IT1074135B - Ultrasonic alarm system for movable objects - detects a phase difference between reflected and reference signal (NL150377)
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Ultrasonic alarm system for movable objects - detects a phase difference between reflected and reference signal (NL150377)
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Publication number
IT1074135B
IT1074135BIT5123176AIT5123176AIT1074135BIT 1074135 BIT1074135 BIT 1074135BIT 5123176 AIT5123176 AIT 5123176AIT 5123176 AIT5123176 AIT 5123176AIT 1074135 BIT1074135 BIT 1074135B
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Priority claimed from JP11111575Aexternal-prioritypatent/JPS5938555B2/en
Priority claimed from JP50111114Aexternal-prioritypatent/JPS5235599A/en
Application filed by Matsushita Electric Works LtdfiledCriticalMatsushita Electric Works Ltd
Application grantedgrantedCritical
Publication of IT1074135BpublicationCriticalpatent/IT1074135B/en
The alarm system has an ultrasonic generator, an h.f. oscillator generating a reference signal of the same frequency and a receiver for ultrasonic waves reflected from an object. An alarm stage is operated by the phase difference signal. A phase discriminator (5) is inserted between a phase comparator (4) and the alarm stage (5'). The discriminator (5) can distinguish the sense of the phase difference detected by the phase comparator (4), which indicates the presence of a moving object. It operates the alarm stage when it detects such a phase difference.
IT5123176A1975-09-131976-09-10Ultrasonic alarm system for movable objects - detects a phase difference between reflected and reference signal (NL150377)
IT1074135B
(en)