CA1098611A - Alarm system with acoustically coupled transmitters and receiver - Google Patents

Alarm system with acoustically coupled transmitters and receiver

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Publication number
CA1098611A
CA1098611A CA311,898A CA311898A CA1098611A CA 1098611 A CA1098611 A CA 1098611A CA 311898 A CA311898 A CA 311898A CA 1098611 A CA1098611 A CA 1098611A
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CA
Canada
Prior art keywords
signal
alarm
state
signals
receiver
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.)
Expired
Application number
CA311,898A
Other languages
French (fr)
Inventor
Michael M. Meyer
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Individual
Original Assignee
Individual
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Classifications

    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B23/00Alarms responsive to unspecified undesired or abnormal conditions
    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B1/00Systems for signalling characterised solely by the form of transmission of the signal

Abstract

ABSTRACT
An alarm system in which local transmitters emit sub-stantially pure acoustic signals for at least a predetermined minimum interval. The receiver includes a microphone and amplifier for transducing the acoustic signals into electrical signals. These electrical signals pass through two bandpass stages, the second being a phase locked loop circuit. An RC
timing network is connected to the second bandpass circuit.
After about 7500 cycles of the electrical signal have been received an "alarm received" signal occurs. The "alarm received" signal is applied to the triggering input of a free-running pulse generator which supplies pulse trains to a counter and is itself halted when the counter reaches a first intermediate state. A second "alarm received" signal is required to restart the free-running puIse generator and thus advance the counter beyond said first intermediate state.
Thereafter, when the counter reaches a second intermediate state, the occurrence of the corresponding second intermedi-ate state signal actuates a suitable alarm signal to warn of intrusion or some other hazardous condition.

Description

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2`~ ~c~tion 23 ~ he present invention 29 relate~ to alarm sy~tem~, ~uch a~ intrusion alarms, ~lre alarm~,
3~ I etcO, and m~re particularly to "wirelass" alarm systems in which 31 ¦ in~ormation i~ tranYmitted from local transmitter unit~ to one or 32 ¦ more centr~l rec:eiver unit~ without the aid o wiresO

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~L~8613 1 ¦ Da~cription of the E~rior Art. Alarm ~y~temq 2 ¦wherein emergency condition ~ensors (e.~, for senaing in~iplent 3 ¦ ire, intrusion, flooding, et.c~) ~re distribut~d about premi~e~
4 ¦ to be protoctad and ~nterconnected wit11 one or more central eon-
5 ¦ trol unit~ are well-known in the prior art.
6 ¦ As i~ further well-known in the prlor art, such
7 ¦central control unita control tl~e operation of alarm ~ignal pro-
8 ¦duclng mean~, ~uch a~ bells, gonqs, bu~zers, electronic ~ounder~,
9 ¦and the like. Further, such ~rior art alarm syst~m central units
10 ¦are commonly provided with delay means ~or delaying the actuation
11 ¦o ~aid alarm ~ignal produclng means until a predetermined ti~e
12 ¦after an e~ergency condition signal iB tran~mitted to a central ~3 1 receivirlg unlt from one of ~aid amergency condition ~en30r~, and 14 urther provlded wlth key-operated dlsanmlng ~witch mean~ whereby 1~ 1a key-holdar may dlsarm the sy~tem and thu~ prevent the smi~sion 16¦ of ~aid alarm ~ignal~ by in~erting ~nd turning the key during th~
171 delay interval provided by ~aid delay mean~.
18¦ It iR al~o known in the art to provide ex~t d~lay 191 mean~, whereby the key-ho}der may arm, i,e., electrically aetuate, .
~1 tho alarm ~tem, and then leave thQ protected premls~ w~thout .
21¦ triggarin~ an alarm, provided the key-holder leave~ the protectad 22¦ premi~e~ within a ve~y ~hort predetermined delay inte~val.
231 I~ i~ al~o known in ~he prior art to reduce the 241 co~t and inaonvenience attending the installation o priQr art ~51 alarm ~y~tems by providin~ "w~reless" lnterconnection~ bekw~on 26¦ group~ ~ emerqancy condition ~en~or~ and the central control uni~
271 or uni~ a8aociated with ~aid groups; each such ~roup of emer~ency i8¦ conditl~n ~en~or~ being phy~ically located in clo8e pxox~mity to 291 each other~ e.gO, ~n a 8ingle room or wing of a bulldln~, whsreby 3~1 they can ea~ily be interconnected with a local tr~n~mitter unit by 311 m~a~ o light~ ~ub~tantlally invisible wire~. In th~e prior art ¦ "wirs1-s3- a srm 9y8tsma, ~11 of ths local tran~m1ttJrs of the , . , ' ~
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1 ¦ ~ystem are cormected by wirele~i~ llnlc me~n~, e.g., radlo wave~ or 2 ¦ carrler signals on ps:wer wirlng, to a ~uitable receiver which it i3 ¦ ~elf ~orm~ a part of the central control unit.
4 ¦ I~ ha~ been found, however, that both the priox 5 ¦ axt radio wave and caxrier tyE)es of "wireless" alar~ 9y3tem8, ancl 6 ¦ e~pec:ially those o~ relstlvely llttle electronic complexity, and 7 ¦ thu~ low coqt, are susceptible~ to "fal e alarmsn, prc-duced when stray electrical ~lgnal~, e.g.,, emana~ed b~r diatherrny, r~dar, ~ talevi910n, an~ radio equipment, and certain tr~nsien~s on power 10 ¦ 11neY~ are "recalved" by the receiver o~ the central aontrol unit 11 I and int~rpreted a~ emergency conditlon ~ignals.
13 1 Swmna~ o~ the Invention 1~ ¦ It is therefore an ob~ect of the pra~ent lnven-16 ~lon to p~ovide "wis-ele~s " alarm and ot~er control sy~t~m~ whis:h 17 ¦ are r~latively inexpen3ive and ea~y to in~tall, and at tbe ~ame 18 ¦ tlma ar~ r~l~ti~rely ~re~ ~rom "~alse ~larm~1' trlggered by ~tray 19 1 electrlcal ~ignal~.
It i~ another object o~ the present inventiora to 211 pro~rid~ "wlxele~ " alaxm a~d o her ~ontrol systems wher~in the 2~ 1 ame~gency ~:ondition information provlded by er~ergenc:y ::ondition 23 1 sensoxs i~ tr~n~mitted to the c~3ntral control u~it or control u~it 2~ 1 by acou~tlc signal~ emitted by local transmitt~x unit~ ~
~5 1 I~ i~ yet another object o~ the px0sent inv~nt~ on 2~1 to p~o~rida un lque acou~tic ~ig~aals ~or u~e in acouatic wlrele~
27 1 al~ yst~m~ ,, which unique ala(:lUBtiC 3ignal~ 30 di~ti~agulsh from 28 gene~lly prava~l$~q stray acou~tic signals a~ to be dl~ingu~sh-2$~ abl6~ ~ro~ vlr1:ually all ~uch st3ray acou~ti~ . ignals by a ~oc:Lat~d 301 roceivers, thu8 greatly reducing or completely ellminating "~lse 3~ 1 al~m~sn .

