The machine driven Panel and Rotary gauipments are of the non-decimal. type employing larger switches and. permitting larger Junction groups. They are identical except that Panel equipment uses Varger switches than Rotary and therefore permits even larger junction groups. They will operate Satisfactorily on either 24 volts or fon 48 volts though 48 volt equipment is generally preferred, The adoption of 24 volt equipment on tthe original order for Rotary equipment for Shanghai ws entire ly to local factors such as a desire to use the then existing power plant and the belief that in an unusually humid climate, the lower would result in lo: rasion of contacts, But this question of voltage has but slight importance. With proper maintenance of the equipment and usual standards of construction and maintenance of outside plant, the 24 volt Rotary equipment gi tirely satisfactory service and is thoroughly modern in every respect. Tu the two additional exchanges now on order, the Telephone Company will use. 48 volt equipment. First cost will be less because the 48 volt equipment is manufactured in larger quantities, the exchanges ave now offices with no existing power equipment and it is now apparent that the corrosion problem thas been overcome.
Question of Economy:
'The ute in the Panel and Rotary' types of equipment of larger groups permits greater flexibility and very' Jarge economies in junction cables The use of large switches is mad possible by an ingenious device Known as the "register." It is the yogister which translates the impulses sent on a decimal basis (from the subscriber's dial) to non-decimal impulses controlling 200 witches in the If it were not for the register, all switches would have to be on a decimal basi as the 100 line switches Step-by-Step system. In permitting ins, oargee function rou, at value, as flexibility and junction cable economies are of aminating importance in large metropolitan areas. This accounts for the adoption of panel equipment for cities like New York, Chicago, Philadelphia and Boston and of Rotary equipment for Madvid, Brudees, Copenhagen sla,
Text read from the printed page and cleaned; old type leaves the occasional error.