None
Weight (in kilogrammes) = D^ TT I yd- O 7-5 4,000 = o-oo6 D* / y (i - T^) about . . . (133) In this formula we designate by y the reduction of the section due to interposed paper, as well as slots, etc. y = 0*85 to o"9 for smooth armatures. y = o'75 to o 85 for toothed armatures. External diameter of armature T = Internal diameter of the same Weight of Copper, From equation (33), we have (see p. 75). w Weight in kilogrammes = 0*45 -^, DYNAMOS. 393 w being the loss of ^atts due to the resistance of the copper^r c — amperes per square millimetre. Weight of Pulleys, The following empirical formula is established by means of data relative to a great number of pulleys, varying in diameter from o'l m. to 3 m., with an internal diameter attaining as a maximum to 23 cm. Weight in kilogrammes = c l D^ L representing the length of the pulley in centimetres ; D ,, diameter „ ,, Table of \ '^AI.UES FOR C. D, in centimetres. c D, in centimetres. c 10 25 50 0*00130 0*00100 0*00095 0*00085 70 100 1 150 225 0*00080 0*00076 0*00073 0*00070 The above formula leads to sufficiently concordant results ;: the greatest discrepancy between the observed and the calcu- lated values will not generally amount to more than ±15 per cent. For example, a pulley of 100 cm. diameter and a length of 50 cm. weighs 0*00076 x 56 x loo^ = 380 kgrm. Weight of Yoke. The weight of the yoke, properly so called, taken apart fron^ the base-plate and journals, can be determined with a certain amount of accuracy, when the length, L, of the lines of force and the section, S, are known, from the formula Weight in kilogrammes = I -Lirt ^m "*" -L* m  field magnets are made of cast steely we may replace the coefficient 7*2 by 7*8 or 7*9. B. Dimensions. The following tables do not refer to special machines, but may rather be considered as giving the mean values deter- mined from a great number of dynamos. They may therefore be of service in designing dynamos. W« = specific output in kilowatts. CONTINUOUS CURRENT VKSTicAt. HORSBSHOE Type. Fic . 272- w. , 4 8 .. 20 30 SO 75 100 1 150 „ 7tO 270 330 400 440 490 <40 62 i; 710 785 910 l8o -Ifio 600 650 710 7S( iSgo PMS .,060 1,160 lio 180 440 S20 S70 740 960 ..oso t.130 VO 4ZO 500 590 750 X '•yxj 340 400 470 520 790 960 1.050 X 720 8,0 1060 1,190 ■« 1,790 2,000 340 400 470 530 ^ 790 1,050 W, t 2 4 8 :2 20 30 50 75 . 100 150 a |23o 290 340 410 470 550 620 700 735 i 7SO 780 290 iSo 340 225 2S0 470 310 550 380 620 430 ( (700)' / 720 (735) )' ~ (J5^) )i «^° 910 f lis; 600 6S0 250 770 820 350 950 410 ■•:s ''sss ..3to .,485 650 730 1,670 850 / jS5o A i 150 720 iSo 870 225 1,060 2S0 1,180 320 I-340 380 1,480 430 \ (1.690 500 550 580 6jo Oveihanging ]iuUL-y. BlTOI^R Verticai. TVI'B. w. 0-4 07 , I'S 3 5 8 " '5 18 i 4 360 176 395 290 420 310 445 335 230 475 535 445 310 576 510 36S 640 585 415 690 635 450 720 680 475 745 245 275 290 320 380 430 495 550 575 600 f / = f 4- a mall quantity. W. .0 1 20 30 50 75 .00 130 160 200 ^ 460 470 490 530 s8o 610 700 730 790 ai 575 600 620 725 860 930 970 400 h 48s 650 675 i d • S,o 86S 900 975 .,obS 1,150 1,340 550 595 650 790 970 t 1,070 1,120 1,225 1.350 i,5'° '.540 ! 1,590 39^ CONTINUOUS CURRENT AMOS (Tvres WITH Si>f, Eight, or mohr Poles). w. 300 500 7SO „^!„» 1,000 2700 ^ 8jo S60 900 970 1000 1,040 1,100 .,030 1.090 i.iiS 1,170 1.270 1,330 SJO 665 710 750 790 740 S4S goo (,000 1,050 1,000 1,500 1,850 2,150 3,100 3,400 3,600 3,200 / 1,700 .,890 I,IJO 3.300 2.580 a,770 2,960 i.HO 1,700 2,140 2,400 .,«„ C- Calculation of Cost of Construction. The following figures must naturally be considered as subject to variation between wide limits, according to the situation of the workshops and the prices of labour and of materials. In regard to the expenditure on salaries and wages, it is assumed that several machines are at all times simul- taneously in course of construction. When the cost of con- struction of a single machine, made by itself, is required, we must multiply the prices given by a suitable factor, greater than i. Moreover, the cost of patterns for the cast- iron parts has not been included in the grand total. The cost 0/ construction comprises : 1. The cost of raw materials, to which must be added rent, waste, and cost of carriage. 2. Wages for manual labour. DYNAMOS. 397 3. General expenses, expressed generally as a percentage of the wages for manual labour. The relative weights of different substances used in the •construction of a dynamo are roughly as follows : Cast iron or cast steel Wrought iron Wrought-iron discs .. Ounmetal Copper 70 to 80 per cent, of total weight. 3 to 5 8 to 12 2 to 5 8 to II 99 >> >f 99 99 99 99 The cost of materials is considered in the following table iP' 398)- The third column refers to the weight lost in machining the various parts, and might be considered worth- less, copper wires not excepted. The length of these latter should always be taken 2 or 3 per cent, in excess of that actually required, whilst the waste cannot generally be used for other purposes. We should add about 15 to 20 per cent, to the above values for rent, breakages, and ordinary waste. The total cost of manual labour (in Switzerland) could be estimated in the following manner, assuming average wages : Kilogrammes Cost, in pence, per kilogramme... 