Propagation of Electric Currents in Telephone & Telegraph ConductorsVan Nostrand, 1911 - 316 pagini |
Alte ediții - Afișează-le pe toate
The Propagation of Electric Currents in Telephone and Telegraph Conductors ... Sir John Ambrose Fleming Vizualizare completă - 1911 |
The Propagation of Electric Currents in Telephone and Telegraph Conductors ... Sir John Ambrose Fleming Vizualizare completă - 1912 |
The Propagation of Electric Currents in Telephone and Telegraph Conductors ... John Ambrose Fleming Vizualizare completă - 1912 |
Termeni și expresii frecvente
a+jb Accordingly æther alternating current amplitude angle attenuation constant barretter battery calculated capacity centimetres charge circuit condenser conductor Cosh Cosh ax Cosh Pl Coth denoted diameter dielectric differential equation distance dot signal earth electric current electric force electric strain electromagnetic electromotive force equal expression farads formula galvanometer given gutta-percha harmonic helix Hence high frequency hyperbolic angle hyperbolic functions I₁ inductance coils initial sending end insulated intervals kilometre length constant lines of electric loaded cable loading coils magnetic flux measured microfarads mile naut obtained ohms oscillations phase Pl+Z potential potentiometer propagation constant quantity R₁ ratio received current receiving end receiving instrument represented Sech sending end impedance shunt simple periodic sine curve Sinh Pl Spec'n standard cable submarine cables Tanh telegraph telephone cable unit of length V₁ vector velocity voltage wave form wave length wire zero
Pasaje populare
Pagina 45 - ... is the ratio of the specific heat at constant pressure to the specific heat at constant volume, is a constant.
Pagina 16 - Conic, is the locus of a point which moves so that its distance from a fixed point is in a constant ratio to its distance from a fixed straight line.
Pagina 17 - PF'/PH'= e, by the definition of the curve. Furthermore :J (b) \PF—PF'\=2a. In fact, the hyperbola is often defined as the locus of a point which moves so that the difference of its distances from two fixed points is constant.
Pagina 282 - APPENDIX XI. SPECIFICATION FOR ANGLO-FRENCH SUBMARINE TELEPHONE CABLE. 1. Conductors. — The conductor of each coil shall be of an approved stranded type, shall weigh not less than 160 Ibs. per knot, and shall at a temperature of 75° F. have a resistance not higher than 7^452 standard ohms per knot for a conductor of this gauge. The lay of the stranded conductor shall be left-handed. 2. Insulator or Dielectric. — The conductor of each coil shall be insulated by being covered with three alternate...
Pagina 280 - ... space. COMPARATIVE SIZE OF PLANETS. (Chambers.) — The following scheme will assist in obtaining a correct notion of the magnitude of the planetary system. Choose a level field or common ; on it place a globe two feet in diameter for the Sun : Vulcan will then be represented by a small pin's head, at a distance of about 27 feet from the centre of the ideal sun ; Mercury by a mustard-seed, at a distance of 82 feet ; Venus by a pea, at a distance of 142 feet ; the Earth, also, by a pea, at a distance...
Pagina 282 - Chatterton-s compound and gutta-percha, beginning with a layer of the said compound, and no more compound shall be used than may be necessary to secure adhesion between the conductor and the layers of gutta-percha. The dielectric on the conductor of each coil shall weigh not less than 300 Ibs. per knot, making the total weight of the conductor of each coil when covered with the dielectric not less than 460 Ibs. per knot. 3. Inductive Capacity. — The inductive capacity of each coil of such insulated...
Pagina 284 - ... too thin, any sign of a reddish deposit of metallic copper on the wire. If, after the examination of any particular quantity of iron wire, 10 per cent, of such wire does not meet all or any of the foregoing requirements, the whole of such quantity shall be rejected, and no such quantity or any part thereof shall on any account be presented for examination and testing, and this stipulation shall be deemed to be and shall be treated as an essential condition of the contract. Before being used for...
Pagina 283 - Each coil of core before being placed in the temperature tank for testing shall be carefully labelled with the exact length of conductor and the exact weight of copper and dielectric respectively which it contains.
Pagina 284 - Postmaster-General for the purpose of inspecting and testing the wire, taking samples from any coil or coils and plunging them into a saturated solution of sulphate of copper at 60° Fahrenheit, and allowing them to remain in the solution for one minute, when they are to be withdrawn and wiped clean. The galvanising shall admit of this process being four times performed with each sample without there being any sign of a reddish deposit of metallic copper on the wire...
Pagina 284 - If, after the examination of any parcel of wire, 5 per cent, of such parcel fail to meet all or any of the requirements of this Specification, and of the Table, the whole of such parcel shall be rejected, and on no account shall such parcel or any part thereof be again presented for examination and testing ; and this stipulation shall be deemed to be, and shall be treated as, an essential condition of the contract. (8) Each piece when approved by the Inspecting Officer shall be made into a coil and...