Abstract:
An apparatus for deterring removal of electrical wiring that is installed in a building includes a controller, and a wiring module responsive to the controller and forming a monitored circuit with installed electrical wiring by coupling to an end of the wiring located at a load distribution junction. The other end of the wiring is electrically coupled, and can be coupled with a controlled impedance, or with a protected asset. The apparatus is configured with control logic to issue an alert if the integrity of the monitored circuit has been compromised.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Pursuant to 35 U.S.C. §119, priority is claimed to U.S. Provisional App. Ser. No. 60/993269, filed Sep. 11, 2007, and which is incorporated by reference as if fully set forth herein. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
       [0002]    The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears. 
         [0003]      FIG. 1  is a functional schematic of an exemplary security system apparatus as claimed hereinbelow; 
         [0004]      FIG. 2A  is a functional schematic showing one method of connecting the wiring module to the protected system; 
         [0005]      FIG. 2B  is a functional schematic showing another method of connecting the wiring module to the protected system; 
         [0006]      FIG. 3  is a wiring diagram of an embodiment of the exemplary security system of  FIG. 1 ; 
         [0007]      FIG. 4  is a functional schematic of another exemplary embodiment of a security system as claimed hereinbelow; 
         [0008]      FIG. 5  is a flow diagram of an exemplary process executed by a system controller; 
         [0009]      FIG. 6  is a flow diagram of an exemplary process executed by a wiring module; and 
         [0010]      FIG. 7  is a flow diagram of an exemplary process executed by an optional remote anunciator. 
     
    
     DETAILED DESCRIPTION 
       [0011]    The various embodiments of the present invention and their advantages are best understood by referring to  FIGS. 1 through 7  of the drawings. The elements of the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention. Throughout the drawings, like numerals are used for like and corresponding parts of the various drawings. 
         [0012]    The drawings represent and illustrate examples of the various embodiments of the invention, and not a limitation thereof It will be apparent to those skilled in the art that various modifications and variations can be made in the present inventions without departing from the scope and spirit of the invention as described herein. For instance, features illustrated or described as part of one embodiment can be included in another embodiment to yield a still further embodiment. Moreover, variations in selection of materials and/or characteristics may be practiced to satisfy particular desired user criteria. Thus, it is intended that the present invention covers such modifications as come within the scope of the features and their equivalents. 
         [0013]    Furthermore, reference in the specification to “an embodiment,” “one embodiment,” “various embodiments,” or any variant thereof means that a particular feature or aspect of the invention described in conjunction with the particular embodiment is included in one or more embodiments of the present invention. Thus, the appearance of the phrases “in one embodiment,” “in another embodiment,” or variations thereof in various places throughout the specification does not necessarily limit the implementation of a described feature to a particular embodiment. 
         [0014]    An exemplary security system  100  which achieves the purposes of the invention claimed below is designed to provide theft protection of unpowered electrical wiring  107  installed in construction sites or unoccupied buildings, the premises. Electrical wiring  107  is understood to be a length of two or more conductors that will form a circuit when fully installed and powered. The system uses the rough-installed electrical wiring being protected as an integral part of the system. The system structure is designed to be inexpensive to manufacture and require minimal labor to install and maintain, without impacting standard construction practices. The wiring module  102  couples to the ends of the electrical wiring  107  installed in a standard load distribution junction  311 , or circuit breaker panel, such ends referred to hereinafter as the “near ends.” The system controller  101  controls function and manages power to one or more wiring modules to accommodate sites having more than one load distribution junction. The system  100  preferably uses a controlled impedance device  104  coupled to the distal ends of the installed wiring  107  to create a circuit and to circumvent attempts to defeat the alarm system at the wiring module(s)  102 , eliminating the need to ruggedize all of the system elements. The system  100  is designed to be self-powered to accommodate sites where power may not be available. The internal batteries  403  may be recharged in the system with an optional charger  106 , or be removed by the user for replacement or off site recharging. The system  100  may be used to protect assets  108  other than installed electrical wiring  107 , such as uninstalled bulk wiring, devices with electric motors, or electric appliances, that are within reach of electrical wiring on the premises. The system will alert individuals in the vicinity of a tamper or theft violation with a loud audible siren. 
