U.S. patent number 3,598,919 [Application Number 04/772,536] was granted by the patent office on 1971-08-10 for pre-recorded alarm-reporting system and control element therefor.
Invention is credited to Thomas M. Lott.
United States Patent |
3,598,919 |
Lott |
August 10, 1971 |
PRE-RECORDED ALARM-REPORTING SYSTEM AND CONTROL ELEMENT
THEREFOR
Abstract
In response to an alarm detector element a tape player coupled
to a conventional telephone line generates pulses which serve to
call an appropriate authority and provide a prerecorded audible
alarm report message followed by request that the authority confirm
the authenticity of the report by returning the call within a
predetermined period thereafter. If the called authority returns
the call within the predetermined period, the tape player then
calls additional parties and makes appropriate reports to such
parties. By returning the call, controls are activated which serve
to inhibit the repetitious further repeat calling of the same alarm
report call. Ultimately, in the event that no called party calls
back to verify receipt of a call from the tape player, a signal is
generated which activates a local audible alarm proximate to the
premises being protected.
Inventors: |
Lott; Thomas M. (San Mateo,
CA) |
Family
ID: |
25095401 |
Appl.
No.: |
04/772,536 |
Filed: |
November 1, 1968 |
Current U.S.
Class: |
379/40; 379/51;
379/74; 379/41; 379/73 |
Current CPC
Class: |
H04M
11/045 (20130101) |
Current International
Class: |
H04M
11/04 (20060101); H04m 011/04 () |
Field of
Search: |
;179/5P,5
;340/164,213.1,326 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Claffy; Kathleen H.
Assistant Examiner: Stewart; David L.
Claims
I claim:
1. In an alarm system of a type having means for detecting a
predetermined condition to be reported, the combination comprising
transmitting means responsive to detection of the condition and
serving to call a predetermined party and immediately to transmit a
prerecorded message to said predetermined called party and then to
condition the transmitting means to an "on-hook" condition, means
operative during a limited period following termination of said
message and serving to generate a reply signal in response to an
incoming verification call originated by said called party, said
limited period being sufficient to accommodate dialing of said
verification call by said called party, and control means coupled
to operate said transmitting means and responsive to generation of
said reply signal to cause said transmitting means to transmit a
prerecorded confirmation message to said called party.
2. In an alarm system according to claim 1 further including means
responsive to transmission of said prerecorded confirmation message
to transmit at least one additional prerecorded message to another
predetermined called party.
3. In an alarm system according to claim 1 wherein said control
means causes said transmitting means to transmit said confirmation
message only in response to generation of said reply signal within
a predetermined period following transmission of said prerecorded
message.
4. In an alarm system according to claim 1 wherein said
transmitting means includes communication transceiver means and
tape transport apparatus operably coupled to transmit via said
transceiver means and having a tape record including a plurality of
prerecorded tracks thereon, a first of said tracks being prepared
with signals adapted to operate communication equipment to provide
a connection from said tape transport apparatus to said called
party and also prepared with recorded electrical signal
representations reproducible audibly by said tape transport
apparatus to provide the first named said message, a second of said
tracks being prepared with recorded electrical signal
representations serving to provide said different message.
5. In an alarm system according to claim 4 further including a
local audible alarm means and wherein said first track further
includes prerecorded control signals serving to operate said local
alarm.
6. In an alarm system according to claim 1 wherein said
transmitting means serves to repeat the transmission of the first
named said message and said control means further serves to operate
said transmitting means in response to receipt of said reply signal
to inhibit transmission of said repeated message.
7. In an alarm system of a type having means for detecting a
predetermined condition to be reported, the combination comprising
transmitting means responsive to detection of the condition and
serving to transmit repetitively a prerecorded message to a
predetermined called party, means serving to generate a reply
signal in response to an incoming call originated by said called
party, and control means coupled to operate said transmitting means
in response to said reply signal to cause said transmitting means
to inhibit transmission of said repeated message, said control
means further serving to originate a call to another called party
promptly after inhibiting transmission of said repeated
message.
