Modular emergency or weather alert interface system
Contents
1. It has been found that a digital voice recorder DVR chip is very effective for recording alert message 18 Many such chips are available and this technology is advancing forward at a dramatic rate Any such chip now known or hereinafter invented in which approxi mately twenty 20 seconds of warning message may be placed upon and which will run thorough one message each time a logic signal is sent from alert message timer 14 can be used in emergency alert interface system 2 For reference FIG 5 is a schematic of a simple play record circuit the ISD Information Storage Devices DVR integrated circuit called the ISD 1000A which may be used in the herein disclosed invention It is preferable to have the ability to record and change alert message 18 onto the DVR through press ing record button 60 and placing audio into electret microphone 44 connected to the DVR board This enables the control operators to record custom mes sages for specific listening audiences In commercial amateur radio and public service fire police ambu lance utility etc a two second audible alert tone fol lowed by the words Check for weather alert on 162 55 Megahertz has been found to be an understandable and efficient alert message The message may be customized for various services as needed For example acknowl edging that the system is tested at least once a week it may be preferable to have a more discrete alert message such as Manager che2. adjustable It was found in trials that this was too often and was ex tremely annoying to the listeners The invention de scribed herein permits the user to adjust alert message timing cycle From experience this was found to be optimally approximately once per minute The audio mix level between the alert message audio level and the second communication system audio is not independently adjustable on the RC 85 In practice the RC 85 alert message level effectively blocked commu nication on the second communication system during each alert message which occurred each 15 fifteen seconds during the alert cycle For the alert system to be accepted by the users of the second communication system it must not interfere with potential emergency communication on the second communication system The feature of setting the audio level of the alert mes sage at a level to not interfere with ongoing communi cation is not disclosed in the controller manual Addi tionally the feature on the controller to be used for the weather alert is primarily for a latching repeater site alarm which is meant to be loud to catch listener s atten tion without respect to permitting ongoing communica tion 5 444 433 5 The RC 85 alarm once activated can only be deacti vated by the use of a usually secure code usually held only by control operators of system In most cases the control operators will not be available to reset the sys tem in the ev
3. frequencies the second communication system effectively acts as a repeater for the NWS weather radio thereby increasing the effective range and coverage of the NWS transmit ter without further cost or equipment Instead of being limited to approximately a forty mile radius coverage from the NWS transmit antenna the new area of cover age becomes the second communication system s area of coverage From experience it has been found that most people who purchase weather radios locate them in their home or in an unattended office where the listener may not find out about an alert for hours or days after the alert until that person returns to the radio When the impor 20 25 30 40 45 55 60 65 4 tance of the alert requires a response time often mea sured in minutes the fact that the alert was issued an unknown time possibly hours or days before being discovered makes the warning close to meaningless The time when a weather alert becomes extremely urgent is when people are away from their usual shel ters and are out in their cars boats airplanes or are simply outside In these circumstances a weather alert radio sitting at home or in the office is essentially worth less Even if the weather radio is in an attended office such as the principal s office of a school it still takes a knowledgeable person to understand the meaning of the weather alert alarm to find out the details of the alarm and to issue
4. from the first communication system In operation an emergency alert signaling tone is re ceived from the first communication system by the emergency alert interface system which causes a prere corded alert message to automatically be transmitted on the second communication system for an adjustable number of cycles wherein the audio from the prere corded alert message is mixed with the audio from the second communication system so as to permit both audio messages to simultaneously be transmitted on the second communication system Additional features taught herein include the transmission of a subaudible signaling tone on the second communication system to permit listeners on the second communication system to filter out all non emergency communication on that system until the subaudible signal is transmitted and the ability to permit a second communication system lis tener to access and link and the first communication system to the second communication system to permit immediate access to the alert message on the first com munication system through the second communication system 20 Claims 5 Drawing Sheets 5 444 433 Sheet 1 of 5 Aug 22 1995 U S Patent 301340 1SV9J403 SMN 40193130 ONY a walsis AAS WJA LUSTY XM VANJINV NWO ONS ji 342631 g JIWSNVUL OV XM O YiT Ndi An l 9 be VNAGINY a TES 313034 OIQVY XM 9E ae fy ey ee E PWE SAN Ne w I Z U S Patent Aug 22 1995 Sheet 2 of 5 5 444
