In a hundred-line exchange 24 two-motion selectors are used. Draw the schematic you suggest for this exchange and explain its working. How many simultaneous calls can be made during peak hour in this exchange?

In a hundred-line exchange 24 two-motion selectors are used. Draw the schematic you suggest for this exchange and explain its working. How many simultaneous calls can be made during peak hour in this exchange?
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1 Answer

Answer :

The desired schematic for 100 lines exchange with 24 two motion selectors is shown in Fig.

image  

In the case, 24 simultaneous calls can be put through the switch . Typically, a 24- outlet uniselector is used as a selector hunter. Each of the 24 outlets is connected to one two-motion selector. Thus, a subscriber has access to all the 24 two-motion selectors in the system. The corresponding outlets of all the selector hunters are commoned and thus, all subscribers have access to all the two-motion selectors. This scheme is shown in Fig. The call establishment in this scheme takes place in two steps. Firstly, when the subscriber lifts his receiver handset, his uniselector hunts through the contact positions and seizes a free two-motion selector. At the next step, the two-motion selector responds to the dial pulses for appropriate connection.

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