Abstract:
This document discusses, among other things, a system and method for detecting a physical contact within a specified area of at least one piece of dog agility equipment for the purpose of improving the training and judging involved in the sport of dog agility. A notification of a proper detected physical contact can be provided using a physical indicator, such as a light or a sound, or an electromagnetic signal, configured to be received by an electronic device.

Description:
TECHNICAL FIELD 
       [0001]    This patent document pertains generally to contact sensors, and more particularly, but not by way of limitation, to detecting a physical contact within a specified area of at least one piece of dog or other animal agility equipment. 
       BACKGROUND 
       [0002]    The competitive sport of dog agility includes the task of having a dog traverse various obstacles including ramps, teeter-totters, A-frames, and tables. Typically, there is a performance requirement that the dog touch certain areas, or “contact zones,” on the obstacle while traversing it. For example, the American Kennel Club (AKC) requires that a minimum of a dog&#39;s toenail must be within the contact zone to establish a valid contact. Other canine registries typically impose similar requirements. The present practice generally includes observing the behavior with the human eye and making a judgment as to whether a proper contact was made or not. This can often be difficult and inaccurate due to the speed and physical characteristics of modem canine athletes. World class canine athletes can typically traverse the contact zone in less than 0.2 seconds, and further, many dogs have long hair on their feet that can prevent the judge from making an accurate assessment of a valid contact. Thus, there exists a need to increase the accuracy and consistency of judging a proper contact. 
       OVERVIEW 
       [0003]    This overview is intended to provide an overview of the subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about the subject matter of the present patent application. 
         [0004]    In Example 1, a system is configured to detect a physical contact by an animal, such as a dog or other animal, within a specified area of at least one piece of dog agility equipment. The system includes at least one contact sensor, configured to sense an electrical characteristic indicative of the physical contact. The system also includes a detection circuit, coupled to the contact sensor, configured to detect the physical contact using information from the contact sensor. The system also includes a notification circuit, coupled to the detection circuit, configured to provide a notification of the detected physical contact. 
         [0005]    In Example 2, the system of Example 1 optionally includes at least one piece of dog agility equipment, wherein the at least one piece of dog agility equipment includes at least one of a ramp, a tunnel, a chute, a teeter-totter, a dog-walk, an A-frame, and a table. 
         [0006]    In Example 3, the at least one piece of dog agility equipment of Examples 1-2 optionally includes a grounding circuit, wherein the grounding circuit includes a conductor, and wherein the conductor is configured to be connected to an electrical ground. 
         [0007]    In Example 4, the at least one contact sensor of Examples 1-3 optionally includes a plurality of contact sensors, wherein the plurality of contact sensors are configured to operate as one or more than one contact zone. 
         [0008]    In Example 5, the plurality of contact sensors of Examples 1-4 are optionally configured, individually or in combination, to operate as one or more than one contact zone. 
         [0009]    In Example 6, the contact sensor of Examples 1-5 optionally includes a conductor. 
         [0010]    In Example 7, the contact sensor of Examples 1-6 optionally includes at least one signal conductor and at least one ground conductor. 
         [0011]    In Example 8, the detection circuit of Examples 1-7 optionally includes a signal generation circuit, configured to generate a electrical signal using information from the contact sensor. The detection circuit of Examples 1-7 is also optionally configured to detect the physical contact using information from the generated electrical signal. 
         [0012]    In Example 9, the detection circuit of Examples 1-8 is optionally configured to detect a change in the electrical characteristic indicative of the physical contact. The system of Examples 1-8 also optionally includes a timing circuit, coupled to the detection circuit, configured to determine whether the change in the electrical characteristic meets or exceeds a specified duration. The notification circuit of Examples 1-8 is also optionally coupled to the timing circuit. The notification circuit of Examples 1-8 is also optionally configured to provide a notification using information from the timing circuit. 
         [0013]    In Example 10, the notification circuit of Examples 1-9 optionally includes a physical indicator, wherein the physical indicator includes at least one of a light and a sound. 
         [0014]    In Example 11, the notification circuit of Examples 1-10 optionally includes an electromagnetic signal configured to be received by an electronic device. 
