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EP0446979A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

System for transmitting alarm signals with a repetition

Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1991-02-21
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Granted: —
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Expires: 2011-02-21
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Abstract

Abstract System for transmitting alarm signals, comprising at least one portable transmitting unit and one central receiver, the transmitting unit comprising a control circuit which is connected to an activation device and a transmitting circuit, the control circuit activating the transmitting circuit when the activation device is energised in order to transmit an alarm signal and in order to re-activate the transmitting circuit for the re-transmission of the alarm signal after the elapse of a delay time, the delay time being different from a delay time of another transmitting unit, the transmitting unit having a memory for storing an identification code allocated to the transmitting unit, the central receiver comprising a processing system which is connected to a receiving circuit which is suitable for receiving an alarm signal and the processing circuit activating a signalling device, on receipt of an alarm signal, for the purpose of generating an attention signal, in which system the delay time is dependent on corresponding sections having different values of identification codes allocated to a predetermined group of transmitting units.

Inventors

  • 👤 Petrus Antonius Johannes Steen
  • 👤 Gauke Klaas Zijlstra

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-30 11:02
CPC Classifications
G; G08; G08B; G08B25/00; G08B25/01; G08B25/10

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 174 words
System for transmitting alarm signals comprising at least one portable transmitting unit and one central receiver, the transmitting unit comprising a control circuit which is connected to an activation device and a transmitting circuit, the control circuit activating the transmitting circuit when the activation device is energised in order to transmit an alarm signal and in order to re-activate the transmitting circuit for the re-transmission of the alarm signal after the elapse of a delay time, the delay time being different from a delay time of another transmitting unit, the transmitting unit having a memory for storing an identification code allocated to the transmitting unit, the central receiver comprising a processing system which is connected to a receiving circuit which is suitable for receiving an alarm signal and the processing circuit activating a signalling device, on receipt of an alarm signal, for the purpose of generating an attention signal, characterised in that the delay time is dependent on corresponding sections having different values of identification codes allocated to a predetermined group of transmitting units.
Claim 2
Dependent Claim 36 words
System according to claim 2, characterised in that the least-significant sections of the identification codes of the predetermined group of transmitting units are different, characterised in that the delay time is dependent on the least-significant section.
Claim 3
Dependent Claim 24 words
System according to claim 1 or 2, characterised in that the delay time is determined by processing the identification code with a predetermined algorithm.

References Cited (Backward Citations)

EP0100523A1 Cited
GB2186404A Cited
EP0312431B1 Cited
GB2212642A Cited
EP0368710A1 Cited

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