EP0991042A2 - Signalgeber und Überwachungssystem - Google Patents

Signalgeber und Überwachungssystem Download PDF

Info

Publication number
EP0991042A2
EP0991042A2 EP99307216A EP99307216A EP0991042A2 EP 0991042 A2 EP0991042 A2 EP 0991042A2 EP 99307216 A EP99307216 A EP 99307216A EP 99307216 A EP99307216 A EP 99307216A EP 0991042 A2 EP0991042 A2 EP 0991042A2
Authority
EP
European Patent Office
Prior art keywords
signalling
fault
base
head
circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP99307216A
Other languages
English (en)
French (fr)
Other versions
EP0991042A3 (de
Inventor
Roger Dennis Payne
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Apollo Fire Detectors Ltd
Original Assignee
Apollo Fire Detectors Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Apollo Fire Detectors Ltd filed Critical Apollo Fire Detectors Ltd
Publication of EP0991042A2 publication Critical patent/EP0991042A2/de
Publication of EP0991042A3 publication Critical patent/EP0991042A3/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B29/00—Checking or monitoring of signalling or alarm systems; Prevention or correction of operating errors, e.g. preventing unauthorised operation
    • G08B29/02—Monitoring continuously signalling or alarm systems
    • G08B29/04—Monitoring of the detection circuits
    • G08B29/043—Monitoring of the detection circuits of fire detection circuits

