## Dynamo-electric Machinery: A Manual for Students of ElectrotechnicsE. & F. N. Spon, 1892 - Počet stran: 876 |

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### Další vydání - Zobrazit všechny

### Běžně se vyskytující výrazy a sousloví

alternate currents alternate-current ampere-turns amperes angle arc-lighting armature core armature current bars brushes calculated cent centimetre characteristic commutator conductors connected connexions constant construction copper core-disks curve demagnetizing diameter difference of potential disk eddy-currents effect efficiency electrical efficiency Electrician electromagnet electromotive electromotive-force Engineers equal equation exciting external circuit field-magnets gap-space give given Gramme Hopkinson horse-power inches increase induction insulated internal resistance iron core Kapp lamps lines of force machine magnetic circuit magnetic field magnetic lines magnetic reluctance magnetizing force main circuit Marcel Deprez maximum mechanical method Mordey motive-force motor multipolar n₁ number of lines number of magnetic number of turns Ohm's law ohms output parallel permeability Permeance polar pole-pieces poles proportional represents revolutions per minute rotating self-induction series coils series dynamo shaft shown in Fig shunt coils shunt dynamo Siemens Specification of Patent speed square square centimetre terminals torque volts watts winding wound

### Oblíbené pasáže

Strana 794 - Ampere, which is one-tenth of the unit of current of the CGS system of electromagnetic units and which is represented sufficiently well for practical use by the unvarying current which, when passed through a solution of nitrate of silver in water, in accordance with a certain specification, deposits silver at the rate of 0.001118 of a gramme per second.

Strana 440 - ... rotated. As the two coils and commutator are rotated in the direction indicated by the arrows, the two brushes rub against the segments consecutively and always make contact with the two opposite ones. The brushes...

Strana 30 - The shorter the length of those parts of the conductor not so employed, the stronger will be the current. (12.) Approach being a finite process, the method of approach and recession (of a coil towards and from a magnet pole) must necessarily yield currents alternating in direction. (13.) By using a suitable commutator, all the currents, direct or inverse, produced during recession or approach, can be turned into the same direction in the wire that goes to supply currents to the external circuits,...

Strana 530 - I have already had the honor of delivering, I have treated the dynamo solely in its functions as a generator of electric currents. In this third lecture I come to the converse function of the dynamo, namely, that of converting the energy of electric currents into the energy of mechanical motion. An...

Strana 124 - intensity of the field" at any point is measured by the force with which it acts on a unit magnetic pole placed at that point. Hence, unit intensity of field is that intensity of field which acts on a unit pole with a force of one dyne. There is therefore a field of unit intensity at a point one centimetre distant from the pole of a magnet of unit strength.

Strana 6 - Conductors or electric collectors of copper and lead were constructed so as to come in contact with the edge of the copper disc...

Strana 790 - ... That it is desirable that new denominations of standards for the measurement of electricity should be made and approved by Her Majesty in Council as Board of Trade standards. 2. That the magnitudes of these standards should be determined on the electro-magnetic system of measurement with reference to the centimetre as unit of length, the gramme as unit of mass, and the second as unit of time, and that by the terms centimetre and gramme are meant the standards of those denominations deposited...

Strana 535 - Jacobi enabled him, however, to discern that the observed diminution of current was really due to the fact that the motor, by the act of spinning round, began to work as a dynamo on its own account, and tended to set up a current in the circuit in the opposite direction to that which was driving it. The faster it rotated the greater was the counter-electromotive force (or " electromotive force of reaction ") which was developed.

Strana 439 - ... in pairs, each to that diametrically opposite it, and carefully isolated from those adjacent to them. For each pair of coils there is a separate commutator, so that, for the ordinary ring of eight coils, there are four distinct commutators side by side upon the axis — one for each pair of coils. The brushes are arranged so as to touch at the same time the commutators of two pairs of coils, but never of two adjacent pairs ; the adjacent commutators being always connected to two pairs of coils...

Strana 409 - The electro-thermal unit of conduction resistance, termed a joule, is the amount of heat produced in one second by a current of one ampere flowing through a resistance of one ohm, and is the quantity necessary to raise the temperature of -239 gramme of water one centigrade degree.