32 Other ob~cts o the present inventi~n wil~ in 1 4.
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:~ ¦part b~ obvious and wlll in part appear herelnafter.
2 ¦ The pre~ent inventlon, ~ccordlngly, comprlses ¦ the featur2~ of con~truction, combination of el~men~, and ar-~1 ¦rangement of part which will be exemplified in the construction 5 ¦hereina~ter set ~orth, and the scope of the pr~sent inventlon will 6 ¦be lndicated in the appended clalm~.
7 ¦ In accordance wi~h a principal ~eature o~ the 8 ¦pre~ent invention, a remote con-trol sy~tem is provlded which com-~ ¦prise~ an acou~tic tran~mltter and an acoustlc recelver, control 10 ¦information being transmitted ~rom said acou~tlc tran~mitter to 11 ¦ ~aid acoustlc receiver ~y acoustic signal~ each consistlng o~ at 12¦ least an audible tone of predetermined minlmum duration.
1~ ¦ In accordance with another prlncipal fe~ture of
14¦ the pre3ent inventio.n9 an alarm system i~ provided which compr~e~
15¦ an acou3tic recelv~r and at lea~t one acou~tic transmitter, infor-
16¦ ma~lvn ~elng trans~tted from ~aid at lea3t ons acou~tlc tran~mlt-
17¦ ta~ t~ ~aid acou~tic receivar by aaouB~ic ~ignal~ ~ach aon~ lng
18 ¦ o~ at lea t an audible tone or' predetermined minimum durat~ on.
19 In accordance with another principal 3~e!ature o~
2~ the pre~e2lt ir~vention, a remote control ~y~t~ prov~ded which 21 comprises an acoustic txan~mitter and arl acoustia recei~r~r, con-22 1 trol in~ormation b~ing trail~mltted f~m ~aid acoui~tic tran~mitter 23 1 to ~aid acoustia receiYer by acoustic signal3 each consisti~g of 24 1 at lea3~ a 8u~tained ~ tantially purb sinu~oidal ton~ of prede-2s l t~ned pltch and predetermined minimum duxati on.
26¦ In accordan~e with yet ano her principal ~aa~ure 27 o~ ~he pre~en~ invetltion, an alarm ~y~tem ii~ provided which com-28 priss~ an ~cou$tic reaeiver and at lea~t one acou~ti :: ~ran3mitter, 2~1 inXormation l~ei~g tran~mltted from sald at l~a~t one acou~ti::
3~1 tran~lttar to ~aid acou~tic r~ceiver by acous~ic ~i~nal~ each 31¦ con8i~tlng o~ at least a 9ust~ined ~ubJtantially pure sinu~oidal 32 to~e of predot~mined pitch and prodetexmined min~mum duratlon~