5. 433 THRESHOLD 6 5 CONTROL VOLTAGE COMPARATOR 2 TRIGGER FLIP FLOP 4 RESET E OUTPUT MM OUTPUT ye kd DISCHARGE 7 GROUND AMPLITUDE U S Patent Aug 22 1995 Sheet 3 of 5 5 444 433 Fig 3A Vec 5 to 15v 0 WO 10 00 00 pSEC ySEC mSE mSEC mSEC SE SEC TIME DELAY t U S Patent Aug 22 1995 Sheet 4 of 5 5 444 433 Fig 4A FROM ALERT 14 CYCLE TIMER 5to 15v a 12 OUTPUT PULSES 459 Et 12 WV Htl t2 CHARGE ON CI RI I 1 10 00 10 100 Hz Hz Hz tz KHz KHz KHz FREQUENCY 433 5 Sheet 5 of 5 Aug 22 1995 U S Patent UIXIN wi isaray USXIN Q W K Q LSArGY UaXIN 9 YOVOAV Id Z9 ba AN 5 444 433 1 MODULAR EMERGENCY OR WEATHER ALERT INTERFACE SYSTEM FIELD OF THE INVENTION An object of this invention is to provide an automatic emergency alert interface system between a first com munication system and a second communication system to automatically alert listeners on the second communi cation system to check for an alert message on the first communication system Another object of this invention is to create a reliable inexpensive totally automatic and modular emergency alert interface system between the two communication systems Another object of this invention is to alert listeners on the second communication system of the alert issued on the first communication system while simultaneously not disrup
6. 5 50 60 65 10 ing with any primary communication on secondary communication system 22 In practice it has been found that setting the rebroadcast to be completely and auto matically overridden by audio on second communica tion system 22 to be acceptable since the rebroadcast information is a continuous tape which will repeat every few minutes and since this information is also available from a number of media sources From the above it is apparent that this interface system is extremely simple to construct is extremely versatile and can easily be installed in a multitude of communication systems without much modification Such a system would be extremely useful if placed at the transmitter of a public safety communications sys tem such as police fire or ambulance or public utility communications system such as telephone electric or gas company This system will enable the weather ser vice to automatically alert the members of these vital public services of a impending weather alert without interfering with two way communications already in progress An emergency alert interface system 2 may easily be placed on amateur radio repeaters AM and FM commercial transmitters marine band land mobile aviation and any other conceivable communication systems to automatically alert listeners to an impending weather emergency which may directly affect the lives and property of listeners It will be apparent that numerous modificat
7. United States Patent u Gropper 54 MODULAR EMERGENCY OR WEATHER ALERT INTERFACE SYSTEM Daniel R Gropper 9908 Dale Ridge Ct Vienna Va 22181 21 Appl No 207 537 76 Inventor 22 Filed Mar 7 1994 51 Int CUS sssscccccsaronsensnosasnsanninussesnnessvene Go1W 1 00 52 OO tanta 340 601 340 539 340 309 15 455 57 1 379 37 58 Field of Search 340 601 539 309 15 455 38 2 38 4 67 7 57 1 379 37 38 39 40 41 48 49 50 51 381 119 56 References Cited U S PATENT DOCUMENTS 3 626 098 12 1971 Lee eeesssssssssssesrossssnereresreses 379 51 3 975 583 8 1976 Meadows 348 460 4 031 467 6 1977 Singleton 455 57 1 4 524 243 6 1985 Shapiro rrrrrrrereerererreresaene 379 38 5 148 491 9 1992 Sakamoto et al 00 381 119 OTHER PUBLICATIONS The Bearcat Alert receiver User s manual 1994 ACC Reporter Controller Owner s Manual p 8 4 Apr 1987 Primary Examiner John K Peng Assistant Examiner Julie Lieu 57 ABSTRACT This invention relates to an automatic emergency or Q WX RADIO TRANSMIT ANTENNA 4 NWS FORECAST OFFICE a US005444433A 11 Patent Number 45 Date of Patent 5 444 433 Aug 22 1995 weather alert interface system between a first communi cation system on which an emergency alert signaling tone is transmitted to indicate the occurrence of an emergence condition and a second communication system different