Definitions

  • This invention relates to a signalling device and to a monitoring system.
  • the signalling device has a head which is removable from a base and circuit means for applying a device fault signal to power supply lines.
  • the invention can be used in the field of fire detection where, for example, fire detectors (i.e. signalling devices) are placed in different locations in a fire detecting system (i.e. monitoring system) for detecting a fire, thereby causing an alarm signal to be given.
  • the invention can be used, for example, to generate a device fault signal when the head of a fire detector has been removed from its base, and not refitted after maintenance.
  • the signalling device may be an alarm device having a sounder head which can be removed from a base, the invention similarly being used to generate a device fault signal due to head removal.
  • the term "signalling device” is therefore used broadly to cover any kind of unit which can be used for signalling and where some function may be impaired by head removal.
  • Fault signalling is used in a minority of fire systems, most notably those installed in France, and in such systems a detecting device signals a detector fault by switching either a near short circuit, or an impedance about twice that used to signal detection of fire, across the supply lines.
  • a disadvantage of the short circuit fault signal is that detectors which are not faulty are rendered inoperative while a fault is being signalled by a faulty detector.
  • a disadvantage of the other method of fault signalling is that if two faulty detectors are present the control unit interprets the combined signals as a fire alarm.
  • a digital communications protocol is used to transmit fire and fault signals from detector to control unit, but such systems require more complex and more expensive electronic circuits in detectors and control unit than in the conventional, i.e. non addressable, systems.
  • a "head removal signal” is generated in the form of a pulsating signal. This device fault signal represents only that a head is not fitted to its base.
  • the present invention seeks to provide a signalling device which reveals a device fault that could be due to some problem with the circuitry of the device, as well as when a head is not fitted to its base, and to provide a cost-effective and reliable solution.
  • the present invention provides a signalling device in which a head is removable from a base, and in which:
  • the invention Since only one device fault signal is generated, either for head removal or some other fault, the invention provides an economic, simple and reliable solution. It is of no consequence that either is indicated by the same device fault signal, because as long as the device fault signal is present, inspection of the system would be necessary before it is put back into use and this would reveal (inter alia) a missing head.
  • the "other fault" which is not head removal, could be a predetermined circuitry fault occurring in the circuitry of the signalling device.
  • the device fault signalling means may include a microprocessor which monitors the operation of the circuitry which senses a fire and supplies a fire detection signal to the supply lines.
  • a device fault signal would be generated for any condition that has, or could degrade the performance of the fire detection device. For example, a condition where a compensation limit has been reached in a detector which compensates for long term drift in the output of its fire sensor.
  • a device fault include failure of a voltage regulator supplying an ionisation chamber in an ionisation smoke detector; open or short circuit of a temperature sensitive device, such as a thermistor in a heat detector, and stopping of an oscillator that times the application of pulses to an LED in a photoelectric smoke detector.
  • Known circuit means may be included for monitoring and or responding to the device fault so as to trigger the device fault signal. These means may include a microprocessor.
  • the device fault signal is not of a value or kind where it would be confused with say, a fire detection signal.
  • the invention can use the pulsating signal, which represents that a head is not fitted to its base, as described in our copending UK Application No. 9810900.2, since this can be easily recognised by, for example, a central control unit (CCU) which continuously monitors the supply line for a fire detection signal.
  • the fire detection signal may be one where the detecting device changes from a high to a low line impedance state, so that the current drop on the lines can be detected.
  • the device fault signal is also selected so as not to impose any serious current drain on the supply lines, nor otherwise impair the performance of other signalling devices connected to the same lines.
  • the invention does not essentially require a pulsating signal, since another kind of recognisable signal could be used instead.
  • the invention generally makes use of the same signal to indicate either head removal, or other device fault.
  • a monitoring system includes a plurality of the signalling devices according to the invention and monitoring means for monitoring the latter devices for responding to the detection or fault signal.
  • the monitoring means may be part of a CCU, or an end-of-line device (EOL), or some other means.
  • a centrally controlled fire alarm system usually comprises a "central control unit” (or CCU) for monitoring different groups of fire detecting devices located in different parts of a building.
  • Each group of fire detecting devices can be connected across a common pair of power supply lines which are linked back to the CCU which normally applies say 12 volts to the lines to operate the detecting devices.
