wire be made to communicate at the same time with the outer coating of a jar, and be both presented to the knob of that jar, the greater part of the charge will pass by the wire, and very little by the chain, because the latter is a worse conductor than the former, on account of its discontinuation at every link. When the discharge is 29made by the chain only, sparks are seen at every link, which is a proof they are not in contact. ”

“ The function of a circuit closing relay is to close an electrical circuit, usually direct current, through a trip coil on an oil switch or circuit breaker, or it may short circuit a low voltage release coil, and thereby open the oil switch or circuit breaker on occurrence of the condition upon which the relay is designed to operate. Direct current at 125 or 250 volts taken from exciter bus bars or storage battery system is generally used for the tripping circuit. ”

“ Fig. 2,151.—Diagram of two phase four wire system. It is desirable for supplying current for lighting and power. The arrangement here shown should be used only for lines of short or moderate length, because of the low voltage. Motors should be connected to a circuit separate from the lighting circuit to avoid drop on the latter while starting a motor. ”

“ The electrician, however, not only used much higher power immediately he took the cable in hand—for working his specially devised relay and Morse electromagnetic recording-instrument in connection with his enormous induction-coils—but actually increased the power from time to time up to nearly 500 cells, till the five-foot coils yielded a current urged by a potential of something like 2,000 volts. ”

“ CONDUCTORS AND INSULATORS
Bodies differ from each other in a striking manner in the freedom with which the electric current moves upon them. If the electric current be imparted to a certain portion of the surface of glass or wax, it will be confined strictly to that portion of the surface which originally receives it, by contact with the source of electricity ”

“ Q shows a stout wire or strip of 2 or 3 thicknesses of tin. Suppose we have an apparatus, as, for example, an electric bell, which we want to have ring when someone at a distance desires to call us. If we use a telephone or telegraph instrument we shall want to cut the bell out of the circuit as soon as we hear the call and are ready to talk. Suppose the current comes to us through the wire, A, Fig. ”

“ In use either the prime conductor or cushions are connected by a chain
or otherwise with the earth. Assume it to be the cushions. As the
machine is worked by turning the plate, the glass and cushion being in
contact develop opposite electricities. The glass is charged with
positive electricity, and as it turns carries it off and as it reaches
the prime conductor by induction and conduction robs it of its negative
electricity. Meanwhile the cushions negatively excited deliver their
charge to the earth. The action thus goes on, the prime conductor being
charged with positive electricity. ”

“ This is effected by the use of that property of electricity which causes an electrified wire to attract to it an adjacent piece of wire or iron. In the relay a needle or lever is so adjusted that when a feeble current comes along the main line, it attracts the needle of the relay line, and by means of this connection a fresh current from the local battery flows on to the line, and does the work which the original current had become too feeble to accomplish. This invention was embodied in the first patent of Professor Wheatstone ”

“ A disused and abandoned electric conductor, such as a telegraph
wire.
(c) A wire in use, but through which, at the time of speaking, no
current is passing.
Death, Electrical.
Death resulting from electricity discharged through the animal system.
The exact conditions requisite for fatal results have not been
determined. High electro-motive force is absolutely essential; a
changing current, pulsatory or alternating, is most fatal, possibly
because of the high electro-motive force of a portion of each period. ”

“ In the case, therefore, of the electrical machine, it appears that the accumulation of electricity in an insulated conductor is always accompanied by the excitement of the contrary electricity in the surrounding atmosphere, and in every conductor placed near the former conductor. It does not seem possible, in this case, to produce one electricity by itself. ”

“ SWITCHES, FUSES, AND CIRCUIT-BREAKERS.
Electrical transmission has worked a revolution in the art of switching. As long as the distances to be covered by distribution lines required pressures of only a few hundred volts, the switch contacts for generators and feeders could well be exposed in a row on the surface of vertical marble slabs and separated from each other by distances of only a few inches. ”

“ It sometimes happens that after using power from the local electric illuminating company for some time, conditions arise which make it expedient for the owners to install a private electric plant. If a straight three wire system had been originally installed, the mains and the feeders when used on a two wire system would not be heavy enough by 25 per cent., as the neutral wire of a straight three wire system is the same in size as one of the two outer wires, and theoretically carries one-half the current or less. ”

“ To the engineer and to those who desire to know the trend of electrical development, the most interesting exhibit at the Fair will doubtless be the apparatus designed to show the long-distance transmission of power. Almost at the beginning of the modern electrical era, dreams were indulged in of the command which electricity was to give us of the natural sources of power. ”