U.S. patent number 3,906,491 [Application Number 05/359,987] was granted by the patent office on 1975-09-16 for electronic alarm and emergency voice communication system.
This patent grant is currently assigned to Federal Sign and Signal Corporation. Invention is credited to Earl W. Gosswiller, Dick T. Hsu, Joel G. Iacono, Richard H. Williams.
United States Patent |
3,906,491 |
Gosswiller , et al. |
September 16, 1975 |
Electronic alarm and emergency voice communication system
Abstract
The present invention relates to a combination electronic alarm
and emergency voice communication system which combines a fire
alarm module and an emergency voice communication module in a
single system and also provides for optional inclusion of one or
more general alarm signals, the system being designed to provide
predetermined priorities between voice communication signals, fire
alarm signals and general alarm signals, and including improved
apparatus for interconnecting the various modules and for
supervising the same.
Inventors: |
Gosswiller; Earl W. (Clarendon
Hills, IL), Hsu; Dick T. (Park Forest, IL), Williams;
Richard H. (Wheeling, IL), Iacono; Joel G. (Highland,
IN) |
Assignee: |
Federal Sign and Signal
Corporation (Chicago, IL)
|
Family
ID: |
23416136 |
Appl.
No.: |
05/359,987 |
Filed: |
May 14, 1973 |
Current U.S.
Class: |
340/509; 340/521;
340/533; 340/692; 340/384.72 |
Current CPC
Class: |
G08B
25/014 (20130101) |
Current International
Class: |
G08B
25/01 (20060101); G08b 029/00 () |
Field of
Search: |
;340/409,216,416,221,311,224 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Habecker; Thomas B.
Attorney, Agent or Firm: Pigott, Jr.; Charles F.
Claims
We claim:
1. An alarm and emergency voice communication system comprising, in
combination, alarm signal generating means continuously operable
under normal conditions, voice communication means, amplifier
circuit means, speaker circuit means, separate d.c. supervisory
circuit means including a d.c. supervisory source, means connecting
said voice communication means with said amplifier circuit means
when said voice communication means is activated, switch means
normally maintaining said alarm signal generating means connected
with said amplifier circuit means, normally maintaining said
amplifier circuit means disconnected from said speaker circuit
means and normally maintaining said d.c. supervisory power source
connected to said speaker circuit means whereby an alarm signal is
utilized to supervise said amplifier circuit means and a separate
d.c. signal is utilized to supervise said speaker circuit means,
and control means responsive to an alarm for activation of said
switch means.
2. An alarm and emergency voice communication system as defined in
claim 1 including control means responsive to initiation of an
alarm or activation of said voice communication means for causing
said switch means to connect said amplifier circuit means with said
speaker circuit means and disconnect said d.c. supervisory power
source from said speaker circuit means.
3. An alarm and emergency voice communication system comprising, in
combination, alarm signal generating means continuously operable
under normal conditions, voice communication means, amplifier
circuit means, speaker circuit means, separate d.c. supervisory
circuit means including a d.c. supervisory power source, switch
means normally maintaining said alarm signal generating means
connected with said amplifier circuit means, normally maintaining
said amplifier circuit means disconnected from said speaker circuit
means and normally maintaining said d.c. supervisory power source
connected to said speaker circuit means whereby an alarm signal is
utilized to supervise said amplifier circuit means and a separate
d.c. signal is utilized to supervise said speaker circuit means,
first control means responsive to initiation of an alarm or
activation of said voice communication means for causing said
switch means to connect said amplifier circuit means with said
speaker circuit means and disconnect said d.c. supervisory power
source from said speaker means, and second control means responsive
to activation of said voice communication means for disabling said
alarm signal generating means and connecting said voice
communication means to said amplifier circuit means.
4. An alarm and emergency voice communication system as defined in
claim 3 wherein said speaker circuit means includes a plurality of
speakers connected in parallel, and capacitor means connected with
said speakers for isolating said speakers from said separate d.c.
supervisory signal while permitting normal operation of said
speakers when said amplifier circuit means is connected with said
speaker circuit means.
5. An alarm and emergency voice communication system as defined in
clain 3 including detector means connected with the output of said
amplifier circuit means, said detector means being responsive to a
loss of output signal from said amplifier circuit means so as to
initiate a trouble indication.
6. An alarm and emergency voice communication system as defined in
claim 5 wherein said amplifier circuit means includes first and
second alternate amplifiers and said detector means operates in
response to loss of output signal from said first amplifier to
disconnect the latter and connect second amplifier in said
amplifier circuit means.
7. An alarm and emergency voice communication system as defined in
claim 5 including control means responsive to activation of said
voice communication means for disabling said detector means.
8. An alarm and emergency voice communication system as defined in
claim 3 wherein said alarm signal generating means includes first
and second alarm signal generators and said amplifier circuit means
includes first and second alternate amplifiers, said first alarm
signal generator normally being operatively connected with said
first amplifier and said second alarm signal generator normally
being operatively connected with said second amplifier, and control
means responsive to activation of said voice communication means
for disabling said first and second alarm signal generator and
operatively connecting said voice communication means both to said
first and second amplifiers.
9. An alarm and emergency voice communication system as defined in
claim 3 wherein said speaker circuit means includes a plurality of
speaker lines, each speaker line supplying a plurality of speakers
connected in parallel, a plurality of separate d.c. supervisory
circuits including a d.c. power source connected respectively with
each of said speaker lines for independent supervision thereof, and
control means responsive to initiation of an alarm or activation of
said voice communication means for disconnecting each of said
speaker lines from its corresponding d.c. supervisory circuit and
for connecting said plurality of speaker lines in parallel with
said amplifier circuit means.
10. An alarm and emergency voice communication system as defined in
claim 3 wherein said d.c. supervisory circuit means includes first
voltage sensing means responsive to a voltage in excess of a first
predetermined value for sensing an open speaker circuit and
initiating a trouble indication, and second voltage sensing means
responsive to a voltage below a second predetermined value for
sensing a shorted speaker circuit and initiating a trouble
indication, said d.c. supervisory circuit normally producing a
voltage at said first and second sensing means having a magnitude
intermediate said first and second predetermined values in the
absence of an open or shorted speaker circuit.