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1 ¦ ~n accordanao wlth a yet further ~eature of the 2 ¦ presen~ invention, an acoustic receiver ~or ~n alarm ~ystem i~
3 ¦ provided, said acou~tic receiver comprising transducer means for 4 ¦ receiving acoustic signals and transducing them into correspondlng ~lectrical signals, and bc~dpass means for ~lLmlnating ~rom ~aid 6 correspondlng electrical slgnal~ all :~requency compon~3nt3 lying 7 ¦outside a predetermined pas~ band.
8 ¦ In accordance! with a further :feature of ~he pre~
9 ¦sen inventlon, ~aid bandpa~ means comp~i~es a fir~t ~age and a 10¦ ~econd 9tage.
11 I In accoxdance wi~h a yet further ~3ature o:~ the 1~ ¦ pre~ent invention, said~Qcond ~tage compri~e~ a phase locked loop 13 ¦ circuit.
1~ ¦ In accordance w~th an additlonal fe;~ture o the ii ¦ present invention, said zcoustic receiver y~t furthar comprises 1~ ¦ signal duration deteoting means for recei~J$ng output ~ignal~ ~rom 17 ~aid second ~tage and producing a mil~lmusn duratlon detect~ o~ sig-18 ¦ nal whenevex one of ~aid output signal~ from ~aid 3econd ~tage i~
1~ greater in duration than ~id pred~termirled minimum duxation, 2~ 1 In a~cordance with yet anothQr feature o~ the 211 pres~nt in~rention , ~aid acoustic receiver further comprise~ ~re,e-2'~ 1 rur~ing pul ~e g~nerating mean~ ~or producing a train of pulses in 231 re~po~e to each of ~ald minimum duration ~lgnals, aountar me~n~
24 1 ad~ranc~d ~xom state to ~tat~ by ~aid pulses and producing a ~ir~
25 state signal when ln a iEir~t ~ate and a ~ccond ~ate ~grlal when 2~ in a second ~a~e, and pul~e train lnterrupting means for inter- .
27 ruptinq ~aid pul3e ~rains ln respon~e to tlle occurrance oP e,aah of 28 ~3aid i~lr~t ~ta~ signal~
29 For a ~uller und~r~tanding of th~ nature and ob-301 ~ct8 o~ the i~ventlon, refarence should be had to the ollowing 311 d~tai1sd d~or~ tion~ ~ak~ in connec~on wl~h the ~ccompanyillg . .

32 1 draw~l~gs.
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Brief Descrlp-tion of_the Drawi~
FIG. 1 is a schematic circuit diagram of -the centraL
con-trol unit of a preferred embodiment oE -the presen-t invention, including the acoustic receiver thereoE; and FIG. 2 is a schematic circuit diagram of one oE the acoustic wireless transmitters of said preferred embodimen-t of the present invention.
Detailed Description of the Preferred Embodiment Referring now to Fig. 1, there is shown a schematic circuit diagram of the acoustic receiver of the preferred embodi-ment of the present invention. As will be evident to those having ordinary skill in the art, after being informed by the presen-t specification and drawings, -the schematic circuit diagram oE Fig. 1 also shows the central control uni-t circuit of the preferred embodi-ment of the present invention. It is to be understood -tha-t, in accordance with common practice in the "wireless" alarm system art, the entire circuit of Fig. 1 will sometimes hereinafter be called the "receiver" and will be referred to collectively by the reference numeral 10.
As will be further understood from Fig. 1, receiver 10 comprises a ceramic microphone 12, whereby acoustic signals from the associated alarm signal transmitters are received.
As will be evident to those having ordinary skill in the art, microphone 12 will receive many stray acoustic signals emanating from sources o-ther than associated transmitters of the preferred embodiment, and may also recelve spurious or cloaking acoustic signals from the associated transmitters of the preferred embodiment. All ~;uch stray, spurious, or cloaking signals, from whatever source, will be referred to herein as "undesired acoustic :

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signals", -to distin~uish them all from the particular acoustic signals of the present inven-tion which are the only acoustic sig-nals capable of eliciting corresponding signals on llne 14 of receiver 10 of Fig. 1 As will be evident to those having ordinary skill in the art, informed by the discussion of the transmitters of the pre-ferred embodimen-t hereinbelow, one of the acoustic signals of the present invention is produced whenever one of the associated emer-gency condition sensors, e.g., door switches, window swi-tches, e-tc., is tripped, i.e., whenever an emergency condi-tion is sensed by one of the emergency condition sensors of the alarm sys-tem of the pre-ferred embodiment.
For this reason, the acoustic signals of the present invention will sometimes herein be called "acoustic EC signals"~
~ or the same reason, the significant signals on line 14 o~ receiver 10 will sometimes be called "electrical EC signals"
hereinafter.
In the preferred embodiment, the acoustic EC signal will be a continuous train of three kilocycle per second sinusoids of at least 2.5 seconds duration. In other words, the acoustic EC signal of the preferred embodiment may be thought of as pure (sinusoidal) tone the pitch of which is 3000 vibrations per second and which is sustained for at least 2.5 seconds, or 7500 cycles or vibrations.
It is to be understood, however, that the acoustic EC
signal of the present invention is not limited to a particular frequency, and in particular is not limited to the audible frequen-cies. It is further to be understood that the acoustic EC signal of the present invention is not limited to a particular predeter-mined minimum duration, although the 2.5 second duration of the preferred embodiment has been found in actual practice to - : . , .

