Telephone line connected burglar alarm - has dialling circuit, and microprocessor controlled voice synthesiser and ROM containing bits to generate alarm word display

摘要

The device transmits alarm signals through the autoswitching telephone system and has an interface circuit controlled by a microprocessor to connect, or disconnect the device to the telephone line. Spoken messages are stored and are transmitted when the microprocessor is tripped by, for example, a burglar or other alarm. A random access memory records specific information of telephone numbers to be dialled for message transmission. A read only memory contains the necessary binary information to generate in vocal form ten decimal codes and the word 'Alarm'. The microprocessor controls the of information between the memories, the signal inputs, exchange transmitter and automatic dialling of a desired number when an alarm condition arises, the automatic dialling circuit being actuated only when the telephone current inversion indicates connection to the phone line.