250 4i 500 4 1,000 3i 2,000 4,000 I* 6,000 lO,(M)() It would be useless to give details of these prices, since the cost of certain different operations may vary more than the ' total price given. It would, however, be interesting to know the price of winding, which attains to from 20 to 30 per cent, of the total price of the dynamo. The general expenses will depend entirely on the organisation of the workshop, and the importance of the annual establish- ment charges. The more perfect the plant is, the more important will become the establishment charges ; on the other hand, the cost for manual labour will diminish. Whilst it used to suffice, in certain cases, to add 100 per cent, to the cost of manual labour, in modern workshops from 150 to 180 per cent. 39« CONTINUOUS CURRENT AlM'ROXIMATE CoST PrICB OK RaW MaTKRIAI.S USKD IN DYNAMO Construction. Materials. 1. Iron. Grey cast iron Steel castings Bar iron Steel for shafts Sheet iron for armatures Iron ribbon for disc arma- tures 2. Gi'NMKTAi. Castings ... J. Zinc, in plates 4. Goiter. Drawn wires and bars ... Stranded copper Sheet copper Commutator segments ... Steel binding wires 5. Mica, in crystals i^in. by Sin In larger crystals Sheet micanite 6. Ehonite Shaped pieces Tulxjs, unpolished 7. Amianthus In sheets In l)obbins Vulcasljeston, in sheets \ ,, tubes / 8. Fibre, in sheets 9. Paper. For insulation of arma- ture discs Presspahn Bobbms shaped from / IVesspahn \ Specific Gravity. Loss in Machinery - 1 Approximate Cost Price. 7 2 7 8 to 7 9 7 6 to 7 8 8 3 to 8-8 70 8 8 to 9-0 It If 2-8 II 13 2*1 to 2'8 )i •I »> II 1-28 Per cent. 5107 6 to 8 6 6 15 5 10 10 2 to 3 2 to 3 9s 6d. to 13s. 6d. jjer cwt. Up to 2 cwt. 20s. to 28s. per I cwt. Over 2 cwt., i8s. 6d, to 22s. per cwt. 7s to 9s i^er cwt. ,i2s 6d. to i6s. 6d per cwt. los. 6d. to 13s. 6i\, per cwt. |Alx>ui £1 i^er ton. ,8id to lo^d. per lb. |7id per lb. 17 id to 9id. per lb. [8 or 10 ])er cent more than: I solid copper wires or bars- of the same section. '£(>6 per ton. iio^d to IS. 2d. per lb. 9<1. to is. per lb. 10 to 20 ^* 6d. to 4s. 6d. per Ibi 10 to 20 i4.«T. 6<1. to 25s. per lb* — '3«. 9d. l<» 6s. j^ lb. 6». 3^1. per lb. 4s. 2(1 to 6s. 3d. per lb. ]5s lod. per lb. -I - ■' ' J Aliwut 3s. 4d. i^r lb. These- prices vary with the quality of ebonite: used. }Sk 4(1. to 4s. 2(1 per lb. 2s. 3d. per lb. I \2i\, to 3id i>er lb. ,6<i. to 7id. i>er lb. 1 3s 5(1. to 5s. For the former^ / 4s. 2d. to 8s. 4d. DYNAMOS. 399^ CHAPTER XI. Recapitulation of FoRMULiE to be used ik the Desigk OF Dynamos. The difficulty in designing a machine does not greatly depend on the calculations properly so called, but more ia determining in what manner the existing formulae should be applied. Before commencing, it is necessary, though difficult, to choose from the mass of formulae at our disposal those which will lead most quickly to the desired end. To facilitate this choice, we will give in this chapter a rapid recapitulation of the most important of the formulae deter- mined in the preceding pages in the order in which they will be needed. We are generally given — The output, depending on E and C ; The speed, n ; The commercial efficiency, f. Moreover, a series or shunt winding is generally prescribed. The remaining data for the construction of the machine- must be determined. When a generator is being designed, we can, if the number of poles is not already prescribed, make use of the following rule : Four-pole dynamos should be constructed when the specific output (as previously defined) is greater than 6 kw. to 20 kw. Six-pole dynamos should be constructed when the specific output is greater than 100 kw, to 150 kw. Eight-pole'dynamos should be constructed when the specific output is greater than 200 kw. to 300 kw. The loss calculated on the base of the prescribed com- mercial efficiency should be distributed into the separate constituents, Wa, Wk, Wr, Wm, etC. I I I 400 CONTINUOUS CURRENT Wm should not be smaller than a certain value, since, in the contrary case, the dynamo would be too sensitive to variations in the current strength and speed. The calculations may be divided into A. Those relating to the armature. B. „ „ field magnets. For the choice of the type of dynamo to be used we may consult Plate II. The numbers in parentheses refer in every instance to the .equations in this book. A. Armatures. D = diameter in centimetres. / = length „ ^ D' I. First Approximation to Exterior Dimensions. D - 39^^^ . j = 11-5 y^^.l. (50) and (52) for ring windings. D = 32y?X]-IOyEC7r . (5i)and(5i) ^ n ^ ^ n A for drum windings (see pp. 69 and 70). The formulae for drum-wound armatures apply to gene- rators and give very good results for machines whose outputs are between 15 kw. and 400 kw. ; for smaller machines a value of O slightly greater than that obtained by the formula must be taken ; for more powerful machines a lower value must be used. In the case of motors, we must take E C = 746 h.p. We may equally well consult the table of values obtained from machines actually made (pp. 78 and 79). Verification. — The peripheral speed of the armature should not exceed 25 m. to 30 m. Dimensions of Wire. Approximate section of wire = C S = ic»/-v- square millimetres. . . (56) Pi . loO € DYNAMOS. 