8. cially available weather alert radio intended for home use be encased in a RF resistant metal box to prevent desense and intermodulation from other strong nearby trans mitters which will potentially interfere with the recep tion by that receiver of NOAA Weather Radio Using normal radio engineering techniques it may be prefera ble to take the commercially available weather alert radio out of its plastic housing and to mount the pc board directly in a metal RF resistant metal enclosure Many commercial radio services including the ama teur radio frequencies may permit the retransmission of NOAA Weather Radio broadcasts directly on second communication system 22 This may be accomplished by connecting speaker outputs of the NOAA weather alert radio 8 to second communication system 22 auxil iary input Any presently or hereinafter invented method may be used to initiate the retransmission of NOAA weather radio over second communication system 22 generally designated 34 These may include a listener operated signal such as DTMF or another signaling tone or sequence A timer should be placed in line to automatically terminate the rebroadcast after a set period of time Means should also be provided to permit listeners to manually terminate the retransmis sion Finally the rebroadcast should be set to be in a subservient role to any other ongoing communication on second communication system 22 to avoid interfer 10 20 25 35 4
9. ck for code 99 where it is impor tant to not unnecessarily frighten or panic specific lis teners such as shoppers in a department store In such an instance a manager or a clerk would be trained to check the NOAA weather radio to determine if the situation was a test or an actual emergency that would need to be tactfully publicly announced The versatility of this emergency alert interface system 2 is the ability to adapt itself for numerous situations to be useful with out being unnecessarily annoying or frightening It has been found that a battery back up is important to preserve the readiness of the DVR recorded mes sage as well as to avoid false alerts due to momentary power failures Placing a twelve volt lantern battery 46 in parallel with the power supply where the positive terminals of the lantern battery and the power supply are fed through a diode junction has been found simple and cost effective In this manner when the power supply drops below twelve volts due to a power failure the twelve volt battery maintains the logic and integrity of the DVR and the weather alert radio Since the weather alert radio runs on nine volts instead of twelve volts a simple nine volt fixed regulator may be used to convert twelve volts to nine volts to power the radio During each alert cycle three audio signals are mixed They are 1 the audio from the second commu nication system 26 by mix adjustments 30 2 the alert tone for the sec
10. communication system operator to select and change the warning message on the emergency alert interface system to meet the system s specific needs Another object of this invention is to permit listener access to the alert message on the first communication system through the second communication system Another object of this invention is to save lives and property through the notification of the public of the issuance of a weather or emergency warnings when they are outside and away from shelter but still have access to a second communication system SUMMARY AND BACKGROUND OF THE INVENTION Although this invention may be used as an interface between numerous emergency first communication systems a primary application of this invention is be tween the United States Government s National Weather Service s NWS National Oceanic and Atmo 10 15 20 25 30 35 40 45 50 55 60 65 2 spheric Administration s NOAA Weather Radio as the first communication system and numerous second ary communication systems including but not limited to school office building or hospital public address systems public utility and public safety such as fire and police radio systems commercial land mobile commu nication systems commercial AM or FM broadcast radios marine band radio communication systems ama teur radio communication systems or just about any other type of communication system NWS forecast of
11. d to accomplish this coordina tion is to derive the necessary logic 28 from the output voltage of alert message 18 digital voice recorder Fur ther reference is had to FIG 5 an logic interface section 28 having the legend To Xmitter Press To Talk Logic Line Second Communication System The reference line shows a connection from the press to talk logic line 28 of second communication system 22 to the collector 68 voltage of transistor O1 This voltage is normally held at logic high normally 5 V by Vcc 62 through 47K resistor R8 64 When O1 is energized through O1 s base 66 the logic output 28 connection to O1 s collector 68 is brought to a logic low state 0 V O1 can be ener gized manually through playback switch 54 S1 and 47K resistor R5 70 or automatically through the out put voltage provided by Sp 72 speaker when audio is present at the speaker output as applied through 47K resistor R7 74 Thus when O1 is ener gized collector 68 voltage at O1 drops from 5 V to0 V and press to talk logic line 76 for second communication system 22 is activated to permit alert message 18 to automatically be retransmitted on second communica tion system 22 Second communication system 22 is automatically unkeyed when alert message 18 has fin ished playing as a result of the voltage dropping to zero at SP 72 at the end of each play cycle From experience in actual high RF environment repeater sites it is imperative that the commer
