Telephone charges display device - has presettable tariff store for unit charges, and converter for received charge pulses.

摘要

The converter changes the charge pulses into control pulses. A summator adds, at a control pulse arrival, the price per unit to the already accumulated charge which is displayed. A timer receives the control pulse and switches on the device when a control pulse appears. The timer stops the device after a time interval has elapsed, such an interval being longer than the longest spacing between charge pulses. By this arrangement the apparatus is never unnecessarily in operation, only functioning when actual pulses arrive. At the same time a reading of the already completed part, or indeed of a completely finished conversation is possible.