1959 - History of Ericsson - History of Ericsson

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108 The Ericovox meets the requirements of the Swedish Board of Telecommunications as set forth in Document 40, CCITT's Study Group 12, 1957, 1960. In addition to fulfilling the nine primary criteria listed on page 101, the Ericovox possesses the following valuable features: 10. The microphone is equally sensitive in all directions in the horizontal plane. 11. The loudspeaker is omnidirectional. 12. The instrument receives its power from the telephone line. 13. Microphone and loudspeaker are housed in one unit. The user need not trouble to think of their relative positions. 14. The voice operation does away with the unpleasant echo effect in loudspeaking conversations. 15. The secrecy button gives a greater sense of freedom in use of the telephone. 16. The extra amplification button quickly steps up the volume to a much higher level (increase of 9 db). This button can be simply restored during conversation by pressing the right-hand button, and is automatically restored on completion of the call. Accordingly, every conversation starts at the same receiving level. The continuous volume control also permits attenuation of an unnecessarily high receiving level, especially on short lines. 17. The Ericovox is a complete unit and can be used separately or in conjunction with any low-speaking telephone. The Ericofon, owing to its appearance and method of use, is extremely well suited for this purpose. The Ericovox has been approved by the Swedish Board of Telecommunications for connection to the national network.
Aii Idea Takes Shape How L M Ericsson's new loudspeaking telephone came to birth TORBJORN OLSSON, MEMBER OF THE NATIONAL ASSOCIATION OF SWEDISH ARCHITECTS, STOCKHOLM Fig. 1 X 2398 Work on the development of L M Ericsson's new loudspeaking telephone X 2400 X 2401 Fig. 2 X 2402 The apparatus employed in L M Ericsson's earlier loudspeaking telephone (From left) loudspeaker, telephone, amplifier UDC 745/749:621.395.623.7 The following pages contain an account of some of the principal steps in the work of designing and giving shape to L M Ericsson's new loudspeaking telephone. The account has inevitably had to be abridged and the chronological sequence to some extent rearranged. In actual fact the designers were so pressed for time thai on several occasions they had to work on different lines of development simultaneously. The work described in this article was done by Magnus Ahlgren, Torbjorn Olsson. Sven Silow. Members of The National Association of Swedish Archi tects, with the assistance of Mr. Dean L. Smith. L M Ericsson's earlier loudspeaking telephone was made up of separate parts, a telephone instrument with handset, a loudspeaker and an amplifier (fig. 2). Developments especially within the field of transistors have opened the way for a considerable reduction in the volume of components and in the number of units required. In the new instrument it was desired that the handset should not be tied to the telephone as in conventional types. The handset was to consist of an Ericofon. The new instrument would therefore accommodate a loudspeaker, microphone, amplifier, dial and control buttons. Grouping of the Components The first step was to make a preliminary study of a few conceivable groupings for the main components. To start with, the problem was viewed literally from the outside. We asked ourselves what the main shape of the instrument should be, as it appears to the subscriber. 2*—902202 109
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Page 4 and 5: Ericovox, the One-Piece Loudspeakin
Page 6 and 7: Fig. 3 X 8156 Block schematic of co
Page 8 and 9: Fig. 5 x 8163 The Ericovox, L M Eri
Page 10 and 11: Fig. 8 X 2443 Sending frequency res
Page 14 and 15: Fig. 3 Grouping of components in wi
Page 16 and 17: Fig. 9 X 8132 Case with pyramid-sha
Page 18 and 19: Fig. 12 X8134 Instrument with base
Page 20 and 21: Fig. 18 X8135 The locations of the
Page 22 and 23: Gothenburg Automatic Transit Exchan
Page 24 and 25: Fig. 3 x 8181 Block schematic of gr
Page 26 and 27: Fig. 6 122 x 8180 Block schematic o
Page 28 and 29: Fig. 8 X 2472 Link circuits for ori
Page 30 and 31: Fig. 10 X8182 Traffic supervisor's
Page 32 and 33: Fig. 2 X8167 Relay switchboard AMD
Page 34 and 35: 130 Priority The switchboard is des
Page 36 and 37: Crossbar Exchange Installed on Larg
Page 38 and 39: L M Ericsson to Undertake First C.T
Page 40: The Ericsson Group Associated and c

1959 - History of Ericsson - History of Ericsson

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