12. e logic output of the alert radio receiver is input into an alert cycle timer 12 The alert cycle timer 12 governs the length of time that the emergency alert interface system is in the alert mode as opposed to being in the standby or ready mode The alert cycle timer 12 may be of any conventional type of timer that can be activated by a logic signal now known or here inafter invented As shown in FIGS 2 and 3A an inex pensive and reliable alert cycle timer 12 can be based on a 555 or equivalent timer integrated circuit wired in a standard and known monostable one shot mode In practice configuring the alert cycle timer 12 with an R C circuit with a one megaohm potentiometer 78 and a 470 microfarad capacitor 80 will permit an adjustable approximately ten 10 minute alert timing cycle upon receiving a simple logic signal from the detector 10 A ten minute cycle per alert has been found to be the upper end of optimum for the alert cycle FIG 3B shows the resistor capacitor circuit reset cycle for the 555 timer in the monostable mode For ease of servicing and for users to readily deter mine the status of the emergency alert interface system 2 status light emitting diodes 40 and 20 LED may be connected to the input and output of alert cycle timer 12 LED 40 is connected to the input of alert cycle timer 12 and shows that the alert system is powered up and ready to respond to an alert message LED 20 is attached to the output of aler
13. eed to spend a significant amount of extra money and effort setting up an outside antenna Many NOAA weather radio listeners do not have the time patience money and or expertise to put up such an antenna and accord ingly may miss the warning message Many dwellings do not permit outside antennas Another problem is that the reliability of the radios available to the general public is at best moderate due to a number of economic and engineering factors The weather radios are required to be moderately priced by the requirement that the price needs to be low enough so that people will consider buying a special radio If the price were extremely high fewer people would be able to afford this important communication warning system Since the receivers are required to be moder ately priced in an effort to encourage wide distribution thereof the engineering sensitivity and selectivity tends to be similarly moderate The invention taught herein overcomes many of the above described radio reception problems by placing a weather radio receiver at a central location with good reception for example at a transmitter site These sites are usually in high locations such on top of large build ings or mountains Since only one installation needs to be set up it becomes cost effective to invest in a special directional or yagi antenna to increase reception if needed Additionally where applicable law permits the retransmission of weather radio on other
14. ency alert tone interface sys tem as recited in claim 4 wherein said alert cycle timer is based on a 555 timer 6 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said alert message timer is an electronic timer 7 A weather or emergency alert tone interface sys tem as recited in claim 6 wherein said alert message timer is based on a 555 timer 8 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said audible alert message is electronically recorded 9 A weather or emergency alert tone interface sys tem as recited in claim 8 wherein said audible alert message is electronically recorded on a digital voice recorder 20 30 35 45 50 55 65 12 10 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said alert message further comprises an outgoing subaudible signaling alert tone 11 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said second commu nication system is a maritime radio frequency 12 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said second commu nication system is a public address system 13 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein audio information from said first communication system may be accessed by listeners on said second communication system through said second c
15. ent of a malfunction or a test of the system The proposed invention permits the alert to be instantly reset through the push of a button which can be conve niently physically or functionally located near the users to permit the system to readily be reset as needed Although not disclosed in the description of the alarm function it is possible to preset the duration of the site alarm as a controller function but it is not possible to set the repetition cycle which is fixed at fifteen 15 seconds The RC 85 has a limited digital prerecorded vocabu lary and does not have the ability to record special alert messages such as those containing subaudible signaling tones or discrete alert messages to alert management of the alert without causing undo concern to the listening public In practice these customizing features are ex tremely important to making the alert system accept able to listeners by not causing harmful interference to ongoing communication on the second communication system when the alert sounds The alert feature on the RC 85 is one subfeature of a repeater controller which usually costs near one thou sand dollars It would not be realistic to purchase a repeater controller only to receive weather alerts The proposed invention likely has a cost of a small percent age of the cost of a repeater controller thereby making the proposed invention more likely to be adopted and used by the public In view of the above disadvanta