8. In an alarm system according to claim 7 further including an
audible alarm located in the region of the premises to be
protected, and wherein said control means serves, in the absence of
receipt of a reply signal from said called party, cause said
transmitting means to transmit another prerecorded message to
another called party, and in the further absence of receipt of a
reply signal, said transmitting means serves to operate said
audible alarm.
9. An alarm system to be operably coupled to a telephone line of a
type employing dial-operated telephone equipment, said alarm system
serving to protect premises from a predetermined condition, said
alarm system comprising a detector for sensing said predetermined
condition, a prerecorded tape player and a tape element associated
therewith, said player being operably coupled to respond to said
predetermined condition of said detector to commence playing a
first track of the tape, said player being further operably coupled
to said telephone line for transmitting via said line from said
first track prerecorded communication control signals adapted to
control communication means for making connection with an
appropriate called party and a prerecorded alarm report message for
transmission to said called party and a prerecorded "on-hook"
signal of predetermined duration, a second track of said tape being
prepared with a prerecorded confirmation message, switching means
operably coupled to receive signals from said telephone line and
serving to switch said player to transmit said confirmation message
from said second track in response to receipt of a reply from said
called party occurring within the duration of said "on-hook"
signal.
10. An alarm system according to claim 9 further including an
audible alarm locally disposed on the premises being protected and
wherein said first track includes a repetition of said
communication control signals and prerecorded alarm report message
and "on-hook" signal, said first track being further prepared with
prerecorded communication control signals for making connection
with another called party and another prerecorded alarm report
message and prerecorded "on-hook" signal of predetermined duration,
and said first track further being prepared with signals for
operating said audible alarm, and means for transmitting the last
named signals to operate said audible alarm in the absence of
receipt of a reply from any of said called parties.
11. In an alarm system of a type having means for detecting a
predetermined condition to be reported, the combination comprising
transmitting means responsive to detection of the condition and
serving to transmit a prerecorded message to a predetermined called
party and to repeat said transmission a predetermined number of
times, means serving to generate a reply signal in response to an
incoming call originated by said called party, said transmitting
means further serving, in the absence of receipt of said reply
signal, to transmit a prerecorded message to another called party
subsequent to said predetermined number of transmissions of the
first named call.
Description
BACKGROUND OF THE INVENTION
This invention pertains to alarm systems of a type employing means
for transmitting prerecorded alarm report messages to a called
party such as an appropriate local authority. The invention also
pertains to a control element for operating such an alarm system.
The system, disclosed herein, is particularly useful in providing a
burglar alarm system, fire alarm system, vandalism alarm system or
other types of alarms, as desired, wherein a predetermined
condition serves to activate the system.
Heretofore, alarm systems of the above type have been provided with
means for generating a prerecorded alarm report message to an
appropriate local authority, such as the police, but these systems
have been subject to one or more shortcomings. For example, prior
systems have provided no means for permitting verification by the
authority receiving the call of the authenticity of the incoming
alarm report call. Further, many of these systems have employed
means for repetitively transmitting the alarm to an appropriate
authority with no means at hand for the called authority to
discontinue the repetitious receipt of the same alarm message.
Thus, after the emergency is initially reported, these alarm
systems serve to congest a switchboard or other communication
system employed by the receiving authority, and the receiving
authority has no means to inhibit further receipt of the alarm of
which they have already been apprised. Many systems of the kind
described above depend upon use of conventional telephone lines and
to this extent have been subject to total debilitation merely by
cutting the telephone connections leading into the premises being
protected.
Also, heretofore, if the prerecorded call to the police should fail
for any reason, no further alarm report is likely to be made. For
example, upon failure to reach the police (or other authority), the
telephone operator can, by the system disclosed herein, be
contacted and requested to make the call.
One aspect of the system involves the problem that the telephone
line may have been cut by a burglar or other vandal or destroyed by
fire before setting off the alarm system. In this instance, all of
the prerecorded announcement messages which would have otherwise
been sent to the proper agencies of the Government will be
nullified. Therefore, it becomes an objective of this invention, at
least to sound a local alarm in an effort to either frighten the
vandal or burglar or to draw attention to a fire which may
exist.