ll affeotively discriminate agairlst virtually all stray acoustic slg 21 nals found in the usual home or apartmerlt environment, incl~lding 3 ¦the loudspeaker outputs of television sets and high fidelity sets, 4¦ resulting in a very low "false alarm rate" as compared with radio 51 wave link or power line carrier link alarm systems of comparable 6 ¦cost to the consumer.
7 Referring again to Fig. 1, and assuming the Eirst ~¦ vibra-tion or cycle of an acoustic EC signal of the preferred ~m~
9 ¦bodiment of the present invention to have just been received by 10¦ microphone 12, the operation of receiver 10 which produces the 1~¦ correspo~ding electrical EC signal on line 14 about 2.5 seconds 12 ¦later will now be described.
13¦ As will be apparent to those having ordinary 14 ¦skill in the art, the output signal from microphone 12 is condi-15 ¦ tioned by a matching network 16 of well-known type and then ampli-16 ¦fied by an integrated circuit operational amplifier connect~d as a 17 Ihigh quality audio amplifier 18, producing at point 20 a signal 18 ¦which i~ the electrical equivalent of the to~al ~coustic signal re-19 ¦celved ~y microphone 12, including no~ only the said acous~ic EC
20 ¦si~nal but also any spurious or cloaking signals produced by the
21 ¦transmitter producing ~aid acou~tic EC signal and stray acoustic
22 ¦signal~ ~rom other sour~ee. The matching network and the auxi-2~ ¦ llary components making up audio amplifier 18 are such as may be 24 ¦9~1ec~d by tho~e having ordinary skill in the art without the 25 sxerci~e of i.nvention.
~6 ¦ For clari~y, it is pointed out here that the 27 signal at point 20 is not the electrical EC signal descrlbed here-28 I inabove and pro~uced on line 14.
29 Re~erring again to Fi~. 1 it will be understood 30 ¦ by tho~s having ordinary skill in the art/ without the exercise of 31 ¦invention, that audio amplifier 18 is connected in cascade with an 32 integrated circuit operational amplifier connected wi~h certain I . ` 9 .
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discrete circuit components to provide a very narrow band pass fil-ter 22, and with ano-ther stage of high ~ualiky audio arnplifica-tion 2~. The integrated circuit operational amplifier and associ-ated discrete components of active band pass filter 22 are so sel-ected that the center of frequency of ac-tive band pass filter 22 is 3 kilocycles per second (3kHz) and the Q of this filter is about 5 to 20.
Thus, it will be understood that the signal occurring at point 26 at the abovesaid assumed time, i.e., -the time when the first cycle or vibration of an acoustie EC signal has just been re-ceived by mierophone 12, will be the equivalent oE the signal at point 20 s-tripped of nearly all spurious, stray, and eloaking sig-nals, i.e., will consist prineipally of a substantially pure 3000 eyele per seeond eleetrical sine wave. The signal at point 26 is supplied to the input terminal of a second band pass stage 30 via lead 28.
It is to be unders-tood that for elarity subeircuits 22 and 30 are sometimes herein referred to as "band pass means", sub-eircuit 22 being referred to as a first stage or first band pass stage and subcircuit 30 being referred to as a second stage or seeond band pass stage.
Referring again to Fig. 1, it will be seen that second band pass stage 30 eomprises a well-known NE567 phase locked loop integrated eircuit, sometimes sold variously as SE567, LM567, or NE567, and sold by the Radio Shaek Corp. under Stoek No. 276-1721.
As will be evident to those having ordinary skill in the art, informed by the present speeifieation and drawings, and parti-cularly Fig. 1, the NE567 integrated eircuit of seeond band pass stage 30 is intereonnected with eertain diserete eomponents to pro-vide a eomplete phase loeked loop eircuit. The seleetion o eompon-i ~; ,t i` -- 10 --.. - ' . :