16. er rupt the routine weather broadcast and substitute spe cial warning messages The forecasters will transmit an alert tone of 1050 Hertz Hz to activate specially de signed NOAA weather radio warning receivers tuned to special NOAA weather radio frequencies A single alert tone is normally transmitted for up to thirteen 13 seconds for selected watches and warnings Special alert receivers upon detecting the NWS sin gle alert tone are usually configured to activate an audible siren alarm in the radio and or open the squelch of the radio to let the listener hear the alert message and or flash a signaling light usually a light emitting diode or LED to alert the listener that an alert has been issued The radios can be set in a latching mode meaning that the siren or light will flash or sound continuously until manually reset or be set in an automatic reset mode which will reset shortly after the alert tone is detected Each of these alert modes has disadvantages If the radio latches in the siren mode the siren will sound continuously until the radio is manually reset If the owner of the radio is away the siren will be sounding unnecessarily for hours or even days The usefulness of the alert is usually for a short period of a few minutes for a tornado or thunderstorm up to a few hours for a winter storm Therefore since the majority of impor tant alerts are useful for only a short time frame it is not useful having the alert so
17. esentative NWS forecast office is designated 4 and the NWS NOAA weather radio broadcast antenna 10 20 25 30 35 40 45 50 55 60 65 6 is designated 6 It will be understood that the described emergency alert interface system 2 will work with any type of warning device which can be detected whether it emanates from the NWS or from any other agency on any means including hardwire and radio For clarity the remainder of this specification will relate to NWS NOAA weather radio The emergency alert interface system 2 has a number of components They include a commercially available NWS NOAA weather alert radio receiver 8 having an alert signal detector 10 and a receive antenna 36 The alert signal detector 10 should be capable of detecting the alert signal from the first communication system generally 38 and producing a voltage logic output usually 5 volts or 0 volts in response thereto It will be understood that the weather alert radio receiver 8 and alert signal detector 10 can be any past present or future communications technology capable of receiving and detecting an alert signal and producing a logic output in response thereto The standard weather alert tone is a sine wave having a 1050 Hertz frequency FIG 6 is a representative drawing of an electrical signal as viewed on an oscilloscope having one section of audi ble audio 56 and one section of a modulated tone 58 with a frequency of 1050 Hz Th
18. fices around the United States con tinuously broadcast taped weather messages which are repeated every four to six minutes and are routinely revised every one to three hours or more frequently if needed Most of the stations operate twenty four hours a day Under a January 1975 White House policy state ment NOAA Weather Radio was designated as the sole government operated radio system to provide direct warnings into private homes for both natural disasters and nuclear attack This capability is to supplement warnings by sirens and by commercial radio and televi sion Due to the expense unreliability and ineffective ness of warning sirens many siren systems around the country have been deactivated The NWS operates about three hundred and eighty 380 NOAA weather radio stations Approximately ninety 90 percent of the nation s population is within listening range of NOAA Weather Radio broad casts A similar network of about fifteen stations using the same frequencies broadcast continuous weather information across much of southern Canada NOAA Weather Radio broadcasts are made on one of seven high band FM frequencies ranging from 162 400 to 162 55 megahertz MHz These frequencies are not found on the average home radio now in use However a number of radio manufacturers offer special weather radios to operate on these special frequencies with or without the emergency warning alarm During severe weather NWS forecasters can int
