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Show ELECTRICAL EXPERTS TELL OWNERS AND CHAUFFEURS HOW GENERATOR OUTPUT IS REGULATED IN AUTOMOBILE 1 , . . THE output of n generator In watts Is equal to the product of tbe current cur-rent in amperes the generator is delivering de-livering and the pressure In ToltS between be-tween the termlnnls of tho machine. Flther the current or pressnrc may vary in value, the other remaining practically constant, or both mav vary In value. In the majority of cases, however, an attempt is made to maintain main-tain either the pressure, frequently called the voltage, or the current practically prac-tically constant in vnlne, thus giving two main types of pystems, known as the constant vol tape ind constant current cur-rent systems, respectively. There are four different methods of regulating the output of a generator, and they may he classified as follows: tat Inherent Regulation. This type of regulation is that obtained as a result re-sult of the characteristics of the generator gener-ator without the use of any moving parts In this class are included cumulative cumu-lative and differential series field windings wind-ings and a type of generator having one or more brushes in addition to those required In dllverlng a current in the battery and known as a third brush machine The field current for the shunt winding Is taken from the third brush and one of the main brushes. mrptic of Klrctro-Mncncta. (bi Electro-magnetic Regulation This type of regulation is produced by the action of electro-run gneK which may act to Inerea6e the resistance ofj the shunt field circuit or to open the field circuit or to change the connections connec-tions of the field winding. (c) Mechanical R e g u 1 a tJon This type of regulation Is produced by the actlun of centrlfugally operated governors, gover-nors, which may act to prevent the speed of the generator Increasing above a certain definite value or to insert a resistance In series with the field winding wind-ing or in series with the generator and the battery. yd) Regulation by Ampere-Flour Meter. This type of regulation is produced pro-duced by means of an ampere-hour meter, which changes the resistance of the field circuit, depending upon the number of ampere hours that may pass Into or out of the storage battery. All the above types of regulation are found in many different applications and in combination with each other, giving rise to numerous distinctive types as used by the different manufacturers manu-facturers of motor car generators. . f umolntlve Action of Windlass. When the magnetizing action of the current in the series and shunt field windings of a generator are both in the same direction tbe action is snld to be cumulative, and the generator is railed a cumulative compound wound machine ma-chine A compouud wound machine of this kind is used In combination with a constant speed machine. A good example exam-ple of such a combination Is found In some of the older types of equipment manufactured by Gray & Davis, in which the generators were driven at a constant speed by means of a centrifugal centrifu-gal clutch. A diagrammatic scheme of connec- ! 3BUNT SERIES SHUNT SILKIES 1 ( -r ' 7 r f? 9Ff? t I -g-.! 553 'tFt? Bp ,. n SWITCH LAMPS . .. mrrzt-r 1 battery '"w' ' '- 1 I I ... J ' ' " ' Fia. 1 -Regulation pro- Fig 2 Regulation produced pro-duced by cumulative action of duced by differential action of series and shunt fields. The series and shunt fields The series field carries only the cwr- series field carries the total cur-J cur-J rent supplied to the lamps rent supplied by the generator SHUNT SERIES - M. . ffiffMr , Courtesy of Motor A$re f Ml 1 1 p -. ,: . ff BATTERY ,; . A J J jjfejl v y J 1 : ' i Fig. 3 Regulation produced by bucking-coil. A coil whose resistance changes with .temperature is connected in parallel with the series field, which acts differentially with respect to the shunt field. Here the shunt is shown connected directly across the brushes for simplicity, but i)i practice the terminal shown here connected to the upper brush is connected to the battery line between be-tween the battery and the juncture of ,thc series field and ballast coil. This gives a more even pressure tfons for this type of regulation Is shown in Fig. 1. When there are no lamps lighted tho shunt winding Is acting act-ing aloue and sufficient pressure Is generated gen-erated lu the armature winding to over- Icome the pressure of the battery andl produce a ehurginjr current When the' lamps are turned n the current through i i them passes through the series field and increases the magnetic field in i Which the armature Is rotating thus In creasing the electrical pressure generated. gener-ated. By a proper adjustment of the turns in the series field In relation ti the current taken by the lumps it is possible to Cause the generator to p.irry the lamp load and to continue to charge the battery at the same rate it was charging the battery before the lamps were t Dined on. Differential Action of Winding. When the magnetizing action of tho current in the series and shunt field windings of n generator are in opposite directions the action Is said to be differential, dif-ferential, and