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ent values, bias voltage magnitudes, etc., is such that -the voltage on outpu-t pin 8 of -the NE567 in-tegrated circuit is about 6.~ volts positive (direct current volts above system ground) whenever no 3 kilocycle per second signal is present at input pin 3 of the NE567 integrated circuit.
When, however, a 3 kilocycle per second electrical signal appears on input pin 3 of the NE567 integrated circuit, -the signal at pin 8 thereof drops -from the "norn~al" 6.2 volt level toward system ground, the magnitude of the drop from the "normal" voltage level being dependent upon the amplitude of the 3 kilocycle per second signal on input pin 3 of the NE567 integrated circuit.
The selection of the NE567 integrated circuit and its associated discrete components is such that in order to produce the just-described drop of the voltage signal on output pin 8 of the NE567 integrated circuit, the voltage signal on input pin 3 must have a fre~uency of 3 kilocycles per second plus or minus 4~.
Referring again to Fig. 1, it will be seen that the out-put signal on pin 8 of the NE567 integrated circuit is applied -to the common point 32 of an RC-network consi~ting of capacitor 34 and resistor 36 through a silicon diode 38.
As further seen in Fig. 1, the non-common terminal of resistor 36 iS directly connected to one input terminal (pin 8) of - an integrated circuit operational amplifier 40, and the other in-put terminal of integrated circuit operational amplifier 40 (pin 13) is connected to a relatively fixed voltage level.
s also seen in Fig. 1, the output signal from integrat-ed circuit operatlonal amplifier 40, on line 14, is the above-des-cribed electrical EC signal, or electrical emergency condition signal.
The values oE capacitor 34 and resistor 36, and the circuit type of integrated circuit operational amplifier 40, ~ along with the then relatively fixed bias potential on the lower : ¢~
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1 ¦or poL~i-tive input terminal 42 of lntegrated circuit operational 2 ¦amp1ifier ~0, are so cho~en t:hat wh~n th~ output pin 8 of the 3 ¦NES67 integrated circuit amp1ifier i9 at its above-de~cribed 4 ¦"normal" 6.2 volt positive le~ve1 capaci-tor 34 i~ continuous1y 5 ¦di~char~ed through si1icon diode 3~, and -the vo1taye oE point 32 6 ¦is c10se ~o system ground; and that when 3 kilocycle per second 7 ¦sinusoidal signals are being received at input pin 3 of the NE567 8 I integrated circuit operational amplifi~r, and thu5 the volta~e on 9 ¦output pln 8 has dropped toward system ground, diode 38 is ~lock-10 ¦ed, and capacltor 34 accumulates charge throu~h a path lncludlng 11 ¦reqistor 36 and the interna1 circui~ of inte~rated circuit opera-12¦ tional amplifier 40.
13 ¦ The effective parameters of RC-network 34, 36, 14¦ including the impedance of said internal circuit oE integrated 15¦ circult opurational amplifier 40t are so cho~en that the potential 161 at point 32 duo to increa~ing charge on capac$tor 34 w$11 not reach a ~uf iclentl~ hlgh level to excead the potential on input 18 1 terminal 42, and thus produce a ~ignal ~the electrical EC signal) ~91 until approximately 75~0 ~ucce~siv~r sub~tantlally uninterrupted 20¦ cycle~ o~ 3 kilocycle p~r ~econd signal have occurred at input pln 21¦ 3 of the NE567 integrated phase locked loop circuit.
~21 ~ut di~erently, an e1ectrica1 EC signal occuxs 231 on lead 14 after/ and only after, the compo~ite acou~lo 8ignal 241 received by microphone 12 ha~ immediately previou~ly compri~ed an 25¦ aooustic ~C slgnal, i.e.; an uninterrupt-ed pure ~inusoidal to~e 26¦ ~u9tain~d for at least 2.5 ~econds ~750~ c~c1es or ~ibration~).
271 I~ the acoustic EC signal continue9 for 2.5 sec-81 ond~ the voltage on line 14 will go to it~ L level (the H l~vel ~9 being the "n~armal" lev~1) and will remain at its L 1evel unti1 the 301 acoustic EC ~ignal ceaRes~ unl~s~ meanwhile th~ potential on ter-31¦ minal 42 change~ a~ descrlb~d hereinbelow~ in which cas~ the L
32 level ~i~nal will remain on line 14 a~ter ~he acou~tic EC signa1 I 12. `
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l ¦ ceases, ~ ¦ The acoustic receiver portion of the rece.iver or :3 ¦receiver unit lO of the preferred embodiment o~ the pres~nt inven-¦tion having been de~cribed in detail hereinahove, the central con-trol portion of receiver unit lO will now be de~cribed in detail.
6 ¦ The principal subcircuit~ of the central control 7 portion o~ raceiver lO a~e a free-running pul~e generator 48, a . ¦counter 50, an output relay amplifier 52, and output relay 54, : ¦condition ~ignal lights 56, 5a, and 60, and a key-operated arming 1a ¦~witch 62 o~ well-known -type.
11 1 Switch ~2 is interposed between th0 alternative 12 ¦circuit power sources 63 and 64 and a voltage regulator 67 which 13 ¦serves to malntain on common positive supply points 65 a relative-14 ¦ ly stable direct ~urrent voltage of approximately lO volt~. Source 15¦ ~3 i~ a 9 volt transi~tor battery (alkaline) of well-known type.
16¦ Souxce 64 is an alternating current adaptor of well-known t~pa 17 ¦ adapted to be plugged directly lnto a wall outlet, and to provide 18 ¦ approxlmately 12 volt~ direct curxent at 200 milliamperes at 1~1 po~rlt 64.
20¦ Free-running pul~e generator 48, which in the 21 ¦ preferred embodiment comprise~ the gates of a well-knowm CD4001AE
22 ¦ int~rated circuit interconnec$ed in well-known mann~r to ~erv~
23 ¦ as a ~ree-running pulse generator is triggered by each slectrical 241 EC si~nal on laad 14 to produce a train of pul~e~ on lead 6fi, 2s1 whlch pul~e~ ~erve~to advance counter 50 through it~ suace~sive 2~1 ~tate~ in the~ well-known manner. In the`preerred em~odimant 271 coun er 50 i~ a type CD4024AE integrated circuit counter.
28 In now describing the operation of the centr~l 291 control unit portion of the receiver lO o:f Fig. 1 it will first be 301 assumed tha~ the alarm ~y~tem of the preferred embodim~nt is in-31 ¦ stalled In am apartment. This installation includes one trAn~mlt-32 ter (as 1at r d~cribed in conn ctlon with rig. 2) locatqd ln e~ch~

