The current produced by the mechanical generator has a greater amperage and more heat value than that obtained from transformer coils excited by battery current.
If there are a smaller number of turns in the secondary coil than there are in the primary, the secondary voltage is less than the primary, and the transformer is called a step-down transformer.
Construction of a Small Bell-Ringing Transformer By A.
Andrews Part II--Construction Transformers may be divided into two main groups, the classification being made according to the relation between the magnetic circuit of the transformer and the primary and secondary windings.
If, on the other hand, there are a larger number of secondary turns than of primary, the secondary voltage is greater than the primary voltage, and the transformer is called a step-up transformer.
The dimensions of the complete magnetic circuit, of the transformer you are going to construct, are given in Fig.
These pieces can now be clamped across the ends of the transformer with small bolts, as shown in Fig.
Andrews Part I--Fundamental Principles The transformer in its simplest form consists of two separate and electrically independent coils of wire, usually wound upon an iron core.
Insulate the joint with a piece of paraffin paper or cloth, and bind the piece of heavy wire to the core of the transformer with a piece of linen thread.
The coil of the transformer that is connected to the source of energy is called the primary coil, and the one that is connected to the load, the secondary coil.
Method of Clamping Transformer Together] A circuit can now be run from a 110-volt lighting or power circuit, observing the same rules as though you were wiring for lights, and connected to the heavy wires, or primary circuit.
These heavy wires should be firmly fastened to the iron part of the transformer inside the box, so that any outside strain placed upon them will not, in time, break them loose from the smaller wires.
A transformer is simply two coils of wire wound on an iron core.
The transformer works in the same way, the only difference being that in the transformer the two coils are on the same iron core.
The simplest transformer is the form used by Faraday when he discovered electromagnetic induction.
We shall see later how the dynamo and the transformer developed in the nineteenth century.
It is a new current induced in the secondary coil of the transformer by the magnetic field of the primary coil.
With an alternating current this can be done and the current changed by means of a transformer to a current of low pressure.
But in the transformer the two coils are insulated so that no current can flow from one coil to the other.
A peculiar transformer which produces an alternating current that changes direction millions of times in a second has been made by Nikola Tesla.
This still left them twenty light-years from Thetis, with a cupful of transformerfuel in the emergency tank.
Coming out of transformer drive with at least a drop of fuel left, they switched to atomics.
The panel contains a changing switch which makes it possible to double the range of a regulator, since the transformer connections can be changed to both raise and lower to an extent equal to the full range of the transformer.
The floating coil is a part of the secondary winding of the regulating transformer which is insulated from the main portion of the winding, and is sub-divided by taps into a number of equal sections.
This form of variable ratio transformer regulator consists of a regulating transformerand a dial type switch as shown in the accompanying illustrations.
Westinghouse unit switch type pressure regulator, designed for handling heavy currents where a variable ratio transformer type of regulator is desired.
Because, the additional cost of a seriestransformer is small in comparison with the cost of building a dial with a large current carrying capacity, and the cost of bringing out a number of heavy leads from a small transformer.
Unless certain precautions are taken, such a static disturbance on the low tension side may cause serious stresses in the secondary insulation of a transformer with a high ratio of transformation.
The primary of the series transformer is connected in series with the line and two leads from the secondary winding are connected to the dial.
An auto-transformer or "balance coil" as it is sometimes called should be used as at B.
For balanced two phase circuits one compensator and one transformer connected in one of the phases is sufficient.
In the second case, where one large transformer may be placed at a distribution center, to supply several customers, as in fig.
The primary current of a transformer working with its secondary on an open circuit is a practical example of a current which represents very little energy.
This is illustrated by the fact that a peaked wave causes less hysteresis loss in a transformer core than a flat topped wave, owing to the higher form factor of the peaked wave.
By means of this series transformer the voltage delivered to the rectifying commutator and the fields is much less than that generated by the machine.
The apparatus necessary for direct current consists of a motor dynamo set which is considerably more costly than a transformer and not so efficient.
If the same transformer were placed in a direct current circuit and the current turned on it would at once burn out, as very little resistance would be offered and a large current would pass through the winding.
In this connection the primary objects of the choke coil should be: 1, to hold back the lightning disturbance from the transformer or generator until the lightning arrester discharges to earth.
Since the primary coil of a transformer has a high reactance, very little current will flow when an alternating pressure is applied.