11. An alarm and emergency voice communication system as defined in
claim 3 including primary tone signal generating means and at least
one general tone signal generating means, power supply means for
supplying power to said primary tone signal generating means and
said general tone signal generating means, said power supply means
normally being connected with said primary tone signal generating
means and disconnected from said general tone signal generating
means, first control means responsive to initiation of a general
alarm for disconnecting said power supply means from said primary
tone signal generating means and connecting said power supply means
to said general tone signal generating means, and second control
means connected in overriding relation to said first control means
and responsive to initiation of a primary alarm for disconnecting
said power supply means from said general tone signal generating
means and connecting said power supply means to said primary tone
signal generating means.
12. An alarm and emergency voice communication system comprising,
in combination, alarm signal generating means continuously operable
under normal conditions, voice communication means, amplifier
circuit means, speaker circuit means, separate d.c. supervisory
circuit means including a d.c. supervisory power source, switch
means normally maintaining said alarm signal generating means
connected with said amplifier circuit means, normally maintaining
said amplifier circuit means disconnected from said speaker circuit
means and normally maintaining said d.c. supervisory power source
connected to said speaker circuit means whereby an alarm signal is
utilized to supervise said amplifier circuit means and a separate
d.c. signal is utilized to supervise said speaker circuit means,
first control means responsive to initiation of an alarm or
activation of said voice communication means for causing said
switch means to connect said amplifier circuit means with said
speaker circuit means and disconnect said d.c. supervisory power
source from said speaker circuit means, second control means
responsive to activation of said voice communication means for
disabling said alarm signal generating means and connecting said
voice communication means to said amplifier circuit means, detector
means connected with the output of said amplifier circuit means,
said amplifier circuit means including first and second alternate
amplifiers and said detector means operating in response to loss of
output signal from said first amplifier to disconnect the latter
and connect said second amplifier in said amplifier circuit means
and also to initiate a trouble indication, and third control means
responsive to activation of said voice communication means for
disabling said detector means.
13. An alarm and emergency voice communication system as defined in
claim 12 wherein said speaker circuit means includes a plurality of
speakers connected in parallel, and capacitor means connected with
said speakers for isolating said speakers from said d.c.
supervisory signal while permitting normal operation of said
speakers when said amplifier circuit means is connected with said
speaker circuit means.
14. An alarm and emergency voice communication system as defined in
claim 12 wherein said alarm signal generating means includes first
and second alarm signal generators, said first alarm signal
generator normally being operatively connected with said first
amplifier and said second alarm signal generator normally being
operatively connected with said second amplifier, and wherein said
second control means operates in response to activation of said
voice communication means to disable said first and second alarm
signal generators and operatively connect said voice communication
means both to said first and second amplifiers.
15. An alarm and emergency voice communication system comprising,
in combination, alarm signal generating means, voice communication
means, amplifier circuit means, speaker circuit means, said alarm
signal generating means normally being connected with said
amplifier circuit means, said speaker circuit means normally being
disconnected from said amplifier circuit means, and said voice
communication means when activated being connected with said
amplifier circuit means, first control means responsive to
initiation of an alarm for operatively connecting said amplifier
circuit means and speaker circuit means thereby causing an alarm
signal to be conducted to said speaker circuit, and second control
means responsive to activation of said voice communication means
and connected in overriding relation to said first control means
for disabling said alarm signal generating means and operatively
connecting said voice communication means with said amplifier
circuit and speaker circuit thereby enabling voice signals to be
conducted to said speaker circuit.
16. An alarm and emergency voice communication system as defined in
claim 15 wherein said alarm signal generating means includes first
and second alarm signal generators and said amplifier circuit means
includes first and second alternate amplifiers, said first control
means operatively connecting said first alarm signal generator with
said first amplifier and said second alarm signal generator with
said second amplifier, and said second control means operatively
connecting said voice communication means with both said first and
second amplifiers.
17. An alarm and emergency voice communication system as defined in
claim 16 wherein said first amplifier is normally connected in said
speaker circuit means and said second amplifier is disconnected,
and detector means responsive to a loss of output signal from said
first amplifier for disconnecting the latter and connecting said
second amplifier in said amplifier circuit means, and third control
means responsive to activation of said voice communication means
for disabling said detector means.
18. In an alarm and emergency voice communication system of the
type having alarm signal generating means, voice communication
means, amplifier circuit means and speaker circuit means, an
improved d.c. supervisory circuit for detecting both an open and a
shorted speaker circuit comprising, in combination, a d.c.
supervisory circuit including a d.c. power source connected with a
speaker circuit to be supervised, first voltage sensing means which
blocks voltage signals less than a first predetermined voltage
while conducting higher voltage signals, second voltage sensing
means which blocks voltage signals less than a second predetermined
voltage while conducting higher voltage signals, circuit means
interconnecting said first and second voltage sensing means, means
in said supervisory circuit operable in the absence of an open or
shorted circuit for producing at said circuit means a normal
voltage intermediate said first and second predetermined voltage
whereby said normal voltage is blocked by said first sensing means
and conducted by said second sensing means, first trouble circuit
means connected with said first voltage sensing means for producing
a trouble signal in response to a voltage signal conducted past
said first voltage sensing means in the event of an open speaker
circuit, and second trouble circuit means connected with said
second voltage sensing means for producing a trouble signal in
response to blockage of a voltage signal by said second voltage
sensing means when a short occurs in said speaker circuit.
Description
BRIEF SUMMARY OF THE INVENTION
It is known in the art to combine a fire alarm system with a music
or paging system and to provide means for giving priority to the
fire alarm system whereby upon initiation of a fire alarm signal
the music or paging system is disconnected from a speaker circuit
and a fire alarm tone generator is connected thereto. It is also
known to provide means in such a system for supervising the fire
tone generator and the amplifier and speaker circuits so as to
detect malfunctions therein and produce a visual or audible trouble
signal when such problems occur.
A known system of the foregoing type is shown in Goodwater U.S.