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1 ¦room of the apar~ment~ Every door arld window of ~he ap~rkment i~
2 ¦provlded wlth a sultable alarm swi~ch unit. ~or example, the main 3 ¦door of the apartment is provicle~ with an encapsulated magnetic 4 ¦reed switch mounted on its frame and a magnet mounted on the door 5 ¦its~lf, so that~ in the well-known manner, the magnetic reed switc~
S is open whenever the main doo:r oE the apartment i8 open. The two 7 ¦terminals of this magnetic reed switch are connected in series B ¦ with othex switches similarly protecting windows in the same roo ~ ¦o~ the apartment, and thl~ series connec~ion of door and window 10 ¦alarm switches i9 itself connected across ~he two sensor terminala . .
11 ¦of the t~ansmitter for that room of the apartment, all by mea~s of 12 very liyht, virtually invisible wiring of the kind sometimes us~d 13 ¦for intexconn~cting high fidelity speakers and their a~sociated 14¦ amplifiors. Thu~, lt will be saen that if any door or window pro-15¦ tacted by on~ o~ the~e alarm ~witches is opened, the ~lrcult be 16 ¦ tween the sen~or terminals o~ the transmitter will be bro3cen or 17 ¦ Op~nad.
18 As explained hereinafter, the breaking or opening 19 of the circuit ~nt~rconnecting ~he two sen~or terminal~ of any 20 tran8m~tter cau~es the loudspeaker o~ that tran3mitter to emit an 21 ¦ acou~tic EC signal of the kind de~cribed at len~th herelnabo~re, 22 which acou~tic ~C slgnal will be sustained ~or slightly moxe than 231 7500 Yibration~ or cycles, even if the opening of the cir~uit be-241 tween the ~ensor terminals of the transmitter i~ only momentar~
2sl ~.g., 15 millisecond~ ln ~uration.
26 Further, it will be initially assumed ln describ-271 ing the operation o the central control uni~ portion of receiver ~8 lQ (F~g. l) t;hat key-operated switch 62 is opan, and that thus 291 supply poi~t~ 63 and 64 are disconnec~ed from ~he balance of t},e 30 receiver cirouit.
311 I~ æhould be noted at this point that none o~ the 321 transmitter~ l~ provlded with an on-of~ power ~Yitch. Ra~her, the ,`
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circuit of each transmit-ter is directly and permanently connected to the supply battery terminals, so that opera-ting bias is supplied to the transmi-tter circuit whenever batteries are in place in -the suitable cavity provided in the transmitter housing.
Given these presumed initial conditions, then, let it fur-ther be assumed that the sole occupant of the apartmen~ wishes -to leave the apartment, and to arm the alarm system, so that the opening of any door or window in the apartment thereafter, i.e., so long as the alarm system is armed, will result in the closing of the the contacts oE relay 54, and the consequent sounding of an alarm device connected across -the terminals of relay 54.
To thus arm -the alarm system of the preferred embodi-ment, the occupant inserts his key in key switch 62, which is mounted on the face panel of receiver 10, and operates key switch 62 to its ON state or 'icircuit closed state", thereby connecting the circuit of receiver 10 to supply points 63 and 64.
Thereafter, whenever the occupant leaves the apartment through any protected door or window (and promptly recloses that door or window) the resulting acoustic EC signal emitted by the transmitter associated with that door or window is picked up by microphone 12 (Fig. l) and, as hereinabove described, causes free-running pulse generator 48 to supply a train of pulses to integrat-ed circuit binary digital counter 50 (Fig. 1).
This train of pulses emitted by pulse generator 48 ad-vances counter 50 through its successive states of operation until it reaches a first intermedlate state of operation at which a Q6 state signal is produced at pin 4 of counter 50. Pin 4 of counter 50 is so interconnected to pulse generator 48 via line 70 and capacitor 72 that the occurrence of this first intermediate state signal on pin 4 terminates the operation of pulse generator 48, - 15 ~

.

leavincl counter 50 in its Q6 or first intermedia-te state.
It is to be par-ticularly no-tecl, however, that at -this -time, i.e., when the occupant leaves the apartment, alarm relay 54 is not operated, since the inp~t signal to relay ampli~ier 52 on line 76 is not provided by the first intermediate or Q6 state signal outpu-t pin 4, but rather is supplied from the second intermediate or Q7 state signal ou-tput pin 3 of counter S0.
The associated alarm signal means will no-t be actuated un-til the subsequen-t opening o~ an apartmen-t door or window causes the production of a second acoustic EC signal, resu]tlng in the production of an elec-trical EC (L level) signal on lead 14, thus starting pulse genera-tor 48 and causing it to emit a further train of pulses. This train of pulses successively advances counter 50, state-by-state, until the second in-termediate state or Q7 state is reached.
(In accordance with a particular feature of the present in-vention, however, the associated alarm signal means will be actu-ated if the occupan-t, on leaving the apartment, leaves the exit door standing open. In this case, the associated alarm signal means will be actuated after the exit door has stood open for approximately 15 seconds).
As is well-known to those having ordinary skill in the art, pin 3 of a type CD4024AE integrated circuit binary digital counter occupies a firs-t or L electrical signal level while this counter is in its ZERO or RESET state, and while this counter is progress-ing, state-by-state, to its Q7 state, and occupies a second or H
signal level while this counter is in its Q7 state, and while this counter is advancing, state-by-state, to its ZERO or RESET state.
Thus, when counter 50 reaches its second intermediate or Q7 state, while being advanced state-by-state by pulse generator ~ - 16 -:, ~, , . -, , ,: -: ' ' ,' ..' . ' . . ' ' .. . .. ~ .- . . . . .. .

48, an H signal appears a-t pin 3, and remains on pin 3 until pulse genera-tor 48 has pulsed counter 50 back to i-ts ZERO or reset state.
The E-l signal on pin 3, applied to pin 13 of in-tegrated circuit opera-tional amplifier ~0 via resis-tor 43, produces an H
signal at pin 13 of pulse genera-tor ~8, thus assuring that pulse generator 48 will continue operatillg ~ntil counter 50 has returned to its reset state.
Thus, the H signal on line 76, amplified by relay am-plifier 52, energizes and switches alarm relay 54 and causes alarm relay 54 to remain in its alarm device operating state until coun-ter 50 is advanced to its ZERO or RESET sta-te~
As will now be described, two features of the present invention result from the just-described mode of operation of pulse generator 48, counter 50, etc.
The first of these features is the "reentry interval"
feature which makes it possible for the occupant of the apartment on returning to the apartment to open a door of the apartment go directly to receiver 10 and turn off or disarm the system by means of key switch 62, all without sounding the associated alarm signal producing device.
This "reentry interval" mode of operation is made possible by the fact that on opening a protected door or window while the system is in the armed state and counter 50 is in the first intermediate state or Q6 state relay 54 is not operated im-mediately, or after the above said 2.5 second interval, but is only operated when counter 50 reaches the second intermediate or Q7 state. In the device of the preferred embodiment the value of resistcr 78 is so chosen and the value of capacitor 80 is so chosen that 20 seconds elapses during the advance of counter 50 from the flrst intermediate or Q6 state to the second intermediate - -~ 17 -- , .. ~ . , . , - . .