         [0015]    In Example 12, a system includes means for sensing an electrical characteristic indicative of a physical contact by an animal within a specified area of at least one piece of dog agility equipment, such as by using at least one contact sensor, configured to sense an electrical characteristic indicative of the physical contact. The system also includes means for detecting the physical contact using the sensed electrical characteristic, such as by using a detection circuit, coupled to the contact sensor, configured to detect the physical contact using information from the contact sensor. The system also includes means for providing a notification of the detected physical contact, such as by using a notification circuit, coupled to the detection circuit, configured to provide a notification of the detected physical contact. 
         [0016]    In Example 13, a method includes sensing an electrical characteristic indicative of a physical contact by an animal, such as a dog or other animal, within a specified area of at least one piece of dog agility equipment using a contact sensor. The method also includes detecting the physical contact using the sensed electrical characteristic. The method also includes providing a notification of the detected physical contact. 
         [0017]    In Example 14, the sensing of Example 13 optionally includes sensing an electrical characteristic within one or more than one specified area using a plurality of contact sensors. 
         [0018]    In Example 15, the sensing of Examples 13-14 optionally includes using a contact sensor that includes a conductor. 
         [0019]    In Example 16, the sensing of Examples 13-15 optionally includes using a contact sensor that includes at least one signal conductor and at least one ground conductor. 
         [0020]    In Example 17, the method of Examples 13-16 optionally includes generating an electrical signal using information from the sensed electrical characteristic. The detecting the physical contact of Examples 13-16 also optionally includes using information from the generated electrical signal. 
         [0021]    In Example 18, the method of Examples 13-17 optionally includes detecting a change in the electrical characteristic indicative of the physical contact. The method of Examples 13-17 also optionally includes determining whether the change in the electrical characteristic meets or exceeds a specified duration using a timing circuit. The providing a notification of Examples 13-17 optionally includes using information from the timing circuit. 
         [0022]    In Example 19, the providing a notification of Examples 13-18 optionally includes providing a physical indication, wherein providing the physical indication includes providing at least one of a light and a sound. 
         [0023]    In Example 20, the providing a notification of Examples 13-19 optionally includes providing an electromagnetic signal, configured to be received by an electronic device. 
         [0024]    This overview is intended to provide an overview of the subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about the subject matter of the present patent application. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    In the drawings, which are not necessarily drawn to scale, like numerals describe substantially similar components throughout the several views. Like numerals having different letter suffixes represent different instances of substantially similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
           [0026]      FIG. 1  illustrates generally an example of a system including a piece of dog agility equipment, contact zones, electrical cabling, a piece of electronic equipment, a light indication, a sound indication, an electromagnetic signal indication, a computer, a dog, a human operator, and wherein the contact zone includes cross section AA, cross section BB, and electrical connectors. 
           [0027]      FIG. 2  illustrates generally an example of portions of a system including a portion of a piece of dog agility equipment, a conductive layer, a non-conductive layer, electrical connectors, an electrical insulating collar, threaded fasteners, electric cabling, and wherein the portion of the piece of dog agility equipment includes a frame, wood, and a non-conductive coating. 
           [0028]      FIG. 3  illustrates generally an example of portions of a system including a portion of a piece of dog agility equipment, a contact zone, gaps, and interdigitated zones. 
           [0029]      FIG. 4   a  illustrates generally an example of portions of a system including a portion of a piece of dog agility equipment, a conductive layer, a non-conductive layer, an electrical connection, a detection circuit, an electrical ground, and wherein the portion of the piece of dog agility equipment includes a frame, wood, and a non-conductive coating. 
           [0030]      FIG. 4   b  illustrates generally an example of portions of a system including a portion of a piece of dog agility equipment, a conductive layer, a non-conductive layer, an electrical connection, a detection circuit, an electrical ground connection, an electrical ground, and wherein the portion of the piece of dog agility equipment includes a frame, wood, and a non-conductive coating. 
           [0031]      FIG. 5  illustrates generally an example of portions of a system including an electrical characteristic and a detection circuit, wherein the detection circuit includes a sensor interface circuit, an analysis circuit, and an indicator circuit. 
           [0032]      FIG. 6  illustrates generally an example of a system timing cycle including a main timing cycle, a clock signal, control signals, wherein the main timing signal includes a count interval and a control interval, and wherein the clock signal includes clock pulses during the count interval and clock pulses during the control interval. 
