Such an apparatus consists of a direct current dynamo, driven direct from the shaft of a motor, which, in turn, is energized by current from the line circuit.
Take the instant when the balance coil taps are directly under the direct currentbrushes as shown at position AE.
The common point to which the neutral wire is connected must at all times be neutral to the - and + direct current brushes.
All but the tantalum lamp operates equally well on alternating or direct current.
A rotating machine having a field excited by a direct current and an armature winding connected to a commutator and a set of collector rings.
Any apparatus used to change an alternating current to a direct current by periodically interrupting or changing the direction of the alternating current so that the derived current is always in the same direction.
But a steady direct current can be obtained from an alternating current only by coupling an alternating current motor to a direct current dynamo.
Alternating current can be produced from a direct current by using an induction coil, or spark coil as it is called.
There are certain advantages in the use of direct current, and in this country it is more commonly employed than alternating current, but the substation plant is more costly and requires skilled attendance.
Electric motors are classified as direct-current motors or alternating-current motors, according as the electric power taken by the motor is in the form of a direct current or an alternating current.
The nature of the low-voltage distribution from the substations, whether alternating current or direct current, depends largely on the requirements of the consumers.
An electric current may be constant in direction (direct current), or may alternate in direction with a certain frequency (alternating current).
We shall find out how a dynamo may produce a direct current at another time.
I made connections with the electric lighting circuit (that in my laboratory is what is called a direct current), and sent a current of electricity around the coils.
It is interesting to note that when a direct current is used the evaporation from the carbon filament always takes place at the negative end alone, that is, the end from which the current is leaving the lamp.
The simplest method, and that which was first used, is separate excitation from some other source of direct current, which may be either a primary or a secondary battery or another dynamo (fig.
Although separate excitation is the more usual method, the alternator can also be made self-exciting if a part or the whole of the alternating current is "rectified," and thus converted into a direct current.
Since an alternating current cannot be used for exciting the field-magnet, recourse must be had to some source of a direct current.
Machines of this class are similar in general construction todirect current motors.
Since, as stated, commutator motors are similar to direct current motors, the question may be asked: Is it possible to run a direct current motor with alternating current?
They are produced by properly connecting the groups of coils and not by windings concentrated at certain points on salient or separately projecting masses of iron, as in direct current machines.
For synchronous motor and three phase operation the revolving field with projecting poles and slip rings would be used, the field being excited from a direct current supply.
A direct current of electricity is then caused to flow through the copper plate and into the iron plate or surface, and the plating proceeded with until the iron surface has a thin film of copper deposited thereon.
Brushes in a Direct Current Dynamo: Alternating, Positive and Negative Poles.
Illustration: A direct current dynamo] Unless this dynamo were properly protected, the effect of such a catastrophe would be immediate and probably irreparable.
It is often desirable to transmit electrical energy in the form of alternating current, and distribute it as direct current or vice versa.
What similarity does the test for induced current show between movement through a magnetic field and the making and breaking of a direct current?
This transformer, as heretofore explained, does not change the voltage of the current, but simply transforms what was an alternating into a direct current.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "direct current" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.
