U.S. patent number 3,820,102 [Application Number 05/274,806] was granted by the patent office on 1974-06-25 for premises entry and exit signaling system.
This patent grant is currently assigned to Aerolite Electronics Corp.. Invention is credited to Howard C. Schubert.
United States Patent |
3,820,102 |
Schubert |
June 25, 1974 |
PREMISES ENTRY AND EXIT SIGNALING SYSTEM
Abstract
The system includes a signaling circuit adapted to provide a
signal when the protected premises have been entered or left by
authorized personnel and a gate means controlling the operation of
the signaling circuit. The gate is operated by a second circuit
which includes a warning light, a master multi-position switch
located inside the premises, a normally-open switch, and a
normally-closed outside switch located outside the premises. The
connections are such that the master switch is used to operate the
system when authorized personnel enter the premises, but the
combined action of the master switch and outside switch are
required when authorized personnel leave the premises. Tampering
with the outside switch is of no effect once the system has been
set.
Inventors: |
Schubert; Howard C. (Leonia,
NJ) |
Assignee: |
Aerolite Electronics Corp.
(Union City, NJ)
|
Family
ID: |
26957089 |
Appl.
No.: |
05/274,806 |
Filed: |
July 24, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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879258 |
Nov 24, 1969 |
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Current U.S.
Class: |
340/506;
340/545.1; 340/691.5; 340/691.8; 340/528; 340/692; 340/512;
340/533 |
Current CPC
Class: |
G08B
13/08 (20130101) |
Current International
Class: |
G08B
13/02 (20060101); G08B 13/08 (20060101); G08b
013/08 () |
Field of
Search: |
;340/276,274,214,409 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Caldwell; John W.
Assistant Examiner: Swann, III; Glen R.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No.
879,258, filed Nov. 24, 1969 and now abandoned.
Claims
What is claimed is:
1. A premises protection system comprising
a power supply,
an alarm-sensing circuit,
a signalling circuit for indicating the setting of said
alarm-sensing circuit,
a multi-position switch having a rotor and a plurality of operating
positions including an OFF position, an ON position, and an
intermediate position,
a two-position switch,
a two-position relay having an armature, first and second contacts,
and an electrical winding, the armature being normally in a first
position in which it is in contact with said first contact,
said intermediate contact of said multi-position switch being
connected to one side of said power supply and the rotor of said
multiposition switch being connected to the other side of said
power supply,
movement of the rotor of said multi-position switch from said OFF
position through said intermediate position to said ON position
completing a current flow path through said winding of said relay
and causing said armature of said relay to switch from its first
position to a second position in which said armature is in contact
with said second contact and said power supply is disconnected from
said alarm-sensing circuit,
operation of said two-position switch disconnecting said winding of
said relay from said power supply and releasing said armature from
said second position in which it is in contact with said second
contact and causing it to return to its first position in which it
is in contact with said first contact whereby said power supply is
connected to said alarm-sensing circuit and said signalling circuit
is energized to transmit a signal which indicates that power has
been connected to said alarm-sensing circuit.
2. The system defined in claim 1 and including in said
alarm-sensing circuit
first alarm signalling means,
a first electronic circuit module including first bistable
switching means having two states of operation, in one of which it
is unenergized and quiescent and, in the second of which, it senses
a first alarm condition and generates a first electrical signal in
response thereto, said first electrical signal operating said first
alarm signalling means,
a second electronic circuit module including second bistable
switching means having two states of operation, in one of which it
is unenergized and quiescent and, in the second of which, it senses
a second alarm condition and generates a second electrical signal
in response thereto, said second electrical signal operating said
first alarm signalling means,
a third electronic circuit module coupled to said first and second
electronic circuit modules and having input terminals coupled to
said first and second circuit modules and having first and second
output terminals for indicating which of its two states each of
said first and second electronic circuit modules is in, and
a fourth circuit module including second signalling apparatus and
coupled to said first and second output terminals,
said output terminals of said third electronic circuit module
carrying one set of potentials and energizing one portion of said
fourth circuit module when said first and second circuit modules
are in an unenergized and quiescent state, said output terminals
carrying a second set of potentials and energizing another portion
of said fourth circuit module when one or both of said first and
second electronic circuit modules is in an alarm-signalling
state.
3. The system defined in claim 2 wherein one of said first or
second circuit modules includes time delay means for delaying its
operation of said first alarm signalling means.
4. The system defined in claim 2 wherein said fourth circuit module
is coupled to said third module and
said second signalling apparatus includes a first indicator means
indicating a normal state for said system when said output signal
is not present and said third module is in its first state, and a
second indicator means indicating an alarm state when said output
signal is present and said third module is in its second state.
5. The system defined in claim 4 wherein, in said fourth module,
said first indicator means includes a normal condition indicator
and a gate, and said second indicator means includes an alarm
condition indicator and a gate,
first power supply means coupled to and applying an AC signal
across both said alarm condition indicator and gate, and said
normal condition indicator and gate, each said gate preventing said
AC signal from turning on its associated indicator, and
a second power supply means coupled through control means to said
gates for applying an enabling signal thereto and for operating the
same and their associated indicators under control of said control
means.
6. The system defined in claim 2 wherein said first and second
output terminals of said third circuit module are coupled through a
first pair of oppositely oriented diodes to first and second
switching devices which are connected so that they turn ON and OFF
together in response to the potentials on said first and second
output terminals of said third module,
said first switching device being coupled through a first circuit
path to a first "trouble" indicator having a first gate, said
second switching device being connected through a second circuit
path to a second "normal" indicator having a second gate,
said first and second output terminals also being connected through
a second pair of oppositely connected diodes to third and fourth
circuit paths, said third path including a switching device
connected to a third "alarm" indicator having a third gate, said
fourth path being coupled to a fourth remote "alarm" indicator
having a fourth gate, and
a signal source providing signals for operating said first, second,
and third indicators and coupled to said first, second, and third
circuit paths, said paths being open or blocked to said signals
depending on the conductive state of said switching devices, and
the state of said diodes being determined by the potentials on said
first and second output terminals of said third circuit module.
7. The system defined in claim 1 wherein said alarm-sensing circuit
includes
positive and negative buses, and said alarm-sensing circuit in
addition is coupled through transmission lines to a remote
indicator circuit at a location remote from the protected
premises,
a normally open switch across said transmission lines, and
a series-connected transistor switch and lamp connected between
said positive and negative buses whereby closure of said switch
turns on said transistor switch and said lamp.
8. The system defined in claim 7 including
an auxiliary switch ganged to said three-position switch and
including OFF and ON terminals, between which a potentiometer is
connected, the slider of said potentiometer being connected to
positive potential, and
a circuit connected between said transmission lines at said remote
location comprising a transistor switch having a meter in its
output circuit, said meter providing one reading when said
auxiliary switch is in the OFF state and a second reading when said
auxiliary switch is in the ON state.
9. The system defined in claim 1 wherein said alarm-sensing circuit
includes an alarm means,
a microphone and a first audio amplifier at said premises, said
first audio amplifier having a pair of output lines and a power
line, all normally open,
a remote indicating circuit at a remote location coupled through
transmission lines to said first alarm-sensing circuit,
means associated with and operated by said alarm means and coupled
to said output and power lines to couple said output lines of said
first audio amplifier to said transmission lines to transmit sound
from said premises along said transmission lines,
a second audio amplifier and a speaker connected to said
transmission lines at said remote location whereby said sounds can
be heard at said remote location.
