BATTERY RINGING TELEPHONES
The telephones described below BC 3001, BC 3011 and BC 3012 are particularly suitable for private telephone installations of the most simple type. They may be connected to ordinary electric bell systems and are suitable for lines up to 300 m with good insulation. The connection is very simple.
Domestic telephone for battery ringing
microtelephone RE 9312 with key and cord RS 4252, terminal block of black polished wood (dimensions 75 x 116 mm) with press button for signalling, bell, terminals and suspension hook for the microtelephone.
Weight 0.6 kg.
Two telephones can be
connected over a line up to 300 m with good insulation. If the distance is less than 50m one common battery
will be sufficient. For greater distances it is advisable to use one battery for each telephone; two conductors between the telephones are then
If several telephones are to be connected, a separate simple switch with a number of contacts corresponding to the number of telephones in the system is required at each telephone. In such systems only those telephones with switches can call and talk with the others.
An installation with up to 5 telephones can be obtained by means of an inductive resistance with condenser, BC 3060, and a switch for each telephone. All telephones can then call and talk with each other. Only one conversation can be carried on at a time. The length of the lines should not exceed 50m. A suitable battery is composed of 2 dry cells RK 210 connected in series. A suitable battery case is RK 2300. Lead cable, Type EEB, is suitable for the wiring.
Taken from the L. M. Ericsson Telephones and Signalling Material Catalogue No. 188 (1934)
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