Patent EP0102229A1 successfully refreshed from Google Patents.
EP0102229A1
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Alarm system
Assignee: Monicell Ltd
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Filing: 1983-08-22
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Granted: —
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Expires: 2003-08-22
Abstract
Abstract An alarm system in which signalling between spatially separated units is effected over a mains supply network to which each of the units can be connected by conventional plugs inserted into outlets of the mains network. A master control unit is used to control each of a plurality of slave units by applying control signals to the mains network. Each slave unit comprises alarm condition sensors which are turned on and off by the control signals, alarm indicators which are activated when an alarm condition is sensed, and a transmitter for applying alarm signals to the mains network when an alarm indicator is activated. Each slave unit is also responsive to the alarm signals so that when one slave unit indicates an alarm condition the resulting alarm signal turns on the alarm indicators of the other units. I
Inventors
- 👤 Allen David Muirhead
- 👤 John Richard Hawke
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 06:46
CPC Classifications
G; G08; G08B; G08B25/00; G08B25/01; G08B25/06; G08B27/00; H; H02; H02J; H02J13/00; H02J13/13; H02J13/1311; H02J13/1313; Y; Y02; Y02B; Y02B90/00; Y02B90/20; Y02E; Y02E60/00; Y04; Y04S; Y04S40/00; Y04S40/12; Y04S40/121
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
176 words
An alarm system for use in locations provided with a mains power supply network, comprising a master unit, a slave unit having an alarm condition sensor and an alarm indicator, and a further alarm indicator, the master unit, slave unit and further alarm indicator being provided with means for making electrical connection with the mains network, wherein the master unit comprises means for selectively applying slave unit control signals to the mains network, the slave unit comprises means for detecting the control signals, means for turning the alarm condition sensor on and off in response to detected control signals, means for detecting the sensing of the alarm condition by the sensor, means for turning on the slave unit alarm indicator when sensing of the alarm condition is detected, and means for applying an alarm signal to the mains network when sensing of the alarm condition is detected, and the further alarm indicator is associated with means for detecting the alarm signal and means for turning on the further alarm indicator when the alarm signal is detected.
Claim 2
Dependent Claim
176 words
An alarm system for use in locations provided with a mains power supply network, comprising a master unit, a slave unit having an alarm condition sensor and an alarm indicator, and a further alarm indicator, the master unit, slave unit and further alarm indicator being provided with means for making electrical connection with the mains network, wherein the master unit comprises means for selectively applying slave unit control signals to the mains network, the slave unit comprises means for detecting the control signals, means for turning the alarm condition sensor on and off in response to detected control signals, means for detecting the sensing of the alarm condition by the sensor, means for turning on the slave unit alarm indicator when sensing of the alarm condition is detected, and means for applying an alarm signal to the mains network when sensing of the alarm condition is detected, and the further alarm indicator is associated with means for detecting the alarm signal and means for turning on the further alarm indicator when the alarm signal is detected.
Claim 3
Dependent Claim
23 words
An alarm system according to claim 1, wherein the further' indicator and the alarm signal detecting means are incorporated into the master unit.
Claim 4
Dependent Claim
24 words
An alarm system according to claim 1, wherein the further indicator and the alarm signal detecting means are incorporated into a further slave unit.
Claim 5
Dependent Claim
90 words
An alarm system according to claim 1, comprising a plurality of slave units, wherein each slave unit is allocated an address code, the master unit comprises means for generating slave unit address codes for transmission with said slave unit control signals, each slave unit comprises means for detecting address code enabling response only to alarm and control signals transmitted with the slave units address code, and each slave unit comprises means for generating the address code of each of the other slave units for transmission with the said alarm signal.
Claim 6
Dependent Claim
96 words
An alarm system according to claim 4, wherein the master unit comprises an alarm indicator and means for detecting the alarm signal and turning on the alarm indicator when the alarm signal is detected, and wherein the master unit is allocated an address code, the master unit comprises means for detecting address codes enabling response only to alarm signals transmitted with the master units address code, and each slave unit comprises means for generating the address code of each of the other slave units and of the master unit for transmission with the said alarm signal.
Claim 7
Dependent Claim
54 words
An alarm system according to claim 4 or 5, wherein the address code generating means comprises an encoder, a plurality of code defining inputs, a plurality of signal defining inputs, and a transmission initiation input, the output of the encoder controlling a voltage controlled oscillator coupled to the mains network by a tuned transformer.
Claim 8
Dependent Claim
75 words
An alarm system according to claim 6, wherein each slave unit comprises a latch for receiving and storing the signal defining inputs applied to the encoder and indicating the condition of the slave units alarm indicators, a series of gates for comparing the signal defining inputs and the stored content of the latch, and a monostable circuit for generating the transmission initiation input when the gates detect a difference between the signals applied to them.
Claim 9
Dependent Claim
80 words
An alarm system according to claim 4, 5, 6 or 7, wherein the address code detecting means comprises a decoder, a plurality of code defining inputs, and a data input connected to the mains network via a phase locked loop and a tuned transformer, the decoder comparing received code data with the code defining inputs and applying subsequently received data to a plurality of data outputs only after identity between received code data and the defined code has been established.
References Cited (Backward Citations)
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