401 cE - resistance loss (0*02 E to o*o6 E). Thickness of insulation (pp. 65 to 68). Referring to Fig. 47, and supposing that N' is the number of turns for a length of Ui, the total number of wires will be N = ^ N' ; and we must have N < 6-37 ?^i^. B/ being the density of lines of force in the air-gap. S = the air-gap in centimetres, and for jS (see Fig. 126). In a similar manner the pole-pieces may also be designed. We obtain B/ from equation (10) : B « E'6o X 10^ ^ I. ' ' «N^ bl ' in which b is the arc of a pole-piece, in centimetres = /3. E' « the E.M.F. = (i + e) E. € = the drop in voltage « 2 e to 3 e (about), when account is taken of the armature reactions. 2. Second Approximation. n = / E- P^ u, 12 X io« ^ ^ ^ ( ) (See p. 72.) Verification. — Determination of L, the exact length of the winding : Diameter of wire S = pno F n ^ ^^' "^'"' " ^^9^ We must determine whether this winding could be executed. Rules for executing a winding (pp. 20 to 35). Comparison of drum with ring windings (pp. 35 to 38). As the maximum number of commutator sections is equal N to Nj = — for drum windings, and to N in the case of ring windings, we mtnt assure ourselves, particularly in the case 26 402 CONTINUOUS CURRENT of a high-voltage dynamo, that the maximum pressure between two commutator sections Co = _ E 2/) N. is not greater than 30 or 40 volts. Eventually, we may modify the winding or the number of poles. The saturation in the slots of the armature should not exceed 16,000 to 17,000. 3. Determination of the Interior Diameter of the Armature. (See pp. 75 to 77.) ^, E60xlO«p , n N p (io> i> j> We have approximately Ba = 14,000 to 16,000 in the case of two-pole dynamos. = 12,000 to 14,000 „ four = 9,000 to 12,000 „ six On the other hand, dynamos actually made give approxi- mately the following values for r^ = — : Number of Poles. 2 4 6 8 10 12 14 o'3 to o*4 o*6 to 0*65 0*65 to 0*70 070 to o'8o 078 to 0-83 o-8o to 0*85 o'9 Calculation for Verification. Loss of watts due to hysteresis Wh = n B^^-^ft) V 10""^ . , _, p n (34> O) 60 V =» volume of iron in cubic centimetres. DYNAMOS. 403 In making a more exact calculation, we may determine also the hysteresis losses in the slots, and subtract that from the loss in the following calculation : Suppose that Dj = the interior diameter ; D = diameter of circle passing through crests of teeth ; D' =» the diameter of the circle passing through the bottom of the slots (D' = D in thfe case of smooth armatures) ; then We may find most rapidly by the aid of Table VIII. (p. 414) (1 - t) '-' ^ 2^ ^0_^ 1 a> ^. Table VIII. gives the value of t for any value of A. We have approximately r = i - A. 4. Calculation of the Heating. Rise in temperature, in degrees Centigrade — 225 X (Wa + Wh ) Surface (in sq. cms.) According to another formula, we have — Rise in temperature, in degrees Centigrade 645 (Wa + Wh ) (58) r^> Surface (1 + 0"3 >/v) V representing the peripheral speed, in metres. 5. Dimensions of the Commutator. These dimensions should be as small as possible. For metallic brushes we have — Surface for rubbing contact (in square millimetres per ampere) = 5 + about 200 ^ ^ ^. Amperes per line of brushes In the case of carbon brushes we will take as a minimum 13 to 15 square millimetres per ampere. 26* 404 continuous current 6. Determination of Lead of Brushes. r T D ^ B/ Pi 7 « ( ) In'this formula, we designate by y (see Fig. 126), the arc of contact of a brush, in centimetres. Dj, the diameter of the commutator, in centimetres. tCy a coefficient which is equal to 2'3 in toothed armatures ; 3 in armatures with half-closed slots ; 4 to 5 in tunnelled armatures ; o*4 in smooth armatures ; ^, the number of wires per slot ; in the case of smooth armatures, 9 = ^• In generators we must take (i + e), in motors (i - O. The corresponding value of 17 will be given in Table XL, and we may hence calculate the lead of the brushes a = .y M2 + (c + ^)' - M . . . (106) (for c, <S, and f, see Fig. 126). In this equation M=yi^ (X07) For well-made dynamos we shall have — <o*6; if the c quotient is greater than 07, the dynamo may be useless, or at best will work very badly. In the case of motors the angle of lead is smaller than that calculated from the above formula; the same thing applies to machines with carbon brushes. 7. Diameter of Shaft. Let us denote by i, the diameter of the smallest section in centimetres (this will be found between the commutator and the armature) ; n, the speed ; W, the commercial output in kilowatts ; H.P., the commercial output in horse-power. DYNAMOS. 