Pat. No. 3,656,158. The latter patent discloses a system comprising
a fire tone signal generator, an input from a paging or music
system, an oscillator for producing a low level supersonic signal,
and an audio circuit which includes an amplifier and speaker
network. Under normal conditions the input from the paging or music
system is connected with the audio circuit, and the fire tone
signal generator is disconnected, the fire tone generator being
continuously operable and being connected to a relay for
supervisory purposes. Moreover, under such normal conditions, the
oscillator is connected with the amplifier and speaker network by a
pair of lines which extend from the signal generator module to the
remotely located speakers which are connected in parallel. A return
supervisory loop extends back to a supervisory relay associated
with the signal generator module at a central control station. In
this manner, the entire audio circuit including the amplifier
network and the speaker network is supervised by a low level
supersonic signal produced by an oscillator.
A system of the foregoing type has certain limitations and
disadvantages due to the components provided and the manner of
interconnecting and supervising the same. In such a system
comprising only a single amplifier and fire tone generator, there
is the obvious limitation that the system will not function if
either such component is inoperative, since there is no provision
for an alternate amplifier or fire tone signal generator. Moreover,
such a system is designed to combine one amplifier module with a
corresponding tone generator module, and there is no provision for
utilizing a single tone generator module to power a plurality of
remote amplifier modules. Furthermore, use of a supersonic signal
to supervise the amplifier and speaker networks has the diadvantage
of requiring a vast amount of cable due to the need for a return
supervisory loop, i.e., the necessity of having two lines extend
from the generator module at a central control station out to all
of the remote speakers which may be located throughout a building
and then back to the central control station.
It is therefore a general object of the present invention to
provide an improved fire alarm and emergency communication system
having unique supervisory means which minimizes the amount of cable
required for supervising a remote speaker network.
Another object of the invention is to provide a combination system
as above-mentioned including a continuously operating fire tone
signal generator which under normal conditions is connected to an
amplifier circuit for supervisory purposes, together with means
which connects the amplifier circuit with a speaker network only
during an alarm condition or upon activation of a voice
communication module.
A further related object of our invention is to provide a separate
d.c. signal source which under normal conditions is connected with
a speaker network for supervising the latter and which is
disconnected from the speaker network during an alarm condition or
upon activation of a voice communication module.
An additional object of the invention is to provide a combined fire
alarm and voice communication system including means for
disconnecting the fire tone signal generator from the system
whenever the voice communication module is activated thereby giving
priority to the voice communication portion of the system to assure
that the latter can be operated during a fire alarm.
Still another of our objects is to provide a system as last
above-mentioned including detector means for detecting the loss of
an amplifier output signal during a fire alarm condition or under
normal conditions in the absence of an alarm, and means for
disabling such detector means whenever the voice communication
module is activated.
A further object is to provide a combined fire alarm and voice
communication system which permits use of a single signal generator
module in combination with a large number of amplifier modules,
each amplifier module being used in conjunction with a network of
associated speakers.
A still further one of our objects is to provide a combination
system as above-mentioned wherein a fire tone signal is utilized to
supervise the amplifier circuit and a separate d.c. signal is
utilized to supervise the speaker circuit, and wherein each of the
speakers is connected with an associated capacitor which isolates
the speaker from the d.c. supervisory signal while permitting
normal functioning of the speaker when the amplifier circuit is
connected thereto during an alarm condition or upon activation of a
voice communication module.
An additional object is to provide a combination system as last
above-mentioned which permits connection of an auxiliary amplifier
to the speaker circuit for music, paging or other auxiliary input
without interfering with the normal supervision of the speaker
circuit by the separate d.c. power source.
The foregoing and other objects and advantages of the invention
will be apparent from the following description, taken in
conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1a and 1b are a schematic drawing of a signal generator module
comprising a portion of a combination system in accordance with the
present invention; and
FIG. 2a and 2b are a schematic drawing of an amplifier module for
use in conjunction with the signal generator module, it being
understood that a large number of amplifier modules of the type
shown may be used in conjunction with a single signal generator
module of the type shown.
Now, in order to acquaint those skilled in the art with the manner
of making and using our invention, we shall describe, in
conjunction with the accompanying drawings, a preferred embodiment
of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, there is shown in FIG. 1 a plurality
of terminals including terminals 10 and 12 connected with a fire
alarm relay 14, terminals 16 and 18 connected with a first general
alarm relay 20, and terminals 22 and 24 connected with a second
general alarm relay 26. When a fire alarm is initiated, a circuit
is completed between the terminals 10 and 12 causing energization
of the fire alarm relay 14. The fire alarm relay 14 may be
energized by manually pulling a fire alarm box, or by automatic
sensing devices such as automatic smoke detectors, etc. In a
similar manner, initiation of a first general alarm causes
energization of the relay 20, and initiation of a second general
alarm causes energization of the relay 26. There is further shown a
voice communication relay 28 which as explained later herein is
energized upon manual actuation of a microphone switch which
permits voice transmission over the combination system described
herein. It should therefore be understood in connection with the
following description of the combination system of the present
invention that initiation of a fire alarm energizes relay 14,
initiation of a first general alarm energizes relay 20, initiation
of a second general alarm energizes relay 26 and manual actuation
of a microphone switch associated with a voice communication module
energizes relay 28.
FIG. 1 further shows a pair of fire tone signal generators 30 and
32, a first general tone signal generator 34 and a second general
tone signal generator 36. A source of 24 volts d.c. power is
indicated generally at 38 and is connected over lines 40 and 42 to
a low voltage regulator indicated generally at 44. The low voltage
regulator 44 produces a voltage of 12 volts on a line 46, 12 volts
on a line 48, and 6 volts on a line 50. The 12 volt d.c. power on
line 46 is conducted over lines 46, 52 and 54 to a time delay unit
indicated generally at 56. The line 54 includes a normally closed
relay contact 28a, and it will thus be understood that 12 volts
d.c. power is conducted to the time delay device 56 except upon
activation of the voice communication module which energizes relay
28 and opens the relay contact 28a.
The purpose of the time delay device 56 is to provide a short delay
in transmission of power from the 12 volt line 54 to the various
tone generators 30, 32, 34 and 36. As will become more apparent
from the following description, the fire tone generators produce
continuous signals which are utilized for the purpose of
supervising the amplifier portion of the system, and under normal
conditions the amplifiers are disconnected from the speaker lines.
