Voltage

“ The Voltage Standard.—In order to determine the voltage we must know something of resistance. Different metals do not transmit a current with equal ease. The size of a conductor, also, is an important factor in the passage of a current. A large conductor will transmit a current much better than a small conductor. We must therefore have a standard for the ohm, which is the measure of resistance. ”

“ In the case of continuous current, the power factor is unity, and the effective value of the current or voltage is the true mean value. As the electrical measure of a power is always a product involving current and voltage, we may transform the character of the power by increasing or diminishing the current with a corresponding decrease or increase of the voltage. A transformer which raises voltage is generally called a step-up transformer, and one which lowers voltage a step-down transformer. ”

“ If a greater number of turns be used in the series winding than is required for constant voltage at the brushes for all loads, the voltage will rise as the load is increased, and thus make up for the loss or drop in the transmission lines, so that a constant voltage will be maintained at some distant point from the generator. ”

“ Decreasing size of pipes is increasing resistance and decreases flow of water, so also introduction of resistance in an electrical circuit decreases current flow with a given voltage or pressure.
Wall. Jar sides and ends.
Washing. Removal of sediment from cells after taking out elements; usually accompanied by rinsing of groups, replacement of wood separators and renewal of electrolyte.
Watt. The commercial unit of electrical power, and is the product of voltage of circuit by amperes flowing. One ampere flowing under pressure of one volt represents one watt of power. ”

“ CHOKE COILS.--Coils that prevent the high voltage oscillations from surging back into the transformer and breaking down the insulation.
CHOPPER MODULATION.--See Modulation, Chopper.
CIRCUIT.--Any electrical conductor through which a current can flow. A low voltage current requires a loop of wire or other conductor both ends of which are connected to the source of current before it can flow. A high frequency current will surge in a wire which is open at both ends like the aerial. ”

“ Fig. 2,485.—Diagram showing a set of phase characteristic curves taken from a General Electric synchronous motor. These curves show the current input to the motor at various loads with constant voltage and varying field excitation. There is a certain field current at each load that causes a minimum current. Any increase or decrease of field from the value increases the current and causes it to lead or lag with respect to the line voltage. ”

“ In external appearance they are not distinguishable from ammeters.
FIG. 236.—A voltmeter.
The unit of electromotive force is called the volt. The voltage of a dry cell is approximately 1.5 volts, and the voltage of a voltaic cell and of a gravity cell is approximately 1 volt.
316. Current, Voltage, Resistance. We learned in Section 287 that the strength of a current increases when the electromotive force increases, and diminishes when the electromotive [345] force diminishes. Later, in Section 288, we learned that the strength of the current decreases as the resistance in circuit increases. ”

“ As it is a law of every electric circuit that the rate of transformation of electric energy to heat or work in each of its several parts is directly proportional to the drop of voltage therein, it follows that a drop of 500 or 1,000 or 2,000 volts in the conductors of a 10,000-volt transmission line at full load would correspond to a power loss of five to ten or twenty per cent respectively. ”

“ Showing the analogy of water to volts and amperes of electricity
The same is true in figuring the power of electricity. We multiply the amperes by the number of electric impulses that are created in the wire in the course of one second. The unit of velocity, or pressure of the electric current is called a volt. Voltage is the pressure which causes electricity to flow. A volt may be likened to the velocity in feet per second of water in falling past a certain point. ”

“ A transmission that would be entirely impracticable with any percentage of line loss that might be selected, if carried out at some one voltage, might represent a paying business at some higher voltage and any one of several sizes of line conductors. The power that could be delivered by a line of practicable cost, operated at one voltage, might be too small for the purpose in hand, while the available power at a higher voltage might be ample. ”

“ The energy of any current is determined by and is equal to the product of two of its properties, its volume or ampèrage and its pressure or voltage. Letting C represent the ampères and V the voltage, we have that the energy C V. In passing any current over any wire there is a loss of voltage determined by and equal to the product of two things—i. e., the ampèrage of the current and the resistance of the wire ”

“ For any given size of wire and distance apart of wires there is a certain voltage at which the critical density or critical gradient is reached, where the air breaks down and luminosity begins—the critical voltage where corona manifests itself. ”

“ A much more effective and generally adopted method of regulation of voltage at the generating plants of transmission systems is based on the action of an attendant who varies the current in the magnet coils of each generator so as to raise or lower its voltage as desired. ”

“ Regulation of voltage at incandescent lamps is a serious problem in the distribution of electrically transmitted energy. Good regulation should not allow the pressure at incandescent lamps rated at 110 to 120 volts to vary more than one volt above or below the normal. ”

“ The alternating current pressure can be kept constant through the full range of direct current voltage by changing the main field so as always to give an equal and opposite flux change to that of the regulating field. ”

“ The cells shown will not have sufficient voltage to operate ordinary ignition apparatus requiring a potential of six volts, hence the multiple system must be modified in order to have an increased voltage, and at the same time secure the advantages of multiple connections. ”

“ The voltage and the conductivity of the layer we draw power from, both depend on ionization. When the intensity of sunlight drops, the voltage drops and the conductivity drops, too. It's harder for less power to flow to the area the grid can tap—and the voltage-pressure is lower to drive it. ”

“ 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. ”

