IL27907A - Fire alarm system with monitoring devices for fire alarms connected in groups to a central station - Google Patents

Description

PATENT ATTORNEYS REINHOLD COHN MICHAEL COHN I 1 H D Π ISRAEL SHACHTER Ί ΙΙ ΙΙΙ ΝΊ Flle 26484 PATENTS AND DESIGNS ORDINANCE SPECIFICATION alarm system with monitoring fire alarms connected in groups to a central station y CERBERUS incorporated under the laws of of Switzerland do hereby declare the nature of this invention and in what manner the same is to be to be particularly described and ascertained in and by the following The present invention to an alarm a central signal to which electric alarms are connected in number of conductors central signal station and fire alarms is of the number of the inventive alarm additionally includes an apparatus electrical teat signals toy means of which are produced at the fi o bring about an electrical change i condition at an intact fire furthe the inventive system includes apparatus for and In fire generally exist quirement the operational reliability Of individual fire alarms at regular To this and in accordanc with a workable conditions are manually delivered to the individual fire alarms one after the other or in The response of the relevant alarm is controlled at its locality or a the central this technique above extremely and the consists of a number of fire for one hundred fire s or such regular a shorter time intervals can no longer come under consideration for is for these reasons that methods have been developed in which it is possible to achieve from the central conditions at ire alarms through use of electronic and to check the response conditions of all fir alarms at the central The di with such above in the reliable determination of whether ail fire of group have actually In a known a separate conductor is load each alarm back to the central During tho cheeking a signal appears at such conductor which is of response condition of the relevant This system has the drawback that requires extensive additional which of particular importance i such a monitoring device should be installed in already existing fire i is desirable provide monitoring device in whic the of conductors leading from central to the fire alarms is independent of the number of connected fire In a known of this all of the fire alarms are simultaneously caused to the of 1 the central means of a current devic at tho central station provided at one of both current delivery conductors of the fire the response of fire alarms is whereby there is checked the coincidence of total with some reference Apart from the great current consumption which has an e fect upon the choice and of the the network the emergency tower this ment is limited to groups having relatively few fire Because of the diversity of the electrical characteristics of the structural elements in alarms as well as because of limited measuring accuracy of total current the reference an analogous this technique is unreliable a larger number of fire alarms and often results false it is a object of present inventio provide monitoring device for a fire of previously type which it is possible to or monitor of per invention by the fact that the or at the central station i testing or change of electric condition of into the tho Of e tho response conditions is of of connected to of the inventive fire alarm are provided at the fire alarms which bring the checking a response of individual fire is staggered in the evaluation device determines by of counting operation whether all alarms of group According to a second of inventive ire alarm of a group are coupled with another by of a and that the logic tho checking then delivers binary signal to evaluation device whereby all the group have ponded a one fire alarm not responded will understood those will become apparent consideration to following detailed description reference to the annexed Figure 1 a of the of the fire alarms la obtained a aeries of the dividual is of the fire embodiment of the invention in the sequential of fire obtained is a circuit diagram of a second embodiment of the in which individual are connected another into circuit diagram of a aeeond example the embodimen of the in he individual fire associated therewith oscillation the d it understood that the depicted in of ionization 1 and the air content of whic rendered pletely or partially conductive preparation is known the thio fire alarm 17 switch in formed by a effect transistor Xonisation chamber functions a whereas ionization chamber 2 employed chamber and can also be replaced by or an la possible instead of the a di another semiconductor or a cold 1 2 are in seriea respect to coupled via the 10 a with the central station at are connected wit oltage gate of translator is at the point of connection of both 1 and anode coupled via a relator 5 with tho negative conductor its cathode via a with a positive feed conductor resistor 5 at the ease a par circuit incorporating the resistor and the diode wherein the and potential at the he ect transistor is selected in a translator during the operating The anode of transistor is coupled the control control rectifier 6 the cathode of is connected to the negative conductor and the connected to the positive feed conductor 10 throug the oltage divider the resistor and The loop laarranged parallel to resistor and 2ener diode la connected to tho translator the there voltage reduction is for the reason that the current which during the checking as explained not actuate any relay or simila the intact of the which connected parallel to that fire alarm 14 at supply conductors 10 to respond the chocking it in value of total current the supply conductors that total current is order of magnitude of current whic in the of an actual alarm upon of The anode current of the controlled 6 of the individual alarms can have relatively great the evaluation not place in the previously utilised analog rathe akes plaoe in accordance the invention in digital it will recognised that at the central station the winding of 11 is connected in the conductor and the secondary of to input of the evaluation circuit of individual controlled shaped at the input of the evaluation circuit which in binary form condition of a fire fire has not The evaluation of binary signals takes place digitally the form of counting certain period lm the counting of this evaluation read and co a capacitor 9 arranged parallel to reference c that t to a the of the occurs of the conductor 10 is lowered by but at the of the translator constant for 9 potential the via the of tho fie a can be selected by suitable off tho value capacitor Each capacito the dividual alarm to thus effecting a sequential through all alarms of a certain is also possible to natural delays of the Individual alarms can e order to t coincidence with to the counter with respect to the each can carried out or In switch which Interrupts the curren e of only serves to or return after a operation of delivering the all and the of the fire by delay possible to achieve in accordance the During tho tho central SZ of lino c that alarms connected to tho euppl Tho charged via tho to t aro in tho blocked if combustion gases ono there appears tho a on tube potential whereby and draws a current via tho roalotor and supply conductor current causae an device central to a Onl voltage appears the of i alarm that fire remain tho Tho checking operation la initiated by opening tho awitoh potential of tho eupply conductor now appears at tap of voltage divider tho roalotor tho roalotor increased in a ssannor that tho cathode tube of appropriate of 0 individual in tho in tho of the conductor in the does not have any effect upon tho fire a current flows in tho closed circuit of tho fire ccraprlaes tho capacitor conducting and tho roalotor current capacitor to tho voltage o tuba In eo all fire of a group in a relay in the of tho fire relay energised r a interval upon of the alarm and a wo oontaot work a can for i an at the central tho of localising or faulty alarm to dispensed it la a do with the transformer 11 and to connect work a in the a connection betwee both of the supply conductors L and Then a high current for a period of the resistor the and alarm caused to roapond durin or the operation tioning of all firo tho resistor io such manner to bo enough that the current longer about energisation of tho rela then an of tho voltage at tho point or location can bo criterion for for tho rela firo In this tho voltage a point simultaneously about of tho that after termination of the tho switch to bo to place tho in Of transformer d can also bo combined wit Tho chocking operation which can for up to at appropriate digital of eignalo which in chocking a chango of the oondi ion of also can realised by of a logic cirouit instead an illustrate particularly advantageous of typo 3 two 59 and of identical construction and which arc connected in parallel to via supply and as as via on signal conductor with the central individual and essentially correspond with larms of In the correlatio the alarms and 4o to Of will bo by following appearing in represent the of ion 23 capacitor anode ehown AS and controlled 26 In contrast of cirouit of indicating 51 28 no longer conneotod to supply but to now conductor again a roaletor 3 in loll indicating lamp of tho individual in tho normal operating whereby an of tho one or alarm arrives via conductor at central station any upon In accordance tho operation tsnncr that a tho central fire has not realised in conductor 29 by a voltage by of its smlier than tho voltage of voltago is smaller than in tho forward direction Via resistor d tho indicating and curren tho conditioha through for short time tho to thua diode in supply conduotor which initially the capacitor to partially of the switch produced the e of the translator conditions thua about of translator thereby tho controlled rectifier practical voltage of tho which toy definition smaller than If tho fire of group then the conduotor without On other appearing conducto 29 that or not the connection point a connection of further capacitor and a between the conductors L V capacitor resistors an current flows through tho tube which the capacitor for of until the voltage dropped the to the extinguishing the capacitor and As tho across tho again until it reaches individual registered at winding of a provided station If combustion enter measuring chamber the V as above and a current through the event tho of tube larger than the ignition of the tho of the associated transmitter The current during of the tube V can employed in for triggering a relay A cr another e operation initiated by dropping suppl voltage for abort period of In the C di during reduction in voltage the diode 0 to the supply voltage if tho supply voltage is again old then blacks and the capacitor via tor ao initially at an e fcy the and the v of this potential in such that The oscillations in that only w di which at the of evaluation circuit or 19 when or firo have the transformer in such an completion of the tho slightly the of tho V thereafter slowly to tho full in tho operation repeated at in the insufficientOCRQuality