         [0015]    With reference to  FIG. 4 , a system controller  101  may comprise a processor, or microprocessor  308 , which is configured with control logic to execute the control functions as described in greater detail below. The primary function of the system controller  101  is to provide the command, control and user interface for the system  100 . Microprocessor  308  is coupled to an audible siren device  411  through a siren driver circuit  412 , and is also coupled to a visible armed indicator lamp  413 . A user interface  414 , which may be, without limitation, a keypad, touchscreen, or other input device known in the art, is included for user input and is also configured to provide system status indications to the user. Power for the microprocessor  308  and other devices is supplied by the power supply circuit  409  coupled to battery  403  which may be a replaceable rechargeable battery. If a recharging battery is implemented, system controller  101  may include charger connector  404  which supplies current to the battery through a polarity protection diode  405  and an over current protection fuse  406 . 
         [0016]    The microprocessor  308  also may be coupled to an auxiliary alarm status output  415  which allows the connection of optional user supplied accessories that can react to an alarm state. The auxiliary status output  415  may be implemented with a conventional single-pole, double throw (SPDT) switch coupled to terminals which may be connected to devices which, when appropriate predetermined conditions exist, may throw the switch to couple a signal indicative of status to an external device to establish a communications though a distributed communications network (not shown) with a remote communications device (also not shown) such as a cell phone, a pager, an email device, or the like. In this manner, system status may be communicated to a remote user. 
         [0017]    The wiring module  102  provides interconnection between the system controller  101  to one or more lengths of electrical wiring  107  previously installed on the premises. Each length of wiring  107  is connected to a unique terminal on the wiring module  102  and is terminated on the far end with a controlled impedance device  104 . The wiring module  102  contains the logic necessary to determine which terminals are presented with the proper controlled impedance  104 A and which terminal(s) are presented with an impedance that exceeds the acceptable limits of the controlled impedance  104 A. On command from user input the wiring module  102  will display by way of light emitting diodes (LEDs) which terminal(s) are presented with the proper controlled impedance  104 A and will display which terminal(s) that were previously identified as being presented with the proper impedance  104 A exceeded the acceptable limits during a previous armed state of the alarm system  100 . In the embodiment shown in  FIG. 1 , the wiring module(s)  102  connect to the system controller  101  by way of the wiring module interconnect cable(s)  105 . It will be appreciated, however, that wiring module(s)  102  may be one or more structures co-located with the structure performing the functions of system controller  101  within a common housing. 
         [0018]      FIG. 2A  depicts a connection embodiment using the controlled impedance device  104  to enable monitoring of electrical wiring  107  by a monitoring circuit  201 . The wiring module  102  will contain one or more monitoring circuits  201 . The monitoring circuit  201  shown here is a representation of any of the monitoring terminals of the wiring module  102 . As depicted, typical electrical wiring  107  is constructed with at least two, but usually three conductors. Two of these conductors  202  are covered with insulation  203 , and when in service are intended to carry the current load to and from the powered equipment. The third conductor  204  is not insulated and is intended to be used as a safety ground that only carries current when a fault condition exists. The three conductors are bundled together and covered with an insulating sheath  207 . 
         [0019]    As stated above, the electrical wiring  107  is not energized and is out of service when the system  100  is installed and the controlled impedance  104  is connected for monitoring purposes. The controlled impedance device  104  is connected between the two insulated conductors  202  at the far end of the protected electrical wiring  107 . At the near end of the protected electrical wiring  107  one of the insulated conductors  202  will be connected to a dedicated monitoring circuit  201 . The other near end insulated conductor  202  is connected to a common ground node (usually at the load distribution junction) or directly to the ground node of the monitoring circuit  201 . The third conductor  204  is not used in this embodiment. When properly connected the impedance  104 A presented to the monitoring circuit  201  will be equivalent to the controlled impedance  104 , and the monitoring circuit  201  provides to a microprocessor within in the wiring module  102  an acceptable limit status signal for the presented impedance  104 A. 
         [0020]    The presented impedance  104 A will exceed acceptable limits if an open circuit is created at any point along either of the two conductors  202 . In such a case the monitoring circuit  201  provides to the microprocessor in the wiring module  102  an over range limit status for the presented impedance  104 A. The presented impedance  104 A will exceed acceptable limits if a short circuit condition is created at any point between the two conductors  202 . In such a case the monitoring circuit  201  provides to the microprocessor in the wiring module  102  a short circuit limit status for the presented impedance  104 A. If an attempt is made to bypass the controlled impedance  104  by connecting any other impedance across the two conductors  202  at the monitoring circuit  201  and then disconnecting the electrical wiring  107 , the presented impedance  104 A will exceed acceptable limits either when (a) the other impedance is connected creating an under range limit status or (b) the electrical wiring  107  is removed creating an over range limit status. This is true since any impedance that is within the acceptable limits of the controlled impedance  104  cannot present an impedance  104 A that is within the acceptable limits when it is connected in parallel with the controlled impedance. 