19. ges the RC 85 and similar controllers are not an acceptable substitute for the proposed invention The terse description in the controller s owner s manual does not suggest the impor tant features of the instant invention which have been found in practice to be the features that make the inven tion useful and acceptable to the listening public BRIEF DESCRIPTION OF THE DRAWINGS FIG 1 is a system block diagram of the emergency alert interface system FIG 2 shows 555 specifications and an internal block diagram of the 555 integrated circuit FIG 3A shows the basic monostable timer circuit FIG 3B shows the resistor capacitor circuit reset cycle for the 555 timer in the monostable mode FIG 4A shows a basic astable circuit based on the 555 integrated circuit FIG 4B shows the resistor capacitor reset cycle for the 555 timer in the astable mode FIG 5 is a schematic of a simple play record circuit for the ISD 1000A DVR integrated circuit and the logic interface to the second communication system FIG 6 is a representative drawing of an electrical signal as viewed on an oscilloscope having one section of audible audio and one section of a modulated tone with a frequency of 1050 Hz DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION FIG 1 is a system block diagram of the emergency alert interface system 2 Block 86 in FIG 1 represents the components in FIG 1 on which greater detail is shown in FIG 5 A repr
20. ions of the above invention may be made without departing from the nature intent or spirit of the invention as claimed herein What I claim is 1 A weather or emergency alert interface system comprising a a first communication system b a signaling tone transmitted on said first communi cation system a receiver tuned to said first communication sys tem further comprising a detector to detect said signaling tone wherein said detector generates a changed logic level output in response to detecting said signaling tone an alert cycle timer having a controlled logic level output wherein said alert cycle timer is activated by said changed logic level output from said detec tor and wherein said logic level output of said alert cycle timer changes for a set period after said alert cycle timer has been activated by said changed logic level output from said detector an alert message timer having a controlled logic level output wherein said alert message timer is activated by said changed logic level output from said alert cycle timer and wherein said logic level output of said alert message timer periodically pulses at preset intervals during the period when said alert cycle timer has been activated f an audible prerecorded alert message having an adjustable outgoing audio level wherein said audi ble prerecorded alert message plays a complete message cycle in response to each logic pulse from said alert message
21. ommunication system 14 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said second commu nication system is a public safety communication sys tem 15 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said second commu nication system is a public utility communication sys tem 16 A weather or emergency alert tone interface sys tem as recited in claim 1 further comprising a listener activated alert cycle timer reset switch 17 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said first communica tion system is NOAA weather radio 18 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said second commu nication system is land mobile radio 19 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said signaling tone has a frequency of 1050 hertz 20 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said audible prere corded alert message may be changed by the system control operator UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO 5 444 433 DATED August 22 1995 INVENTOR S Daniel R Gropper it is certified that error appears in the above indentified patent and that said Letters Patent is hereby corrected as shown below On the title page under item 56 Refe
22. ond communication system 16 by mix adjustment 50 and the 3 alert message 18 by mix ad justment 52 The relative balance of these three audio levels is critical to the successful operation of the inven tion The audio from the second communication system 26 is set at the normal levei for effective communica tion The alert tone for the second communication sys tem 16 is set at about twenty percent 20 deviation so as to reliably open squelches but not so loud as to be noticeable to the listeners The alert message 18 audio level is to be set at a level so as to mix into the back ground of any ongoing communication on the second communication system 26 but not so high as to interfere with ongoing communication A fifty percent 50 to 5 444 433 9 seventy percent 70 deviation level of the alert mes sage 18 relative to the audio level of the second commu nication system 26 has been found effective The com bined and adjustably mixed audio is designated 48 and are input into the second communication system 22 and transmitted from the second communication system antenna 32 Any type of audio mixer now known or hereinafter invented in which the relative amplitude input levels are independently adjustable may be used with the invention taught herein To be completely automatic the emergency alert interface system 2 must also key the second communica tion system transmitter 22 when the alert message 18 is playing A simple metho
