. Practical wireless telegraphy; a complete text book for students of radio communication . d be observedthat the D. C. armature coils lie lengthwise in slots on theiron core and their terminals are soldered in slots at the endof each commutator segment. Fig. 36 shows the terminalsof the armature coils placed in the slots ready for construction of the commutator should be noted. It ismade up of a number of copper bars separated by fiberinsulating material. 43. The Alternating Current Transformer.—Wehave shown in paragraphs 28 and 29 how a varyingmagnetic field threading in and ou
. Practical wireless telegraphy; a complete text book for students of radio communication . d be observedthat the D. C. armature coils lie lengthwise in slots on theiron core and their terminals are soldered in slots at the endof each commutator segment. Fig. 36 shows the terminalsof the armature coils placed in the slots ready for construction of the commutator should be noted. It ismade up of a number of copper bars separated by fiberinsulating material. 43. The Alternating Current Transformer.—Wehave shown in paragraphs 28 and 29 how a varyingmagnetic field threading in and out of a coil of wire wound over an iron core caninduce a flow of current into another coil wound about it. Mention was made ofthe fact that direct, current flowing through the first coil must be interrupted orits strength changed periodically to induce a current in the second coil. It is clear from Fig. 19, that the lines of force produced by winding P cut eachturn in S just once, and, therefore, the pressure or electromotive force induced 5 s Fig. COWWUTATOR33—-Simple Armature Fig. 34—Development of Wave Winding. in winding S increases or decreases accordingly as the number of turns in S aregreater or less than in P (see paragraph 31). The apparatus built upon this principle is known as a transformer_ and thedifferent types are called step-up or step-down with respect to the ratio of theprimary and secondary turns. 34 PRACTICAL WIRELESS TELEGRAPHY. The essentials of a transformer are: (1) A primary winding; (2) A secondary winding; (3) An iron core. In order that the current may be induced in the secondary of a transformer, theprimary winding must be traversed by either a pulsating or interrupted direct currentor an alternating current. Fig. 35—Construction of Crocker Wlieeler Motor Generator Armature. / / \ Ca«HUT»lfl« StOIS CWUiJlATOR StSUtMTS
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