405 Shaft in Forged Iron. d = 18 Shaft in Steel. (115) This formula gives, for dynamos of less than 100 h.p., a diameter slightly too large, and for dynamos below 15 h.p. a diameter too small. Compare with table referring to shafts actually made. Table for keys, XL, p. 416. B. Field Magnets. It is now assumed that the armature has been designed in such a manner as to satisfy the conditions imposed at the outset, and that we have satisfied ourselves, by means of a brief and approximate calculation, that the dimensions of the dynamo are well proportioned. It may be remarked, in passing, that this calculation to verify the dimensions chosen? should never be omitted. It now remains to determine the dimensions and winding of the field magnets. We will roughly design the field magnets, reserving an approximate space for the winding. As, in general, dynamos require from two to four times (or on an average 2\ times) as many ampere-turns as are required in the armature, we will suppose, as a first approximation, C^ N^ for the magnetic circuit = 2*5, where represents the ampere-turns round the armature. The approximate space for winding will then be given (see p. 321) : _ (Ampere-turns per bobbin)^ /totX - c — ^— L . . 1131; L being the mean length of the winding, in metres ; w, the loss in watts per bobbin. We must substitute for c a value obtained from the following: table : Diameter of wire, d, in mm. o'S I 2 3 4 5 and over^ Rectangular winding c = Conical winding c — 5 375 2*9 2*2 2*15 1-6 1-86 1-4 1-68 I 26 I 18 4o6 CONTINUOUS CURRENT When, in this manner, we have determined approximately the probable length of the lines of force, we can proceed to make a more exact calculation of C^ N^. making use of the method employed in obtaining equation (76), p. 154. Part of Magnetic Circuit. Pole-pieces Yoke Armature. Air-gap .... Section S in sq. cm. Leakage Coefficient p or K. Density of Lines of Force, B, per sq. cm. Length of Lines of Force, L, in cm. Ampere - turns per cm. Length, /(B). Total Ampere- turns, Cm Nuk Total... For V, see Table X. (p. 415) ; for «c, p. 161 ; for/{B), Plate L This table suggests the following observations : 1. In the case of series- wound dynamos we may deter- mine from the E.M.F. — that is to say, from the brush voltage + the drop in voltage ( - in the case of motors) ; it is the same for shunt-wound dynamos. 2. In the case of compound-wound dynamos we must make two calculations ; we take the flux 0, calculated from the brush voltage, for the base of the first (this gives the shunt winding), and for base of the second we take <l> calculated from the E.M.F. The difference of the two values will give the ampere-turns of the compound winding (see p. 197). Section of wire S = - — ^-^^4.-- ^- square millimetres, Nj being the number of coils mounted in series, C,h Nm the ampere-turns of one coil, and E the pressure at the extremities of the field-magnet windings. In series or compound wound dynamos E is equal to the total drop in voltage (e E) ; in a shunt-wound machine it is equal to the brush voltage. To effect the necessary regulation, the wire should be rather thicker in a shunt-wound machine. DYNAMOS. 407 Number of Turns per Bobbin. N_ Cm Nm Cm Nm /z: ,\ m — — ^p = ^ — .... (04) Verification. — We should assure ourselves that the windings can be performed in the space provided, and when needed, the calculations must be repeated. Heating of Field Magnets. Rise in temperature, in degrees Centigrade, ^ 33 5 X Loss in watts per bobbi n Surface of a bobbin in sq. cm. When the dynamo has been calculated out in the manner indicated, it is necessary to make a summary of the figures, so as to be able to judge at a glance of their relative fitness as well as to make it possible for a second person to verify them at any time. The following practical hints may not be useless in this connection : If the dynamo is definitely determined, the given electrical conditions, and those which are indispensable in the construc- tion, should be written on a detached leaf — similar to that given at the end of this book; they should afterwards be preserved and classified. The back should be reserved for experimental results. It is of course unnecessary to repeat results obtained with machines identical in construction. On the other hand, when any variation is effected, whether in the dimensions or the winding, or even in castings, the weights can equally well be suppressed when the new machine is of a known type. As far as concerns the trials, the following should be noted : 1. The characteristic curve, when the machine is working on open circuit, taken in connection with the excitation and the voltage. 2. A certain number of voltage curves obtained with a constant exciting current, and a variable strength of the armature current. 3. A measurement of the armature and field - magnet resistances. I 408 CONTINUOUS CURRENT 4. The insulation between the windings and the base-plate^ 5. The increase in temperature of the machine after several hours' working; whenever this is possible, the increase in temperature should be calculated from the resistance of the windings. 