BURGLAR ALARM Russian patent published in 1995 - IPC

FIELD: computer engineering. SUBSTANCE: alarm has interface units 1.1-1. N to guarded entity, matrix commutator 2, buzzer generator 3, switch 4, analog-to-digital converter 5, flip-flop 6, register 7, data control and processing unit 8, current generator unit 9, standard resistance box 10, telephone sets 11.1-11.N according to number of guarded entities, unit 12 to change over communication between telephone exchange and guarded entities. EFFECT: improved reliability and validity in operation due to use of true value of line resistance for analyzing signals arriving from sensors and provision for self-diagnostic equipment. 3 dwg