OBJECTS
In general, it is an object of the present invention to provide an
improved prerecorded alarm message-reporting system overcoming the
foregoing and other objectionable limitations of prior systems.
SUMMARY OF THE INVENTION
The present alarm system, in general, relies upon means for
detecting a predetermined condition to be reported, such as
conventional fire alarm detectors or burglar alarm detectors or
other types of sensors which respond to a predetermined condition
and provide an alert or signal indicating the existence of such
condition. The signal in the present instance provides a momentary
ground connection. This of course, could be a permanent ground
connection, if desired.
In general, the system employs transmitting means responsive to the
detection of the condition to be reported and which also serves to
transmit a prerecorded message to a predetermined called party or
suitable person in authority having an appropriate relationship to
the condition to be reported. Thus, the prerecorded message of the
system which pertains to a burglar alert signal is appropriately
reported to the police station while fire-detecting alert signals
are reported to the fire department. Control means are further
provided which operate the transmitting means in response to
receipt of a reply signal developed by a reply call originated by
the called party so as to condition the transmitting means to
transmit a different prerecorded message to the called party. The
different message preferably will be a verification message,
indicating that the called party has reached the proper number
originating the alarm report.
In addition, receipt of the reply signal by the control means
serves further to inhibit the repetitive transmission of the
prerecorded alarm message.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic diagram showing the system, according to the
invention;
FIG. 2 is a diagram disclosing the nature of the prerecorded
information carried by a pliable tape record employed as a control
element in the system, according to the invention;
FIG. 3 is a schematic wiring diagram showing a preferred system,
according to the invention; and
FIG. 4 is a schematic diagram for a reply call responsive
arrangement, according to another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An alarm system according to the invention is shown schematically,
in general, in FIG. 1. The system 10 relies upon conventional means
for detecting a predetermined condition to be reported, such as for
example, the sensors of a type which provide a momentary electrical
grounding of a line to produce a control signal. Sensors 11, 12 and
13 are shown and respectively represent a burglar alarm, a fire
alarm, or other alarm.
The alarm system 10 as disclosed herein preferably cooperates with
conventional telephone company lines 16 and equipment 17 but can be
adapted to be employed in conjunction with other systems of
communication.
In general, the alarm system 10 employs transmitting means in the
form of a tape transport apparatus 14 of a type capable of playing
a plurality of prerecorded tracks or channels of information
signals and for transmitting these signals to a communication
system characterized by the telephone line 16 and box 17. Box 17
represents conventional telephone communication switching equipment
of a type responsive to receipt of dial telephone input signals for
making line connection to one of the called parties 18, 19, 20. The
communication system is capable of transmitting and receiving
messages as generally represented by the telephone
transmitter/receiver (transceiver means) 43 (FIG. 1).
Tape transport apparatus 14 is of a conventional type suitable for
cyclically playing a tape prepared with prerecorded information. As
shown in FIG. 1, a tape cartridge 21 containing a roll of tape 22
wrapped in an endless loop fashion whereby the tape filament 23 may
be withdrawn from the central hub portion of roll 22, led out of
cartridge 21 to pass along one end of the cartridge past a
transducer head assembly 24 equipped with a number of laterally
disposed reproducing head elements (not shown) for cooperation with
associated tracks of recorded information on tape 23. Tape 23 is
moved by engagement between a pinch roller 26 and a capstan 27
thereby advancing the tape 23 in the direction of arrow 28. Thus,
by compressing capstan 27 against the stationary pinch roller 26,
tape 23 will advance in a cyclic manner to repetitively present the
program recorded thereon to the reproducing head assembly 24.
Means for activating capstan 27 in order to compress same against
pinch roller 26 and thereby drive the tape includes the solenoid or
relay 29 which becomes energized upon closure of the switch
armature 31 connected to a suitable power supply in response to
sensing an alarm condition as described more fully below. A drive
motor 36, mechanically coupled to drive capstan 27, is similarly
coupled via a switch armature 37 also connected to a suitable power
supply at such times.
The selected output from transducer head assembly 24 is fed via
output lines 32 to the amplifying and reproducing circuitry 33 of a
type normally found in tape players.