23. r the coordination of the ten minute cycle of the alert cycle timer 12 and the one minute alert message timer 14 permits the optimum output of an alert message generated on the second communication system 22 of once per minute for the ten minutes following the alert signal on the first communication system 12 The alert tone 16 for the second communication sys tem 22 is generated for the entire time usually ten min utes that the alert cycle timer 12 is active In this man ner any communication during the ten minute alert period also has a subaudible alert signaling tone 16 as part thereof In this manner any listener who has the equivalent of tone squelch set on his or her radio re ceiver and who hears the receiver unsquelched even during the approximately forty 40 seconds of each minute that the alert message 18 is not playing will immediately know that a tone alert has been issued on the first communication system 12 This is especially important where there is a time critical warning such as for a tornado Subaudible alert tone 16 may be generated by any known or hereinafter invented means including a spe cial CTCSS tone generating board such as one pro duced by Communications Specialists These boards are commonly commercially available in a multitude of frequencies Such boards have a level adjust potentiom eter to set the subaudible level to the correct overall output level 20 25 30 35 40 45 65 8
24. rence Cited line 13 Insert Attorney Daniel R Gropper Signed and Sealed this Second Day of January 1996 Attest hs pae Ol nisz BRUCE LEHMAN Attesting Officer Commissioner of Patents and Trademarks
25. ssage timer 14 as well as a current source for the alert tone for the second communication system 16 FIG 4 shows a basic astable circuit based on the 555 integrated circuit FIG 3B shows the resistor capacitor reset cycle for the 555 timer in monostable mode The alert message timer 14 is set up in a commonly known astable multivibrator mode The alert message timer 14 is powered up only during the time the alert cycle timer 12 is active The alert message timer 14 generates a logic pulse to the alert message 18 inte grated circuit to start the transmission of a message cycle It will be understood that any continuously cy cling logic activated message recording device such as a tape recorder may be used in this circuit A manual or remote alert cycle timer 12 reset switch 42 should be included in the system to reset the timer as needed especially during the weekly test of the system If the 555 or equivalent timer is used the standard timer reset switch configuration may be used as is shown in FIG 3A The alert message timer 14 may be a 555 or equiva lent integrated circuit with the circuitry to permit ap proximately a one 1 minute timing cycle during the time when alert cycle timer 12 is activated Use of a one megaohm potentiometer 82 and a 47 microfarad capaci tor 84 in a common astable multivibrator format as shown in FIG 4A will permit an approximate one min ute cycle which has been found to be optimum In this manne
26. t cycle timer 12 and shows that the system is in the alert mode LED 20 will tum off when the alert cycle timer 12 resets A power shut down switch 24 for the alert cycle timer 12 should be included in the circuit between the alert detector 10 and the alert cycle timer 12 This switch should be remotely operable in the event that the alert system malfunctions The switch can be any known type or hereinafter invented including relays and semiconductors This is extremely important where the alert system is placed at a transmitter site which may be a great distance from the listeners By shutting down power to the alert cycle timer 12 power is also instantly shutdown to the alert message timer 14 and the alert tone for the second communication system 16 thereby effectively and efficiently disabling the entire emer 5 444 433 7 gency alert system 2 The emergency alert system 2 is configured to permit the passive passage of audio from the second communication system 22 through the emer gency alert system 2 even when the emergency alert system 2 is powered down in order to maintain the reliability of the second communication system 22 de spite the status of the emergency alert system 2 A 555 type integrated circuit can produce an output logic voltage and will also act as a source of output current Using these features of the 555 integrated cir cuit the output of the alert cycle timer 12 is used as a current source input for the alert me
