. Practical wireless telegraphy; a complete text book for students of radio communication . and direct current, but the dynamotor of Fig. 70 has twodistinct windings (on the same armature) one to rotate it as a motor and theother for the production of alternating current. Explanation of the circuits of the rotary converter of Fig. 69 follows: Direct currentfrom an external source enters the armature coil C, D through brushes A, B, and alsoflows to the shunt field windings (wiring not shown) causing the armature to revolve inthe usual way. Taps taken from this winding at the commutator segments
. Practical wireless telegraphy; a complete text book for students of radio communication . and direct current, but the dynamotor of Fig. 70 has twodistinct windings (on the same armature) one to rotate it as a motor and theother for the production of alternating current. Explanation of the circuits of the rotary converter of Fig. 69 follows: Direct currentfrom an external source enters the armature coil C, D through brushes A, B, and alsoflows to the shunt field windings (wiring not shown) causing the armature to revolve inthe usual way. Taps taken from this winding at the commutator segments directly under- 58 PRACTICAL WIRELESS TELEGRAPHY. neath the brushes are connected to the collector rings on the opposite ends of the shaftthe circuit continuing through the A. C. external circuit E. The voltage of the alternatingcurrent will be maximum when the taps to the collector rings are underneath the brushesand minimum when midway between the brushes. It is easily seen that as C, D revolvesand attains the position opposite to that in Fig. 69, the current taken from the collector. 110 VOLT Die. Vww Fig. 70—Fundamental Circuit of Dynamotor. rings will flow in the opposite direction and therefore as the armature revolves, an alter-nating current can be taken from the armature, the frequency of which varies withthe speed. An important point in connection with this machine is that if the D. C. supplyis 110 volts, the effective A. C. E. M. F. cannot exceed 11 volts. If 110 volts is desired asmall step-up transformer must be used. The A. C. voltage of the converter may bd increased by increasing the speed of themotor, but the frequency of the current increases simultaneously. The converter does notpermit the nicety of control of the voltage and the frequency as does the motor generatorand, therefore, it operates at a disadvantage. The circuit of the dynamotor is shown in Fig. 70. Here the armature coils for theproduction of alternating current have no connection with the coi
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