. : . ; , . . :, -: . :
.. . . . . .
- .

or Q7 state, thus giviny the occupant of the apartmen-t ample time to open a door of the apar-tmen-t walk to receiver 10 and deenergize receiver 10 by means of key switch 62 before relay 5~ operates and the associated alarm signal produc:ing device is actuated. Other values of reentry delay interval may be made selectable by means o~
a switch on the rear panel of receiver 10, such as a 12 second interval and a 35 second interval.
(It is also due -to these selected values o~ resistor 78 and capacitor 80, determining the period o~ pulse generator 48, that if the occupant accidentally leaves open the door -th.rough which he leaves the apartment the associa-ted alarm means is not actuated until the expiration o-E approximately 15 seconds, as pointed out supra.) The second of these two features is what is called the "alarm saver feature".
As is well-known to those having ordinary skill in the art, high intensity alarm bells and the like are sub~ect to burning out, i.e., being completely destroyed by heat build up from high currents ~n their operating coils, when continuously operated for ~0 as little as an hour or two.
: It is well-known to be highly desirable, on the other hand, in alarm systems in general, to substantially continuously operate the alarm slgnal producing device, e.g., high intensity bell or the like, until the alarm system is disarmed by means of : the usual key switch.
: In the preferred embodiment of the present invention this problem is solved by providing a reset connection 84 whlch .:
overrides the pulse tràin interrupting action of connection 70 dur-: ing every cycle of pulse generator 48 except any cycle immediately ; following the ree.nergization of receiver 10 by key switch 62, thus . ' . ' ' . , -'' '' : ' : ' - ~ . - ~ . , : -: ~ - . . .

.: : . . ~ . . . .
; ;'. '' ' , ,'''. . " '', ''. ' . . ',':. ' ~: ' . :

assuring -that the alarm signal producing device connected to aLarm relay 54 will be operated on approximately 50~ duty cycle by the continual cycling of counter 52 until receiver 10 is disarmed by means oE key swi-tch 62, unless the door or window the opening of which trig~ered the alarm is subsequen-tly closed.
Referring now to Eig. 2, there is shown a schematic circuit diagram of one of -the transmitters of -the preferred embocli-ment of the present invention.
The transmi-tter of Fig. 2 will ~enerally be referred to hereinafter by the reference numeral 90.
A principal subcircuit of transmitter 90 is sine wave generator 92.
Sine wave generator 92 comprises the four gates oE a CD4001AE inte~rated circuit interconnected in the well-known manner to produce a sinusoidal signal on line 94 when properly excited.
As is well-known -to those having ordinary skill in the art, such oscillators are in general very stable, in that they tend to produce very pure sinusoidal waves of substantially fixed fre-quency.
It will be noted, however, that a screwdriver potentio-meter 96 is provided for factory calibra-tion to assure that the fre-quency of the sinusoidal output wave on line 94 is very close to - 3 kilocycles per second.
Another principal subcircuit of transmitter 90 is the minimum tone duration circuit 98. Minimum tone duration circuit 98 is an RC-network the time constant o which is so selected as to assure that whenever sensor terminals 100~ 102 are disconnected, having previously been connected, sine wave generator 92 will commence to produce a continuous sine wave at terminal 94 and continue to do so for at least 2.5 seconds, even if sensor terminals ~ .

-:. :.:

- . : . . , . - :
, - : : .- . . : .

100,102 are immediately reconnected. If, however, sensor terminals 100, 102 are disconnected for more than 2.~ seconds, the subs-tan-ti-ally pure sinusoidal signal on terminal 94 continues to exist until s~nsor terminals 100, 102 are reconnected.

In accordance with a fur-kher feature of the present invention, a switch 106 is connected be-tween sensor terminals 100, 102, whereby transmitter 90 may be prevented from emitting any acoustic signals simply by operating switch ]06 into its closed position (OFF position).
As further seen in Fig. 2, each transmitter of the pre-ferred embodiment also comprises a power amplifier 110 which am-plifies the sinusoidal signal on line 94 and impresses the amplified signal upon the coil of a loudspeaker 112. Loudspeaker 112 serves as the emitter of the acoustic EC signals for the door or window switches or the like connected across the sensor t~rminals 100, 102 of the associated transmitter.
In the preferred embodiment each transmitter 90 is powered by a 9 volt alkaline transistor battery 114.
I-t will thus be seen that the objects set forth above, among those made apparent from the preceding description, are effic-iently attained, and since certain changes may be made in carrying out the above method and in the construction set forth without de-parting from the scope of the invention it is intended that all matter contained in the above description or shown in the accompany-ing drawings shall be interpreted as illustrative only and not in a limiting sense.
It is partlcularly noted that although the method and apparatus of the invention have been disclosed as emhodied in an alarm system the lnvention also embraces remote control and other communication systems embodying the method of the invention.