6. Observations concerning the formation of sparks and the displacement of the brushes should be noted. DYNAMOS. 409 CHAPTER XII. Tables. I. — Table of Specific Resistances.* po = speoifio reeiatanoe at 0° C. ff = tamperatare ooeffioient per 1° C. Substancei. Alaminium Aluminium bronze Antimony Biomuth.. BraflB Carbon Carbon (retort) Constantan (Basse and Selve, Altona) Copper Grerman silver Iron Kruppine (F. Krupp, Bssen) Magnesium Mercury Nickel Nickeline (Fleitmann, Witte&Co., Soiiwerta Phosphor bronze Platinum Silver Steel Tin Zinc Po 0-03 to 0-06 0-12 0-6 1-2 007 to 0*08 100 to 1.000 40 to 120 05 0161 to 0-018 015 to 0-36 0-1 to 0-12 0-85 0-22 04 0-96 016 0-44 10 0-12 to 0-16 0016 to 0-018 0-10 to 0-26 010 06 a. 0-0039 0-001 0-0041 0-0037 00016 0-0003 to 0-0008 40 to 120 0-00003 0037 to 00039 0-0003 to 0-0004 0-0045 0-0008 00041 0039 0-00091 0-0067 0-0002 to 0-00008 0-0024 to 00036 00034 to 0-004 00052 0-0042 0-0042 Observations. 58 Cn, 41 Ni, 1 Mn. Lazare, Weilleri and Co., Paris. 56 Ou, 26 Ni, 19-6 Zn. R = P (15). p = Po{l+fft) (16). * Taken from " Halfsbuoh^fiir Elektrotechnik " by Grawinkel and Strecker, fourth edition, Berlin, 1896. 4X0 CONTINUOUS CURRENT IL— WiBE Table. Diameter. SeotioD. Weight of 1 km. ResistaDce of 100 m. Diameter. Section. VVeiKht of 1 km. Resistance of 100 m. nun. mm*''. kgrm. ohms. mm. mm^. kffrm. ohms. 0-1 0-008 069 212-892 3-60 10-18 905 0-16450 0-2 0031 0-279 53 298 3-70 10-75 95-6 0-16604 0-3 071 0-6-29 23-688 3-80 11-34 100-8 0-14758 0-4 0126 1-118 13-348 3-90 11-95 106-2 014006 .0-6 0-196 1-745 7-545 4-00 12-57 111-8 0-13348 •0-6 0-283 2-52 5-922 4-10 13-20 117-8 0-12690 7 0-385 3-41 4 352 4-20 13*85 123 4 0-12032 0-8 0-503 4-47 3-328 4-30 14-52 129-2 0-11468 0-9 0636 5-67 2-632 4-40 15-20 135-6 10998 100 0-785 6-98 2-128 4-50 15-90 141-3 0-10628 1-06 860 7-69 1-922 4-60 16-62 148 1 010068 110 0-950 8-42 1-765 4-70 17-35 154-1 009682 1-16 1-041 9-20 1-607 4-80 18-10 1610 0-09212 1-20 1131 10 02 1-48 4-90 18-86 168-0 0-08836 1-26 1-2-29 10-88 1-36 5-0 19 64 174-6 0-07545 1-30 1-327 11 79 1-28 5-5 23 76 212 0-07060 1-35 1-431 12-70 1166 6 28-27 252 005922 140 1-639 13 64 1-081 6-5 33 18 294 0-05038 1-46 1-631 14-62 1017 7 38 14 341 004362 1-50 1-767 15-67 0-949 7-5 44-18 392 0-03788 1-55 1-887 16-80 0-884 8-0 50-27 447 0-03328 1-60 2-001 17-90 0-8272 8-5 56-74 505 0-0-2962 1-65 2-138 19 05 0-7802 9 63-62 567 0-02632 1-70 2 270 20-20 0-7332 9-5 70 88 629 002359 1-75 :^-405 21-43 0-6956 10-0 78-55 698 0-02124 1-80 2 544 22^65 0-6580 10-4 85 766 0-0196 1-85 2-688 23-86 0-6204 10-7 90 801 0186 1 90 2-835 25-24 0-5922 110 95 845-5 00175 1-96 2 982 26-85 0-5612 11-3 100 890 0-0166 2-00 3-142 27-90 0-53298 118 110 979 00152 210 3-464 30-80 0-4794 12-35 120 1,068 0-0139 2-20 3-976 33-90 0-4418 12-87 130 1,137 0-0128 2-30 4-155 36-90 0-4042 13-35 140 1.246 0-0119 2 40 4-524 40-30 0-3666 13-81 150 1335 00111 2 50 4-909 43-60 0-34028 14-27 160 1,424 0-0104 2-60 5-309 47-30 0-3196 14-7 170 1,613 0-0098 2-70 5-726 51-00 0-2914 15 15 180 1,602 00927 2-80 6-158 54-80 0-2726 15-5 190 1 691 0-0088 2-90 6-605 68-9 0-2538 15-95 200 1,780 0-00836 3 00 7-069 62 9 0-2.3688 167 220 1958 00760 3 10 7 548 67*1 0-22090 17-5 240 2.136 00696 320 8-043 71-6 0-20774 18-2 260 2.314 00641 3-30 8-553 761 019552 18-9 280 2.492 000596 3-40 9-08 80 8 0-184-24 19-5 300 2,670 0-(K)566 3-50 9-62 85-8 0-17390 DYNAMOS. 411 III. — Table of Cables (Lazabe, Weilleb, and Co.). T^ambfir Diameter of each Wire. mm. Diameter of Cable. mm. Solid W ire Eq ui valen t Weight ofi Kilometre. kgrm. Reeiatanoe of a of Wires. Diameter, mm. Sectional Area, mm'. Kilometre at 15-6*' C. ohmB. 3 3 3 0-608 609 0711 107 129 1-60 0-86 1-06 1-24 0-685  1-42 163 1-83 2-03 1-54 1-83 213 2-28 2-51 2 74 3-04 3 66 4 27 4-88 5-49 610 1*36 1-62 1-90 2-03 2-23 2 43 2-71 3 25 3 78 4-34 4-87 5-41 1-423 2-075 2 849 3242 3-923 4-65 5-77 8-30 11-28 14-73 18-66 22*98 13 19 25 29 35 42 52 74 100 132 166 205 12-43 8-63 6-337 5-525 4-561 3 835  234 2*64 4-67 5 08 6 10 7-10 8-12 914 10-1 116 13-2 4 03 4-47 5-35 6-27 716 8 05 8-94 10-7 116 12-74 15 72 22-66 30-91 40-25 50-96 62-77 83-20 106 30 113 140 201 274 .358 453 559 740 945 1-404 1  2 16-3 18-4 10 11-2 125 14-3 16-2 78-6 996 122 7 162-7 207-7 699 885 1,093 1.445 1,847 0-2274 0-1797 0-1456 OllOl 00861 61 61 2.S4 264 21-0 237 18-5 20-9 268-7 343-4 2,389 3,052 0*0666 0-0521 412 CONTINUOUS CURRENT IV. — Hysteresis Coefficients (17). (After Mr. Ch. P. Stkinmetz (see p. 49.) Metal. V Soft iroD wire (E wing) Thin sheet iron (1) Thick sheet iron \^) ti ti ••• Cast steel (annealed) A 001 BCUUA %•• ■•• .». ••• ••• ••• •». Cast Steel of minimam sasceptibility vnBO irOD ... ... ti* ••• ••• ••• ••* ••* Cast Steel (tempered) •• ••• ••• ••• »•• ••• ••• ••• >•! •!• •«• ••• • ••• *•• ••• •• ■.« t.« ••* ■•• ••• ••• ••• •• ••• •• ••« • ••• ••• •■• •■ ••• ••• ••• 0-002 0-003 0-0033 0-0042 to 0-0045 0008 0-0094 00120 0162 0260 V. — Hysteresis Coefficients (1;). (From the Experiments of Dr. Hopkinson.) Metal.  