Circuitry 33 is normally inactivated and becomes energized upon
closure of a switch armature 34 which is also coupled to a suitable
power supply in response to sensing an alarm condition.
As noted above, tape 23 has been prepared with a number of
prerecorded channels of information of a type as now to be
described with respect to FIG. 2 which diagrammatically represents
tape filament 23 to be fed in the direction shown by arrow 28'.
Thus, tape filament 23 includes a first channel 38 prepared with
prerecorded control signals, such as dialing signals 39, which,
when transmitted along output line 16 to equipment 17, serve to
make connection with an appropriate called party, such as the
police represented by called party 18.
In advance of control signals 39 (FIG. 2), a short period of a
5000-cycle tone, 50, is recorded followed by a short period of
silence. As is known, this causes an "on-hook" condition on the
line 16 to exist followed by an "off-hook" condition and a dial
tone, all in known manner. Thus, the ("on-hook") 5000-cycle
recorded tone can be considered an "on-hook" signal and the short
period of silence thereafter considered an "off-hook" signal. As is
further known, such action serves to clear the line of any attempt
to preempt the line 16 by outsiders hoping to preclude functioning
of the system. It also readies the circuit to receive the outgoing
control or dialing pulses 39 which follow immediately.
The first prerecorded portion 41 of channel 38 further includes a
prerecorded alarm report message 42 of a type constituting
prerecorded electrical signal representations reproducible as an
audible alarm report message preferably carrying information such
as the location of the premises being protected. The message should
terminate with a request that the called party verify the report by
dialing the telephone number associated with the premises, such as
that of telephone 43, and with the further request that such
verification reply call be placed within a predetermined period
following the conclusion (or other starting point) of the alarm
report message.
Thus, channel 38 further includes a prerecorded signal 44 of
predetermined duration, such as 30 seconds, which (when reproduced
and played on telephone line 16) serves to provide a so-called
"on-hook" signal capable of indicating to conventional telephone
communication equipment 17 that telephone 43 is not in use and is
ready to receive calls.
Accordingly, in FIG. 1, the foregoing action is schematically
represented by an inhibit function or means shown as line 46 which
normally acts to inhibit incoming conventional dialed reply pulses
arriving via telephone line 16 and line 47 which would otherwise
operate head selector mechanism 48. Inhibit means 46 responds to
the reproduction of the prerecorded "on-hook" signal 44 to permit
the gating of incoming reply dial signals appearing on telephone
line 16 and incoming line 47 to thereby operate head selection
mechanism 48 to cause transducer head assembly 24 to switch and
activate another transducer to cooperate with a second channel such
as channel 49 and to deactivate the first transducer from
reproducing its associated track 38.
Channel 49 serves to provide a confirmatory audio report to persons
dialing the telephone number of telephone 43, located at the
premises, so as to provide them with additional information or
instructions.
Thus, as soon as tape transport apparatus 14 commences playing the
confirming track 49 the prerecorded electrical signal
representations constituting a confirmatory message 51 will be
repeated and transmitted on telephone line 16 for listening by the
called party. It will, therefore, be readily evident that by
switching from channel 38 to reproduce channel 49 the further
repetitious placing of calls to party 18, such as the fire
department or police, will have been inhibited by the reply call
from the called party in confirming the origination of the alarm
report message.
Upon sensing the predetermined condition for which sensors 11, 12
13 have been provided, a signal will appear on one of the lines 52,
53, 54 respectively. This signal is picked up by a switch operator
56, such as a relay or solenoid device, which serves to close
switch armatures 31, 34, 37 respectively and thereby initiate
operation of drive motor 36, capstan 27 and energization of the
electronic circuitry 33 of transport apparatus 14. Upon activation
of operator 56, suitable connections 57, 58 serve to operate a
latching circuit 59 so as to maintain operator 56 energized and
tape transport apparatus 14 in an active condition until its tape
23 has been fully played.