However, manual operation of a microphone switch for purposes of
voice communication disconnects the fire tone signal generators
from the amplifiers and from the power supply and causes the
amplifiers to be connected to the speaker circuits. Accordingly,
the time delay device 56 serves the purpose of delaying the power
supply to the fire tone signal generators after use of the voice
communication system, the delay serving to assure that the
amplifiers have again been disconnected from the speaker lines
before power is restored to the fire tone generators. In other
words, the purpose of the time delay device 56 is to prevent
sounding of a false fire alarm as might otherwise be caused
subsequent to operation of the voice communication system.
The power output from the time delay device 56 is conducted over a
power line 58. It will be seen that under normal conditions in the
absence of any alarm signals the 12 volt d.c. power on line 58 is
conducted over lines 58, 60, 62, 64, 68, 70 and 72 to the input of
the fire tone signal generator 30. The line 60 includes a relay
contact 14a and the line 66 includes relay contacts 20a and 26a,
but each of the foregoing relay contacts is normally closed and
thus 12 volt d.c. power is conducted to fire tone signal generator
30 under normal conditions in the absence of any alarm signals.
Moreover, the above-mentioned line 70 connects with lines 74 and 76
leading to the input of the second fire tone signal generator 32.
It will thus be understood that whenever power is supplied to the
first fire tone signal generator 30 the interconnection provided by
the lines 74 and 76 will supply power simultaneously to the second
fire tone signal generator 32. It will further be understood that
fire tone signal generators 30 and 32 are continuously supplied
with power under normal conditions in the absence of any alarm
signal, and in accordance with the present invention the continuous
output from the fire tone signal generators is utilized to
supervise the amplifier portion of the combination system.
The power supply line 60 connects with lines 78 and 80 leading to
the input of the first general tone signal generator 34 for
supplying 12 volts d.c. power to the latter. The line 78 includes a
normally closed relay contact 26b and the line 80 includes a
normally open relay contact 20b. Thus, upon initiation of a first
general alarm the relay 20 is energized thereby closing the relay
contact 20b so as to supply power from the time delay unit 56 to
the signal generator 34. In a similar manner, the line 78 connects
with a line 82 leading to the input of the second general tone
signal generator 36, and the line 82 includes a normally open relay
contact 26c. Accordingly, when the second general alarm is
initiated the relay 26 is energized thereby closing the relay
contact 26c so as to supply power to the signal generator 36.
When a fire alarm is initiated, the relay 14 is energized thereby
opening the relay contact 14a in the power supply line 60. When the
relay contact 14a is open it is not possible to transmit power to
either of the general tone signal generators 34 or 36 and thus fire
tone signals take priority over the two general tone signals. A
line 84 interconnects the power supply line 58 with the line 68
which leads to the inputs of the two fire tone signal generators 30
and 32. The line 84 includes a normally open relay contact 14b
which is closed upon initiation of a fire alarm due to energization
of the relay 14 thereby supplying 12 volts d.c. power to the fire
tone signal generators 30 and 32 while disconnecting the power
supply lines to the general tone signal generators 34 and 36. It
will be borne in mind however that actuation of a microphone switch
associated with the voice communication module energizes relay 28,
in a manner to be explained hereinafter, with the result that the
relay contact 28a in the power supply line 54 is opened thereby
disconnecting the power supply from the time delay unit 56 so as to
cut off power to all of the signal generators 30, 32, 34 and 36.
Accordingly, in the combination system described herein, the voice
communication module takes priority over the fire alarm and general
alarm components of the system.
The output signals from the fire tone module 30 are conducted to
the input of a first pre-amplifier 86 over a circuit comprising
lines 88, 90, 92 and 94. The first general tone module 34 is
connected to line 90 through an output line 96, and the second
general tone module 36 is connected to the same output circuit
through a line 98. The line 92 of the foregoing circuit includes a
normally closed relay contact 28b, and it will thus be noted that
upon use of the voice communication microphone the energization of
the relay 28 will open the relay contact 28b thereby disconnecting
the three tone modules 30, 34 and 36 from the pre-amplifier 86. The
output signals from the second fire tone module 32 are connected to
the input of a second pre-amplifier 100 over a circuit comprising
lines 102 and 104. The line 102 includes a normally closed relay
contact 28c and thus upon use of the voice communication microphone
the energization of the relay 28 will open the contact 28c and
disconnect the fire tone module 32 from the second pre-amplifier
100.
As noted hereinabove, the voice communication module of the
combination system described herein includes a microphone having a
manually operable buttom switch or the like which is actuated in
order to render the voice communication module operative and
disconnect the fire alarm and general alarm components of the
system. The circuitry relating to actuation of the voice
communication module is indicated generally at 106 and includes the
relay 28, a pair of transistors 108 and 110, a power line 112
connected to the 24 volts d.c. power source 38, and a line 114
representing the negative side or ground of the circuit referred to
herein as "common".
A line 116 leading from a "mike key" terminal 118 to a point 120 in
the circuit 106 is normally open, and under such conditions there
will be a voltage at the point 120 of approximately 8-9 volts which
is applied to the base of the transistor 110 to maintain the latter
on whereby the transistor 108 will normally be maintained off.
Consequently, the relay 28 will normally be deenergized. However,
when the mike key or microphone switch is actuated the terminal 118
is shorted to one of the "common" terminals such as shown at 122
and 124 thereby removing the voltage from the base of transistor
110 causing the latter to go off and causing the transistor 108 to
go on and conduct. When the transistor 108 conducts a circuit is
completed through the relay 28 and transistor 108 from the 24 volts
d.c. power line 112 to the common line 114 thereby energizing the
relay 28.
A pair of terminals 126 and 128 and associated lines 130 and 132
transmit voice signals to an audio pre-amplifier 134, and the
output from the pre-amplifier 134 is conducted to the pre-amplifier
86 through the circuit comprising lines 136, 138 and 94. The line
138 includes a normally open relay contact 28d which is closed when
the relay 28 is energized upon actuation of the mike key. The
output from the audio pre-amplifier is also conducted to the second
pre-amplifier 100 through the circuit comprising lines 136, 140 and
104, the normally open relay contact 28e in the line 140 being
closed upon energization of the relay 28. It will further be noted
that when the audio pre-amplifier 134 is connected to the two
pre-amplifiers 86 and 100 upon energization of relay 28, the relay
contact 28b in the line 92 and the relay contact 28c in the line
102 are opened thereby disconnecting the various tone modules 30,
32, 34 and 36 from the corresponding pre-amplifiers 86 and 100. The
output signals from the pre-amplifier 86 are conducted along line
142 to terminal 144, and the output signals from pre-amplifier 100
are conducted along line 146 to terminal 148.