         [0021]      FIG. 2B  depicts the same arrangement as in  FIG. 2A  without the use of the controlled impedance  FIG. 2A   104 . Here the two insulated conductors  202  are shown as being twisted together  206  at the far end forming a direct electrical connection. This could be considered the same as using a controlled impedance  104  with an impedance value of 0 Ohms. In such a case the monitoring circuit  201  provides to the microprocessor in the wiring module  102  a short circuit limit status of the presented impedance  104 A. Should this method of protecting electrical wiring  107  be employed, then the tamper detection is limited and may be easily defeated. However, some protection would still be provided. 
         [0022]      FIG. 3  depicts the system controller  101  interconnected to a wiring module  102 . The wiring module  102  is connected to three lengths of electrical wiring  107   b - d.  Two sections of the electrical wiring  107   b ,  107   d  have controlled impedance devices  104  connected at the respective ends distal from the load distribution junction  311 . The remaining section of electrical wiring  107 c has the two insulated conductors twisted together  206  at the far end. Each section of the electrical wiring  107  has one near end insulated conductor connected to a unique monitor circuit terminal  302 . The other near end insulated conductors are electrically interconnected by way of a neutral connector strip  301 , as is found in a conventional load distribution junction  311 . The neutral connector strip  301  is also connected to the monitor circuit ground terminal  303  thereby creating a circuit with the wiring module  102 . As a result of user input relayed by the system controller  101  through the monitor circuit indicator LEDs  304  are illuminated to indicate the limit status of the corresponding monitoring circuits. Differentiation of the various limit status conditions can be achieved with the use of different colors, and or blinking of the monitor circuit indicator LEDs  304 . 
         [0023]    The primary function of the controlled impedance device  104  is to electrically terminate the far end of the electrical wiring  107  in such a manner that tampering that results in discontinuity, short circuit condition or a measurable impedance change across two conductors of the electrical wiring  107  may be easily detected by the wiring module  102 . The impedance of the controlled impedance device  104  is selected such that the inherent resistance of the interconnecting electrical wiring  107  has only a negligible effect on the controlled impedance  104 A presented to the wiring module  102 . If the system  100  is installed to monitor a protected asset  108 , then the controlled impedance device  104  is located on or within the protected asset  108  in such an arrangement that the controlled impedance  104 A presented to the wiring module  102  will exceed acceptable limits if the protected asset  108  is removed. In such a case the interconnecting wiring  107  will be protected along with the protected asset  108 . 
         [0024]    The system controller  101  provides power to the wiring module  102  by way of the wiring module interconnect cable  105 . The wiring module interconnect cable  105  carries bidirectional communications between the system controller  101  and the wiring module  102 . Logic in the microprocessor  308  of the system controller  101  can detect the loss of communications with the wiring module should the wiring module interconnect cable  105  be tampered with or removed. Logic in microprocessors  309 ,  308  of the wiring module  102  and system controller  101  will store in memory the limit status of the monitoring circuit terminals  302  as a result of user input and can determine which monitoring circuit terminals  302  experience a change in limit status. Changes in limit status or tampering with the wiring module interconnect cable  105  can be indicated to the user or cause entry into an alarm state depending the current mode of operation of the system  100 . Alarm state can be indicated by a variety of alert devices including, without limitation, a sound device  411 , and lighting  413 . 
         [0025]    The system  100  shown in  FIG. 1  also may include an optional, and desirable component, namely, a remote annunciator device  103  coupled to system controller  101  through separate wiring  107 A which may be, for example, rough installed electrical wiring. The primary function of the remote annunciator device  103  is to provide a remote audible siren to deter theft and tampering activities with the electrical wiring  107  or protected assets  108 . The remote annunciator  103  is interconnected to the system controller  101  by way of electrical wiring  107 A previously installed on the premises. The remote annunciator device  103  is capable of receiving charge current from the system controller  101  by way of the interconnecting electrical wiring  107 A. If more than one remote annunciator device  103  is used then each remote annunciator device  103  will be interconnected to the system controller  101  by way of a separate section of electrical wiring  107 A. The remote annunciator device  103  is self powered and contains the logic necessary to communicate with the system controller  101  by way of the interconnecting electrical wiring  107 A. The remote annunciator device  103  contains sensors and logic necessary to detect tampering that result in dismounting, enclosure intrusion or disruption of the interconnection to system controller  101 . 
         [0026]    With reference again to  FIG. 4 , the system controller  101  and the remote annunciator  103  are interconnected by way of electrical wiring  107 A. The interconnection may be made using dedicated terminals  401  on the system controller  101  and dedicated terminals  402  on the remote annunciator  103 . Preferably, the interconnection is made using all three conductors of the electrical wiring  107 A previously installed on the premises. 