As explained more fully below, at the end of a complete playing of
tape filament 23, there is provided a means, such as a short length
of electrically conductive foil, serving to generate a release
signal via a line, such as 61, to deenergize latching circuit 59
and upon release of latching circuit 59 , operator 56 drops out so
as to decouple drive motor 36, solenoid 29 and electronic circuitry
33 from their respective power supplies thereby terminating a cycle
of operation.
Signals transduced from tape 23 are fed via line 32 and electronic
circuitry 33 onto output line 35. Output line 35 may be suitably
coupled into the telephone system by means of known alarm coupler
devices, such as 40, whereby the output line 35 feeds onto
telephone line 16.
From inspection of FIG. 2, it will be readily apparent that tape 23
contains a first repetition and a second repetition of the alarm
report message and then in the event that the head selector 48 has
not yet been switched whereby channel 49 is to be played, signals
62 reproduced from channel 38 provide dialing signals serving to
generate pulses on telephone line 16 appropriate to call the
telephone operator. These dialing pulses 62 are followed by the
transmission of an alarm report message represented by the
prerecorded electrical signals 63 which, in turn, is followed by an
"on-hook" signal 64 to permit the operator to call back to the
telephone number of telephone 43 at the premises and thereby obtain
confirmation of the origin of the call.
In the event that the foregoing procedure shall have failed to
cause the transducer head assembly 24 to switch to channel 49, it
may reasonably be assumed that the telephone lines leading into the
premises have been cut from outside the building.
Accordingly, in channel 38 there is then provided prerecorded
electrical signal representations 66 which, when transduced by head
assembly 24, are amplified by an amplifier 67 which is coupled to
activate an audible alarm 68 located on the premises.
In the event that the telephone lines have not been cut, it is
believed that there is a high likelihood that at least one of the
prerecorded alarm report messages will have been transmitted to a
called party and that the called party will have verified the call
and thereby switched transducer assembly 24 to cooperate with
channel 49.
Thus, following the initial reporting to the more important
authorities, the program recorded on tape filament 23 in channel 49
continues to generate dialing pulses such as dialing pulses 71, 72,
73 to place calls to various interested parties, e.g., plant
superintendent, neighbor, etc. Associated with each of these dialed
call signals, a particular pertinent message is indicated in FIG. 2
by the prerecorded electrical signal representations 74, 75, 76
respectively.
Having the foregoing general arrangement in mind, the construction
and functioning of the operating layout shown in FIG. 3 may be
readily understood.
Similar reference numbers have been employed in FIG. 3 as employed
in FIG. 1 where parts generally correspond, such as the sensors 11,
12, etc.
Referring to FIG. 3, and assuming a burglary has been detected by
sensor 11 on the premises being protected, a momentary electrical
grounding on sensor line 53 serves to operate relay 56 via line 55.
Relay 56 locks into its energized state by virtue of the latching
point 90 and switch armature 82 connecting to line 119 grounded as
explained below. At the same time, transducer 83 becomes connected
to feed audio amplifier 84 via the closed contact points 86,
87.
With respect to the latching point 90 contacted by switch armature
82 (and 107 for fire alarm portions of the system), it is apparent
that if the point 90 is connected to ground, line 55 will energize
relay 56. Similarly, line 100 when connected to ground serves to
energize relay 108. Either of those two lines 55, 100 is
momentarily connected to ground by one of sensors 11, 12, 13 and
the relay in the line (56, 108) becomes latched in an energized
state by providing a ground circuit through a transistor 112.
Thus, the system power supply 104 may be traced to line 109 via
line 106 and connection 88 or 107 whereby to bias transistor 112
into conduction by the connection of base electrode 113 to a
voltage divider comprised of resistors 114, 116. By thus driving
transistor 112 into conduction, the path from the grounded emitter
117 to collector 118 becomes essentially a short circuit whereby
line 119 is connected effectively to ground to make a point 90
equivalent to a ground point. This point then becomes a latching
point and ground remains on one side of relay 56 whereas the other
side is connected to power supply voltage.
Fire relay 108 is operated in a similar manner forming a latching
point 121 grounded via lines 122, 119 when system power supply is
coupled to line 109 upon the closure of armature 107, the latter
being connected to power supply 104 via line 106.