the generator Is called a differential compound wound machine! A good example of Inherent regulation in which the shunt and series fields produce opposing magnetizing effects Isi found In one type of equipment mado by the Auto-Lite Company. A diagram-matlc diagram-matlc scheme of connections for this type of regulation is shown in rig. 2. The action, in brief. Is as follows; The voltage of the machine is built up wltli an increase In speed and shunt field current until the cutout connects tho generator to the. battery. After thin connection Is mado a current will be established In the series field winding in such a direction that Its magnetizing action is opposite to that produced by the shunt field, and hence the magnetic Meld is weakened. With a further Increase In speed thero will be an increase in generated pressure pres-sure In the armature of the generator, which will cause nn Increase In tho value of the current produced in the series winding and battery and also an Increase in the current In the shunt field winding. Blnce the magnetising action of the series field Is opposed to the magnetizing action of the shunt field the Increase In generated pressure due to an Increase in speed will not bo as great when both fields are acting as when the shunt field Is acting alone. In this case all the current supplied bv tho dynamo passes through the series field winding. Diirklne Serlra Kleld Winding. The bucking series field winding Is really a differential or reserved series field winding, the only difference being that the series field winding does not carry all or necessarily a definite part of the current delivered by the generator. gener-ator. The operation of the bncklug coll may be explained by reference to Fig. 3, which Is exactly the same as Fig. 2 With a coll of iron wire, W, connected in parallel with the series field winding. wind-ing. The resistance of lrou wire increases in-creases with an iucrease In temperature and this increase Is very rapid after a certain temperature has been reachetL Now, when the current delivered by the generator is small, practically alt the current passes through the coll W, as Its resistance is much less than tho resistance of the series field winding. As the current delivered by tbe generator gener-ator increases the temperature of the Iron wire will Increase Hence, thero Is an increase in the resistance It offers, of-fers, and, as a result, a larger part of the total current delivered by the generator gen-erator will pitss through the series field winding. This increase In current in the series field prevents as large an increase in-crease in generated voltage as would occur if no series field were used. When the current supplied by the generator is redu cd the temperature of the Iron wire Is lowered and the division divi-sion of the total current between the series field and coll W is restored to its previous value. This system of regu-. regu-. latlon Is used on some of the equipment . ;of the Bosch Magneto Company; also .'on the equipment of the Uushmoro i Dynamo Works, which Is now a part i of the Bosch Magnetic Company. no trouble encountered with the car, and. arriving at its destination, it as washed and sent to the machine shop for Inspection, and the citizen Inspector Inspec-tor made the report that the car was mechanically perfect and a sale was mado on the spot. The success with which this Sax. OD "Six" survived this gruelling test has led the I'nited States government 1 to place eight six-cylinder Saxons on trial in the last week, and every one of them is making good. The Rovern-ment Rovern-ment demands an extended trial ot every car before making its purchase. They opera! o on the theory that no car Is worth having whose manufac turer is not willing to back its quali-' ties against the toughest conditions' Which can be imposed on It. The progress which motor car manufacturers manu-facturers are making In placing cars with the army should be of Interest to every motorist. The qualities which can survive the army test ire qualities which will carry the average motorist "there and back" with abso, lute surety and safety. Josephus Daniels couldn't resist the luxury and refinement of a Sttde-baker Sttde-baker limousine, and "Undo Joe" Cannon, Can-non, ex-speaker of the house of representatives, repre-sentatives, at once concluded he wanted want-ed a Studebaker. Chicago Studebaker distributors said that December 4 at A their salesrooms gave every evidence ---w of a pre-arranged gathering of Chicago's Chi-cago's most prominent people. They reported 52 sales, among them A. H. Wheeler, president of the Chicago Automatic Telephone company,, J. B. Forgan, president of the First National Nation-al bank, and George K. Schmidt, Cook county assessor. Norman E. Mack, former chairman of the national Democratic committee, commit-tee, Senator Smoot of Salt Lake City, Victor L. Berger, first Socialist representative repre-sentative elected to congress; Senator Lafe Young and other men high up in political and public affairs examined the new Series 18 Studebakers Monday, Mon-day, December 4, and by placing their orders helped to make Prominent Buyers' day the greatest day in automobile auto-mobile history. oo |