Fire alarm power line carrier com-system
First Claim
1. A fire alarm system, in a structure having a pair of commercial power source conductors, said structure not fully wired with a dedicated alarm conductor, said fire alarm system comprising:
- an alarm;
said alarm having an alarm conductor;
an interface (4) between the alarm and said commercial power source conductors;
said interface having two power output conductors;
said interface installed by;
disconnecting the alarm from the two commercial power source conductors that supply the alarm'"'"'s power;
connecting the interface to the two commercial power source conductors;
connecting the alarm to the two power output conductors of the interface; and
connecting the alarm conductor of the alarm to an alarm wire (6CY) of the interface; and
a second interface, similarly installed between a second alarm and said commercial power source conductors;
each interface having;
a circuit (4J);
a pair of interface power input lines (6B, 6W), through which;
power, anda radio signal, as an RF (radio frequency) alarm signal,enter the circuit (4J);
a power line interface (20) through which the RF alarm signal goes;
a collision protector (40) through which the RF alarm signal is filtered, anda receiver interface (42), to which, if said RF alarm signal passes the collision protection, said RF alarm signal is transmitted;
a band limited amplifier (44), which amplifies only a specific frequency used as an alarm frequency of the RF alarm signal;
a sharp band pass filter (46), to further screen and narrow the frequency;
a band limited amplifier (48) which amplifies said RF alarm signal,a discriminator comparator (50), for input of the amplified said RF alarm signal, to ascertain that the input RF alarm signal is the specific frequency used as the alarm frequency;
a noise eliminating microcomputer (10), for;
processing the RF alarm signal from the discriminator comparator (50),ignoring noise,sending the RF alarm signal to an output drive (24),passing the RF alarm signal to a drive enable (30);
the drive enable (30), which actuates a frequency stable oscillator (32) to output the RF alarm signal;
the output drive (24), for actuating a sound warning (26);
a power amplifier (34) for amplifying the RF alarm signal;
a band filter (36) to further narrow the RF alarm signal;
an impedance matching transformer (38); and
a power-line interface (20), where the RF alarm signal is injected into an interface power input line (6B, 6W).
1 Assignment
0 Petitions
Accused Products
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.
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Citations
2 Claims
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1. A fire alarm system, in a structure having a pair of commercial power source conductors, said structure not fully wired with a dedicated alarm conductor, said fire alarm system comprising:
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an alarm; said alarm having an alarm conductor; an interface (4) between the alarm and said commercial power source conductors; said interface having two power output conductors; said interface installed by; disconnecting the alarm from the two commercial power source conductors that supply the alarm'"'"'s power; connecting the interface to the two commercial power source conductors; connecting the alarm to the two power output conductors of the interface; and connecting the alarm conductor of the alarm to an alarm wire (6CY) of the interface; and a second interface, similarly installed between a second alarm and said commercial power source conductors; each interface having; a circuit (4J); a pair of interface power input lines (6B, 6W), through which; power, and a radio signal, as an RF (radio frequency) alarm signal, enter the circuit (4J); a power line interface (20) through which the RF alarm signal goes; a collision protector (40) through which the RF alarm signal is filtered, and a receiver interface (42), to which, if said RF alarm signal passes the collision protection, said RF alarm signal is transmitted; a band limited amplifier (44), which amplifies only a specific frequency used as an alarm frequency of the RF alarm signal; a sharp band pass filter (46), to further screen and narrow the frequency; a band limited amplifier (48) which amplifies said RF alarm signal, a discriminator comparator (50), for input of the amplified said RF alarm signal, to ascertain that the input RF alarm signal is the specific frequency used as the alarm frequency; a noise eliminating microcomputer (10), for; processing the RF alarm signal from the discriminator comparator (50), ignoring noise, sending the RF alarm signal to an output drive (24), passing the RF alarm signal to a drive enable (30); the drive enable (30), which actuates a frequency stable oscillator (32) to output the RF alarm signal; the output drive (24), for actuating a sound warning (26); a power amplifier (34) for amplifying the RF alarm signal; a band filter (36) to further narrow the RF alarm signal; an impedance matching transformer (38); and a power-line interface (20), where the RF alarm signal is injected into an interface power input line (6B, 6W). - View Dependent Claims (2)
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Specification