           [0033]      FIG. 7  illustrates generally an example of portions of a system including an electrical characteristic and portions of a detection circuit, wherein the portions of the detection circuit include a sensor interface circuit and an analysis circuit, wherein the sensor interface circuit includes a variable monostable oscillator, a variable resistor, a thermister, signal lines, a fixed monostable oscillator, a fixed resistor, a fixed capacitor, and a control signal, and wherein the analysis circuit includes a fixed oscillator, combinational logic, a counter, a present value (n), a previous value (n-1), a comparator, and a notification signal. 
           [0034]      FIG. 8  illustrates generally an example of portions of a system including an electrical characteristic and portions of a detection circuit, wherein the portions of the detection circuit include a sensor interface circuit and an analysis circuit, wherein the sensor interface circuit includes a variable astable oscillator, a variable resistor, a thermister, and a clock signal, and wherein the analysis circuit includes a fixed oscillator, a control signal, combinational logic, a counter, present value (n), previous value (n-1), a comparator, and a notification signal. 
           [0035]      FIG. 9  illustrates generally an example of portions of a system including portions of a detection circuit, wherein portions of the detection circuit include a sensor interface circuit and an analysis circuit, wherein the sensor interface circuit includes an electrical characteristic, a variable oscillator, a variable resistor, a thermister, and a variable clock signal, and wherein the analysis circuit includes a fixed oscillator, microprocessor circuitry, general logic, memory, and a notification signal. 
           [0036]      FIG. 10  illustrates generally an example of portions of a system including portions of a detection circuit, wherein portions of the detection circuit include an electrical characteristic, a variable oscillator, a digitally controlled resistor, a clock signal, a fixed oscillator, combinational logic, a counter, a counter signal, a reference value, a comparator, comparator signals, an up/down counter, a notification signal, a delay, a delay signal, a latch, and a latch signal. 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    The following detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments, which are also referred to herein as “examples,” are described in enough detail to enable those skilled in the art to practice the invention. The embodiments may be combined, other embodiments may be utilized, or structural, logical and electrical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents. 
         [0038]    In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one. In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. Furthermore, all publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference(s) should be considered supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls. 
         [0039]    Typically, electrical characteristics of a conductive surface within a contact zone can be used as a sensor to determine if an animal is present. The capacitance of the contact zone generally changes when an animal is present. This change can be detected and used to set an indicator, to start a timer, or to otherwise influence a different type of circuit or mechanism in order to detect contact. This technique can typically provide the speed and accuracy necessary to determine whether or not an animal has established a proper contact within the contact zone. 
         [0040]    Generally, a clock signal can be established with a frequency that is dependent, at least in part, on a capacitance of a contact zone, such as to determine if an animal is present. A control signal can be used to determine a time interval during which clock pulses can be counted. Each count can be saved and compared to a previous count. When a sufficient difference exists between the count and a previous count, an output signal can be set, such as to indicate that an animal is present at the contact zone. The output signal can be used to start a timer. The timer can be used to activate a notification signal. This notification signal can include a light, a sound, or an electromagnetic signal. 
         [0041]      FIG. 1  illustrates generally an example of a system including a piece of dog agility equipment  102 , electrical cabling  103 , a piece of electronic equipment  104 , a light indication  109 , a sound indication  108 , an electromagnetic signal indication  106 , a computer  107 , a dog  105 , and a human operator  110 , wherein the piece of dog agility equipment  102  includes contact zones  101 , cross section AA, and cross section BB, and wherein the contact zones  101  include electrical connectors  111 . 
         [0042]    In this example, the dog  105  makes contact on a piece of dog agility equipment  102 , e.g., an A-frame, with the contact zone  101 . In certain examples, the contact zone  101  can include one or more than one section. In certain examples, the one or more than one section can be used to determine a more precise contact area within the contact zone  101 , or the one or more than one section can be used to train the dog  105 , or other animal, to make contact with a specific section of the contact zone  101 . 
