Circuit for generating dialling signals

摘要

Circuit for generating dialling signals in a telephone set with a last-number redial memory and a number of memories in which telephone numbers are stored which can be called up by means of short-code dialling, where the last-number redial memory is designed as a volatile memory which loses its information when the telephone set is disconnected from the exchange line, whereas the short-code dialling memories are designed as non-volatile memories whose supply voltage is generated through re-programming by means of a voltage transformer which is connected via a switching device to the exchange line which disconnects the telephone set speech circuit from the exchange line when the voltage transformer is connected.