of G, annealed 00262 „ Whitworth „ . 0-09 II If II 000257 >> >i i» . 0-32 It »i II 0*00598 »• f» »i . 0-80 If II II 00786 fi II II . 0-32 II tempered in oil 0-00954 II II If . 0-89 II II 19 001844 Siliceous steel ... . 3-44 If of Si (forf2^ed) ... 0-00937 i» If ••• }» fli annealed ... 0-00784 II II »• ff tempered in oil 0-C1242 Manganese steel... . 4-78 It of Mn (forged) ... 0-05963 II fi ••• »i ff ,, annecded ... 004146 I' ff ••• . 8-74 ff »i f» 0-08184 If II ••• 4-73 If tempered in oil 0-06706 Chrome steel 0-62 f f of (forged) ... 001179 If II '•« 1-2 ft 91 ... 0*01851 II If ••• 0-62 f 1 annealed... 0-00897 Grey cast iron ... 3-47 of (7, 0*17 per cent. Ju n ... ... ... 0-01826 White cast iron ... • • « • • ■ 2-04 ff of C, 0-39 per cent. jun 0-91(U& DYNAMOS. 413 VI. — Table of Values op 17. B^**. (See p. 49.) Hystereaie low = 17 . B»« « V 10 ^ Value of 17 B^ < »for B Value of 17 B»-« for B V = 0-002 17 = 0-003 77 = 0004 17 = 0-002 17 = 0-003 17 = 0004 500 416 62-4 83-2 10,500 5 432 8,148 10,864 1,000 126 2 189 3 252-4 11,000 5.850 8.775 11700 1.500 2412 361-8 482-4 11,500 6,282 9,423 1-2.564 2.000 382-6 573 9 765-2 12.000 6,726 10,089 13,452 2,500 546-4 819-6 1,092-8 12,500 7 178 10,767 14.356 3,000 731-8 1,097-7 1.4636 13,000 7.642 11,463 15,284 ^,500 936-8 1,405-2 1,873-6 13.5i0 8.120 12,180 16,240 4.000 1,160 1,740 2,320 14,000 8,606 12 909 17,212 4,500 1,400 2,100 2.800 14.500 9,160 13,740 18«320 5,000 1.657 2 486 3,314 15 000 9614 14,421 19,228 ^,500 1,932 2.899 3,864 15,500 10.124 15,186 -20,248 «.000 2,222 3.333 4,444 16,000 10 658 15,987 21,316 6,500 2 522 3,783 5,044 16,500 11,196 16,794 22.392 7,000 2,840 4.260 5,680 17.000 11,740 17,610 23.480 7,500 3,166 4.749 6,332 17,500 12,296 18,444 24 592 8,000 3.516 5.274 7,032 18,000 12,868 19,302 25.736 8,500 3,872 5,808 7,744 18,500 13 444 20.166 26,888 9,000 4,244 6,366 8,488 19,000 14,034 21,061 28,068 9,500 4,626 6,939 9,252 19.500 14,624 21.936 29,248 10,000 5,022 7.533 10,044 20,000 15,226 22,839 30,452 VII.— Table of Values of X^-«. (See p. 76.) X X9.6 X x«-« 01 251 0'6 0-736 0-2 0-381 0-7 0-807 0-3 0-486 0-8 0-876 0-4 0-577 0-9 0-988 0-5 0-559 1-0 IDOO 414 CONTINUOUS CURRENT VIII. — Table of Values satisfying the Equation i— i— = A. 1 + r (See p. 76.) A r A T 1 0-439 0-50 0-085 0-95 0*481 0-45 0132 0-90 0-525 040 0-173 085 0-671 0-35 0-212 0-80 0-620 0-30 248 0-75 0-673 026 0-286 70 0-730 0-20 0-323 0-65 789 0-16 0-360 0-60 0-853 0-10 0-400 0-55 0922 6-06 Hence r = 1 - A (approximately). IX.— Table of Values of x = 4 -65 lojf (l + ^y (Seep. 162.) c 6 in Centimetres. 0-3 0-6 0-9 1-2 1-5 20 f 2-6 0-63 1-01 130 1-54 1-75 2-03 6 076 1-26 1-67 2-02 2 34 2-77 a = 180" - 76 0-84 1-41 1-89 2-31 2-69 3-24 10 0-89 1-62 205 2-52 2-95 358 k 15 0*96 1-67 2-28 2-83 3-32 4-07 f 2-6 0-72 116 1-45 1-70 1-92 222 6 0-87 1-47 1-88 2 '27 260 3-08 a = 150" - 7-6 0-96 1-66 2-14 2-62 3 04 3-62 10 1-03 1-78 2-34 2%7 3-34 4-04 k 16 1-12 1-97 2-60 3-23 3-87 4-62 / 2-5 0-83 1-30 165 1*92 215 2-46 i 5 103 1-67 219 260 2-98 3-60 a = 120" i 7-6 1-14 1-89 2-51 3 03 3-50 4*16 1 10 122 2-06 2-75 3-34 3-87 4*65 v 16 1-46 2-28 3 08 3-79 4-43 5*38 / 2-5 0.99 1-45 1-72 1-86 1*92 2*76 6 1-26 2-02 2-61 3 09 3-50 4*06 o = 90P - 7-5 1-41 2-31 3-03 3-64 417 4-90 10 1-52 2-52 3-34 404 4-67 5*66 \ 15 1-68 2-83 3-78 4-62 5-38 6*6 DYNAMOS. 415 ft 5 M i3 § Pn O H n X S GQ .0 S £ CO 0| 00 US 00 c^ fLru<n- S 1-104 8eooiooioo»oQ»oo ooro^cDtou5'^-^ei5^c) ©»0<NOQOUO©100D10(>«0 • • * SS'^^cSooS^S iCtOQtCQlOQOOtO t** QQ CP IQ IQ ^ ^ CO OOOtOQiQQUdO • ••■••* ••• 8oudO«taoioaoio04 • Q900IQ0IQ0IQ0 t^ScoSflS^^mra^ ^ss^?^$^^^s • ••• • •••»» 01 • • B • * tffHOllO 3 I I i i fHOq 4i6 CONTINUOUS CURRENT XI. —Dimensions of Kkys. (See p. 260.) System of Julee Rdmmele (modified). AppUoable to Hnbe in Cast Iron or in Ganmetal ; in the latter case two keys most be nsed. ^s^2= d ti. Diameter of Shalt. d mm. 16 to 20 21 .. 25 26 31 96 41 46 51 £6 61 66 71 76 61 66 91 96 101 111 121 131 141 151 161 171 181 191 201 221 241 261 281 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 110 120 130 140 150 160 170 180 190 200 220 240 260 280 800 Single Key. mm. 5 5 6 7 7 8 9 10 10 11 12 13 13 14 14 15 16 17 18 19 20 21 22 23 24 25 26 28 30 32 34 36 mm. 7 8 10 11 12 13 15 16 17 18 20 21 22 24 25 26 28 30 32 34 36 38 40 42 44 46 48 52 56 60 64 68 Two Keys. 14 14 15 16 17 18 19 20 21 22 23 24 26 26 a h mm. mm. 4 6 4 6 5 7 5 8 6 10 6 10 7 11 7 12 8 13 8 13 9 15 9 15 10 17 10 17 11 18 12 20 13 21 13 22 24 25 26 28 30 32 34 36 38 40 42 44 46 48 DYNAMOS. 417 XII. — Calci'lation of the Size of Pulleys. (S-e p. 276 ) H.P. b = c H.P. = the number of horde-power traoemitted ; V V = the apeed of the belr, in metres per second. h = the breadth of the belt, in centimetrea. HP. V 0-15 0-25 0-6 24 0-75 1 1' 1 5 3 6 7 10 16-7* 29* .Sof c 48 39 20 15 10 6-5 6 4-9 3 7 * Tramway generator, Westinghouse Company, t Steam-engine, J. Farcor, Siint-Ouen. 27 to f f^ MO I I j S CURR J. FISOHEAM -120,000 riNuous c J. FI2 » . -* . I . — 1 CONTIxVUC Jons,(Ws) 'V. 1 J iisriDEs:. -**- A. AccumuUtors 93 Charginir 89, 99 Rise of Voltage daring Cbarg- ine: 90 for Tramways 106 Acbien-Gesellscbaft Sachs Electrici- tatswerke 269 Admiralty Regulation 62 Adt. Gebr 324 Air-Gap 63, 68, 74. 