         [0043]    In the example of  FIG. 1 , the electronic equipment  104  can include a detection circuit or a notification circuit, and generally can determine the presence or absence of an animal, such as a dog  105 , in a contact zone  101 , or detect a physical contact by an animal, such as a dog  105 , in a contact zone  101 . In certain examples, the electronic equipment  104  can be connected to the contact zone  101  with electric cabling  103  and can provide a switching mechanism to select one or more than one section of the contact zone  101 , or one or more than one contact zone  101 . In other examples, the electronic equipment  104  can provide a timing function to activate one or more than one indication, such as a light indication  109 , a sound indication  108 , an electromagnetic signal indication  106 , etc., for a specified time, or the electronic equipment can provide a timing function to determine how long an animal, such as a dog  105 , remains in the contact zone  101 . 
         [0044]      FIG. 2  illustrates generally an example of portions of a system including a portion of a piece of dog agility equipment  102 , a conductive layer  204 , a non-conductive layer  205 , electrical connectors  111 , threaded fasteners  206 ,  207 , electric cabling  103 , and wherein the portion of the piece of dog agility equipment  102  includes a frame  201 , wood  202 , and a non-conductive coating  203 . 
         [0045]    In this example,  FIG. 2  displays the cross section AA of a contact zone  101  of the piece of dog agility equipment  102 . In an example, the frame  201  of the piece of dog agility equipment  102  can be constructed of metal, wood, or other material. A covering, such as the wood  202 , fiberglass, or other material, can be attached to the frame  201  to provide support. The non-conductive coating  203 , typically includes a latex or oil base paint, though other materials can be used. 
         [0046]    In the example of  FIG. 2 , the conductive layer  204  can be applied to the piece of dog agility equipment  102  to create a contact sensor. The area of the contact sensor includes the contact zone  101 . In an example, the conductive layer can include a conductive paint, an epoxy, a metallic film, or other electrically conductive materials. In another example, the non-conductive coating  205  can be applied to protect the conductive layer  204 . The electric connectors  111  can provide an electrical contact between the conductive layer  204  and the electric cabling  103 . In an example, the electrical connectors  111  can include mechanical fasteners, bolts, or other electrical connectors to through the piece of dog agility equipment  102 . In this example, the threaded fasteners  206  can provide mechanical stability to the electrical connectors  111 . In another example, the threaded fasteners  207  and the electrical connectors  208  can provide an electrical connection between the electrical connectors  111  and the electric cabling  103  by compressing the electrical connectors  208  between the threaded fasteners  207 . An electrically insulating collar  209  may be required to electrically isolate the electrical connector  111  from the piece of dog agility equipment  102  if for example, the frame  201  of the piece of dog agility equipment is made of a conductive material, such as aluminum, steel, or other conductive materials. In an example, the electrically insulating collar  209  can include plastic, paper, or other insulating material of sufficient length to isolate the electrical connector  111  from the piece of dog agility equipment  102 . 
         [0047]      FIG. 3  illustrates generally an example of portions of a system including a portion of a piece of dog agility equipment  102 , a contact zone  101 , gaps  301 ,  303 , and interdigitated zones  302 ,  304 . 
         [0048]    In this example, the contact zone  101  of the piece of dog agility equipment  102  includes gaps  301 ,  303  and interdigitated zones  302 ,  304 . The contact zone  101  generally includes at least one conductor. In this example, the contact zone  101  includes a first interdigitated zone  302  that can be used for an electrical signal and a second interdigitated zone  304  that can be used for an electrical ground. Generally, an electrical ground in close proximity to an electric signal results in a composite electric field closer in proximity to the contact zone  101 , which typically allows for detection in the contact zone with an increased specificity. Further, in this example, the contact zone  101  includes gaps  301 ,  303 . Generally, gaps  301 ,  303  decrease the possibility of falsely detecting a human operator  110 . In an example, the gap  303  at the end of the contact zone  101  can be minimized to increase the differentiation of the contact zone  101  and the remaining piece of dog agility equipment  102 . In other examples, other structures or geometries, such as a serpentine geometry, etc., can be used including a first conductor and at least a second conductor, wherein at least one of the conductors includes an electrical ground. 
         [0049]      FIG. 4   a  illustrates generally an example of portions of a system including a portion of a piece of dog agility equipment, a conductive layer  204 , a non-conductive layer  205 , an electrical connection  402 , a detection circuit  401 , an electrical ground  404 , and wherein the portion of the piece of dog agility equipment includes a frame  201 , wood  202 , and a non-conductive coating  203 . 