10. The system defined in claim 1 wherein said alarm-sensing
circuit includes
an alarm means,
a relay connected across said alarm means and having three
armatures,
a first audio amplifier having a pair of output lines coupled to
but normally not contacting two of said armatures,
a power lead extending from said audio amplifier to said third
armature but normally not in contact therewith,
a remote indicating circuit at a remote location coupled through
transmission lines to said alarm-sensing circuit,
said two of said armatures being connected to said transmission
lines whereby, when said armatures close into contact with said two
output lines, the output of said audio amplifier can be transmitted
along said transmission lines to said remote indicating circuit,
and
a second audio amplifier and a speaker connected to said
transmission lines at said remote location whereby personnel at
said remote location can receive transmissions from said first
audio amplifier.
11. The system defined in claim 1 wherein said first alarm-sensing
circuit includes
an alarm means,
a connection from said alarm means to a semiconductor amplifier
means and to a programmable unijunction transistor having a time
delay circuit at its input,
the output of said unijunction transistor being connected through a
switching circuit to a relay having a normally closed switch means
in the power line of said system whereby operation of said alarm
means turns on said semiconductor amplifier and charges said time
delay circuit which fires said unijunction transistor and said
switching circuit to operate said relay and thus to open said power
line and disable said alarm-sensing circuit whereupon said relay
closes said switch and re-establishes the continuity of said power
line.
12. The system defined in claim 2 wherein said first output
terminal is coupled to a first pair of oppositely oriented diodes
and said second output terminal is coupled to a second pair of
oppositely oriented diodes,
said first pair of diodes being coupled through first and second
switching devices to first and second circuit paths, the first
circuit path including a "trouble" indicator means and the second
circuit path including a "normal" indicator means,
said second pair of diodes being connected through third and fourth
switching devices to third and fourth circuit paths, the third
circuit path including a first "alarm" indicator means and the
fourth circuit path including a second "alarm" indicator means,
and
a signal source providing signals for operating said first, second,
and third indicator means and coupled to said first, second, and
third circuit paths, said paths being open or blocked to said
signals depending on the conductive state of said first and second
pairs of switching devices, and the state of said diodes being
determined by the potentials on said first and second output
terminals of said third circuit module.
13. The system defined in claim 12 wherein said first, second,
third and fourth switching devices are semiconductor devices.
14. The system defined in claim 12 wherein said first, second, and
third switching devices are transistors having at least three
electrodes and said fourth switching device is a three-electrode
controlled rectifier.
15. The system defined in claim 12 wherein one diode of said first
pair of diodes is connected to an input electrode of each of said
first and second switching devices and one diode of said second
pair of diodes is connected to an input electrode of each of said
third and fourth switching devices.
16. The system defined in claim 12 wherein said fourth circuit path
includes a time-delay pulse generating circuit which comprises said
fourth switching device and a capacitor, said fourth switching
device being rendered conductive to operate said second "alarm"
indicator means when said capacitor is charged by current flowing
in said fourth circuit path as the result of an alarm condition
sensed by said system.
17. The system defined in claim 12 and including a normally open
relay connected across said "trouble" indicator means and coupled
to said fourth switching device whereby, whenever said "trouble"
indicator means turns on, said fourth switching device and said
second "alarm" indicator means are operated.
18. The system defined in claim 6 wherein
said first and second switching devices comprise first and second
semiconductor devices coupled together and adapted to be ON or OFF
together in response to signals on said first and second output
terminals of said third module,
when said first and second switching devices are ON together due to
first ones of said signals on said output terminals, said second
switching device couples signals from said signal source to said
second gate to operate said "normal" indicator and said first
switching device prevents said signals from said signal source from
operating said first gate and said first "trouble" indicator, and
when said first and second switching devices are OFF together due
to others of said signals at said output terminals of said third
module, said others of said signals operate said third switching
device and said fourth gate and said third and fourth circuit paths
are operative and operate the "alarm" indicators therein.
19. Premises protection apparatus comprising
a signaling circuit,
a double-acting master switch coupled to said circuit for fully
setting said circuit into operation or for partially setting said
circuit, depending on which of the two actions of said switch is
employed,
a first switch coupled to said signaling circuit and adapted to be
operated by authorized personnel to complete the setting and
operation thereof when said circuit has been partially set and
authorized personnel leave the premises,
a second switch coupled to and operated by said master switch for
partially setting said circuit, said first switch being coupled to
and operating said second switch for completing the setting of and
operation of said circuit,
said master switch including an OFF contact, an ON contact, and an
intermediate contact, said intermediate contact being coupled to
and causing operation of said second switch to partially set said
signaling circuit,
said second switch including a contactor arm and first and second
contacts,
said apparatus further including
a power source,
said signaling circuit including a first gate portion and a second
portion which can operate a signal system,
turning of said master switch through said intermediate contact
serving to momentarily complete a circuit path from said power
source through said second switch whereby said contactor arm is
moved from normal contact with said first contact into contact with
said second contact whereby power is coupled to said signaling
circuit and said first gate portion thereof is energized but not
said second portion thereof,
said first switch being normally closed and being in said circuit
path, momentary opening of said first switch de-activating said
second switch and moving said contactor from said second contact to
said first contact, whereby power is removed from said first
portion of said signaling circuit whereby said second portion of
said signaling circuit can operate and can energize said signal
system.
20. The circuit defined in claim 19 wherein
said first gate portion of said signaling circuit includes a
capacitor arrangement which charges and holds off said second
portion of said signaling circuit,
discharge of said capacitor arrangement when said first switch is
operated serving to energize said second portion of said signaling
circuit.
21. The circuit defined in claim 19 wherein
said first gate portion of said signaling circuit includes a
capacitor arrangement which charges and holds off said second
portion of said signaling circuit,
discharge of said capacitor arrangement when said first switch is
operated serving to energize said second portion of said signaling
circuit, and
said second portion of said signaling circuit including a first
sub-circuit and a second sub-circuit, said first sub-circuit having
a short time constant for operating a remote light-flashing
arrangement, said second sub-circuit having a longer time constant
for controlling the time duration of the operation of said first
sub-circuit.
22. A premises protection system comprising
a power supply,
an alarm-sensing circuit,
a signalling circuit for indicating the setting of said
alarm-sensing circuit,
a multi-position switch having a rotor and a plurality of operating
positions including an OFF position, an ON position, and an
intermediate position,
a two-position switch,
a two-position relay having an armature, first and second contacts,
and an electrical winding, the armature of said relay being
normally in a first position in which it is in contact with said
first contact,
said intermediate contact of said multi-position switch being
connected to one side of said power supply and the rotor of said
three-position switch being connected to the other side of said
power supply,
a door in said premises and a door switch mounted in said door,
said switch being open when the door is closed and closed when the
door is open,
a first connection from said ON position of said multi-position
switch to said door switch,
movement of the rotor of said multi-position switch from said OFF
Position through said intermediate position to said ON position
completing a current flow path through said winding of said relay
and causing said armature of said relay to switch from its first
position to its second position in which said armature is in
contact with said second contact and said power supply is
disconnected from said alarm-sensing circuit,
a switching circuit including said two-position switch coupled to
and adapted to operate said relay and having a second connection to
said first connection through said door switch, said switching
circuit including a transistor having its input coupled to said
second connection and its output coupled to first and second
semiconductor switches, said transistor and said first
semiconductor switch being turned on when said multi-position
switch is turned ON, subsequent closing of said door and opening of
said door switch serving to apply operating potential to said
second semiconductor switch to operate said relay and said
signalling circuit to signal the arming of said alarm-sensing
circuit.
