DEVICE FOR BURGLAR AND FIRE ALARM Russian patent published in 2003 - IPC

FIELD: detection of violator or fire breeding ground at controlled objects with transmission of alarm messages over radio channel. SUBSTANCE: each controlled post is assigned its address code and each type of information is given its own information code. Controlled object has alarm sensors, coding unit with switch of signal repetition period, signal duration selector, address coding unit and transmitter with phase manipulator. Receiving post includes signal processing and demodulation unit with phase detector, units decoding address and information and unit identifying false operation. Usage of phase-manipulated signals ensures high secretiveness of transmitted signals with wide range of change of transmitted messages. EFFECT: increased noise immunity and authenticity of alarm signals transmitted to receiving post. 5 dwg