The coil should be so arranged that if continual surges be set up in the circuit, a resonant voltage due to the presence of the choke coil cannot build up at the transformer or generator terminals.
All three connections between the armature coils and the collector rings run through primary circuits of the series transformer within the armature, these three primaries each giving their own effect upon the secondary.
Because of the low voltage and enormous quantity of the current passing from the transformer to the furnace very large conductors are required.
A transformer is an apparatus that changes the current from one voltage to another.
We have now described the principle of a transformer as it is worked out in an ordinary induction-coil.
It is carried to Buffalo through wire conductors that are strung on poles, and is there "stepped-down" again through another transformer to the voltage required for use at that place.
This heat would be sufficient to destroy the transformer if some arrangement were not provided to carry it off.
There is another kind of transformer that is used when it is necessary to have the current always running in the same direction.
In principle the transformer is nothing more or less than an induction-coil on a very large scale.
The new circuit from the transformer is indicated by the arrows enclosed in circles.
The primary circuit taken from the alternating current mains by the cord B, embraces the primary winding of the transformer T, a condenser C, and the coils P, of the vibrating units, fig.
On balanced load, the coils take a small alternating exciting current from the collector rings as any transformer does when connected to an alternating current line with its secondary open.
The secondary circuit from the transformer embraces the massive carbon and copper contacts (N and O, fig.
They are built of standard transformer parts, and are placed in cases similar to those of ordinary small transformers.
At the instant the terminal H of the supply transformer is positive, the anode A is then positive, and the arc is free to flow between A and B.
The dynamotor in the direct current circuit corresponds to the transformer in the alternating current circuit.
This is a step-down transformer and the secondary coil contains fewer turns of wire than the primary coil.
The parts C and D compose the screw base and the cover, in which is fitted the transformer B.
The construction of the transformer coils shown in Fig.
The primary wires of the transformer are attached to the service wires in the house and from the secondary wires voltages are taken to suit the desired purposes.
In principle, the action of the transformer is the same as that of the induction coil, a detailed explanation of which will be found in any text-book of physics.
Miniature lamp transformer complete and the parts of which it is composed.
Each impulse of current in the primary coil of the transformer magnetizes its core and the magnetism thus excited induces a corresponding current in the secondary coil.
A transformer is a simple device composed of two coils of wire wound on a closed core of iron.
The transformer in this figure is a single "interlocked" transformer in which the fields are magnetically connected and not independent of each other as in Fig.
The connections for the primary circuit of a transformer with six coils are shown diagrammatically in Fig.
In the old gas engines the ignition was derived from a few dry-cell batteries and some sort of a transformer coil, whereas nowadays the magneto takes care of this work.
The upper wire runs from the spark gap to the aerial, and the lower runs through a battery of Leyden jars, through a high tension transformer (as does the other side of the circuit), and thence to the ground.
Either a single transformer or several transformers in series may be employed to step up to the required voltage, but a single transformer will usually give better regulation and greater accuracy.
Such a cable may work at the regular line voltage, or a transformer station may be established on one side or on each side of the body of water.
With three-phase transformers each generator and its transformer may form an independent unit that can be connected with the line at pleasure, thus tending to keep transformers at full load.
This result is reached by the connection of a number of sections at one end of the transformer winding to a terminal board, where they may be cut in or out of action at will.
One type of regulator for this purpose consists of a transformer with its secondary coil divided into a number of sections and the ends of these sections brought out to a series of contact segments.
In another transformer used for regulating purposes the primary coil is connected to the bus-bars as before and the movable secondary coil is put in series with the line to be regulated.
Some disadvantages of such an arrangement are its high cost per unit of transformer capacity and its low efficiency.
Because your transformermust be wired into your regular house current, you should have some help on this from an electrician or other qualified person.
You can get these low voltages by using one or more batteries, or by using a transformer connected to your house current.
A push on the button, which is just a switch that is normally held "open" or off by means of a spring, sends the current from the battery or transformerthrough the circuit.
Inside, you will connect your transformer and the various buttons and bells with ordinary indoor bell wire.
DO NOT attempt to substitute alternating current, as from a model railroad transformer because its alternating current will cause the compass needle to swing rapidly from one side to the other.
Sometimes the heat produced by an electric current in the wires of a device such as a transformer is so large in amount that especial means of cooling are employed.
This is a small closed iron core transformer of peculiar design and having a primary and a secondary coil wound on it.
