| I claim: j A fire alarm system 4 for a structure, said fire alarm system comprising: a two-wire interconnected transceiver 4 J that uses power line carrier technology to inject a radio signal onto two power conductors, 6B & 6W, the transceiver 4J comprises: a transmitter circuit 7; and a receiver circuit 9; the transmitter circuit 7 of comprises a trigger circuit 10, attachable to an output line of a local fire alarm 5, said trigger circuit 10 can monitor said output line for an alarm condition output signal; said transmitter circuit 7 responds to said alarm condition output signal by injecting the radio signal onto the two power conductors; said radio signal would activate any second fire alarm system attached to power lines in said structure. 2. A fire alarm system according to claim 1, in which said trigger circuit 10 includes a microprocessor 10A, for determining a validity of an alarm status, before activating said microprocessor's local alarm. 3. A fire alarm system according to claim 1, in which said the transmitter circuit 7 echoes the alarm condition output signal, thus serving as a repeater to increase a range and a reliability of the alarm condition output signal. 4. A kit comprising the fire alarm system according to claim 1, and at least a second fire alarm system according to claim 1. 5. An installation in the structure, said installation comprising the fire alarm system according to claim 1 , and at least a second fire alarm system according to claim 1. 6. A fire alarm system according to claim 1, said fire alarm system comprising: a two-wire interconnected transceiver circuit 4 J that uses power line carrier technology to inject an RF signal onto two power conductors 6B & 6W, the transceiver circuit 4 J comprises: a transmitter circuit 7; and a receiver circuit 9; the transmitter circuit 7 comprises a trigger circuit 10, attachable to an output line of a local fire alarm, said trigger circuit 10, can monitor said output line for an alarm condition output signal; said trigger circuit 10 includes a microprocessor 10A, for determining a validity of an alarm status, before activating said microprocessor's local alarm; said transmitter circuit 7 responds to said alarm condition output signal by inj ecting a radio signal onto the two power conductors; said radio signal would activate any second fire alarm system attached to power lines in said structure; in which said the transmitter circuit 7 echoes the alarm condition output signal, thus serving as a repeater to increase a range and a reliability of the alarm condition output signal. 7. A kit comprising the fire alarm system according to claim 6, and at least a second fire alarm system according to claim 6. 8. An installation in the structure, said installation comprising the fire alarm system according to claim 6, and at least a second fire alarm system. 9. A fire alarm system according to claim 6, in which the radio signal is 455KHz. 10. An installation according to claim 9, in which two alarm systems are not on a same phase, further comprising a bridge circuit 11, installed between the two phases. 11. An installation according to claim 9, in which two alarm systems are not on a same phase, in which an installer changes the position of one of said two alarm systems, so that the two alarm systems are on the same phase. 12. An installation according to claim 1, wherein: a section of the structure already has a group of alarms interconnected by a third conductor and additional smoke alarms; and only one fire alarm system 4 is connected to the group. 13. A method of interconnecting alarms in a structure, without installing a third conductor, said method comprising the steps of: installing a transceiver between an alarm and said alarm's commercial power source, by: disconnecting the alarm from two power conductors that supply the alarm's power; connecting the transceiver to the two power conductors; connecting the alarm to two power input conductors of the alarm; and connecting the alarm's alarm output conductor to the an alarm input of the transceiver; similarly installing a second transceiver between a second alarm and said alarm's commercial power source. 14. A method of operating alarms, interconnected according to claim 13, comprising the further steps of: said transceiver responding to an alarm from the alarm by injecting a radio signal onto the two power conductors; said power conductors transmitting said radio signal to the second transceiver; said second transceiver receiving said radio signal; said second transceiver reacting to said radio signal by transmitting an alarm signal to the second alarm's input conductor, thereby activating the second alarm. 15. A method of operating alarms, interconnected according to claim 14, in which, following said second transceiver receiving said radio signal, there is an additional step of: verifying a validity of said radio signal as an alarm signal, before transmitting an alarm signal to the second alarm's input conductor. 16 A method of operating alarms, interconnected according to claim 14, in which in the alarm's input conductor and the alarm's output conductor are the same conductor. 17. A method of interconnecting alarms according to claim 13, when there is a group of alarms that are already interconnected by an alarm conductor 6R, including the additional step of: connecting the group by said group's alarm conductor to one transceiver. 18. A method of interconnecting alarms according to claim 13, when two transceivers 4A & 4B are used in a structure, and said two transceivers are not on a same phase, said method including the additional step of: installing a bridge circuit 1 1 between the two phases. 19. A method of interconnecting alarms according to claim 13, when two transceivers 4 A & 4B are used in a structure, and the two transceivers are not on a same phase, including the additional step of: changing one circuit supplying one of the transceivers onto the same phase as the other of the transceivers. |
Priority
This application takes priority from US Provisional Application: 61345056, filed
14-MAY-2010.