  • Alarm devices which are triggered by a higher voltage, can be connected across the same pair of common supply lines and the CCU can respond to a "fire detection signal", signalled on the supply lines, so that CCU then causes say 24 volts to be applied the lines so as to operate the alarm devices to give "alarm signals”.
  • This system avoids an excessive amount of wiring compared with a system where detecting devices and alarm devices are connected to respective dedicated supply lines.
  • the supply voltage is below a threshold of, for example, 18 volts, and each fire detection device has a high line impedance, thereby drawing little or no current from the supply.
  • the fire detecting device produces a detection signal by changing from a high line impedance to a low line impedance, for example, by switching a known resistance across the supply lines.
  • the detection signal is detected by a control unit which then applies the higher voltage (24v) to the lines.
  • the alarm devices are activated to produce warning signals.
  • the detecting devices include means for limiting the current they draw from the lines. Such a system is disclosed in our copending UK Application No. 9808094.8 to which reference may be made for further details.
  • an alarm device may produce a warning signal when the polarity of the supply is reversed.
  • a fire detecting device comprises a mounting base (1) with terminals L1 IN and L2 for connection to supply lines and a detachable detector head (2) .
  • the base contains signalling circuitry (3) as described in co-pending patent application GB 9810900.2.
  • the circuitry (3) senses the absence of an input signal on terminal L1 OUT.
  • the circuitry (3) periodically applies a predetermined impedance across supply lines L1 IN and L2 thereby signalling a fault condition (head removed) to a central control unit.
  • the central control unit detects the fault condition signal either directly or via an end of line device as disclosed in GB 9810900.2.
  • the head contains circuitry (4) for sensing a fire, circuitry (5) for processing the output of the fire sensing circuit, and circuitry (6) for generating a fire detection signal (to cause the operation of alarm devices, not shown) when the processing circuitry resolves a fire condition.
  • the head also contains signalling circuitry (7) which applies a signal to the head terminal corresponding with base terminal L1 OUT, the signalling circuitry being responsive to the processing circuitry so as to remove the signal from terminal L1 OUT when the processing circuitry resolves a fault condition, thereby making the signalling circuitry (3) in the base responsive to removal of the head and to another fault condition. In both instances the same device fault signal is produced by the base circuitry.
  • the processing circuitry (5) may comprise threshold-sensing means responsive to the output of the fire sensing circuitry (4).
  • the processing means is a device such as a National Semiconductor COP 8ACC5 microcontroller or a microprocessor.
  • the processing circuitry (5) or fault signalling circuitry (7) or both are located in the base.
  • the output of the signalling circuitry (7) is arranged by logic or switching circuits (not shown, but which can be of known construction) to cause operation of signalling circuitry (3) when a fault is resolved and the head is still applying a signal to terminal L1 OUT.
  • the detector is provided with an indicator connected to switching means responsive to processing circuitry (5) such that in the event of the processing means resolving a fault condition, the indicator changes state or produces a coded signal whereby the detector that has developed a fault can be more easily identified.
  • the signalling circuitry (3) in the base preferably includes means for applying a pulsating signal to the terminals L1 IN and L2 when a device fault condition exists; the signalling means also being operative, when another pulsating signal is already on the supply lines, substantially to preserve the waveform of the pulsating signal on the supply lines, whereby the pulse waveform is independent of the number of heads removed from respective bases. This is described in our copending UK Application No. 9810900.2.
  • signalling circuitry (3) in the base includes additional means for inhibiting a pulsating signal (which is the device fault signal) when a voltage applied to the detection device either exceeds a predetermined threshold, or changes in polarity or both.
  • Figure 2 shows a diagram of signalling circuitry (3). A full description of the operation of the circuit is given in GB 9810900.2.
  • the pulsing output of this circuit is inhibited when a voltage close to the negative of the rectified supply is imposed on terminal L1 OUT (pulled down).
  • FIG. 3 shows in detail the circuit arrangement in the head of a detecting device according to the invention.
  • Terminal L1 OUT shown in this Figure engages with base terminal L1 OUT.
  • the output designated FAULT of the processing circuit (5) is arranged to be high so as to turn-on the open collector transistor (8) thereby pulling terminal L1 OUT negative (active pull down) when no fault is present.
  • transistor (8) is turned off thus removing the negative signal from L1 OUT and thereby causing the signalling circuit in the base to signal a fault.
  • the circuit arrangement including transistors (9) and (10) and indicator (11) show simple means for visibly indicating that a detector is faulty. More complex fault indication means may be used e.g. means in which a single indicator flashes when the detector is operating normally, stops flashing or changes frequency or changes colour when the detector is faulty, and is on continuously when a fire is detected.
EP99307216A 1998-09-28 1999-09-21 Signalgeber und Überwachungssystem Withdrawn EP0991042A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9821059 1998-09-28
GB9821059A GB2341964B (en) 1998-09-28 1998-09-28 Signalling device and monitoring system