“ Fig. 117. Arc-Lighting Circuit.
A high voltage is necessary in order to cause the current to leap across the gap made by the separation of the electrodes
p. 166
The Incandescent System.—This method is entirely different from the arc system. It has been stated that certain metals conduct electricity with greater facility than others, and some have higher resistance than others. If a certain amount of electricity is forced through some metals, they will become heated. ”

“ If one light is of less intensity than another and both of them receive their impulses from the same source, there must be something which interferes with that light which shows the least brilliancy. Electricity can also be interfered with, and this interference is called resistance.
Voltage.—Water may be made to flow with greater or less force, or velocity, through a pipe, the degree of same depending upon the height ofp. 61 the water which supplies the pipe. So with electricity. It may pass over a wire with greater or less force under one condition than another. This force is called voltage. ”

“ Turning the primary in one direction increases the voltage induced in the secondary, thus increasing the feeder voltage like the action of a booster on a direct current circuit while turning the primary in the opposite direction from the neutral position, correspondingly decreases the feeder voltage. ”

“ Surging, depending as it does on the current ruptured, may, and indeed often does, give particularly formidable effects on circuits of moderate voltage, while on high voltage transmission circuits the usually moderate current and the large margin of safety in the insulation are important ameliorating influences. ”

“ The E.M.F. or tension corresponds to pressure, to use the mechanical analogy of a water pipe, and the ampèrage to volume, and the voltage of the supply currents in this country are usually between 100 and 250 volts. Private lighting sets are frequently as low as 50, and current derived from accumulators may be anything from a few volts and upwards. Power currents, such as commonly employed for tramways, &c., are usually about 500 volts, but the use of these currents for lighting purposes, though practicable, is not to be advocated. ”

“ Where a transmission at high voltage is to be accomplished with continuous current, two or more dynamos are usually joined in series at the generating station, and a similar arrangement with motors is made at the receiving station, so that the desired voltage is available at the line though not present at any one machine. ”

“ Inductance not only sets up a counter-electromotive force in the line, which reduces the voltage delivered to it by generators or transformers, but also causes a larger current to flow in the line than is indicated by the division of the number of watts delivered to it by the virtual voltage of delivery. ”

“ Although any conductor of electricity has capacity to some degree, that property is substantially enhanced in a circuit by the use of a condenser, consisting of two or more metal plates separated by a non-conductor, such that when a voltage is applied to the circuit one plate will become positively and the other negatively charged.↑ A coherer was a device disclosed by Branly as early as 1891. ”

“ For instance, take the current that is sent to Buffalo, a distance of from twenty to thirty miles. The current first runs to a transformer connected with the power-house, where it is "stepped-up" (to use the parlance of the craft) from a voltage of 2200 to 10,000. ”

“ Except under abnormal conditions the shunt field always predominates giving a voltage which is added to that of the lighting bus bars, so that the voltage across the power busses is always higher than that across the lighting by an amount equal to the booster voltage. ”

“ Among the startling facts brought out in these experiments is that although a current of electricity, either direct or alternating, from ordinary dynamos under fifteen hundred or two thousand volts electro-motive 'force will kill, yet under alternations of a million to a million and a half per second a voltage of fifty thousand produces no shock or injury. ”

“ On the Rio Grande River in Colorado they are constructing several plants where water power will be utilized to generate electricity for use more than one hundred and fifty miles away. For transmitting electricity to such a distance they step up the voltage, or electro-motive force as it is called, to 100,000 volts. ”

“ For this reason, low voltage machines that are intended to deliver a great amperage have only a few conductors of large cross section, while high tension machines have a great number of conductors of small size. ”

“ The effective voltage between the external leads may in the same way be calculated by a vector diagram, and with the above star connexion the voltage between the outer pair of wires a and c is √2, or 1.414 times the voltage between either of the outer wires and the common wire bd. ”

“ In one the exciting armature is rotated, producing the working voltage of 250, 500 or 1000 volts. In the other gap are pivoted two coils wound on an iron core and connected at nearly a right angle to each other. ”

“ The storage cell is made in various capacities and a fully charged cell on open circuit has a voltage of approximately 2.1 volts which, when placed on discharge, becomes approximately 2 volts and drops to about 1.8 volts when completely discharged. ”

“ The quantity of electricity passed by a current of one ampere in one
hour. It is used by electric power and lighting companies as the unit of
energy supplied by them, because they maintain a constant potential
difference in their leads, so that only the amperes and hours need
measuring or recording to give the energy, viz. : volt-ampere-hours.
The same unit is applied to batteries to indicate their potential
energy, because they also are assumed to be of constant voltage or
electro-motive force. ”

“ Electrical engineering deals with electric energy and its flow, that is, electric power. Two classes of phenomena are met: permanent and transient, phenomena. To illustrate: Let G in Fig. 1 be a direct-current generator, which over a circuit A connects to a load L, as a number of lamps, etc. In the generator G, the line A, and the load L, a current flows, and voltages ”

“ Deptford, Eng., alternating current plant. It is observed that the
potential difference between the members of a pair of mains rises or
increases with the distance the place of trial is from the station.
[Transcriber's note: This effect is due to the voltage drop across the
line inductance (due to charging current) being in phase with the
sending end voltages. Both capacitance and inductance are responsible
for producing this phenomenon. The effect is more pronounced in
underground cables and with very light loads.]
252 STANDARD ELECTRICAL DICTIONARY.
Ferro-magnetic. ”