         [0027]    Charging current is supplied from the system controller  101  to the remote annunciator  103  by way of the remote charge current control circuit  407  under control of the microprocessor  308 . An over current protection fuse  406  is employed between the remote charge current control circuit  407  and the terminals  401  of the system controller  101 . Bidirectional data is exchanged between the system controller  101  and remote annunciator  103  through an input/output buffer  410 . The data clock is provided from the system controller  101  microprocessor  308  to the remote annunciator  103  by interrupting the remote charge current provided through the remote charge current control circuit  407 . 
         [0028]    The remote annunciator  103  provides redundancy in the system. The remote annunciator  103  contains many of the same components that are found in the system controller. A microprocessor  420  is configured with control logic to perform the functions described in greater detail below. Power for the microprocessor  420  and other devices is supplied by the power supply circuit  409 . The remote annunciator  103  may also be self powered by a user replaceable rechargeable battery  403 . Charging current may be provided through the charger connector  404  of the remote annunciator  103 . When present, the charging current is supplied to the battery through a polarity protection diode  405  and an over current protection fuse  406 . When the system is in use, charging current is supplied from the system controller  101  by way of the terminals  402  through a polarity protection diode  405 A. The polarity protection diode  405 A prevents the system controller  101  from drawing power from the remote annunciator  103 . Bidirectional data is exchanged between the remote annunciator  103  and system controller  101  through an input/output buffer  410 . The data clock is provided to the remote annunciator  103  microprocessor  420  from the system controller  101  through the opto-isolator  416 . The remote annunciator  103  provides an audible siren device  411  that is controlled by the microprocessor  420  through a siren driver circuit  412 . Tamper circuitry  417  is connected to the microprocessor  420  provided in the remote annunciator  103  to detect unauthorized dismounting or opening of the remote annunciator  103  enclosure. 
         [0029]    The flowchart in  FIG. 5  shows an example of control logic for a processor implementing the control method of a system controller  101 . The processor establishes communications with the wiring module(s)  102  and the remote annunciator(s)  103  (if present) 501 . Next, the processor determines if a command was received from the user interface  502 . If a command was received then control goes to  503 . If a command was not received then control goes to  504 . At step  503 , the system processes user command and modifies the status of the system controller  101  as necessary. At step  504 , it sends status or updates messages to remote annunciator(s)  103  and wiring modules  102 . Next, the system determines if the system  100  is an armed state  505 . If the system  100  is in an armed state then control goes to  506 . If the system  100  is not in an armed state then control goes to  502 . At step  506 , the system determines if the alarm siren  411  is on. If the system  100  is in an alarm state then control goes to  507 . If the system  100  is not in an alarm state then control goes to  509 . At step  507 , it determines if the alarm timeout has expired. If the alarm timeout has expired then control goes to  508 . If the alarm timeout has not expired then control goes to  502 . At step  508 , the alarm siren  411  is deactivated and control returns to  502 . If the alarm is not on, the system determines if a tamper sensor  417  has been triggered  509 . If a tamper sensor  417  has been triggered then control goes to  513 . If no tamper sensors have been triggered then control goes to  510 . At step  510 , it determines if communications has been lost with the wiring module(s)  102  or the remote annunciator(s)  103 . If any communications have been lost then control goes to  513 . If communications are intact then control goes to  511 . At step  511 , it determines if a wire fault message has been received from a wiring module  102 . If a wire fault message has been received then control goes to  513 . If a wire fault message was not received then control returns to  512 . At step  512 , it determines if a tamper alarm message has been received from a remote annunciator  103 . If a tamper message has been received then control goes to  513 . If a tamper message was not received then control returns to  502 . At step  513 , the system commands to activate the alarm siren  411 , reset alarm timeout, and return control to  502 . 
         [0030]    The flowchart in  FIG. 6  shows an embodiment of control logic for a processor implementing the control method of a wiring module  102 . First, the processor selects which monitoring circuit  201  to monitor  601 . Next, the processor causes current to flow from the selected monitoring circuit  201  through the controlled impedance  104  by way of the conductors  202  of the interconnected electrical wiring  107  ( 602 ); Then, the voltage across the presented impedance  104 A of the selected monitoring circuit  201  is sampled  603  and the sampled voltage is compared to stored threshold values in order to determine if the value is within acceptable limits  604 . At step  605 , a decision is made on the fault status of the sampled value. If a fault condition is not chosen then control goes to step  606 . If a fault condition is chosen then control goes to step  607 . At step  606 , the LED  304  corresponding to the selected monitoring circuit  201  is set to indicate an acceptable status and control returns to  601 . At step  607 , however, the electrical wire  107  connected to the selected monitoring circuit  201  is designated as being in a fault condition. In such case, the LED  304  corresponding to the selected monitoring circuit  201  is set to indicate a fault status  608 . Then, the processor determines if the system  100  is in an armed state  609 . If the system  100  is in an armed state then control goes to  610  in which case, the system controller  101  is notified by communications over the interconnecting cable  105  of an alarm condition ( 610 ) and control returns to  601 . On the other hand, if the system  100  is not in an armed state then control returns to  601 . 
