Abstract:
A fire alarm system includes a transceiver. The transceiver has: a housing; conductors for receiving power from power lines; power output conductors for transmitting the power to a local alarm; and a connector for the alarm conductor of the local alarm. The transceiver has a trigger circuit, responsive to an alarm condition. A transmitter circuit responds to the alarm condition by injecting a signal onto a power conductor, using power line carrier technology. A receiver circuit responds to a second signal, similar to the first signal, by triggering the transmitter circuit; and by triggering the local alarm.

Description:
PRIORITY 
     This application Continuation-In-Part of and takes priority and benefit from Ser. No. 13/320,497 filed Nov. 14, 2011 and all its parent applications, for any common subject matter, and is a continuation in part thereof for any new matter. 
     Ser. No. 13/320,497 is currently pending and allowed a Bypass Continuation-In-Part of, and takes priority and benefit under 35 USC111(a) from PCT Application: PCTUS2011/036233, filed May 12, 2011, pending, for any common subject matter, and is a continuation in part thereof for any new matter. 
     Said PCT application is a non-provisional bypass application, of and takes priority from U.S. Provisional Application 61/345,056, filed May 14, 2010, when the PCT Application was filed. The present application also takes priority, for any common subject matter. 
     The present application also takes priority, for any common subject matter, from said U.S. Provisional Application 61/345,056, filed May 14, 2010, through said PCT Application. 
     Those Applications are all hereby incorporated by reference. 
    
    
     FIELD 
     The present invention is a device, and a two-wire interconnection scheme, that serves as an adapter  4  to interconnect and activate numerous residential 120 VAC operated smoke alarms  5  without the addition of a third red electrical conductor wire  6  required to trigger the independent audio alert line at the local alarm drive A. The present invention includes methods of installing and operating such a device. 
     BACKGROUND OF THE INVENTION 
     Fire Codes for buildings in most States require that one and two story dwellings maintain and often upgrade the alarm systems by interconnecting their smoke alarms and CO detectors for simultaneous operation. After interconnection, when one alarm sensor detects a hazard at one end of the house, all other installed alarm sensors, even ones located at the other end of a house, as well as each bedroom, are energized simultaneously and begin to emit their alarm sound. ( FIG. 3 ) 
     Alarm interconnection has been proven to give people more time to escape from a structural fire. That extra time results in the saving of lives and property in a far greater proportion than when interconnection is not used. 
     The conventional method of accomplishing the necessary interconnection is to install each device with a third electrical wire connection  6 . Two wires, white  6 W and black  6 B, provide the commercial power, such as 120 VAC 60 Hz power in the United States, or other commercial power, such as 230 VAC 50 Hz found in other countries. 
     A third trigger wire, usually red, is normally strung between alarms and is employed for interconnecting the low voltage signal needed to activate the other alarms installed within the building. This is typically a standard 9 VDC. Most United States Building and Fire Codes require this form of alarm interconnection in all new construction. Property Maintenance Codes require existing homes to be upgraded in this manner when and where it is feasible. When a fire or CO alarm actuates, it shorts this 9 VDC to its yellow alarm wire, which is conductively connected to the structure&#39;s red alarm wire system. 
     THE PRESENT INVENTION 
     This present invention makes it possible for all existing homes to receive the enhanced safety benefit of interconnecting all alarms in a house, while eliminating the expensive burden and inconvenience of rewiring, while still complying with state and local codes regarding alarm systems. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a circuit diagram of the present invention. 
         FIG. 2  is a perspective view of the present invention. 
         FIG. 3  is a block diagram showing use of three units of the invention in a dwelling. 
         FIG. 4  is a circuit diagram of the present invention, similar to  FIG. 1 , with a modified power supply. 
         FIG. 5  is a block diagram of the elements of the transceiver  4 . 
         FIG. 6  is a perspective view of an alternate embodiment. 
         FIG. 7  is a perspective view of another alternate embodiment. 
         FIG. 8  is a perspective view of another alternate embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 2  shows that this present invention is a interface  4  also called in this application a transceiver  4 , which simply mounts between:
         an electrical receptacle  3  that supplies the structure&#39;s 120 VAC commercial power, and   a local smoke alarm or CO detector  5  as in  FIG. 2 .       