         [0050]    In this example,  FIG. 4   a  displays the cross section BB of a contact zone  101  of the piece of dog agility equipment  102 . In an example, the detection circuit  401  can be configured to receive an electrical characteristic from the conductive layer  204  using the electrical connection  402 . In this example, the contact sensor includes the conductive layer  204 . 
         [0051]      FIG. 4   b  illustrates generally an example of portions of a system including a portion of a piece of dog agility equipment, a conductive layer  204 , a non-conductive layer  205 , an electrical connection  402 , a detection circuit  401 , an electrical ground connection  403 , an electrical ground  404 , and wherein the portion of the piece of dog agility equipment includes a frame  201 , wood  202 , and a non-conductive coating  203 . 
         [0052]    In this example,  FIG. 4   b  displays the cross section BB of a contact zone  101  of the piece of dog agility equipment  102 . In an example, the electrical ground  404  of the detection circuit  401  can be configured to be connected to the frame  201  of the piece of dog agility equipment  102 . In another example, if the frame  201  does not include a conductor, a conductive layer can be applied on the back of the piece of dog agility equipment  102 , which can then be connected to the electrical ground  404  of the detection circuit  401  using the electrical ground connection  403 . In other examples, other electrical ground connections of the system can be configured to be connected to the frame  201  or an applied conductive layer on the back of the piece of dog agility equipment  102 . Generally, the electrical ground connection  403  can provide a more controlled electrical capacitance. Typically, connecting the frame  201  to electrical ground ensures that the potential effects of the frame  201  will not adversely affect the detection circuit or other components. 
         [0053]      FIG. 5  illustrates generally an example of portions of a system including an electrical characteristic  501  and a detection circuit  104 , wherein the detection circuit  104  includes a sensor interface circuit  502 , an analysis circuit  503 , and an indicator circuit  504 . 
         [0054]    In this example, the contact zone is represented by an electrical characteristic  501 . Generally, the contact zone  101  includes an electrical capacitance related to its physical size and proximity to other conductive objects. When an electrically active object, such as a dog  105 , or other animal, is present in the contact zone  101 , the electrical characteristic  501  of the contact zone  101  typically changes. The electrical characteristic  501  can be determined by the detection circuit  104 . In an example, the sensor interface circuit  502  can be configured to receive the electrical characteristic  501 . The analysis circuit  503  can be configured to determine if the electrical characteristic  501  has changed. The indicator circuit  504  can be configured to provide an indication if the analysis circuit  503  determines that a sufficient change in the electrical characteristic  501  has occurred. In certain examples, the indication can include a light indication  109 , a sound indication  108 , an electromagnetic signal indication  106 , etc. 
         [0055]      FIG. 6  illustrates generally an example of a system timing cycle including a main timing cycle  601 , a clock signal  602 , control signals  603 - 606 , wherein the main timing signal  601  includes a count interval  607  and a control interval  608 , and wherein the clock signal includes clock pulses  609  during the count interval  607  and clock pulses  610  during the control interval  608 . 
         [0056]    In this example, the main timing signal  601  includes the count interval  607  when the detection circuit  104  is detecting the electrical characteristic  501  and a control interval  608  when the detection circuit  104  is processing the electrical characteristic  501 . In an example, the count interval  607  can extend from time marker A to time marker B and the control interval  608  can extend from time marker B to time marker C. In certain examples, the clock signal  602  can be used to generate clock pulses  609  that can be counted during the count interval  607 , or the clock signal  602  can be used to generate control signals  603 - 606  using the clock pulses  610  during the control interval  608 . The control signals  603 - 606  can be used to control various circuit functions, such as transferring a previous count, latching the present count, latching the result of a comparison, activating an indication if a valid contact is determined, etc. 