Finally, unlatching of points 90, 121 is accomplished by the fact
that on tape element 23, there is a predetermined length of
conductive tape extending on the order of about an inch which
serves to provide a short circuit across points 124, 126 so as to
remove the bias which is maintaining transistor 112 in its
conductive state. Thus, transistor 112 is taken out of conduction
so that line 119 can return to its original potential and remove
the voltage across relays 56, 108.
The manner in which the points 124, 126 become directly coupled
through the metallic portion of tape 23 is simply that there are
two spaced transducer heads (not shown) on tape transport apparatus
14 which contact the metallic surface. One of the two heads is
insulated from ground (not shown) and upon being shorted, via the
metallic strip on the tape, forms a ground connection across
emitter 117 (FIG. 3) so as to ground out base electrode 113 whereby
transistor 112 no longer sustains its conductive state.
Further, by energizing relay 56, transport apparatus 14 is
activated. Power supply voltage on the order, for example, of 24
volts is connected to the circuit causing solenoid 29, drive motor
36 and amplifier 84 to operate from the power supply connection
point 88 as to coupled to line 106.
Thus, motor 36 commences operation and capstan 27 is urged against
pinch roller 26 to cause tape 23 to advance. As the tape commences
to advance, relay 91, as now to be described, provides an
"off-hook" condition on the phone line in order to clear the line
of any attempt to preempt it by a burglar or vandal or other party
and to place the line in readiness whereby the circuit for the
outgoing dial pulses 39 will be clear to permit the called party to
be reached.
As mentioned above the conventional telephone lines using an alarm
coupler operated by a tone-keying circuit 110 can be cleared in
known fashion by providing a short period of 5000-cycle tone
signals to the keying circuit 110 followed by a short period of
silence whereby an "on-hook" condition is followed by an "off-hook"
condition and dial tone.
The above line-clearing function is achieved herein by use of
suitable known, conventional alarm coupler means 98 whereby an open
circuit between leads 96, 97 serves to generate an "on-hook" signal
while a closed circuit between leads 96, 97 generates an "off-hook"
signal on telephone line 16. In the "off-hook" condition the audio
output and dialing control signals 39 are carried, via line 35 and
coupler means 98, onto telephone line 16.
Thus, tape 23 is prerecorded to carry a short length or period 50
of a 5000-cycle signal immediately ahead of the first of the
dialing signals 39. Thus, when reproduced, the signal is coupled
via leads 65 or 70 to amplifier 84 and via lead 69 to operate relay
91.
A filter circuit 93 passes no other frequency signals whereby only
signal 50 will operate a suitable known keying circuit 110 to
energize relay 91. As relay 91 is energized, armature 94 will open
the connection between leads 96, 97 for the duration of signal 50.
A spring (not shown) returns armature 94 to closed position upon
terminating signal 50.
This serves to clear the line as above described. The 5000-cycle
tone may also be recorded for a period on the order of 30 seconds
duration at the end of the transmission of the prerecorded alarm
message in order to provide an "on-hook" condition during which
time the called party can dial into telephone 43 located on the
premises being protected.
Thus, for the period while armature 94 serves to open the
connection between leads 96, 97 any incoming 20-cycle ringing tone
appearing on telephone line 16 will also cause relay 99 to become
energized via line 103 and so become latched continuously in an
energized state.
This is accomplished by the "on-hook" signal 44 (or similar signal
92 for fire) recorded in one of the channels of tape 23. Signal 92
is of a predetermined frequency such as 5000-cycles recorded on
tape 23.
Hence, when transducer 83 reproduces signal 92, audio amplifier 84
serves to feed the amplified 5000 cycles via filter 93 to operate
relay 91 for the period corresponding to "on-hook" signal 92. By
energizing relay 91, armature 94 opens the circuit between leads
96, 97 to generate an "on-hook" signal on line 16. Thus, it is only
during the existence of the "on-hook" signal on line 16 that a
reply will be able to be received by the system. At that time,
however, incoming ringing signals on line 16 of conventional type,
such as the 20 cycle telephone signals which operate the
telephone's usual bell, can be used to operate relay 101 whereby
the reply by the called party generates a confirmation message.