     Other commercial power voltages will be preferred in various other countries. 
     The interface  4  comprises a 2-wire interconnected transceiver circuit, generally designated  4 J, ( FIG. 1 ) that uses power line carrier technology to inject an RF signal onto the two conductors: Black  6 B and White  6 W ( FIG. 2 ), that deliver the commercial power. 
     Three wires feed from the alarm to the transceiver, which is part of the interface unit, whose exterior housing is shown as  4 H in  FIG. 2 . From standardized connector  6 C leads: a black AC power line  6 CB; a white AC power line  6 CW; ands a Yellow line  6 CY, also shown in  FIG. 1  as Yellow A, at the local alarm drive. The transceiver  4 J ( FIG. 1 ) comprises both a transmitter circuit  7  and a receiver circuit  9 . The standard connectors  6 C vary by smoke detector brand. 
     The transmitter portion  7  of the present invention is equipped with a trigger circuit  10  used to monitor the activity of output line Yellow A, usually a yellow wire Yellow A, of the local fire alarm sensor  5  it is attached to. When a low voltage (9 VDC) output signal is received on wire Yellow A ( FIG. 1 ), from the red wire ( FIG. 2 ) of a local fire alarm  5 , the Radio Frequency (RF) transmitter  7  is activated, resulting in a Radio Frequency signal, preferably in this embodiment a sine wave of 455 KHz, being injected via wires  6 B &amp;  6 W onto the 2 wire 120 VAC power lines  6 W &amp;  6 B within the building for the purpose of activating any other fire alarm system transceiver  4  ( FIGS. 2 &amp; 3 ) attached to the same 120 VAC power lines anywhere within the same structure, and thereby sounding the local fire alarm  5 . 
     Should the 455 KHz receiver portion  9  ( FIG. 1 ) of the present invention detect the presence of a 455 KHz signal injected into the power lines  6 W &amp;  6 B from any other fire alarm sensor  5  on the 120 VAC power line, it processes that signal through a state-of-the-art microprocessor  10 A ( FIG. 1 ) using specialized software for determining the validity of the alarm status. Such software can, for example, check the duration and or frequency of the alarm signal to make sure it&#39;s not a transient signal. When the validity of the alarm condition is confirmed, the microprocessor  10 A ( FIG. 1 ) activates the local fire alarm unit  5  ( FIG. 2 ) attached to the present invention, and begins to emit the alarm sound through wire at Yellow A ( FIG. 1 ) shown also as  6 CY in  FIG. 2 . 
     This system allows as many alarms to be interconnected as desired. A smoke alarm and a carbon monoxide alarm could be in each room of as many rooms or zones as there are rooms or zones supplied by the commercial power circuit. If each alarm  5  were connected through an interface transceiver such as  4 , all would be interconnected. All would alarm in response to an alarm from any one smoke, fire, or CO alarm. 
     A further feature of the present invention is to execute an “echo” transmission of the 455 KHz. signal, when a confirmed alert is detected from another alarm  5 , so that it also acts as a 455 KHz. generator for the purpose of activating all other fire alarm units  5  attached to the building&#39;s 120 VAC power lines. This feature makes each transceiver  4  a repeater, and thereby increases the range of each alarm to every other alarm on the house circuit. 
     As in  FIG. 3 , when there is a section of a house, such as:
         Bed  1 , Hall and Bed  2 ,       

     that is already interconnected by a third conductor  6  Red, which is one of the three-wire conductors  16 - 17  therebetween, and 
     additional smoke alarms such as  5 D,  5 E and  5 G need to be interconnected to them, ( FIG. 3 ) then, 
     only one adapter, such as  4 A, is needed to connect all the transceiver  4  equipped local alarms  5  such as  5 A,  5 E &amp;  5 G to the group ( 5 G,  5 B and  5 C) that is pre-wired by three-wire conductors  16 - 17 . 
     Similarly, transceiver  4 B connects the three-wired conductor  18  group of:
         1st Floor alarm  5 D and Master Bed alarm  5 E,       

     to all the other in-house alarms  5 A- 5 C &amp;  5 G. 
     Any further additional transceiver mounted alarms would also be thereby connected to the pre-existing interconnected alarm group through the group&#39;s transceiver  4 B. 
     If:
         two devices, such as  4 A &amp;  4 B are used in a house; and   they are not on the same phase, (e.g. Circuit  2  &amp; Circuit  3 ) of the electrical supply; then a bridge circuit  11  must be installed between the two phases (Circuit  2  &amp; Circuit  3 ) in the panel box  14 .       

     Or, the installer can change the position of that particular circuit onto the same phase as the others, as by moving the 2 Wire from Circuit  3  to Circuit  2 . He can usually do so at the circuit breaker panel box  14 . 
     Thus, as many alarms can be interconnected in a structure, as there are existing commercial power supply points, without hiring a licensed electrician to run a new three-wire alarm circuit for each new local alarm  5 . 
       FIG. 4  is a circuit diagram, similar to  FIG. 1 .  FIG. 4  shows another embodiment with a slightly different power supply  20 , which is preferably a Powerex M57184N, in transmitter section  7 . To further simplify installation, transceiver  4  can be equipped with an AC plug  60   FIG. 6 , to plug directly into AC receptacles, where fire codes don&#39;t forbid such installations. This plug obviates the need to open boxes and twist wires. A disadvantage of a plug  60  is that, it may be easily unplugged, which would disable the alarm. 
       FIG. 5  is a block diagram of the elements of the transceiver  4 . Power is supplied through 110 Volt power wires  6 B and  6 W. 
     This power goes through a power line interface  20 , which provides low voltage DC power to the transceiver  4 . 
     When a 9 VDC alert input comes from detection of the smoke or CO alarm through wire  6 ; or when a manual input occurs through pressing:
         the test button on the alarm  5 , or   an optional test button  22  ( FIGS. 2, 6, 7, 8 ) on transceiver  4 ,       