Claims (1)

1. CLAIMS The embodiments of tho in which en or privilege A alarm central signal station to which electric are in whereby the of conductors independent of of an apparatus generating an electric signal b of which conditions be produced at alarms the in bring about a change in the condition at as well device for evaluating these by the features that means provided at the fire or at the central signal station the transform the of the electrical condition of the fire alarms into binary and that the evaluation device digitally the incoming binary whereby monitoring of the condition its independent of the number of connected alarms per A fire alarm according to c b the features that are provided at tho alarms which b during tho the individual fire alarms which staggered and that the evaluation device determines by of a operation whethe all alarms of a group have fire alarm to characterised by the that the of group aro connected in with one and tho for condition of a alarm binary at tho tho for in tho A to claim that a with fire of indicates of o alarm the functioning of A alarm according to having at least one chamber which to of or thermal surrounding end a switch which can controlled by this characterised that at all of fire a abou of and o are arranged to measuring and varying of which brings about tho of points of tho of tho individual fire alarms A alarm to characterised by the features that firo a a group are connected to one another in circuit that logic during the i op then a binary signal to the evaluation all iro of a have or at least firo has not responded A firo system according to by tho that tho for tho response of individual firo into binary are connected b of via a conductor with central A to by tho that oscillator ia cpcrably associated individual fire alarm which ia controlled by alarms in such a that fire alarm tho oscillations and that vidual oscillators connected via an circuit with evaluation A alarm system according to claim by features the aro connected via one conductors with tho central signal station that tho circuit ia by of a tho primary winding of which tho conductor and the secondary winding which ia connected with tho evaluation A alarm system to claim tho foaturoa that aforesaid oscillator of tooth generator Dated this 2nd May For Reinhold Cohn insufficientOCRQuality