157. 170 Alioth and Ck) 284, 3(K2, 333 AUgemeine Electricitats - Gesell- schaft 360 Almanna Svenska Elektriska Bolaget 364 Alteneck, Hefner von 26 Alternating Current 10, 289 Amianthus 297, 398 Ampere's Rule 1 Ampere-Turns 3 (Unit) 17 Amplitude of Undulationp 11 Angle between Two Lines of Brushes 23, 31 Apparatus for Determining Perme- aWlityoflron 182188 Fisher-Hinnen's 184 Hopkinson's 182 Arc Embraced by Pole-Piece ... 16. 67 Arc Light Dynamos 237 Field of 81 Armature — ^Alteration of 62 Approximate Dimensions of, 69.400 Coils, Time Constant of... 219, 220 Compensation for Weight of, 264, 353 Conductors, Maximum Dia- meter ot 51 Discs 50 Discs, Insulation of 53, 279 Discs, Thickness of 53 Dimensions, Exact Determina- tion of 72 Displacement of 262 Drum, Advantages and Dis- advantages of «.^ 37 External Diameter of 69 Flat Ring 34, 38 Armature — Flywheel 35* Insulation 305 Internal Diameter of 75 Losses 44, 175, 181 Reaction 39, 41, 84. 85, 227 Ring, Advantages and Dis- advantages of .» 36 Slotted 28 Spider 52, 279, 392 Varnish 66 Weight of 392 Armatures, Table of Dimensionn and Winding of ^.... 78,79 Armatures—Smooth, Toothed or Slotted, and Tunnelled 36 Ventilation of 346 Weight of 391 Armature Windings, Force on 18. (See also Windings, Shaft, Bear- ings, Commutator, Brushes, Spider, Cross - Connections, Bolts.) Arnold 20, 25. 31, 285, 350- Atlantic Avenue Railroad Com- pany 277 Audincourt 49 Autenheimer 264 Automatic Regulators 93. Auxiliary Poles 43, 231 B. Ball Bearings 270- Bars, Copper 65 Bar Windings 30O Bearings — Ball ,^.m»,^ >«•.. 2/0 Collar 273 Footstep 273 Losses in 55 Ordinary 265. Pressure on 57 Roller 271 Bell, Louis 121 Belts, Dimensions of 276 Bending of Shafts 257 Berghausen 127 Bernstein 82 Bessemer Steel 308, 412 Binding Wires ^ 307 Blondel, L 235. 27^ II. INDEX. Bolts. Insulation of 289, 294 Booster 90 Bore, Eccentric 25 Bosanquet 144 Braidinfs^ 66 Brakes, Electric 130 Bref^uet 35:^ Brett 13 Brown 44 Brown, Boveri, and Co ... 285 Brush 14 Brush Company 386 Dynamo 248 Brushes — Adjustment of 38 Anfi^le between Two Lines of . . . 23 Carbon 314 Contact Surface of 59, 299 Fixed 10 Lead of 39. 159 217 Lubrication of 60 Normal Position of 25 Number of Lines of 13 23 29 Pressure of 59, 319 Brush Holders 312 Buck 59 Bushes 267,270 C. Cables 65,411 Economy in 11)4 Hemp 277 Calculation of Resistance 18 Calibration of Galvanometer 183 Capacity for Work ... „ 254 Carbon — Brushes 314 Specific Resistance of 409 Carbonisation of Insulation 66 Carhart, H. S 239 Carter, Tremlett 278 Castinf^s, Imperfections in 25 Centrifugal Force, Action of, on Commutator Sections 298 Characteristic Curves 80, 189 of Motor 110 Primary and Secondary 85 Straight Portion of 84 Tracing 189, 191 for Variable Speed 207 Charsring Accumulators 89. 99 " Chignon " Windings 225 Chrome Steel 412 Coefficient — of Friction 58 of Hysteresis 49,412 Induction 214216 Leakage (Table) 415 (Temperature) of Resistance, 19, 409 of Traction 107 Useful Leakage 160 Collar Bearings 273 Collector 10 Collectors, Auxiliary 311 Commutator Sections, Number of... 21 Commutators 10, 294-299 Connection with 306 Sections 22, 297 Compagnie de Fives Lille 268. 360 Compagnie de la Industrie Elec* trique 336 Com pensation Coils 42. 366 for Armature Reactions ...228 233 (See also Fig. 247, pp. 356 7) Connections 323 Cross 297 Cooling Surface 61, 6i Cox 59 Critical Velocity ....... .. ............ 131 Crosby, O. T 121 Cross Connections 297 Current in Armature Conductor ... 22 Current in Short- Circuited Arma- ture Coil 212 Cutler 125 Cylinder Windings 33 D. Dahlander 365 Degree of Saturation 81-85 Delta Metal :^08 Deprez, Marcel 106 Desroziers 34, 38, 354 Dettmar 251 Dimensions of Dynamos 394, 396 Disc Windings 33 Dobrowolsky, Dolivo 253 Driving Horns 305 Drop of Voltage 44 193 Drum Windings 10, 26 Dubs 101 Durana Wire 308 Dynamo — Characteristic of ...194^ 196 Complete Calculation for Con- struction of 172,181 Compound- Wound 13, 95, 196 Compound- Wound, Regulation of 99 for Constant Speed 71 Cost of Construction of 396 Direction of Current Gene- rated 126 Direction of Rotation 125 for Electrolysis 352 for High Voltage 105 with Lateral Poles .. 280, 375, 386 Multipolar 74, 77, 386, 391, 399 Self-Exciting 13, 126 Series-Wound 13, 81, 102 Series-Wound, Regulation of 82 for Ships 62 Shunt-Wound 13, 86 INDEX. 111. Dynamo— Shunt- Wound, Drop of Voltage in 193 Shunt - Wound, with Low Saturation 95 Shunt- Wound, Regulation of, 91. 197, 200 for TransmiBBion of Energy, 83, 338 Dynamos, Glaesification of 63 Running in Parallel 93. 100 Small lUf) Dyne 18 E. Eaeton, Anderson, and Co 378 Ebert, H 3 Ebonite 398 Economy in Cables 104 Efficiency 69 Efficiency, Maximum.. .*. 60 Eickemeyer 302 Electrical Brakes 130 Electromagnet 1 E.M.F.