         [0057]      FIG. 7  illustrates generally an example of portions of a system including an electrical characteristic  501  and portions of a detection circuit, wherein the portions of the detection circuit include a sensor interface circuit  502  and an analysis circuit  503 , wherein the sensor interface circuit  502  includes a variable monostable oscillator  703 , a variable resistor  701 , a thermister  717 , signal lines  702 ,  704 , a fixed monostable oscillator  705 , a fixed resistor  715 , a fixed capacitor  716 , and a control signal  601 , and wherein the analysis circuit  503  includes a fixed oscillator  706 , combinational logic  707 , a counter  708 , a present value (n)  710 , a previous value (n-1)  712 , a comparator  713 , and a notification signal  714 . 
         [0058]    In this example, the control signal  601  can be created using the electrical characteristic  501 , the variable monostable oscillator  703 , the fixed monostable oscillator  705 , and various other circuit components. In an example, the count interval  607  can be created using the output of the variable monostable oscillator  703 . The count interval  607  can be connected to the fixed monostable oscillator  705  using a signal line  704 . The control signal  601  can be created using the output of the fixed monostable oscillator  705 . Output of the fixed monostable oscillator  705  can be fed back to the variable monostable oscillator  703  using the signal line  702  this feedback connection can create an astable oscillator that can be used to create the control signal  601 . In an example, the count interval  607  duration can be established using the electrical characteristic  501 , the variable resistor  701 , and the thermister  717 . Generally, the variable resistor  701  can be used to compensate for differences in the electrical characteristic  501  of the piece of dog agility equipment  102 , differences in temperature, differences in humidity, etc, and the thermister  717  can be used to accommodated temperature dependency of various electrical components or other components of the system. The control interval  608  duration can be established using the fixed resistor  715  and fixed capacitor  716 . 
         [0059]    In the example of  FIG. 7 , the analysis circuit  503  can be configured to receive the control signal  601 . In an example, the counter  708  can be used to count the number of cycles of the fixed oscillator  706  during the count interval  607 . In certain examples, the analysis circuit  503  can be configured to store the present value (n)  710  of this count, and the analysis circuit  503  can be configured to store the previous value (n-1)  712  of this count. The comparator  713  can be configured to compare the present value (n)  710  and the previous value (n-1)  712  to determine if any change has occurred. In an example, the notification signal  714  can be created using the output of the comparator  713 . 
         [0060]      FIG. 8  illustrates generally an example of portions of a system including an electrical characteristic  501  and portions of a detection circuit, wherein the portions of the detection circuit include a sensor interface circuit  502  and an analysis circuit  503 , wherein the sensor interface circuit includes a variable astable oscillator  801 , a variable resistor  701 , a thermister  717 , and a clock signal  802 , and wherein the analysis circuit  503  includes a fixed oscillator  706 , a control signal  601 , combinational logic  707 , a counter  708 , present value (n)  710 , previous value (n-1)  712 , a comparator  713 , and a notification signal  714 . 
         [0061]    In this example, the clock signal  802  can be created using a sensor interface circuit  502  and an electrical characteristic  501 , wherein the sensor interface circuit  502  includes a variable astable oscillator  801 , a variable resistor  701 , and a thermister  717 . Generally, the clock signal  802  varies depending on the electrical characteristic  501  and the variable resistor  701 . In an example, the electrical characteristic  501  includes the capacitance of the contact zone  101 . The variable resistor  701  can be used to compensate for variance in the capacitance of the contact zone  101  between different pieces of dog agility equipment  102 , temperature, humidity, or other system variables. In an example, the thermister  717  can be used to compensate for the temperature dependency of various system components. 
         [0062]    In the example of  FIG. 8 , a control signal  601  can be provided using the fixed astable oscillator  706 . In certain examples, the count interval  607  and the control interval  608  can be determined using the control signal  601 . The counter  708  can be used to count the number of cycles of the variable astable oscillator  801  during the count interval  607 . In certain examples, the analysis circuit  503  can be configured to store the present value (n)  710  of this count, and the analysis circuit  503  can be configured to store the previous value (n-1)  712  of this count. The comparator  713  can be configured to compare the present value (n)  710  and the previous value (n-1)  712  to determine if any change has occurred. In an example, the notification signal  714  can be created using the output of the comparator  713 . 
