DEVICE FOR REGISTERING PARTICULARLY TARIFF UNITS OF TELEPHONE CALLS FOR CHECKING OF STATEMENT OF CHARGES

摘要

The invention relates to a device for recording the charge units of telephone calls which has a charge monitor for looping into the connection line of a telephone set. The charge monitor has a microprocessor to read the dialled telephone number and to record the call duration. Furthermore, a data memory is provided which has a computer for recording the charge rate to be applied and for calculating the charge units via the call duration. A display panel indicates the calculated charge units and the resulting telephone charges. IMAGE