Metering device for timed local calls - permits easy conversion for local calls accounting from standard exchange system

摘要

The telephone exchange circuit, which permits a simple conversion for local timed calls accounting, uses a system in which the counting relay is directly controlled by an arm in the selector for local or trunk call differentiation. For a local times call the individual decades except for that controlled by trunk calls are fed at an increased pulse rate corresponding to the tariff metering; a device is introduced with a reducing stage in the control wheel before the switching arm to control the counting relay at the counting pulse rate until the connection is completed during a local call, whilst the control is earthed during a trunk connection.