         [0031]    The flowchart in  FIG. 7  shows an embodiment of control logic for a processor implementing the control method of a remote annunciator  103 . First, the system determines if a command has been received from the system controller  101  ( 701 ). If a command was received then control goes to  702 . If a command was not received then control goes to  703 . At step  702 , the remote annunciator processes the command from system controller  101  and modifies the status of the remote annunciator  103  as necessary. Next, it determines if the system  100  is in an armed state  703 . If the system  100  is in an armed state then control goes to  704 . If the system  100  is not in an armed state then control returns to  701 . At step  704 , the remote annunciator determines if the alarm siren  411  is on. If the alarm siren  411  is on, the control goes to  705 . If the alarm siren  411  is not on then control goes to  707 . At step  705 , the remote annunciator determines if the alarm timeout has expired. If the alarm timeout has expired then control goes to  706 . If the alarm timeout has not expired then control returns to  70   1 . At step  706 , the remote annunciator deactivates the alarm siren  411  and returns control to  701 . At step  707 , it determines if a tamper sensor  417  was triggered. If a tamper sensor  417  was triggered then control goes to  709 . If no tamper sensors  417  have been triggered then control goes to  708 . At step  708 , the remote annunciator determines if communications have been lost with the system controller  101 . If any communications have been lost then control goes to  709 . If communications are intact then control returns to  701 . At step  709 , the remote annunciator activates alarm siren  411 , resets alarm timeout, and returns control to  701 . 
         [0032]    Many of the functions of the above-described apparatus may be implemented with logic circuitry as would be understood by those skilled in the relevant arts. Those functions may also be controlled or executed by one or more processors. A processor, or microprocessor, can be implemented by a field programmable gated array (FPGA), a central processing unit (CPU) with a memory, or other logic device. 
         [0033]    The processor in effect comprises a computer system. Such a computer system includes, for example, one or more processors that are connected to a communication bus. The computer system can also include a main memory, preferably a random access memory (RAM), and can also include a secondary memory. The secondary memory can include, for example, a hard disk drive and/or a removable storage drive. The removable storage drive reads from and/or writes to a removable storage unit in a well-known manner. The removable storage unit, represents a floppy disk, magnetic tape, optical disk, and the like, which is read by and written to by the removable storage drive. The removable storage unit includes a computer usable storage medium having stored therein computer software and/or data. 
         [0034]    The secondary memory can include other similar means for allowing computer programs or other instructions to be loaded into the computer system. Such means can include, for example, a removable storage unit and an interface. Examples of such can include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM, or PROM) and associated socket, and other removable storage units and interfaces which allow software and data to be transferred from the removable storage unit to the computer system. 
         [0035]    Computer programs (also called control logic) are stored on computer-readable media in the main memory and/or secondary memory. Computer programs can also be received via a communications interface. Such computer programs, when executed, enable the computer system to perform certain features of the present invention as discussed herein. In particular, the computer programs, when executed, enable a control processor to perform and/or cause the performance of features of the present invention. Accordingly, such computer programs represent controllers of the computer system of security system. 
         [0036]    In an embodiment where the invention is implemented using software, the software can be stored in a computer program product and loaded into the computer system using the removable storage drive, the memory chips or the communications interface. The control logic (software), when executed by a control processor, causes the control processor to perform certain functions of the invention as described herein. 
         [0037]    In another embodiment, features of the invention are implemented primarily in hardware using, for example, hardware components such as application specific integrated circuits (ASICs) or field-programmable gated arrays (FPGAs). Implementation of the hardware state machine so as to perform the functions described herein will be apparent to persons skilled in the relevant art(s). In yet another embodiment, features of the invention can be implemented using a combination of both hardware and software. 
         [0038]    As described above and shown in the associated drawings, the present invention comprises a security system for protecting construction site assets. While particular embodiments of the invention have been described, it will be understood, however, that the invention is not limited thereto, since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. It is, therefore, contemplated by the following claims to cover any such modifications that incorporate those features or those improvements that embody the spirit and scope of the present invention.