23. A premises protection system including
an alarm-sensing circuit for detecting alarm conditions at said
premises,
a signaling circuit for indicating the state of said alarm-sensing
circuit and whether it has been disabled or enabled by an occupant
of the premises,
a first switch which is a multi-position switch and includes an OFF
position, an intermediate position, and an ON position,
a door associated with said premises,
a door switch coupled to said door and open when said door is
closed and closed when said door is open,
a power supply,
a first relay having an armature, a first contact, a second
contact, and a winding,
said first contact being connected through a normally closed switch
to a second relay having a contact, an armature, and a winding,
said armature of said first relay being connected to one side of
said power supply,
a connection from said intermediate contact of said multi-position
switch through said winding of said first relay to the other side
of said power supply,
a circuit loop including a transistor coupled through a diode to a
first SCR switch to a second SCR switch through a diode and a third
SCR switch to the winding of said second relay,
a connection from said ON contact of said switch through said door
switch (1) through a diode to said transistor and (2) through a
lead to the alarm-sensing circuit,
a connection from a contact of said multi-position switch to said
alarm-sensing circuit,
a connection from said intermediate position of said multi-position
switch to said winding of said first relay whereby, when the rotor
of said multi-position switch is moved from the OFF position
through the intermediate position to the ON position, a current
flow path is completed from said power supply through said winding
of said relay and said armature is moved to said second
contact,
a connection from said ON position to said signalling circuit for
partially setting the same when said rotor is moved from said OFF
position to said ON position and potential is coupled from said
power supply to said signalling circuit,
opening of said door causing said door switch to close and couple
potential from said power source to said transistor to cause it to
conduct and apply operating potential to an electrode of said
second SCR switch,
closing of said door causing said door switch to open and apply
positive potential to the gate of said second SCR switch which
fires and causes said second relay winding to conduct and open and
cut off current from the winding of said first relay whereby its
armature goes back to said first contact to apply arming potential
to said alarm-sensing circuit and to operate said signalling
circuit.
Description
BACKGROUND OF THE INVENTION
Burglar alarm systems are usually designed so that they can be
turned on and off with a key and key-operated switch that is
accessible from outside the premises to be protected. Usually, the
key-operated switch is mounted outside the premises at a door. Such
a system has the serious defect that the external switch, which is
the control heart of the system, can be tampered with and the
system can be disabled.
SUMMARY OF THE INVENTION
The present invention includes a signaling circuit for generating a
signal to show authorized entry and exit from the protected
premises and an interior switch for providing first step
energization of the system, and an external control means which
completely energizes the system but has no effect on the system if
it is tampered with.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a system embodying the
invention and a portion of a burglar alarm system with which it can
be used;
FIG. 2 is a schematic representation of another portion of said
burglar alarm system;
FIG. 3 is a schematic representation of a modification of a portion
of the system of FIG. 1;
FIG. 4 is a schematic representation of another modification of a
portion of the system of FIG. 1;
FIG. 5 is a schematic representation of still another modification
of a portion of the system of FIG. 1;
FIG. 6 is a schematic representation of another modification of a
portion of the system of FIG. 1;
FIG. 7 is a schematic representation of another modification of a
portion of the system of FIG. 1; and
FIG. 8 is a schematic representation of another modification of a
portion of the system of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A system 12 embodying the invention includes an actuator or control
portion or module 22 and a signaling control portion or module 32.
The portion 32 is adapted to generate a signal or the like which
represents the authorized and proper setting of the system, and
control portion 22 is adapted to control the operation of portion
32.
The actuator portion 22 of the system includes a master control
switch 42 which is preferably key-operated and has a key-operated
rotary contactor 52 and a plurality of operating contacts or
positions including an OFF contact 62, a battery test contact 72, a
system test contact 82, a door set contact 92, and an ON contact
102. The switch 42 and its associated circuit is preferably mounted
in a suitable box or housing (not shown) at a convenient location
inside the premises with which the invention is associated and
which are to be protected.
The system 12 includes a primary power source, for example, a first
battery 112, which has its negative terminal connected by lead 122
to the movable arm 132 of a C-type reed switch 142. The movable arm
132 of switch 142 is normally closed in contact with terminal 144
which is connected by a lead 152 to the rotor 52 of switch 42.
Thus, negative battery potential is normally always applied to the
switch rotor 52.
The system test contact 82 and the ON contact 102 of the switch 42
are connected together by lead 162 to an associated burglar alarm
system of any suitable type. One such burglar alarm system is
disclosed and claimed in U.S. Pat. No. 3,603,947. This system,
including module 20 (FIG. 1) and modules 110 and 420 (FIG. 2), is
also shown and described herein to illustrate the invention. Module
22 is coupled to on-premises alarm condition sensing module 20 by
lead 162 which extends from contacts 102 and 82 of switch 42 to
negative reference bus 50 of module 20. Module 20 and the other
portions of the burglar alarm system are described in detail
below.
Referring again to module 22 of the system 12, the positive
terminal of battery 112 is coupled by lead 172 to the positive
reference bus 182 of signaling module 32 and by lead 202 to a
normally-closed push button door switch 212 which is mounted at an
accessible location near a door outside the premises. This is
represented by a dash line enclosure. Several such push button door
switches 212 might be provided at several doors and connected in
series to permit entry or exit and operation thereof at more than
one door. Push button door switch 212 is connected by leads 221 and
222 to one end 231 of the inductor winding 232 of reed switch 142.
The other end 242 of the inductor 232 is connected by bus 252 to
the normally-open contact 262 of reed switch 142 and thence by but
272 to door-set contact 92 of key-operated switch 42. End 242 of
winding 232 is also coupled by lead 282 to signaling circuit module
32.
A warning light indicator 292 is connected in parallel with the
inductor winding 232 of reed switch 142 between leads 222 and 282
and is arranged to light only when reed switch 142 is energized, as
described below. One such warning light is provided for each push
button switch 212.
The signal module 32 includes common bus 182 and common bus 302.
Lead 282 from end 242 of the inductor 232 is connected through
parallel connected resistor R1 and capacitor C1 to common bus 182,
and through resistor R2 to the base of transistor T1. The emitter
of transistor T1 is connected to bus 182, and its collector is
connected through resistor R3 to but 302. bus collector of
transistor T1 is also connected through capacitor C2 to lead 364
which is connected through capacitor C3 and resistor R4 to bus 182
and through diode D1. oriented as shown for a purpose to be
described, to bus 302. The junction 394 of resistor R4 and
capacitor C3 is also connected to the base of transistor T2, the
emitter of which is connected to bus 182, and the collector of
which is connected through resistor R5 to bus 302.