— in Armature 13 Back, in Motors 15 Induced 4 Erg 17 Esson 60 Ewing 47 Excelsior Company, New York ... -40 F. Faraday 80 Faraday's Rule 6 Farcot, J 37, 38, 184, 268, 287. 34*2 Field -Coil Varnish 6G Field-Magnet W^indings— Altera- tions in 133 Bobbins 321 Cores 3-20 Examples 136 168 Predetermination of 143 Field Magnets 80, 403 Fleming, J. A 53 Flux — Contraction of 158 Inverse and Transveise 227 Footstep Bearings 273 Forbes 144 16') Force, Magnetic Tractive ... 260 Formation of Sparks 223. 233 Formers 302 Foucault Currents 51 Friction — in Bearings ... 58 of Brushes 59 Coefficient 58 Losses 55 Fritsche 35, 377 Fritsche and Pidchoii 374 Fynn, V. A 378 G. GanzandCo 372 General Electric Company 284 Generators 125 Withdrawal of 103 Girault 360 Gradients 110 Gramme Ring, Advantages and Disadvantages of 36-37 Graphic Methods 189 Grawinkel 27& Grooved Pulleys 278 Griitsch-Miirren Tramway 131 Gnilbert, C. F 125 H. Heating 61 Hochhauseu Dynamo 240 Hopkinson 144 150, 182, 412 Horns, Driving 305 Hysteresis 46 Coefficients 49. 412 Losses 46-50, 413 I. Impregnating Media 6& Incandescent Electric Lamp»'. Lives of 127 Induced E.M.F 4 Indaction. Coefficient of 214-216 IoBulation~of Bolts 289 Thickness of 66 of Wires 65 I ron for Armature Discs 50 J. Jehl and Rupp.. Joints, Soldered 374 225 K. Kapp : 145, 281 Lines 145 Magnetisation Fur mulav..... 148 Keys '. 259,416 Kilogrammetre 17 Kingdon 251 KirchhorsLaw 224 IV. INDEX. L. Xiamp Battery 94 Lap Windings 26. 29 Lazire, Weiller, and' Co 308, 411 Lead — in Motors and Dynamos, 40, 159, 210, 344 404 in Motors 226 Leakage — Coefficient 153 Loss 162, 415 Useful 160 Lifeof Incandescent Electric Lamps 127 Life of Shafts 257 Lighthouse Dynamos 235 Lines of Force 1 Lubricating Rings 265 Lubrication of Brushes 60 Lubricator, Sight-Feed 332 Lundell Ventilator 388 M. Magnetic— Attraction 185 Circuit 152, 154 Cond uc ti vity 1 65 Field, Irregular 5 Resistance 144 Screening 52 Magnetisation — Curve 47 Initial 126 Reversal of 72, 74, 90, 175 Magnetomotive Force 144 Manchester Dynamo 330 Manganese Steel 412 Mather and Piatt 330 Mavor and Coulson 383 Maxwell 185 Megohm 17 Menges 125 Mica 297. 398 Micanite 218, 297, 306, 398 Mont Seldve Railway 340 Mordey 44 CroBS-Connections 22 Motors 14 Motors — Back E.M.F 15 Characteristics of 110 Direction of Rotation 125 to Increase Speed of 170 Limiting Speed of 15 Regulation of 106, 121 Series 105, 128 Shunt-Wound 121, 129 Starting 124 for Tools 389 for Tramways « 105 Used as Brakes 130 Vertical 352 Multiple Wire System 104 Multipolar Dynamos ... 74, 77, 386, 391 Ring Armature.- 22 N. NagloBros 372 Neutral Zone 9,22 0. Oeking and Co 48 Oerlikon Company. 23 36, 93, 104, 116, 121, 124, 131, 177, 281, 327 Ohm 6, 17 Oil Reservoirs 269 Open Windings 240 O ver-Compounding 96 P. Paccinotti Gramme Ring 20, 59 Parallel Windings 22 Permeability 2. 150 Determination of 182-188 Perry 24 Picou ^ 143, 189 Pitch of Winding 24 Pixii 10 Pole— Arc 27,67 Auxiliary 43, 231 Corners ;....« 9, 51 53 Findincr .^ 127 Pieces, Enlargement of 74 Poschmann and Co 269 Position of Commutator Sections... 24 Presspahn 297. 398 Prespure— External 13 Internal 13 Pressure of Brushes 59 Price of Materials 398 Pulleys — between Bearings and O verhanging 56 Dimensions of 276, 417 Ordinary and Grooved 275 Weight of 393 R. Radiating Surfaces 62 Railway, Mont Sel«ve. 340 Raw Materials, Cost of 398 Reerulation of Series - Wound Dynamo 82 Series-Parallel System 116 Tramway Motors.^ 106 Regulators, Automatic 93 Reid.„ 223 Reiffer, J. J 274 Resistance — of Brush Contacts...... 224 Calculation of 18 Magnetic » 144 Regulating.. 197 INDEX. V. ReBifltanoe— Specific 18, 409 Sbartint; ...,^ 124 Ring Armature 8. 359 Winding .^ « 10, 20, 2o Rings — Collecting .* « 10 Lubricating 265 Rise of Temperature of Dynamos, ' ja 61, 62, 403 Roller Bearings 271 Romele, J 260. 416 Rothert 251 Rowland 144 Rules for Winding 22, 28 IS. Sankey and Sons 48 Saturation — of Armature 157 of Gore 75 of Field Magnets 81, 85 Teeth 72 Tramway Motors 112 Sayers 42. 366 Schuckerb Dynamos.. 273, 289 Schweiz 289 Screening, Magnetic 52 Screws for Tightening Belts 325 SeiflFert 278 Self-induction, Coefficient of... 214, 216 Septin 325 Series-Wave Winding 26, 29 Shafts— Bending of 257, 387 Diameter of .„ 258, 404 Life of 257 Table of Dimensions 26 1 Shunt- Wound Motors 121 Siemens and Halske 368 Siemens's H Armature ^ 10 Siemens, Werner 13 Sight-Feed Lubricator 332 Siliceous Steel 412 Sinsteden 13 Slots 68 Number of 72 Slotted Armatures 36 Smooth Armatures 36 Snell 70 Societe Alsa^ienne des Construc- tions Meshaniques 371 ■Society Lahmeyer 281 Sparking 32, 41, 223, 2SS Sperry 34 244 Sprague 106, 114 Scability of Foundations for Dynamo 350 Stability of Working of Dynamos 172 Standard Company's Arc Lamp Dynamo ^ 246 Standard Paint Company 66 .Starting Motors 124 Resistance 124 Steel, Hysteresis Coefficients of ... 412 Steinmetz, C. P 49, 412 Steirmuehl ., - 104 Storey Motor and Tool Company... 389 Strecker « 278 Surface Cooling 61 Svilokossitch, M 254 Swinburne 231 T. 