A Treatise on Telegraphy Volume 2; Prepared for Students of the International Correspondence Schools, Scranton, Pa (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1901 Excerpt: ...the local circuit between gt and y, causing the lever /, of the transmitter T, to first break at x, the extra local circuit containing M, and then to break the eastern main-line circuit between/, and a, . ThusMis first demagnetized and the spring J presses the lever o against the lever g, so that when a moment later R is also demagnetized by the opening of the circuit between at and/, the lever g is still held against/, since the spring s is adjusted to overcome the pull of the spring s, . Thus, the opening of the circuit containing the electromagnet 5 of the transmitter T is prevented. The opening of this circuit, when the western circuit is repeating into the eastern circuit, would be fatal to the successful operation of the repeater. Therefore, when the western key is opened, the eastern circuit is opened without opening the western circuit at the repeating station. In the figure, the instruments are shown in their proper position when the western key is open. 1 5. The chief function of an automatic repeater is to automatically prevent the opening or breaking of the sending circuit at the repeater station. For instance, the transmitter that controls the western circuit must not open the western circuit at the repeating station when the western circuit is repeating into the eastern circuit. The opposite transmitter, a term frequently used, may be defined as being the one controlled by the relay in the circuit that is being repeated into. For instance, when the western circuit is repeating into the eastern circuit, the transmitter T is the opposite transmitter, because it is controlled by the relay R in the opposite circuit, and this transmitter T must remain closed while the western is repeating into the eastern circuit. 16. When the western key is again ...