The collector of transistor T2 is also connected through a diode
D2, oriented as shown, both through a resistor R6 to bus 302 and to
the gate of the three-electrode controlled rectifier, SCR1, the
anode of which is connected through resistor R7 to bus 182, and the
cathode of which is connected to bus 302. The anode of rectifier
SCR1 is also connected by lead 454 through capacitor C4 and
resistor R8 to bus 182 and through resistor R9 to one base of
unijunction transistor UJ1. The junction of capacitor C4 and
resistor R8 is connected to the emitter of UJ1, the other base of
UJ1 is connected through resistor R10 to bus 182, and the
aforementioned one base of UJ1 is connected by capacitor C5 to bus
302.
Lead 454 from the anode of SCR1 is also connected through resistor
R11 to the base of transistor T3, the emitter of which is connected
to bus 182, and the collector of which is connected to a lead 524
which itself is connected (1) through resistor R12 to bus 302, and
(2) through resistor R13 and capacitor C6 to bus 302 and through
resistor R14 to one base of UJ2. The other base of UJ2 is connected
to bus 302, and its emitter is connected both to the junction of
resistor R13 and capacitor C6, and by lead 574 to the base of
transistor T4, the emitter of which is connected to bus 302, and
the collector of which is connected to the base of transistor T5.
The emitter of transistor T5 is connected to bus 182, and the
collector is connected through the inductor 602 of a normally
closed A-type reed switch 611 having normally-closed contacts 612
and 614, connected to terminals 341 and 340, respectively, which
are inserted in one of two telephone lines, e.g., line 400 (FIG. 2)
to be discussed further below. Thus, transistor T5 is coupled to
remote signaling devices at a monitoring station, the devices
including a normal signal light 580, a trouble signal light 560,
and alarm 600. Other signaling devices may be provided, if
desired.
The alarm system described in the above-mentioned patent includinj
modules 20 (FIG. 1) and 110 and 420 (FIG. 2) and its mode of
operation will now be described.
The alarm system module 20 (FIG. 1) has an alarm indicator
including a three-electrode semiconductor gate or switching device
60 known as an SCR connected in series with load resistor 70
between buses 40 and 50 with an alarm bell or horn or the like
represented by block 80 connected across resistor 70. The gate of
SCR 60 is connected through a resistor 82 to bus 50 and to negative
potential supplied by battery 150. Battery 112 provides positive
potential to bus 40 through lead 192. SCR 60 is normally held off
by the applied potentials. The anode of SCR 60 is also coupled
through diode 90, lead 100, and rotor 52' and ON contact 102' of
switch 42' and lead 107 to module 110 (FIG. 2), a
polarity-reversing circuit, to be described. Switch 42' is ganged
to switch 42 and has ON and OFF contacts 62' and 102' which operate
with contacts 62 and 102 of switch 42. Switch 42' is used to
disconnect module 110 from system 12 when switch rotor 52 passes
through contacts 72, 82, and 92.
A first alarm-sensing arrangement in module 20 (FIG. 1) includes a
semiconductor switch 120, preferably a G.E. 4987 switch, having its
anode A connected through a resistor 130 to the bus 40 and thus to
positive potential, and its gate G connected through a normally
closed switch 140 to the positive terminal of D.C. power source
150. The cathode K of switch 120 is connected by lead 160 to the
gate G of SCR 60. Power source 150 normally holds switch 120
non-conducting, and switch 140 represents a mechanical or
electronic alarm-sensor switch or any other sensing mechanism
which, when opened, upsets the bias arrangement and permits switch
120 to conduct current from anode to cathode and to the gate of SCR
60 which also then conducts, energizes alarm 80, and provides an
output current on lead 100 from diode 90. Device 140 represents one
or more alarm-sensing devices which may be connected in series or
parallel as desired, in the windows, doors, or the like of the
premises being protected.
A second similar alarm-sensing arrangement in module 20 includes a
normally open switch 170 which, like switch 140, represents an
alarm sensor connected in series with a resistor 180 between buses
40 and 50. Again, a plurality of similar alarm sensors might be
connected in parallel. This sensing arrangement also includes a
second similar unilateral switch 190 having its anode A connected
through a resistor 200 to bus 40 and its gate G connected to the
lead 210 between resistor 180 and switch 170. The cathode electrode
K of switch 190 is connected both through a variable resistor 220
and capacitor 230 to bus 50 and through a second resistor 240 to
one base A of a unijunction transistor 250. The junction of the
variable resistor 220 and the capacitor 230 is connected to the
trigger or emitter T of the unijunction transistor 250, and the
other base K of the unijunction transistor is connected to the gate
of the SCR 60. Resistor 220 and capacitor 230 comprise an
adjustable timing circuit for controlling the charging time of
capacitor 230 and the turn-on time of unijunction transistor 250.
This time-delay mechanism permits an authorized entrant to trip
sensor 170 and then reset it before alarm 80 is set off.
Sensors 140 and 170 are shown as normally closed and normally open,
respectively, to indicate that module 20 can accommodate alarm
sensors of different types in its two sensing circuit loops.
In the polarity-reversing module 110 (FIG. 2), the lead 107 from
module 20 is connected to the gate G of a unilateral switch 260,
the anode A of which is connected through a resistor 270 to bus 40.
Switch 260 is normally held non-conductive. The gate G is also
connected through a resistor 280 to the bus 40. The cathode K of
the switch 260 is connected to the base of an NPN transistor 290,
the emitter of which is connected to the bus 292, and the collector
of which is connected to the base of a PNP transistor 300. The PNP
transistor 300 has its collector connected to the lead 292 and its
emitter connected by lead 310 to the base electrodes of two PNP
transistors 320 and 330. The emitter of the transistor 320 is
connected to an output terminal 340 and through a load resistor 350
and a lead 360 to the positive terminal of a D.C. power source 370,
the negative terminal of which is connected to the bus 292. The
transistor 320 also has its collector electrode connected to the
bus 292. The transistor 330 has its emitter electrode connected to
the lead 360, and its collector electrode connected both to an
output terminal 380 and through a load resistor 390 to the bus
292.
Module 110 operates as follows. With module 20 (FIG. 1) quiescent
and no alarm condition present, no signal is conducted through
diode 90 to module 110, and this module is quiescent. In the
quiescent state of module 110, switch 260 and all transistors are
non-conducting and terminal 340 connected to (telephone) line 400
carries positive potential, and terminal 380 connected to
(telephone) line 410 carries negative potential. When an alarm
condition in module 20 provides current flow on lead 107, switch
260 conducts and transistors 290 and 300 turn on, and this causes
transistors 320 and 330 to turn on. Now, the emitter of transistor
320 assumes a negative potential, as does terminal 340 and line
400, and the collector of transistor 330 assumes a positive
potential, as does terminal 380 and line 410. Thus, it can be seen
that the normal polarity of terminals 340 and 380 and lines 400 and
410 are reversed during an alarm-indicating condition of the
system.
Lines 400 and 410 are input leads to module 420 and are coupled to
terminals 340 and 380 at the output of module 110. Lines 400 and
410 represent telephone lines or the like to a remote location, for
example, a police station, firehouse, or the like, at which module
420 may be remotely located.