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 results in the saving of lives and property in far greater a 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 6W and black 6B, 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 6R, is normally strung between alarms and is employed for interconnecting the low voltage signal needed to activate the other alarms installed within the building. 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. 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
Figure 1 is a circuit diagram of the present invention. Figure 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.
Detailed Description
Fig 2 shows that this present invention is a transceiver 4, which simply mounts between an electrical receptacle 3 that supplies the structure's 120 VAC commercial power and a local smoke alarm or CO detector 5 as in Fig 2.
The present invention 4 comprises a 2-wire interconnected transceiver circuit, generally designated 4J, (Fig 1) that uses power line carrier technology to inject an RF signal onto the 2 conductors, (Black and White) 6B & 6W (fig. 2), that deliver the commercial power. The transceiver 4 J (Fig 1) comprises both a transmitter circuit 7 and a receiver circuit 9.
The transmitter portion 7 of the present invention is equipped with a trigger circuit 10 used to monitor the activity output line A, usually a yellow wire, of the local fire alarm sensor 5 it is attached to. When a low voltage output signal is received from the red wire 6 of a local fire alarm the 455KHz transmitter 7 is activated, resulting in a 455KHz signal being injected via wires 6B & 6W onto the 2 wire 120 VAC power lines 6W & 6B within the building for the purpose of activating any other fire alarm system 5 attached to the same 120 VAC power lines anywhere within the same structure. Should the 455KHz. receiver portion 9 of the present invention detect the presence of a 455KHz. signal injected into the power lines 6W & 6B from any other fire alarm sensor 5 on the 120 VAC power line, it processes that signal through a state-of-the-art microprocessor 10A 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's not a transient signal. When the validity of the alarm condition is confirmed, the microprocessor 1 OA activates the local fire alarm unit 5 attached to the present invention, and begins to emit the alarm sound.
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 were connected through a transceiver such as 4, all would be interconnected. All would alarm in response to an alarm from any one smoke or CO alarm.
A further feature of the present invention is to execute an "echo" transmission of the 455KHz. signal, when a confirmed alert is detected from another alarm 5, so that it also acts as a 455KHz. generator for the purpose of activating all other fire alarm units 5 attached to the building's 120V AC 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, and the three-wire conductors 16-17 therebetween, and
additional smoke alarms such as 5D, 5E and 5G need to be interconnected to them, (Fig 3) then,
only one adapter such as 4A is needed to connect all the transceiver 4 equipped alarms such as 5 A, 5E & 5G to the group (5 A, 5B and 5C) that is pre-wired by three-wire conductors 16-17.
Similarly, transceiver 4B connects the three-wired conductor 18 group of:
1st Floor alarm 5D and Master Bed alarm 5E, to all the other in-house alarms 5A-5C & 5G.
Any further additional transceiver mounted alarms would also be thereby connected to the preexisting interconnected alarm group through the group's transceiver 4B.
If:
two devices, such as 4A & 4B are used in a house; and
they are not on the same phase, (e.g. Circuit 2 & Circuit 3) of the electrical supply; then a bridge circuit 11 must be installed between the two phases (Circuit 2 & 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. 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 alarm.
To further simplify installation, transceiver 4 can be equipped with an AC plug, to plug directly into AC receptacles, where fire codes don't forbid such installations. This plug obviates the need to open boxes and twist wires. A disadvantage of a plug is that, it may be easily unplugged, which would disable the alarm.