This power transformer is made exactly like the one described in connection with the preceding 100 mile transmitter and pictured in Fig.
The plain spark-gap is more suitable for small spark-coil sets, and it is not so apt to break down the transformer and condenser of the larger sets as the rotary gap.
When a 110 volt direct current is used to energize the power transformer an electrolytic interruptor is needed to make and break the primary circuit, just as a vibrator is needed for the same purpose with a spark coil.
A condenser of this value for a 1/4-kilowatt transformer costs $7.
For this transmitting set you need a transformer that has an input of 325 volts.
A transformer for stepping down a commercial alternating current for lighting and heating the filament and for stepping up the commercial a.
A radio frequency transformer is shown at B and costs $6 to $7.
The magnetic field thus produced sets up in turn electric oscillations in the secondary coil of the oscillation transformer and these surge through the aerial wire system where their energy is radiated in the form of electric waves.
That is, she shows herself the mistress of nature, or rather the transformer thereof; her mighty spell can change character and shape.
He is the transformer of her, not she of him; for she will reduce man to a beast, unless he reduces her to reason.
Moreover, the two bobbins may be supplied by the secondary current of a transformer by producing the difference of phase, as in the first case.
Faraday produced the first transformer during his investigations on voltaic-current induction.
The alternating-current transformer is another gift of Faraday to the commercial world.
So we see it as accelerator, lubricator and transformer of our energies.
Well, you'd better leave that here and find out what your dynamo and transformer are.
Bill had not sent the generator and the transformer to Mr. Kemble.
A mass of iron, usually made of thin plates, upon which the conductor of an armature or of a transformer is wound.
A variety of transformer with open magnetic circuit, the ends of the iron wire core being turned outward and presenting a bristling appearance, whence the name.
It's true that as a tiller of the soil he is a tireless transformer of static soil energy into dynamic plant life energy.
Hiroshito observed that a sudden increase in the temperature of the discharge occurred at the moment when the silver coil of his transformer became white hot, which he explained by some mysterious inductive action of the heat vibrations.
I use a tungsten spiral in a nitrogen atmosphere in my transformer and replace the quartz bulb with a capsule of zircorundum.
Installation of a transformer on pole; view showing method of attachment and disposition of the primary and secondary leads, cutouts, etc.
A large transformer under test may cause primary drop in taking power.
In the operation of a transformer the alternating current causes the core to undergo rapid reversals of magnetism.
The iron core of a transformer acts as a closed conductor in which small pressures of different values are induced in different parts by the alternating field, giving rise to eddy currents.
The polyphase transformer therefore is somewhat lighter and also more efficient.
The oil, heated by contact with the exposed surfaces of the core and coils, rises to the surface, flows outward and descends along the sides of the transformer case, from the outer surface of which the heat is radiated into the air.
It will be evident that this form of transformer possesses excellent ventilation; and this is still further enhanced by opening out the winding at intervals to leave ventilating apertures, as at A, A, A.
The means adopted for getting rid of the heat which is inevitably developed in a transformer by the waste energy is one of the important considerations with respect to its design.
Some companies make a minimum charge per month whether any current is used or not to offset the no load transformer losses and rent of meter.
All danger of confusing the leads or inadvertently making an electrical connection between the high and low tension sides of the transformer is thus averted.
The transformer is one of the essential factors in effecting the economical distribution of electric energy, and may be defined as an apparatus used for changing the voltage and current of an alternating circuit.
In this arrangement a rotatingtransformer g, is employed to convert the low tension direct currents into low frequency alternating currents, preferably also of small tension.
When the transformer terminal T{1} is alternately electrified, currents traverse the open line L and also circuit A and primary P.
It has been asserted by competent English electricians that in a constant-current machine or transformer the regulation is effected by varying the phase of the secondary current.
This may seem large, but since each lamp may be included in the secondary of a transformer of very small dimensions, it would not be inconvenient, and, moreover, it would not produce fatal injury.
In each branch is included the secondary of a transformer or induction coil, which, since they correspond in their functions to the batteries of the previous figure, are designated by the letters E F.
In the branch IIIb a similar disposition to that in Ib is illustrated, with the difference that the currents discharging through the gap d d are used to induce currents in the secondary S of a transformer T.
The employment of an intense magnetic field is of advantage principally when the induction coil ortransformer which charges the condenser is operated by currents of very low frequency.