Line 400 is coupled through a diode 422 oriented as shown to line
430. Line 410 is coupled through an oppositely oriented diode 440
as shown to line 450. Line 400 is also coupled through lead 460 and
diode 470 oriented oppositely to diode 422 to line 430, and line
410 is also connected through lead 490 to a diode 500 oriented
oppositely to diode 440 to line 510. Lines 450 and 480 are
connected together by a lead 520, and line 430 is coupled to the
base electrodes of two NPN transistors 530 and 540. Line 510 is
coupled to the base electrode of another NPN transistor 550.
The module 420 includes a first "trouble" light 560 in series with
an SCR 570 and lead 630, a "normal" light 580 in series with an SCR
590 and lead 630, and an "alarm" light or signal 600 of any
suitable type in series with an SCR 610 and lead 630. The cathodes
of the SCR's 570, 590, and 610 are connected together by lead 620,
and lead 630 is connected to one side of an A.C. power source 640.
The gate electrodes of the SCR's 570, 590, and 610 are also
connected through resistors 650 to a common bus 660 which
represents reference potential and is connected by lead 980 to the
other side of power source 640.
The first-described portions of module 420 and the "alarm" or
"normal" indicators are interconnected as follows. The collector of
transistor 530 is connected by lead 700 through resistor 710 to the
gate of SCR 570 to "trouble" indicator 560 and through resistor 720
and lead 730 to bus 740. The emitters of transistors 530 and 540
are connected through resistors 750 to lead 451 which is connected
to reference bus 660. The emitter of transistor 540 is connected by
lead 760 and resistor 770 to the gate of SCR 590 to the "normal"
indicator 580, and the collector of transistor 540 is connected
through resistor 780 to bus 730 and bus 740 to the power supply
640.
Line 400 is connected through lead 460, diode 470, lead 480,
resistor 790, lead 800 and resistor 810 to the gate of SCR 610 of
"alarm" indicator 600. The emitter of transistor 550 is connected
to lead 800 and resistor 810 to the gate of SCR 610, and its
collector is connected through resistor 820 and lead 740 to the
power supply 640.
A pulse-generating circuit in module 420 includes connections from
lead 510 to the base of transistor 550 and through a resistor 830,
lead 834, and capacitor 840 to bus 660. Lead 510 is also connected
by lead 850 to the anode of SCR 860 which has its cathode connected
through a resistor 870 to bus 660 and through a capacitor 880 and
lead 890 to a remote alarm to be described. The gate of SCR 860 is
connected to lead 834 and through a resistor 900 to bus 660.
The power supply 640 for the system 10 includes the usual 110 volt,
60 cycle A.C. power source 900 coupled to a transformer having
primary and secondary windings 910 and 920, respectively. The
secondary winding of the transformer has one end connected through
a lead 930 to lead 630 which is connected to one side of each of
the signal devices 560, 580, and 600. This connection provides
alternating current across these devices between bus 630 and bus
660. This end of the secondary winding of the transformer is also
connected through a diode 950 and lead 960 to the lead 740 to
provide half-wave rectified D.C. on lead 740 and thus to lead 730.
The other end of the secondary winding of the transformer is
connected by leads 930 and 980 to the reference bus 660. A
capacitor 990 is connected between leads 960 and 980. This
capacitor acts as a filter and phase shifter and provides the
signal for operating the various lights and alarms as described
below.
An auxiliary alarm circuit is also provided including an SCR 1000
having its cathode connected to the lead or bus 980 and its anode
connected through a load resistor 1010, a lead 1012, and a switch
1020 to the lead 960. A suitable alarm 1030 is connected across the
load resistor 1010. The gate of the SCR 1000 is connected both
through a resistor 1040 to the reference bus 980 and to lead 890 to
capacitor 880.
Referring to circuit module 420, as mentioned, when the system is
normal, that is, no alarm condition exists in module 20, line 400
is plus and line 410 is minus. With line 400 plus, positive voltage
is coupled through diode 422 to turn on both NPN transistors 530
and 540. With transistor 530 turned on, its collector is at ground
potential so that the signal voltage which is applied to bus 740
from the capacitor 990 in the power supply is fed to ground and SCR
570 is not turned on and "trouble" light 560 is not turned on. With
NPN transistor 540 on, a path is provided through its
emitter-collector path for the signal on bus 740, and this is
applied to the gate of SCR 590 which opens and passes a current
which turns on the "normal" light 580.
If potential is removed from lines 400 and 410 for any reason,
either due to opening of a line or shorting of the lines, then the
transistors 530 and 540 remain off and "trouble" light 560 is
turned on by the signal voltage on lines 740 and 730 passing
through resistors 720 and 710 to the gate of SCR 570 which is
rendered conductive.
When the potentials on lines 400 and 410 are reversed indicating an
alarm condition, diodes 422 and 440 are blocked, transistors 530
and 540 are off and signal voltage is coupled from the power supply
through lines 740 and 730 through resistor 720 to the gate of SCR
570 which conducts and "trouble" light 560 goes on. Also, diodes
470 and 500 open, and the positive potential on line 410 now
operates through diode 500, to turn on transistor 550. The
emitter-collector path of transistor 550 passes signal voltage on
line 740 through lead 800 and resistor 810 to the gate of SCR 610,
which thereby conducts and turns on the alarm 600.
In addition, plus voltage applied to diode 500 is applied to the
anode of SCR 860, and current flow through resistor 830 charges
capacitor 840 which, when charged, acts on the gate of SCR 860 to
turn on SCR 860 and send a pulse through capacitor 880 to turn on
remote SCR 1000 and thus activate remote alarm 1030 shown in the
power supply circuit. This arrangement using capacitor 840 prevents
spurious noise pulses from turning on SCR 860 since such pulses are
fed to ground through resistor 900 and do not charge the capacitor.
Switch 1020 can be used to de-activate or turn off alarm 1030, if
this is desired, without affecting the other alarms in the
system.
Reference is now made to the operation of modules 22 and 32 of
system 12. System 12 is intended to be operated when personnel
leave, say a business bulding, at the normal time at the end of a
work day and when they enter the building at the normal time at the
beginning of the work day. When the system is operated at these two
times, signaling circuit 32 operates to flash warning lights off
and on at a remote location such as a police station. The police
station personnel are alerted to watch for the system's operation
at these times, and, as a result, they are automatically alerted if
the timed operations do not occur. Of course, it will be clear that
the system of the invention, and particularly signal module 32,
could be used in some other fashion other than to operate remote
flashing lights. In any case, the arming of the system, to be
described, would be the same however module 32 is used.
Referring now to system 12, operation thereof is as follows.
Consider the system at some time during the day and before the
end-of-the-day setting. At this time, the rotor 52 of switch 42 is
in the OFF position, and negative battery potential from battery
112 is absent from bus 282. Consequently, there is no complete
circuit to capacitor C1, and this capacitor cannot charge although
it is always connected to the positive battery terminal by way of
bus 172. Any previous charge on capacitor C1 is, or has been,
discharged by resistor R1. When negative battery potential is
absent from the R1-C1-R2 combination, transistor T1 is
non-conducting. Transistor T1 is also held off by positive hold-off
battery potential fed over resistors R1-R2 to the base of
transistor T1. Capacitor C2 is discharged by resistor R3 and
positive pulse clipper diode D1, and coupling capacitor C3 is
charged over resistor R4, and this provides positive bias on the
base of transistor T2, thus assuring tha transistor T2 is held off
when switch 42 is off.