In accordance with the present invention, there is provided a
control line 150 which transmits a predetermined voltage depending
upon the condition of the system. Thus, under normal conditions in
the absence of an alarm, the line 50 which extends from the voltage
regulator 44 and which carries 6 volts d.c. is connected to the
control line 150 through a circuit comprising lines 152, 154, 156
and 158, whereby the control line will conduct 6 volts d.c. to a
control terminal 160. When a fire alarm is initiated, the line 48
which extends from the voltage regulator and carries 12 volts d.c.
is connected to the control line 150 through a circuit comprising
lines 152, 154, 156 and 158. The line 48 includes a normally open
relay contact 14c which will be closed during a fire alarm
condition due to energization of the relay 14.
When the voice communication module is activated, the 24 volts d.c.
power source 38 will be connected to the control line 150 through a
circuit comprising lines 166, 168, 170, 172, 156 and 158. The line
172 includes a normally open relay contact 28f which will be closed
during activation of the voice communication module due to
energization of the relay 28. When the first general alarm is
activated causing energization of relay 20, the 24 volts d.c. power
source 38 will be connected to the control line 150 through a
circuit comprising lines 166, 168, 170, 174, 176, 178 and 158. The
line 178 includes a normally open relay contact 20c which will be
closed upon energization of the relay 20. It will further be noted
that the line 174 includes a normally closed relay contact 14d
which opens during a fire alarm condition thereby preventing 24
volts d.c. form being conducted to the control line 150. When the
second general alarm is activated causing energization of relay 26,
the 24 volts d.c. power source 38 will be connected to the control
line 150 through a circuit comprising lines 166, 168, 170, 174,
180, 154, 156 andd 158. The line 180 includes a normally open relay
contact 26d which will be closed upon energization of relay 26. It
will now be understood that under normal conditions in the absence
of any alarm the control line 150 will conduct 6 volts d.c.; during
a fire alarm condition the control line will conduct 12 volts d.c.;
and when either of the two general alarms or the voice
communication module is activated, the control line will carry 24
volts d.c. However, a general alarm will not produce 24 volts d.c.
on the control line if a fire alarm is also initiated due to the
relay contact 14d which gives priority to the fire alarm, whereas
activation of the voice communication module will also produce 24
volts d.c. on the control line. The purpose of the foregoing
control line 150 will be explained more fully hereinafter.
Reference is now made to a trouble circuit for providing a trouble
signal in the event a problem is detected in the operation of the
system. A pair of terminals 182 and 184 and associated lines 186
and 188 comprise a trouble loop. As will be described hereinafter,
the terminals 182 and 184 are normally shorted together to provide
a closed trouble loop circuit, and when a problem is detected the
foregoing terminals are disconnected thereby opening the trouble
loop. The trouble loop circuitry includes a trouble relay 190 and a
transistor 192. The line 186 connects with the 24 volts d.c. power
line 112, and thus as long as the trouble loop is closed a voltage
will be applied by line 188 to the base of transistor 192 so that
the latter will be on and will conduct.
It will further be seen that while the transistor 192 is
conducting, a circuit is completed between the power supply line
112 and the common line 114 which circuit includes the relay 190
and transistor 192, whereby the relay 190 is normally maintained
energized. A terminal 194 representing 24 volts d.c. input is
connected to the common line 114 through a circuit including a
relay contact 190a and a trouble light 196. Since the relay 190 is
maintained energized in the absence of trouble, the relay contact
190a will be maintained open and the trouble light 196 will not be
activated. However, whenever the terminals 182 and 184 are
disconnected due to detection of a problem with the system, as will
be explained later herein, the relay 190 will be deenergized, the
relay contact 190a will be closed, and the trouble light 196 will
be activated. It will of course be understood that various types of
trouble indicators including audible signals may be provided in
addition to the trouble light 196 which is described by way of
example only. Thus, there are illustrated additional trouble
indication circuits 193 and 195 associated with terminals 197, 199
and 201. The foregoing circuits includes relay contacts 190b and
190c. If the above-described trouble loop is opened deenergizing
the normally-energized relay 190, the contact 190b will be opened
and the relay 190c will be closed thereby affording means for
effecting such additional trouble indications as may be
desired.
Reference is now made to FIG. 2 which illustrates the amplifier and
speaker circuits for the combination system of the present
invention. The output signal from the pre-amplifier 86 is conducted
from terminal 144 over a line 198 to a first power amplifier 200,
and the output signal from the pre-amplifier 100 is conducted from
terminal 148 over a line 202 to a second power amplifier 204. A
line 205 supplies 24 volts d.c. to the amplifier 200, and power is
supplied over line 207 to the amplifier 204. A supervision and
switching circuit 209 associated with the control line 150 controls
the switching between the power amplifiers and the speaker network.
It will be borne in mind that the control line 150 carries 6 volts
d.c. under normal conditions in the absence of an alarm signal. The
control line 150 connects with three parallel lines 206, 208 and
210, and the latter three lines include respective diodes 212, 214
and 216 so as to transmit a signal from the control line 150 only
in the event the voltage on the line 150 is above a predetermined
value. In the particular embodiment being described, the diode 212
will conduct a signal exceeding 3.3 volts, the diode 214 will
conduct a signal exceeding 16 volts and the diode 216 will conduct
a signal exceeding 8.2 volts. Accordingly, when the control line
150 carries 6 volts d.c., as under normal conditions, a signal will
be conducted past the diode 212 but will be blocked by the diodes
214 and 216.