20 -~

I-t ls further particu:Larly noted that although the invention has been disclosed as ernbodied in an alarm system located entirely in a single building the method and apparatus of -the inven-tion also embrace alarm systems in which the protected space or apparatus is located in more than one building, or located ou-t of doors. Thus, in one embodiment of the invention, a -transmi-t-ter oE
the kind shown in Fig. 2 is installed in the personal automobile of the occupant of said apartment, whlch is parked outside the apart-ment, and the power amplifier 110 and speaker 112 of the transmitter installed in the automobile are sufficiently powerful so -that they can actuate the receiver ~Fig. 1) located inside said apartment. In this case, the terminals 100, 102 of the transmitter in -the occu-pant's automobile will be connected to suitable door switches, hood lock switches, or ignition switch contac-ts, so that the occupant oE
said apartment will be warned by actuation of his receiver (Fig. 1) whenever an attempt is made to vandalize or make off with his auto-mobile. Similarly, such a high output transmitter or transmitters may be installed in an outbuilding, whereby to warn the owner by means of his receiver, locatedin the main building, of any attempt to enter the outbuilding.
It is yet further particularly noted that although the invention has been disclosed as embodied in an alarm system wherein the transmitters are fixedly located the method and apparatus of the invention embrace alarm systems in which a transmitter is hand-carried or worn by an individual human being, such as a security guard or invalid. Thus, a security guard or invalid may be pro-vided with a small, light, inexpensive transmitter (about the size of a small transis-tor radio), whereby he or she may broadcast an alarm to an associated receiver (Fig. 1) by simply depressing a pushbutton located on the unit. Furthermore, such a portable, ~86~

individual transmitter may be provided with a mercury switch so located within the transmit-ter case as to emit an acoustic EC
signal whenever the transmitter unit is tipped on its side, but to emit no such signal as long as the transmitter unit remains upright. Such an orientation-sensiti.ve transmitter may, for exampl.e, be worn by an invalid or security guard, strapped to the upper body in its non-alarm position, and thus serve to actuate the associated receiver (Fig. 1) when the invalid, or semi-invalid, falls withou-t having closed switch 106, or when the security guard meets with foul play and thus is knocked unconscious and lies in a prone position.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

- - ~
-:

Claims (3)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An acoustic receiver for an alarm system, comprising:
transducer means for receiving acoustic signals and transducing them into corresponding electrical signals;
bandpass means for eliminating from said correspond-ing electrical signals all frequency components lying outside a predetermined pass band, said bandpass means comprising a first stage and a second stage;
signal duration detecting means for receiving output signals from said second stage and producing a minimum duration detection signal whenever one of said output signals from said second stage is greater in duration than said predetermined minimum duration;
free-running pulse generating means for producing a train of pulses in response to each of said minimum duration detection signals;
counter means advanced from state to state by said pulses and producing a first state signal when in a first state and a second state signal when in a second state; and pulse train interrupting means for interrupting said pulse trains in response to the occurrence of each of said first state signals.
2. An acoustic receiver for an alarm system as claimed in claim 1, further comprising alarm actuating means responsive to said second state signal to actuate visible or audible alarm means.
3. An acoustic receiver for an alarm system as claimed in claim 2 in which said second stage comprises a phase locked loop circuit.
CA311,898A 1977-09-26 1978-09-22 Alarm system with acoustically coupled transmitters and receiver Expired CA1098611A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US836,755 1977-09-26
US05/836,755 US4207559A (en) 1977-09-26 1977-09-26 Alarm system with acoustically coupled transmitters and receiver

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CA1098611A true CA1098611A (en) 1981-03-31

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Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4450436A (en) * 1979-09-07 1984-05-22 The Stoneleigh Trust Acoustic alarm repeater system
US4396910A (en) * 1980-05-02 1983-08-02 American District Telegraph Company Coded security switch
CA1141004A (en) * 1981-04-24 1983-02-08 Vincent Varano Alarm system activated by buzzers
US4602357A (en) * 1982-02-12 1986-07-22 Ensco Inc. Coded acoustic alarm transmitter/receiver system
US4755792A (en) * 1985-06-13 1988-07-05 Black & Decker Inc. Security control system
FR2586875A1 (en) * 1985-09-02 1987-03-06 Leray Jacques Home system for altitude and frequency customised one-way logical communications using cylindrical ultrasonic transducers
US4661720A (en) * 1986-06-09 1987-04-28 The Watt Watcher, Inc. Occupancy sensor
US4751399A (en) * 1986-12-11 1988-06-14 Novitas, Inc. Automatic lighting device
US4929925A (en) * 1988-02-24 1990-05-29 Bodine David B Alarm system
US5103214A (en) * 1990-09-07 1992-04-07 Minnesota Mining And Manufacturing Company Auxiliary alarm
US5742231A (en) * 1996-07-16 1998-04-21 Kolodin; Louis Intrusion detection system
US6078253A (en) * 1997-02-04 2000-06-20 Mytech Corporation Occupancy sensor and method of operating same
US5986357A (en) * 1997-02-04 1999-11-16 Mytech Corporation Occupancy sensor and method of operating same
US6078269A (en) * 1997-11-10 2000-06-20 Safenight Technology Inc. Battery-powered, RF-interconnected detector sensor system
GB0010375D0 (en) * 2000-04-29 2000-06-14 Mclaughlin Brian F Smoke alarm
US20130165809A1 (en) * 2010-07-29 2013-06-27 Digisense Ltd. Monitoring physiological condition of a subject

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3440347A (en) * 1966-02-02 1969-04-22 Spenko Intern Inc Remote control plug-in unit
US4001805A (en) * 1975-04-03 1977-01-04 Golbe Alvin V Sound activated alarm system

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