     then ( FIG. 5 ) the signal is filtered through a noise eliminating micro computer  10 . 
     If a test button  22  is provided, there should also be a reset button  23  ( FIGS. 2, 6, 7, 8 ). 
     If, as in  FIG. 5 , the signal passes a screening test by the noise eliminating micro computer  10 , then a 9 VDC alarm signal is sent through output drive  24 , which actuates audible warning device  26 . 
     Additionally drive enable  30  is stimulated to actuate frequency stable oscillator  32 , which outputs a radio frequency wave, preferably in this embodiment 455 kHz, to output power amplifier  34 , which amplifies that wave. We may find as the population of these alarms becomes dense, that it is helpful to provide an adjustable frequency or provide adjustably coded signals, to discriminate between interfering alarm signals. An adjustment control for adjustable frequency or adjustably coded signals is contemplated within the scope of this invention. 
     The radio frequency (RF) wave then passes through filter  36 , through impedance matching transformer  38 , and is injected through the powerline interface  20 , into power lines  6 B and  6 W, for receipt by the other transceivers to actuate their alarms  26 . 
     When another alarm such as  5 A ( FIG. 3 ) actuates its alarm, its transceiver  4  injects a similar radio frequency signal through its powerline interface  20 , and through its powerlines  6 B and  6 W, into the electrical power circuit of the structure. 
     In  FIG. 5 , the power and RF enter circuit  4  through wires  6 B and  6 W ( FIG. 5 ). The signal goes through power line interface  20 . 
     The signal is filtered through collision protection  40 , and if it passes that screening, to receiver interface  42 . 
     A band limited amplifier  44  amplifies only a specific frequency used as the alarm frequency, preferably, in the presently preferred embodiment a frequency of about 455 kHz. Sharp band pass filter  46  further screens and narrows the frequency. This narrowed wave is then input into band limited amplifier  48  which amplifies it. The amplified wave is input to a discriminator comparator  50  which ascertains that the input signal is indeed 455 kHz, or whatever is the preferred frequency of this particular model. 
     The signal is passed from discriminator comparator  50  to noise eliminating microcomputer  10 , and if it is determined not to be noise, a signal is sent to output drive  24  which actuates sound warning  26 . 
     As part of the repeater feature the noise eliminating microcomputer  10  also passes the signal to drive enable  30 , which actuates frequency stable oscillator  32  to output the 455 kHz signal, which is amplified by power amplifier  34 . The amplified wave then passes through band filter  36  to further narrow it. The narrowed wave then passes through impedance matching transformer  38 , and then to powerline interface  20 , where the amplified signal is again injected into power lines  6 B and  6 W, for further transmission down the power line, to other alarms  4 , which might otherwise be out of range of the unit which transmitted the original alarm signal to the unit  4  depicted in  FIG. 5 . 
       FIG. 6  shows an alternate embodiment of transceiver  4  comprising a two prong plug  60  at the end of power cord  61 . Cord  61  comprises power wires  6 B and  6 W. A conventional two prong power plug  60  has a live prong  63  and a neutral prong  64 . Plug  60  may be plugged into any standard 120 VAC electrical outlet. This makes it easy for the electrically inept to install transceivers  4 , where they are not required by code to be permanently wired. 
     An optional test button  22  may be provided for an additional diagnostic tool, although the test button on the fire or CO alarm  5  can also test this part of the circuit. The advantage of the test button on unit  4  is that it allows the interface  4  to be tested independently of the detector  5 . 
     A reset button  23  is a good way to terminate such a test, although the unit can alternately be designed to use a second press of Test  22  to terminate such a test. 
     In  FIG. 7 , a three-prong power plug  62  is provided on three-conductor cord  61 . A ground wire, in cord  61 , connects ground prong  65  of plug  62 . 
     Three prongs should not be necessary, since most fire alarms have two prong plugs. But in case some building code somewhere requires a ground prong  65 , this configuration is envisioned as an alternative to an embodiment that has only two prongs  63  and  64 . 
       FIG. 8  shows a unit  84  in which the smoke detector or CO detector, or both, are integrated into the unit  84 . Additionally an alternative power plug is shown having three prongs  63 ,  64  &amp;  65  integrated onto the surface of the unit  84 . This unit  84  can be mounted on a surface by plugging it  84  directly into a power receptacle in that surface. The friction of the prongs  63 ,  64  &amp;  65  mounts unit  84  to the surface. 
     Alternatively, the integrated unit  84  may be equipped with a cord  60  and a plug  60  or  62 , as shown in  FIG. 6 or 7 . 
     A “Test” switch  22  is important in this unit  84 , because there is no separate alarm unit  5 , providing its switches for testing. A reset switch  23  is nice to have too.