The circuit associated with the line 206 and diode 212 includes a
pair of transistors 218 and 220, the transistor 218 being normally
on so as to conduct, and the transistor 220 being normally off,
providing the normal 6 volt signal is being conducted past the
diode 212 to the base of the transistor 218. The foregoing
components control the state of a transistor 222 associated with
the trouble loop described hereinabove. Thus, the base of the
transistor 222 is connected through lines 224 and 226 to a 24 volts
d.c. power supply line 228 whereby the transistor 222 is normally
on so as to conduct. A circuit is provided between the power supply
line 228 and a common line 230 which comprises line 232, transistor
222, trouble relay 234 and line 236. Accordingly, as long as the
transistor 222 is conducting, a closed circuit is provided between
power line 228 and the common 230 thereby maintaining the trouble
relay 234 energized. FIG. 2 shows the previously described
terminals 182 and 184 which are normally shorted together to form a
closed trouble loop. Thus, the terminals 182 and 184 are connected
by a line 233 which includes a relay contact 234a. The normally
energized trouble relay 234 maintains the contact 234a closed.
However, whenever a malfunction causes deenergization of the
trouble relay 234, the contact 234a is opened thus opening the
trouble loop shown in FIG. 1 and producing the previously described
signals such as activation of trouble light 196. It should be
understood that the trouble indication circuit illustrated in
conjunction with the signal generator module of FIG. 1 is intended
to provide a trouble signal at a central control station where the
signal generator module is located. It should further be understood
that a plurality of remotely located amplifier modules may be
associated with the trouble loop or trouble actuation circuit at
the central control station so as to provide a trouble signal if a
malfunction occurs at any of the remote amplifier modules. An
additional trouble indication may be provided in conjunction with
each of the remote amplifier modules so as to indicate trouble with
that particular module. Thus, there is shown a line 235 connected
between the power supply line 228 and the common line 230 and
including a relay contact 234b and a trouble light 237. As long as
the trouble relay 234 remains energized the contact 234b will be
open, but when a malfunction causes deenergization of relay 234 the
contact 234b will close activating trouble light 237 thereby
providing a trouble signal associated with a corresponding remote
amplifier module.
One condition which will produce a trouble indication is loss of
the normal 6 volts d.c. signal on the control line 150. If the 6
volt signal is lost then the transistor 218 goes off causing the
transistor 220 to turn on and conduct. When the transistor 220
conducts it completes a circuit between a common and the base of
transistor 222, such circuit including common 238, transistor 220,
and lines 240, 242 and 224. Consequently, the base of transistor
222 is connected to common turning the transistor off and causing
trouble relay 234 to be deenergized thereby initiating a trouble
signal. In this manner the control line 150 and related circuitry
is supervised to assure that the same is functioning properly.
Still referring to the circuits associated with the control line
150, when a fire alarm is initiated thereby energizing the fire
alarm relay 14, the control line 150 carries 12 volts d.c. as
previously described. Accordingly, upon initiation of a fire alarm,
a 12 volts d.c. signal is conducted past the diode 216 over a line
244 and applied to the base of transistor 246. The transistor 246
and an associated transistor 248 are both normally off. However,
when a 12 volts d.c. signal is conducted past diode 216 to the base
of transistor 246 the latter is turned on and it turns on
transistor 248 thereby causing the latter to conduct. The
transistor 248 when caused to conduct completes a circuit to effect
energization of a relay 250. The relay 250 is in a circuit
comprising 24 volts d.c. power supply line 228, line 252, relay
250, lines 254 and 256, transistor 248 and lines 258 and 260 which
lead to common. Thus, when a fire alarm is initiated, the control
line 150 will carry a 12 volts d.c. signal causing transistor 248
to conduct and thereby effecting energization of relay 250.
The relay 250 in conjunction with a pair of detectors 262 and 264
controls the circuits which connect the amplifiers 200 and 204 with
the speaker lines associated therewith. Thus, the detectors 262 and
264 will now be described, and reference is first made to the
detector 262 which is associated with the first power amplifier
200. The output signal from the power amplifier 200 is conducted
over lines 266 and 268 and, after conversion to a d.c. signal by a
rectifier 269, is applied to the base of a transistor 270 to
maintain the latter on which in turn maintains an associated
transistor 272 off so that the latter will not conduct. However, if
the output signal from the amplifier 200 is lost, the transistor
270 will go off thereby turning the transistor 272 on causing the
latter to conduct. The transistor 272 is in a circuit comprising
line 274 which is connected to common, transistor 272, lines 276
and 278, relay 280, and line 282 which is connected to the 24 volts
d.c. power supply line 228. It will thus be understood that when
the detector 262 senses the absence of an output signal from power
amplifier 200, the transistor 272 is caused to conduct thereby
effecting energization of relay 280. A pair of resistors 271 and
273 and a capacitor 275 are provided in the detector circuit
between the rectifier 269 and the transistor 270 to afford a
predetermined time delay before transistor 270 will turn off. Such
a time delay is introduced so that the fire tone signal need not be
continuous, and an interruption in the signal for less than a brief
predetermined time interval will not effect energization of the
relay 280.
The circuit between the power amplifier 200 and the speaker lines
includes various contacts controlled by the above-described relays
250 and 280. Specifically, the amplifier 200 is connected through
lines 266, 284, 286 and 288 to a first speaker line 290. A line 292
connects the line 288 with a second speaker line 294, and the two
parallel speaker lines 290 and 294 are connected to a line 296
which connects with the previously described common line 230. The
line 286 includes a normally open relay contact 250a, and the line
184 includes a normally closed relay contact 280a. In addition,
lines 298 and 300 connect the output from the second amplifier 204
with the line 286 leading to the speaker circuits, and the line 300
includes a normally open relay contact 280b. It will thus be
understood that under normal conditions in the absence of an alarm
signal the output from the amplifier 200 is connected with the
detector 262 but is disconnected from the speaker circuits due to
the normally open relay contact 250a, and the output from the
second amplifier 204 is connected through lines 298 and 302 to the
second detector 264 but is disconnected from the speaker lines due
to the open contacts 250a and 280b.