         [0063]      FIG. 9  illustrates generally an example of portions of a system including portions of a detection circuit, wherein portions of the detection circuit include a sensor interface circuit  502  and an analysis circuit  503 , wherein the sensor interface circuit  502  includes an electrical characteristic  501 , a variable oscillator  901 , a variable resistor  701 , a thermister  717 , and a variable clock signal  602 , and wherein the analysis circuit  503  includes a fixed oscillator  706 , microprocessor circuitry  904 , general logic  909 , memory  906 , and a notification signal  714 . 
         [0064]    In this example, a variable clock signal  602  can be created using a sensor interface circuit  502 , wherein the sensor interface circuit  502  includes an electrical characteristic  501 , a variable oscillator  901 , a variable resistor  701 , and a thermister  717 . Generally, the variable clock signal  602  varies depending on the electrical characteristic  501  and the variable resistor  701 . In an example, the electrical characteristic  501  includes the capacitance of the contact zone  101 . The variable resistor  701  can be used to compensate for variance in the capacitance of the contact zone  101  between different pieces of dog agility equipment  102 , temperature, humidity, or other system variables. In an example, the thermister  717  can be used to compensate for the temperature dependency of various system components. 
         [0065]    In the example of  FIG. 9 , microprocessor circuitry  904  can be used to determine the count interval  607  and the control interval  608 . Generally, the microprocessor circuitry  904  can be configured to execute a software code in conjunction with a memory  906  and general logic  909 . In certain examples, the microprocessor circuitry  904  and memory  906  can be configured to count the number of cycles of the variable oscillator  901 . In other examples, the microprocessor circuitry  904  and memory  906  can be configured to store the present value of this count and at least one previous value of this count. The microprocessor circuitry  904  can be configured to compare the present value and at least one previous value to determine if any change has occurred. In an example, the notification signal  714  can be created using the output of the microprocessor circuitry  904 . 
         [0066]      FIG. 10  illustrates generally an example of portions of a system including portions of a detection circuit, wherein portions of the detection circuit include an electrical characteristic  501 , a variable oscillator  901 , a digitally controlled resistor  1002 , a clock signal  802 , a fixed oscillator  706 , combinational logic  707 , a counter  708 , a counter signal  1010 , a reference value  1007 , a comparator  1011 , comparator signals  1004 ,  1005 , an up/down counter  1003 , a notification signal  714 , a delay  1013 , a delay signal  1014 , a latch  1012 , and a latch signal  1006 . 
         [0067]    In this example, a clock signal  802  can be established using a variable oscillator  901 . The frequency of the variable oscillator  901  can be established using an electrical characteristic  501  and a digitally controlled resistor  1002 . The value of the digitally controlled resistor  1002  can be established, in part, using a reference value  1007 , a counter  708 , and a comparator  1011 . The reference value  1007  can include a preset reference value. In certain examples, the count interval  607  and control interval  608  can be established using the clock signal  802 . 
         [0068]    In the example of  FIG. 10 , the counter  708  can be configured to count the number of clock cycles from the fixed oscillator  706  during the count interval  607 . The comparator  1011  can be configured to compare the value of the number of clock cycles using the reference value  1007 . In an example, if the comparator  1011  determines that the number of clock cycles is higher than the reference value  1007 , then the value of the up/down counter  1003  is increased, which increases the value of the digitally controlled resistor  1002 , which causes the frequency of the variable oscillator  901  to decrease. In another example, if the comparator  1011  determines that the number of clock cycles is lower than the reference value  1007 , then the value of the up/down counter  1003  is decreased, which decreases the digitally controlled resistor  1002 , which causes the frequency of the variable oscillator  901  to increase. The notification signal  714  and delay  1013  can be used to ensure that the value of the digitally controlled resistor  1002  is not updated during a valid contact indication. In an example, the notification signal  714  can be delayed using the delay  1013  and the latch  1012  to allow the detection circuit  104  to stabilize before updating the digitally controlled resistor. 
         [0069]      FIGS. 1-10  illustrate various examples, including sensing an electrical characteristic, detecting the physical contact, providing a notification, generating an electrical signal, detecting a change in the electrical characteristic, and determining whether the change in the electrical characteristic meets or exceeds a specified duration, are disclosed. It is to be understood that these examples are not exclusive, and can be implemented either alone or in combination, or in various permutations or combinations. 
         [0070]    It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. 
         [0071]    The Abstract is provided to comply with 37 C.F.R. §1.72(b), which requires that it allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.