geostationary telecommunications satellites electronic telephone set ...

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Fig. 10 Buzzer unit Fig. 9 Tone ringing unit Recall button (R button), number frame In order to simplify the operation of the set as much as possible it was necessary to reduce the number of function elements to a minimum. For this reason the number frame and the recall button have been combined to form one unit. Pos. 1 in fig. 2 shows the button for calling a register. The number frame, pos. 2, is mounted over the R button with one end carried in a bearing. The R button is actuated by pressure on the other end of the number frame. In these cases where the R button is not required, the number frame is fixed. The number frame is mounted with the aid of a snap-on device on the frame. Transmission circuit unit Pos. 3 in fig. 2 shows the transmission circuit unit, fig. 8. The unit contains the electronic speech circuit, electret microphone and cradle contact spring assembly. The electret microphone and the speech circuit are mounted in a common plastic cover. The cover is injection moulded. The speech circuit is protected against amplitude modulated radio signals. The transmission circuit also contains the necessary connection screws for the instrument cord. The printed circuit board is a doublefoil board of glass fibre reinforced epoxy laminate with plated-through holes. Ring unit The ring unit (pos. 4 in fig. 2) is available in three alternative versions: for tone ringing, with an electromechanical buzzer and as a connection unit without any internal calling device (an external calling device, not associated with the set, is used). The ring unit always contains the jack that connects the insert of the set with the impulsing electronics and the receiver, which are mounted in the case. Fig. 9 shows the tone ringing unit and fig. 10 the unit for electromechanical buzzer. Telephone cord The telephone cord (pos. 12 in fig. 2) is of a standard type with colour-coded tinsel conductors with a PVC sheath. Each conductor consists of four-wire, double-tape cadmium-copper tapes wound round a polyester core. A part of the cord is coiled and its normal length is 1.3 m. Fully extended it measures 2.4 m. It is fixed to the frame with mechanical stress relief. The connectors are terminated in cable lugs for screw connection. Mounting the insert The push-button dialling mechanism is screwed into the frame with the aid of two distance pieces which also constitute the holders for the transmission Fig. 8 Transmission unit Fig. 7 Cradle contact assembly, wiring diagram MAKE-BEFORE-BREAK CONTACT 1 and 3 or 1 and 4 are connected together. When the camshaft turns, 1 and 2 close before 3 and 4 break ORDINARY CHANGEOVER 2 and 3 or 1 and 4 are connected together. When the camshaft turns, 3 and 4 break before 1 and 2 close
123 Fig. 11 Cradle contact spring assembly, functional diagram Y///A Closed contacts A a Torsional angle of the camshaft when It turns from position 1 to position 2
Page 1: ERICSSON REVIEW 3 1976 GEOSTATIONAR
Page 4 and 5: Geostationary Telecommunications Sa
Page 6 and 7: 112 forever silent. The next launch
Page 8 and 9: 114 Figs. 1—4 Figs. 5—8
Page 10 and 11: 116 Figs. 17—20 Figs. 21—24
Page 12 and 13: Electronic Push-button Telephone Se
Page 14 and 15: The bottom part (frame) ot the set
Page 18 and 19: Fig. 12 Impulsing unit and ring uni
Page 20 and 21: 126 Fig. 15 Transmission diagram Fi
Page 22 and 23: 128 ed by about 100 kohms. In order
Page 24 and 25: Fig. 20 DC characteristics (speech
Page 26 and 27: 132 use a microphone in which the o
Page 28 and 29: CCM - A Well- tried and Economic Ma
Page 30 and 31: 136 ] Do not allow more staff in th
Page 32 and 33: Ten Years Experience of CCM in the
Page 34 and 35: 140 Table 2 Existing staff requirem
Page 36 and 37: Optimization of Power Supply Equipm
Page 38 and 39: 144 Initial expenditure. This consi
Page 40 and 41: Table 1 Acquisition costs for diffe
Page 42 and 43: 148 Fig. 8 Instead of feeding the p
Page 44 and 45: 150 Fig. 10 Apart from a highly sta
Page 46 and 47: Development, Production and Mainten
Page 48 and 49: 154 combined to meet the needs of e
Page 50 and 51: 156 duction and putting the package
Page 52 and 53: 158 Fig. 5 Working procedure when p
Page 54 and 55: 160 The error message is sent from
Page 56 and 57: Dr. Christian Jacobceus chaired the
Page 58 and 59: 164 Among the reasons that were giv
Page 60: TELEFONAKTIEBOLAGET LM ERICSSON PRI

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