Publications (2)

Publication Number Publication Date
EP0991042A2 true EP0991042A2 (de) 2000-04-05
EP0991042A3 EP0991042A3 (de) 2001-01-10

Family

ID=10839579

Family Applications (1)

Application Number Title Priority Date Filing Date
EP99307216A Withdrawn EP0991042A3 (de) 1998-09-28 1999-09-21 Signalgeber und Überwachungssystem

Country Status (3)

Country Link
EP (1) EP0991042A3 (de)
JP (1) JP2000113341A (de)
GB (1) GB2341964B (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111754744A (zh) * 2020-06-24 2020-10-09 上海芯跳科技有限公司 消防报警控制方法及系统

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9906784D0 (en) * 1999-03-25 1999-05-19 Coventry University Enterprise Detector
WO2010035168A1 (en) * 2008-09-23 2010-04-01 Koninklijke Philips Electronics, N.V. Current limiting controlling for power supply, e.g. led driver, having automatic reset
DE202009015335U1 (de) 2009-11-09 2010-03-25 Job Lizenz Gmbh & Co. Kg Gefahrenmelder

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4369435A (en) * 1979-07-27 1983-01-18 Hochiki Kabushiki Kaisha Fire detector and fire alarm system having circuitry to detect removal of one or more detectors at a signal station
EP0253709A1 (de) * 1986-07-11 1988-01-20 FERCO INTERNATIONAL Usine de Ferrures de BÀ¢timent Société à responsabilité limitée Überwachungsanlage mit in einer Schleife gespeisten Detektoren
US5440293A (en) * 1992-05-29 1995-08-08 Pittway Corporation Detector supervision apparatus and method
GB2313690A (en) * 1996-05-29 1997-12-03 Rafiki Protection Limited Alarm monitoring system identifies line and detector head removal faults
US5798692A (en) * 1996-04-01 1998-08-25 Integrated Sensor Solutions Digital compensation circuit for calibration of sensors

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6346596A (ja) * 1986-08-14 1988-02-27 ニツタン株式会社 火災警報設備

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4369435A (en) * 1979-07-27 1983-01-18 Hochiki Kabushiki Kaisha Fire detector and fire alarm system having circuitry to detect removal of one or more detectors at a signal station
EP0253709A1 (de) * 1986-07-11 1988-01-20 FERCO INTERNATIONAL Usine de Ferrures de BÀ¢timent Société à responsabilité limitée Überwachungsanlage mit in einer Schleife gespeisten Detektoren
US5440293A (en) * 1992-05-29 1995-08-08 Pittway Corporation Detector supervision apparatus and method
US5798692A (en) * 1996-04-01 1998-08-25 Integrated Sensor Solutions Digital compensation circuit for calibration of sensors
GB2313690A (en) * 1996-05-29 1997-12-03 Rafiki Protection Limited Alarm monitoring system identifies line and detector head removal faults

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111754744A (zh) * 2020-06-24 2020-10-09 上海芯跳科技有限公司 消防报警控制方法及系统

Also Published As

Publication number Publication date
GB2341964B (en) 2002-12-11
JP2000113341A (ja) 2000-04-21
GB9821059D0 (en) 1998-11-18
EP0991042A3 (de) 2001-01-10
GB2341964A (en) 2000-03-29

Similar Documents

Publication Publication Date Title
US4555057A (en) Heating and cooling system monitoring apparatus
US4613848A (en) Multiple-zone intrusion detection system
US3665461A (en) Apparatus for monitoring the conductors or lines of fire alarm installations
US5017905A (en) Fire alarm system
EP0616308B1 (de) Alarmanlage
NO159323B (no) Overvaakningsanlegg med flere varslere som ligger i kjede til en varslingslinje.
US6259363B1 (en) Detector removal signalling device
EP0994546B1 (de) Verbesserungen bezüglich Vorrichtungen zur Überwachung für elektrische Schaltungen
US6040769A (en) Detecting device and an alarm system
EP0991042A2 (de) Signalgeber und Überwachungssystem
US5446443A (en) Fire-alarm system
KR100327497B1 (ko) 화재경보 시스템용 라인단선 및 화재발생 감시장치 및감시방법, 이를 갖는 화재 경보 장치
US3942166A (en) Fault detection and signaling system
US3683362A (en) Protective relay using an indicator and alarm circuit
EP1369835B1 (de) Brandmelder
JPH04351422A (ja) 変流器２次回路の開放検出装置
KR100668991B1 (ko) 빌딩경보장치
US4646065A (en) Fault-tolerant control system
GB2065348A (en) Multiple alarm condition detection and signalling
JP2854495B2 (ja) 防災監視装置の過電圧保護装置
EP0967585B1 (de) Alarmanlage
US3624295A (en) Monitoring means for telegraph-type data-communications systems
JPH06266990A (ja) 防災監視装置
JPH0827874B2 (ja) 火災報知装置
JPH09161168A (ja) 防災システム

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

RIC1 Information provided on ipc code assigned before grant

Free format text: 7G 08B 29/06 A

17P Request for examination filed

Effective date: 20010115

AKX Designation fees paid

Free format text: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

17Q First examination report despatched

Effective date: 20040527

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20041007