With the system in the OFF condition, rectifier SCR1 is
non-conducting, so that capacitor C4 cannot charge, unijunction
transistor UJ1 cannot conduct, and transistor T3 cannot conduct.
Because transistor T3 is non-conducting, unijunction transistor UJ2
cannot conduct and capacitor C6 cannot charge. Transistors T4 and
T5 are also non-conducting, with transistor T4 being held off by
the negative bias applied to its base over resistors R12 and
R13.
Since transistor T5 is non-conducting, reed switch 611 is not
energized, is closed, and thus is connected in series with battery
370 and transmission line 400 to the remote signal lights in module
420. Thus, battery potential is supplied to the remote monitoring
station so that the normal light 580 in ON.
At the end of the work day, the system is set as follows.
Authorized personnel, on preparing to leave the premises, turn the
rotor 52 of switch 42 from the OFF contact 62 to the ON contact
102. During this movement of the rotor 52, it momentarily touches
contact 92, whereby a path is completed from the negative terminal
of battery 112 through switch arm 132, contact 144, lead 152,
contact 92, and leads 272 and 252 to the inductor 232 of switch 142
and through the other circuit elements shown, including switch 212,
to the positive terminal of the battery 112. Current now flows in
the inductor coil 232 and through the path including warning light
292, and the light goes on. Current flow in coil 232 attracts the
arm 132 of the reed switch 142 from the contact 144 to the contact
262. The negative battery potential is thus maintained on the
inductor even though rotor 52 is on the ON contact 102, and the arm
132 is locked into contact with switch terminal 262. Thus, the
negative terminal of battery 112 is removed from bus 152 and from
bus 162 to the alarm system which is disabled until the entire
system has been set. Because the door lamp or lamps 292 are in
parallel with the inductor 232 of reed switch 142, they remain lit
as an indicator and reminder to the person locking the premises
that the alarm system is still not fully activated and no remote
indication has been given by signal circuit 32.
Negative potential on bus 252 and bus 282 completes a circuit
through which capacitor C1 charges and turns on transistor T1 by
supplying negative potential to the base of transistor T1 over
resistor R2. Current flow through transistor T1 charges capacitors
C2 and C3. However, transistor T2 does not conduct because its base
is positively biased and coupling capacitor C3 is charged. It is to
be noted that any small noise pulse which might occur at the
junction of capacitors C2 and C3 is clipped by diode D1. Because
transistor T2 is non-conductive, the rest of circuit 32 following
it remains inoperative.
On leaving the premises, the authorized personnel depresses and
thus opens the normally closed push button door switch 212 which is
outside the premises. This momentarily disconnects the battery
positive potential from buses 221 and 222 and interrupts current
flow in the inductor 232 of reed switch 142. This action
simultaneously extinguishes the reminder door lamp 292. Reed switch
142 returns to the normally closed position in which arm 132
contacts terminal 144, and negative battery potential is supplied
over arm 132, bus 152, switch rotor 52 and bus 162 to the burglar
alarm system which is now activated and ready for normal
operation.
Once the push-button door switch 212 is depressed and the door lamp
292 is extinguished, they are disconnected from the battery circuit
because switch 42 in its housing inside the protected premises is
in the ON position and switch arm 132 is in contact with terminal
144. Negative battery potential is now also removed from buses 252,
272 and 282, and, as a result, capacitor C1 gradually discharges
over resistor R1, and transistor T1 slowly returns to a
non-conducting state over the time period during which capacitor C1
discharges.
Capacitors C2 and C3 now discharge over resistor R3 because
positive potential is reduced at the collector of transistor T1.
During the discharge period of capacitors C1, C2, and C3,
transistor T2 becomes conductive and, after a period of time,
returns to a non-conductive state. During this conductive period of
transistor T2, a large positive pulse is generated from its emitter
to its collector that passes through diode D2 and turns on the
controlled rectifier SCR1. Rectifier SCR1 now supplies a negative
potential to capacitor C4 and a negative bias to the base of
transistor T3 which is turned on, and capacitor C4 charges slowly
over resistor R8.
Because transistor T3 is now conductive, capacitor C6 charges
quickly, and the sawtooth waveshape of the charging potential of
capacitor C6 turns on transistors T4 and T5. Transistor T5 supplies
current to the inductor of reed switch 611 through resistor R12.
This opens the contact of the normally closed reed switch and
removes the battery 370 from the transmission line 400. As a
result, at the remote monitor station, the normal lamp 580 turns
off and the trouble lamp 560 turns on.
When capacitor C6 is fully charged, it turns on and discharges
through transistor UJ2, and this turns off transistors T4 and T5,
as a result of which reed switch 611 closes. Now the remote trouble
lamp 560 turns off, and the normal lamp 580 turns on. At this time,
capacitor C4 is still charging through conductive rectifier SCR1
and transistor T3 is conductive, and the cycle of switching of
lights 560 and 580 is repeated by operation of fast charging
capacitor C6 and transistor T4 and T5 to switch the remote normal
light off and the trouble light on. When C6 is fully charged, it
again turns on and discharges through transistor UJ2 and turns off
transistors T4 and T5 and closes switch 611 to turn off the trouble
light and turn on the normal light. This cycle and the flashing of
the normal and trouble lights continues until capacitor C4 is fully
charged.
When capacitor C4 is fully charged, it turns on and is discharged
by transistor UJ1. The momentary conduction of transistor UJ1
supplies a pulse to the anode of rectifier SCR1 which is turned
off. Reed switch 611 returns to the normally closed position to
provide continuous battery power to the remote station so that the
normal indicator lamp remains on. This light cycling operation
represents a normal evening happening to police at the remote
location. It tells them that the premises are empty and the alarm
system is set at the correct time of day.
Typically, capacitor C4 is designed to require a long charging
period, say one minute, and capacitor C6 is designed to charge
quickly, in about one second. Consequently, the telephone line reed
switch 611 opens and closes, and the lights flash about sixty times
during the charging period of capacitor C4.
In the morning, when authorized personnel return to the premises,
switch 42 inside the building is turned back to the OFF position
62, and, as its rotor 52 is turned, it again contacts the door set
position 92, operates switch 142 to close contact 262 and to charge
capacitors C1, C2, C3, as described above. Transistor T1 is on, but
transistor T2 and the rest of module 32 is disabled. When rotor 52
goes to OFF contact 60, it removes negative potential from the
signal circuit 32, and capacitors C1, C2, C3 discharge and cause
the light flashing cycle to operate as above and thus advise the
remote police station that the premises have been entered in normal
fashion. Since the turning of rotor 52 to the OFF contact 62
removes negative battery potential from the circuit and causes the
flashing cycle to be executed, operation of the push button 212 is
not required.