Whenever an alarm signal is initiated, the control line 150 will
conduct a signal, i.e., 12 volts d.c. for a fire alarm and 24 volts
d.c. for a general alarm or upon activation of the voice
communication module, which effects energization of the relay 250,
in which event the relay contact 250a is closed and the first
amplifier 200 is connected with the speaker circuits. The second
amplifier 204 will remain disconnected from the speaker circuits
during an alarm condition unless the detector 262 senses the
absence of an output from the amplifier 200 in which event the
relay 280 will be energized opening the contact 280a and closing
the contact 280b. Accordingly, when the detector 262 senses the
absence of an output from the first amplifier 200, the latter is
disconnected from the speaker circuit and the second amplifier 204
is connected, providing an alarm condition has been initiated or
the voice communication module has been activated so as to close
the relay contact 250a.
In addition to switching from the first amplifier 200 to the second
amplifier 204 when the first amplifier fails to produce an output,
the detector 262 also initiates a trouble signal. When the detector
262 senses the absence of a signal from the amplifier 200 thereby
causing transistor 272 to conduct as described above, a circuit is
completed which includes common line 274, transistor 272 and lines
304, 306, 242 and 224 leading to the base of transistor 222. As
previously described, when the base of transistor 222 is connected
to common, the trouble relay 234 is deenergized and a trouble
signal is initiated.
The detector 264 associated with the second amplifier 204 operates
in a manner similar to the first detector 262 with respect to
initiation of a trouble signal, but it does not effect a switching
function. The output signal from the second amplifier 204 is
conducted over lines 298 and 302 to a rectifier 308 which converts
the output to a d.c. signal which is applied to the base of a
transistor 310 whereby the latter is normally maintained on and an
associated transistor 312 is normally maintained off. If the
detector 264 senses the absence of an output signal from the
amplifier 204 then the transistor 310 will turn off causing the
transistor 312 to turn on and conduct. When the transistor 312
conducts it completes a circuit comprising common line 314,
transistor 312 and lines 316, 306, 242 and 224 leading to the base
of transistor 222, and as previously described a trouble signal is
initiated when the base of transistor 222 is connected to
common.
It will be noted that the line 198 leading to the input of the
amplifier 200 includes a resistance 318 and a bypass line having a
normally open relay contact 250b. Under normal conditions in the
absence of an alarm signal or activation of the voice communication
module the contact 250b will be open and the amplifier 200 will
operate on reduced power. However, when an alarm condition is
initiated or the voice communication module is activated, the relay
250 is energized as previously described thereby closing the
by-pass contact 250b so that full power is transmitted to the
amplifier 200. In a somewhat similar manner, the line 202 leading
to the input of the second amplifier 204 includes a resistance 320
and a by-pass line having a pair of normally open contacts 250c and
280c. The amplifier 204 will normally operate on reduced power.
However, full power will be supplied to amplifier 204 if two
conditions are met, namely, if an alarm is initiated or the voice
communication module is activated so as to energize relay 250 and
effect closing of contact 250c, and if detector 262 senses the
absence of an output from the first amplifier 200 so as to energize
relay 280 and effect closing of contact 280c.
A further function of the control line 150 which will now be
described concerns disabling of the detectors 262 and 264 under
certain conditions. In accordance with the combination system of
the present invention, the detectors 262 and 264 will function
under normal conditions in the absence of an alarm signal, and they
will also function during a fire alarm condition. However, the
present system is designed to disable the detectors when a general
alarm signal is initiated or when the voice communication module is
activated. In this manner, the system will accommodate the use of
various types of general alarm signals which are not necessarily
continuous. Moreover, it is not believed practical to utilize the
detectors when the voice communication module is activated since
voice communication will necessarily produce non-continuous
signals.
The detector 264 includes a pair of resistors 322 and 324 and a
capacitor 326 which afford a time delay before the transistor 310
is turned off, and the detector 262 affords a similar time delay as
previously described. However, such a time delay is not intended to
accommodate significant interruptions of signals as might be
produced by certain types of general alarm signals or by voice
communication. Accordingly, whenever a general alarm signal is
initiated, or the voice communication module is activated, as
previously described the control line 150 will carry a 24 volts
d.c. signal, and such signal will be conducted past the diode 214
so as to produce signals on the parallel lines 328 and 330. The
line 328 transmits the foregoing signal to the detector 262 whereby
the signal is applied to the base of transistor 270 to maintain the
latter on without regard to whether an output signal is received
from the amplifier 200. In a similar manner, the line 330 transmits
a signal to the detector 264 where the signal is applied to the
base of transistor 310 to maintain the latter on without regard to
whether an output signal is received from the amplifier 204.
In the foregoing manner, the two detectors 262 and 264 are disabled
whenever the control line 150 carries a signal of 24 volts d.c. It
will of course be noted that under normal conditions or during a
fire alarm condition the voltage on the control line is less than
16 volts, i.e., 6 volts or 12 volts respectively, and thus such
lower voltage signals are blocked by the diode 214. However, while
the detectors 262 and 264 are disabled under certain conditions as
described above, the present system is designed so that if the
detector 262 senses a loss of output from the amplifier 200 and
thereby effects energization of the relay 280 so as to disconnect
the amplifier 200 from the speaker circuits and connect the
alternate amplifier 204 to such circuits, provision is made to
maintain the relay 280 energized even though the detectors are
subsequently disabled.
In order to accomplish the foregoing, a circuit is provided
comprising 24 volts d.c. power supply line 282, relay 280, lines
278, 332, 256, transistor 248 and lines 258 and 260 which lead to
common. The line 332 includes a normally open relay contact 280d
which is closed when relay 280 is energized. Moreover, as
previously described, the transistor 248 will conduct whenever
there is an alarm condition or the public address system is
activated. Therefore, whenever the detector 262 senses loss of an
output from amplifier 200 and switches in alternate amplifier 204,
the subsequent activation of the voice communication module thereby
disabling the detectors will not disconnect the alternate amplifier
204 as the closing of the relay contact 280d will maintain the
relay 280 energized under such conditions. It will be recalled that
fire alarm signals and voice communication signals are conducted to
both amplifiers 200 and 204, while in the system described herein
general alarm signals are conducted only to the amplifier 200.