27. the appropriate warning over the public address or other alerting system Often the knowledge able person for example the principal or secretary will be away from the radio or will be busy with other mat ters when the alarm sounds thereby creating a poten tially critical delay in relaying the weather alert mes sage to the relevant public The invention described herein overcomes the major ity of the above described handicaps in the NOAA weather radio alert system in a simple inexpensive and reliable manner Previously disclosed alerting systems such as those disclosed in U S Pat No 4 031 467 entitled Alerting Process and System of Apparatus Therefor usually require the use of expensive and dedicated special radio receivers and additional trained personnel to activate the special alerting system For the reasons set out above these are the very defects in the current alerting system Some repeater controllers have the capability of being modified to provide a weather alert feature The RC 85 Repeater Controller manufactured by Ad vanced Computer Controls Inc of Santa Clara Calif Owner s Manual page 8 4 describes in general terms a weather alert feature While the described weather alert feature will transmit an alert on the second communica tion system in response to an NWS tone alert this sys tem suffers from many defects The RC 85 alert message is transmitted once every fifteen 15 seconds This period is non
28. timer asecond communication system for transmitting an outgoing message further comprising means for adjusting the audio level of said outgoing message h means for mixing said adjustable outgoing audio levels of said audible prerecorded alert message and said outgoing message on said second commu nication system in such a manner as to enable listen C 5 444 433 11 ers to said second communication system to simul taneously hear both audio messages i means electronically initiated by the activation of said alert message timer for automatically keying the transmitter of said second communication sys tem during the period when said audible prere corded alert message is playing and j means for transmission of said audible prerecorded alert message mixed with said second communica tion system audio on said second communication system when said second communication system is keyed for the duration of the activation of said alert cycle timer in time periods determined by said alert message timer 2 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said first communica tion system is radio 3 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said second commu nication system is radio 4 A weather or emergency alert tone interface sys tem as recited in claim 1 wherein said alert cycle timer is an electronic timer 5 A weather or emerg
29. ting communication in progress on the second communication system Another object of this invention is to create a simple versatile modular alert interface system which will easily connect to existing second communication sys tems without much if any modification to the second communication system Another object of the invention is to incorporate subaudible signaling tones to remotely activate receiv ers on the second communication system upon activa tion of the emergency alert interface system by the first communication system Another object of the invention is to provide a means for using the emergency alert interface system on sec ond communication systems including radios public address systems commercial AM or FM broadcast radios public safety fire and police communication systems and other communication devices such as cellu lar telephones Another object of this invention is to create an emer gency alert interface system in which the alerting agen cies such as the National Weather Service need to make no changes in their equipment or procedures cur rently in use to activate the emergency alert interface system Another object of this invention is to create an emer gency alert interface system wherein listeners on the second communication system need to make no changes to their communication receiving equipment to be alerted to the emergency condition Another object of this invention is to permit the sec ond
30. und continuously for many 5 444 433 3 hours or days The siren tends to aggravate pets The latching light is not audibly aggravating but since these radios have no time stamp the listener will not know when the alert was issued one minute or one day ear lier Finally the NWS tests the system at least once per week Therefore a latching alert system would latch in the alert setting at least once a week until reset If the system is not set in a latching mode the listener will most likely miss the alert if the listener is not near the radio at the time an alert or test signal is issued These operational problems tend to drastically de crease the effectiveness of the alerting system These defects will tend to cause the listener to turn off or ignore a potentially lifesaving time critical warning which in the case of a tornado may be less than five minutes NOAA Weather Radio broadcasts can usually be heard as far as forty miles from the NWS transmitter site The effective range depends on many factors in cluding the height of the broadcasting antennae the average surrounding terrain quality of the receiver and type of receiving antennae As a general rule listeners beyond the forty mile range need a good quality re ceiver system if they expect to get reliable reception An outside antennae may be required in these fringe areas To reliably receive NWS alerts listeners more than 40 miles from the transmitting antenna often n
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