The present invention provides an efficient system for use in
conjunction with a burglar alarm system for indicating, to police
or other authorities, authorized entry into and exit from the
protected premises. One of the important advantages of the
invention is that the system can be operated inside the premises on
entering and outside the premises on leaving. However, the
mechanism operated outside the premises is not connected to the
primary burglar alarm system so that, even if it is tampered with,
the alarm system is still operable in normal fashion.
It is to be noted that the system described can be used to provide
a signal other than flashing lights and it may be used in
conjunction with other types of burglar alarm systems.
The system of the invention also includes a return-signal indicator
apparatus for the purpose of having the remote station positively
indicate that it has received a status signal from the protected
premises. This apparatus, including a portion of the system
described above, is illustrated in FIG. 3 and includes, in one
suitable arrangement, a switching device 1100, for example, a PNP
transistor having its emitter connected to bus 40 and its collector
connected through a lamp 1110 to the other bus 50. The base of the
transistor 1100 is connected through a suitable resistive path 1120
to the positive terminal of battery 370. The apparatus also
includes a normally open switch 1130 at the remote receiving
station which is connected across leads or telephone lines 400 and
410.
In operation of this apparatus, after the system has been set and a
signal has been transmitted to the remote station by the flasher
circuit 32, an operator there closes switch 1130 to short circuit
leads 400 and 410, and this, in turn, causes transistor 1100 to
conduct and turn on lamp 1110. When the switch 1130 is opened, the
lamp 1110 turns off. A person on the premises thus knows that the
system has operated properly.
Still another adjunct to the system is a monitoring arrangement for
permitting monitoring at the remote station of the status of the
system at the premises. This monitoring arrangement, illustrated in
FIG. 4, includes another deck 42'" associated with switch deck 42,
and this switch deck 42'" includes an OFF contact, an ON contact
102'", and a rotor 52'".
A potentiometer 1140 is connected between the OFF terminal and the
ON terminal 102'" of switch deck 42'" at the premises (FIG. 1). The
slider 1150 of the voltage divider is connected to positive
potential. The switch rotor 52 is connected to telephone line
400.
At the remote station, a switch such as NPN transistor 1160 has its
emitter connected through a diode 1170 to one side of a voltmeter
1180, the other side of which is connected through a bus 1190 to
(telephone) line 410. The emitter of transistor 1160 is also
connected through a resistive path 1200 to bus 1190, and the
collector is connected by lead 1210 to bus 1220 which is connected
both to line 400 and through a resistive path 1230 to bus 1190. The
base of transistor 1160 is connected to resistive path 1230.
In operation, the different potentials appearing across the
potentiometer 1140 when the switch 52 is ON and when it is OFF, are
applied across telephone lines 400 and 410 and through the
transistor 1160 and diode 1170 to the meter. This sensing operation
does not adversely affect the normal and proper operation of the
entire system.
Another modification of the system of the invention illustrated in
FIG. 5 includes an adjunct to remote module 420. This modification
includes means for providing a remote signal indication by alarm
1030 whenever trouble light 560 is energized and for whatever
reason. The circuit is identical to that of FIG. 2 except that the
base of SCR 860 and resistor 830 in lead 834 are connected together
by lead 1240 to one contact 1250 of a normally open switch, e.g., a
reed switch 1254, the other contact 1260 of which is connected to
lead 730. The switch includes a winding 1263 connected across
trouble light 560.
In operation of the circuit of FIG. 5, whenever SCR 570 is fired
and trouble light 560 is energized, current flows through winding
1263 to close contacts 1250 and 1260 of switch 1254. This causes
SCR 860 to fire and to thereby cause alarm 1030 to operate as
described above.
Another adjunct to the system of the invention, illustrated in FIG.
6, is used to permit audio communication between the protected
premises and the remote station. This adjunct includes an audio
amplifier 1270 having the usual audio or microphone input 1280,
power input leads 1290 and 1291 coupled to lines 40 and 50, and
output leads 1300 and 1302 connected to lines 400 and 410 of the
signalling system shown in FIG. 2. One section 1310 of a three-part
normally open switch 1320 is in each of lines 1300, 1302, and 1291.
A winding 1330 is connected across signalling device 80 for
operating the switch sections 1310 (A, B, C) and closing them when
current flows through alarm 80 and permitting the audio amplifier
1280 to transmit output signals along telephone lines 400 and 410.
At the remote station, an audio amplifier 1304 and speaker 1350 are
connected across lines 400 and 410.
In operation of this apparatus, when signalling device 80 receives
current as the result of an alarm condition detected by module 20
(FIG. 1), winding 1330 is energized and closes switch sections 1310
A, B, and C and permits audio signals, for example, an alarm
warning of some kind to be picked up by the microphone 1280 on the
premises and transmitted to the remote station and audio amplifier
1340 and speaker 1350 whereby an operator can hear the transmitted
audio signals and respond accordingly.
It is noted that audio amplifier 1270 is powered up and transmit
only during an alarm condition so that the remote station cannot
eavesdrop on the premises during non-alarm periods.
The system of the invention also includes a circuit module 2000
(FIG. 7) for automatically turning off the alarms and sensors of
module 20 and resetting the system, in the situation where an alarm
condition triggers module 20 and there is no one at the premises to
turn off the alarm after due action has been taken.
This circuit module 2000 includes a connection 2005 from the anode
of SCR 60 in module 20 through a resistor 2010 and a diode 2020 to
the gate G of an SUS switch 2030 which has its cathode K connected
through a resistive path 2040 to the base of an NPN transistor 2050
having its collector connected to bus 40 and its emitter connected
to bus 50. The collector of the transistor 2050 is also connected
to one side of a capacitor 2060, the other side of which is
connected through a resistive path to bus 40. A programmable
unijunction transistor 2070 is provided having its anode and gate
connected across the capacitor 2060 and through suitable resistive
paths to bus 40. The cathode of the unijunction transistor is
connected to series transistors 2080 and 2090, which form a
Darlington circuit, the output of which is coupled to an
electromagnetic relay 3000 including a winding 3010 and two
normally closed contacts 3020 and 3030, contact 3030 being
connected to positive telephone battery potential.
In operation of the circuit of FIG. 7, when an alarm condition is
detected in module 20 and SCR 60 fires, ground potential at the
anode of SCR 60 is coupled through diode 2020 to the switch 2030
which is turned on. The resultant current flow applies a positive
potential to the base of transistor 2050 which turns on and
provides a conductive path for charging capacitor 2060. The
capacitor is selected and the circuit is designed so that a
suitable length of time, for example, ten minutes or so, is
required to charge the capacitor 2060. At the end of this time, the
capacitor is charged to such a potential that the unijunction
transistor 2070 fires, and it in turn fires the two transistors of
the Darlington circuit to provide current flow through the winding
3010 and to open the contact elements 3020 and 3030. This
momentarily disconnects positive battery potential from the system
and thus de-activates the entire system and permits all of the
elements thereof to be reset, at which time the contact elements
3020 and 3030 return to their normal closed condition to reconnect
positive battery potential to the system. If the alarm condition
still remains, it is detected by module 20, and the alarm condition
will persist until circuit 2000 operates again to reset the system.
This cycle of events will occur until someone at the premises turns
off the alarm and corrects the alarm condition.
The system of the invention also includes an electronic key circuit
1103, illustrated in FIG. 8, for automatically signalling the
setting of the system on leaving the premises in the evening or the
disarming of the system on entering the premises in the morning.