Accordingly, when the called party responds promptly, the tape
transport apparatus 14 will be switched to play a confirmation
message to the caller as follows.
A suitable telephone company relay 101 of known type which responds
to receipt of conventional telephone "calling signals" for normally
ringing a remotely located telephone bell becomes activated by
receipt of the reply call signals generated by the called party,
e.g., the police, in reply to the prior report transmitted by
transport apparatus 14. Thus, via line 102, relay 101 provides an
output signal on line 103 to operate relay 99 by forming a
momentary ground point to complete a circuit traced from power
supply 104, via line 106, switch armature 107 (now closed by the
holding action of relay 108), line 109, then to relay 99, and
switch armature 111 held to a grounded point by the holding action
of relay 99 itself.
Another arrangement for generating the output signal on line 103 is
shown in FIG. 4 having the advantage that direct connection to the
telephone lines is not required, as this may be objectionable under
some circumstances. Thus, a pair of telephone lines 77, 78 are
arranged whereby one line 78 passes through a ferrite core 79.
Signals, such as the twenty cycle incoming signals on lines 77, 78
developed by a reply call are sensed by the winding 81 and fed via
a tuned amplifier 80 which amplifies and then rectifies the signal
by means of the diode 120. Condenser 115 smooths the signal which
is then fed via line 103 to momentarily operate relay 99.
The "confirmation" relay 99, in energized state, serves to switch
the transducer or head selector mechanism 48 (FIG. 1) whereby
transducer or head assembly 24 will reproduce signals from a second
track or channel prerecorded on tape element 23, such as channel 49
(FIG. 2). 2). Thus, the holding action of the circuit traced from
power supply 104 through relay 99 latched to a ground point via its
own holding armature 111 serves to ensure the continued playback
from the second (or "confirmation") message track 49 of tape
23.
It is to be understood that where a different type of alarm
condition is sensed by another of sensors 11, 12, 13, channels of
prerecorded signals on tape 23 will similarly be played and
employed as control elements to operated the system.
Thus, it is apparent that relay 108 may be considered to be the
fire sensing relay and relay 56 pertains generally to sensing
burglary conditions.
Detection from the various sensors is mutually exclusive. Thus,
when fire sensor 12 has operated relay 108, this action transfers
switch armature 105 so as to open or inhibit the circuitry for
operating relay 56. Relay 56 would otherwise serve to commence
operations to report a burglary. This aspect of the system is
advantageous, e.g., if a fire is detected and a fireman or a
neighbor enters the building, the burglary alarm will not then be
initiated and interfere with dialing the emergency fire call to the
fire department. Conversely, the reporting of a burglary should not
normally be an occasion for calling out the fire department. This
is guarded against by the presence of switch armature 85.
The present system may incorporate arrangements for directly
initiating local alarms in the vicinity of the building or premises
being protected in a manner acting directly and immediately in
response to the severance to the telephone lines themselves.
One arrangement involves the use of a 5500-cycle filter 127
directly coupled to a conventional tone-actuated circuit 95 coupled
to operate the local alarm 68. Thus, when a prerecorded 5500-cycle
tone on tape 23 is received by circuit 95, the local alarm 68 will
sound. Circuit 95 may be any suitable conventional circuit of a
type responsive to receipt of a tone predetermined frequency and
serving to provide an output signal to activate alarm 68.
Another arrangement for sounding a local alarm requires
energization of the overall system as is done by a sensor 11, 12,
13 described elsewhere herein. Thus, whenever the entire system has
been energized by virtue of the activity of one of the several
types of sensors involved, there is provided a line voltage
detector 128 energized by lead 129 and located in a manner whereby
upon energizing the system 10, the energizing lead 129 serves to
condition voltage detector 128 to sense changes in the voltage as
they may appear on the telephone line itself. Thus, a
voltage-sensing lead 131 extends from the telephone line 16 to
voltage detector 128 for this purpose. Accordingly, the voltage
detector thereby directly operates the local alarm 68 upon
experiencing any untoward change in the line voltage.
* * * * *