In accordance with the combination system of the present invention
as described herein, the amplifier circuit is supervised by
continuous fire tone signals from the fire tone modules 30 and 32,
and under normal conditions in the absence of an alarm the
amplifier circuit is disconnected from the speaker lines. The
speaker circuit is supervised by a separate d.c. power source, and
in the embodiment described each of the two speaker lines is
independently supervised. However, during an alarm condition the
speaker lines 290 and 294 are not supervised but are connected in
parallel with the output from the power amplifier 200. Referring
first to the speaker line 290, a d.c. supervisory circuit is
indicated generally at 334 and comprises line 228 which is
connected to the 24 volts d.c. power source, and lines 336, 338,
340 and 288, the latter being connected with the speaker line 290
which as previously described is connected with a speaker common
line 296. The line 336 includes a resistor 342, and the line 340
includes a normally closed relay contact 250d. The speaker line 290
further includes an end of line resistor 344. In addition, a
plurality of horn assemblies are connected in parallel in the
speaker circuit between the speaker line 290 and the common line
296, and one such horn assembly is shown by way of example at 346.
A capacitor such as shown at 348 is associated with each horn
assembly, and a step-down transformer 350 is provided for reducing
the voltage to approximately 4 volts.
The voltage at point 352 in the d.c. supervisory circuit 334 will
be approximately 7 volts. The circuit further includes a pair of
diodes 354 and 356, the diode 354 being designed to block voltage
signals which do not exceed 9.1 volts, and the diode 356 being
designed to block voltage signals which do not exceed 3.3 volts.
Thus, under normal conditions a voltage signal will be conducted on
line 358 past diode 356 and thus transmitted by line 360 to the
base of a transistor 362 thereby maintaining the latter normally on
which in turn maintains the associated transistor 364 normally off
so that the latter will not conduct. However, if a short occurs in
speaker line 290, the voltage on line 358 will ball below 3.3 volts
and thus will be blocked by the diode 356 with the result that the
transistor 362 will go off causing the associated transistor 364 to
go on and conduct. The transistor 364 is in a circuit including
line 366 which is connected to common, transistor 364, and lines
368, 370, 372 and line 224 leading to the base of transistor 222.
Accordingly, when the transistor 364 in the d.c. supervisory
circuit 334 is caused to conduct due to a short in the speaker line
290, the transistor 222 will go off and deenergize trouble relay
234 thereby producing a trouble signal in the manner previously
described. Moreover, in the event an open circuit develops in the
speaker line 290, the removal of the end of line resistor 344 will
cause the voltage at point 352 to exceed 9.1 volts so that a signal
will be conducted over lines 374, 376 and 378 to the base of a
transistor 380 so that the latter which is normally off will be
turned on and caused to conduct. The transistor 380 is in a circuit
including line 366 which is connected to common, lines 382 and 384,
transistor 380, line 386 and line 370 which leads to the base of
the transistor 222 in the trouble circuit. Thus, if the speaker
line 290 develops an open circuit, the transistor 380 is caused to
conduct thereby connecting common to the base of the transistor 222
which as previously described produces a trouble signal.
The second speaker line 294 includes a plurality of horn assemblies
and related components which are the same as those connected with
the first speaker line 290 and thus are identified by corresponding
primed reference numerals. Moreover, a second d.c. supervisory
circuit is indicated generally at 334', and since the latter
functions in the same manner as the supervisory circuit 334 a
detailed description will not be provided herein. It will be noted
however that the line 292 includes a normally open relay contact
250e. Accordingly, the two speaker lines are independently
supervised, but when an alarm signal is initiated or when the voice
communication module is activated, the energization of relay 250 as
previously described will close contact 250e thereby connecting the
two speaker lines 290 and 294 in parallel with the amplifier output
line 288. In addition, a line 386 is connected with the d.c.
supervisory circuit at line 338 so as to connect the latter with
common line 230. Line 386 includes a normally open relay contact
250f and also a 1K resistor 388 having the same resistance as the
end-of-line resistor 344 in the speaker line 290. During an alarm
condition when the supervisory circuit 334 is disconnected from the
speaker line 290 due to the opening of contact 250d, the contact
250f will be closed so as to connect the 1K resistor 388 in the
circuit. The resistance 388 will thus function as a dummy load to
replace end-of-line resistor 344 and thereby prevent initiation of
false trouble signals during an alarm condition when the
supervisory circuit 334 is disconnected from the speaker line
290.
It is important to note that by utilizing d.c. supervision of the
speaker line 290 and connecting each horn assembly 346 in
conjunction with a capacitor 348, the horn assemblies are isolated
from the d.c. supervisory signal during supervision of the speaker
line but are not isolated from the a.c. output signal received from
the amplifier circuit during an alarm condition or when the voice
communication module is activated.
In the use of a combination system of the type described herein, it
is possible to power several hundred amplifiers from a single tone
generator module. In the particular system described herein, the
output from each of the alternate power amplifiers 200 and 204 is
76 watts, and since each speaker or horn assembly 346 requires 2
watts, it is feasible to utilize 36 horn assemblies in conjunction
with the amplifier module comprising alternate amplifiers 200 and
204. In the present embodiment, two speaker lines are shown, and
thus a total of 36 speakers can be accommodated and divided equally
or in any other desired proportion between the two speaker lines
290 and 294.
In the preferred embodiment as described herein, the alarm signals
comprise a fire alarm signal and a plurality of general alarm
signals, in combination with voice communication, and the system is
designed so that voice signals take priority over alarm signals,
and the primary alarm signal, i.e., the fire alarm signal, takes
priority over the various general alarm signals. While it is
believed that in most applications of the foregoing system the
primary alarm signal will comprise a fire alarm, it will be
understood that the present invention is not limited to this
particular application and an alarm signal other than a fire alarm
may comprise the primary alarm signal.
It will further be understood that in accordance with one of the
features of the present invention, a continuously operable alarm
signal is utilized to supervise the amplifier circuit. In
accordance with a preferred embodiment of the invention, the
primary alarm signal, e.g., the firetone signal, is utilized for
the foregoing purpose. Such an arrangement eliminates the need for
additional means to supervise the firetone signal generator as
would otherwise be necessary under various existing code
requirements. However, if desired, one of the other alarm signals,
such as a general alarm signal, may be utilized to supervise the
amplifier circuit, since it will be understood that in either case
there is achieved the important advantage that the speaker circuits
are disconnected from the amplifier circuit under normal conditions
thereby completely eliminating any undesirable noise from the
speakers during normal supervision of the system.
* * * * *