With this circuit, no switch is required outside the premises to
arm or disarm the system. The circuit of FIG. 8 includes many
elements which are equivalent to elements shown in FIG. 1, as will
be clear to those skilled in the art. The automatic electronic key
circuit includes a three-segment or three-position rotary switch
1110 which may be ganged to switch 42 of FIG. 1. Contact 1110A of
switch 1110 is connected by lead 1120 to the negative terminal of
battery 1130 (which is equivalent to battery 112 of FIG. 1) and
through lead 1140 to a two-position relay 1150. The relay 1150
includes a winding 1160, a movable contactor 1170 and fixed
contacts 1180 and 1190. Normally, contactor 1170 is in contact with
fixed contact 1190. Contact 1190 of relay 1150 is connected by lead
1200 to contact 1110D of switch 1110, and contact 1180 is connected
to lead 1210.
The winding 1160 has end 1160A connected to lead 1220 and end 1160B
connected to lead 1230. A lamp 1240 is connected across winding
1160. Winding end 1160B, through lead 1230, is connected to lead
1250 to the positive terminal of battery 1130. A lead 1260 extends
from the positive terminal of battery 1130 and lead 1230 to bus 40
in circuit module 20. End 1160A of winding 1160 is connected by
lead 1220 to contact 1270, normally closed to contact 1280, of a
relay 1290 having a winding 1300. Lead 1220 is also connected by
lead 1223 to contact 1110B of switch 1110. Contact 1280 extends
through lead 1310 to a normally closed hand-operated switch 1328,
such as a push-button switch, and thence to lead 1210 to contact
1180 of relay 1150.
Winding 1300 of relay 1290 includes end 1300A connected to lead
1310 and end 1300B connected to lead 1320 and to lead 1230 which is
coupled to the positive terminal of battery 1130. Lead 1310 from
winding 1300 is connected to the anode of SCR 1330, the cathode of
which is connected to lead 1340 which is connected by lead 1350
back to lead 1310. The cathode of SCR 1330 is also connected both
to lead 1360 and through resistor 1370 to its gate. The gate of SCR
1330 is also connected through a lead 1380, diode 1390 (oriented as
shown) and a resistor 1400 to lead 1410.
Contact 1110C of switch 1110 is connected by lead 1430 to a delay
switch 1440 having contacts 1450 and 1460 located in a door 1463 of
th premises. The contacts are open when the door is closed and vice
versa. Contact 1460 is connected by lead 1470 and resistive path
180 to bus 40 of circuit module 20. Contact 1110D of switch 1110 is
connected by lead 1480 to the negative bus of module 20 and to the
gate G of SUS switch 120 of module 20 and to lead 1200 to switch
contact 1190.
Lead 1470 from lead 40 of circuit 20 and from door switch 1440 is
also connected by lead 1500 through diode 1510, oriented as shown,
through resistor 1530 to the base of PNP transistor 1540 which has
its emitter connected to lead 1320. The collector of transistor
1540 is connected (1) through resistor 1550 to lead 1560 which is
connected to lead 1360 (to SCR 1330) and (2) through resistor 1570
and diode 1580, oriented as shown, to the gate of SCR 1590 which
has its anode connected to lead 1320 to end 1300B of switch winding
1300. The gate of SCR 1590 is also connected through resistor 1600
and parallel capacitor 1610 to lead 1560. The cathode of SCR 1590
is connected through resistor 1620 to lead 1560 and through lead
1630 to the anode of SCR 1640, the cathode of which is connected
through resistor 1650 to lead 1560 and through lead 1410, resistor
1400, and diode 1390 to the gate of SCR 1330. The gate of SCR 1640
is connected through resistor 1660 to lead 1560 and through lead
1670 and diode 1680, oriented as shown, and resistor 1690 to lead
1700 which is connected to the lead 1520 from the cathode of diode
1510.
The automatic electronic key circuit 1103 is particularly adapted
to operate with the flasher circuit 32 shown in FIG. 1 although it
may be used with other signalling circuits. When used with circuit
32, bus 102 thereof is connected by lead 1703 to the positive
terminal of battery 1130 and bus 302 is connected by lead 1705 to
the negative terminal of battery 1130. Lead 282 from the base of
transistor T1 is connected to lead 1430 and the contact 1110C of
switch 1110.
Under normal conditions during the day, the premises door 1463 is
closed and switch 1440 is open. All circuit elements are inactive,
all transistors are non-conducting, the alarm circuit is inactive,
current flows through winding 1160, and armature 1170 is held
against contact 1180 in relay 1150. When the occupant of the
premises opens the door 1463 to leave, the switch 1440, which is
operated by the door, closes.
The operator turns the rotor 1110R of switch 1110 from OFF to ON,
from contact 1110A through contact 1110B to contact 1110C. In this
case, nothing else happens in switch 1110. As described above, the
switch movement through contact 1110B instantaneously couples
negative potential to end 1160A of winding 1160, causes current
flow through the winding, and causes relay 1150 to move arm 1170
into contact with contact 1180. A circuit is now completed from the
negative terminal of battery 1130, through lead 1430, closed switch
1440, leads 1470 and 1500 to apply a negative potential to the base
of transistor 1540. Transistor 1540 conducts and generates a
positive pulse which is coupled through diode 1580 to the gate of
SCR 1590. SCR 1590 conducts and couples positive potential from the
battery through lead 1233 and lead 1320 and through lead 1630 to
the anode of SCR 1640. SCR 1640 does not conduct because its gate
is negative due to the negative potential which is applied to the
base of transistor 1540 and which is also coupled through lead
1700, resistor 1690, and diode 1680 to the gate of SCR 1640. In
this phase of the operation, flasher circuit 32 is also partially
set, as described above, when negative potential is applied to
contact 1110B.
Now the door 1463 is closed and switch 1440 is opened and the
negative potential which had been coupled through to SCR 1640 is
removed. Now positive potential is coupled from the battery 1130
through lead 1233, lead 1260, bus 40, resistive path 180 to bus
1470, lead 1500, diode 1510, lead 1700, resistor 1690, and diode
1680 to the gate of SCR 1640. SCR 1640 now conducts a positive
pulse over lead 1410, resistor 1400, and diode 1390, and the gate
of SCR 1330. SCR 1330 conducts and passes current through winding
1300 to open switch 1270. This action cuts off current flow through
winding 1160 and releases arm 1170 back to contact terminal 1190.
Now negative potential flows over lead 1140 and lead 1200, to lead
1480 and the negative bus 50 of module 20 to energize the alarm
system. This also causes the flasher to operate, as described
above, to denote proper exit from the premises and arming of the
system.
When the occupant returns to the premises in the morning or at any
other time and the door 1463 is opened, switch 1440 is closed, and
negative potential is coupled through contact 1110C of switch 1110
through leads 1430 and 1470 to turn on SUS 190 and start the delay
of module 20 operating. The occupant of the premises then turns
switch 110 from on to off, and the circuit is de-energized before
the alarm goes off.
It is clear that the various modules described above can all be
connected together to provide a unitary alarm system. If desired,
however, a suitable alarm system can be provided incorporating
fewer than all of these modules.
* * * * *