This invention is related to a system and a method for controlling access to a source of electrical power.
Electric receptacles, through which a source of electrical power is accessible, typically are located in various areas that are open to the public (e.g., airport lobbies and waiting rooms, bus terminals, hotel lobbies). For a variety of reasons, the owner/operator of the premises in which the public area is located may wish to limit access to the source of electrical power to those who are authorized. However, in the prior art, the means for limiting access are generally somewhat inflexible.
For instance, in one typical arrangement, where it is intended that only certain authorized parties (e.g., janitorial staff) have access to electricity via the electric receptacles in the public area, the connection of the receptacles to the source of electrical power is controlled by a manually operated switch, and only those parties are able to operate the switch. Conventionally, the manually operated switch may be secured by a mechanical lock. However, this arrangement has some disadvantages. For example, the switch is only available if one of the authorized parties has an appropriate key for the mechanical lock, which may or may not be convenient. Also, once the receptacles are energized, any member of the public in the public area where the receptacles are located may utilize the electricity available via the receptacles, subject only to interdiction by the authorized parties.
For the foregoing reasons, there is a need for a system and method for controlling access to a source of electrical power that overcomes or mitigates one or more of the defects of the prior art.
In its broad aspect, the invention provides a system for controlling access to a source of electrical power, the system including a readable access information device associated with one or more electrical load devices electrically connectable one or more receptacles, the readable access information device including access information, and a switch device for connecting and disconnecting the receptacle to and from the source of electrical power. The system also includes a reader for reading the access information from the readable access information device, the reader being operably coupled with the switch device. Upon the reader reading the access information and determining that the access information satisfies preselected criteria, and if the receptacle is disconnected from the source of electrical power, the reader generates a connect signal that is transmitted to the switch device. Upon the switch device receiving the connect signal, the switch device connects the receptacle to the source of electrical power, to permit the electrical load device to connect to the source of electrical power via the receptacle. Upon the reader determining that one or more preselected criteria is unsatisfied by the access information while the receptacle is connected to the source of electrical power, the reader generates a disconnect signal that is transmitted to the switch device. Upon the switch device receiving the disconnect signal, the switch device disconnects the receptacle from the source of electrical power.
In another aspect, the reader reads the access information at predetermined time intervals to determine, at the predetermined time intervals, whether the access information satisfies the preselected criteria.
In another of its aspects, the access information includes time credit information.
In yet another aspect, the access information includes a unique address associated with the electrical load device.
In another of its aspects, the access information includes one or more group codes associated with the electrical load device.
In another aspect, the access information includes user identification information for authorizing connection of the receptacle to the source of electrical power for an authorized user.
In yet another aspect, the access information includes one or more preselected characteristics of electrical power provided by the source of electrical power.
In another aspect, the invention provides a system for controlling access to a source of electrical power, including a readable access information device associated with one or more electrical load devices, the readable access information device having access information, a switch device for connecting and disconnecting the electrical load device to and from the source of electrical power, and a reader for reading the access information from the readable access information device, the reader being operably coupled with the switch device. Upon the reader reading the access information and determining that the access information satisfies preselected criteria, and if the electrical load device is disconnected from the source of electrical power, the reader generates a connect signal that is transmitted to the switch device. Upon the switch device receiving the connect signal, the switch device connects the electrical load device to the source of electrical power. Upon the reader determining that one or more of the preselected criteria is unsatisfied by the access information while the electrical load device is connected to the source of electrical power, the reader generates a disconnect signal that is transmitted to the switch device. Upon the switch device receiving the disconnect signal, the switch device disconnects the electrical load device from the source of electrical power.
The invention will be better understood with reference to the attached drawings, in which:
The present invention may be understood more readily by reference to the following detailed description of the invention and the examples provided herein. It is to be understood that the aspects described below are not limited to specific circuits, outlets, receptacles, plugs, or devices, and as such may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.
In this specification and in the claims that follow, reference will be made to a number of terms that shall be defined to have the following meanings.
About: Often, ranges are expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about”, it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.
Articles: As used in the specification and the appended claims, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise.
Command Card: A PCD tag in a format suitable for manual handling. Data contained therein is accessible by a PCD Reader.
Electrical Load Device: “Electrical load device” means any device which can be electrically connected in a circuit and which draws current or passes current. “Electrical load device” can include any component (e.g., such as a damaged extension cord) which, even if not activated, nonetheless can draw actual current.
Outlet: Electrical wiring device containing at least one receptacle. Provides a means for the quick connection and disconnection of an electrical device to an electrical distribution system. For example, the outlet could be an in-wall outlet or in an extension cord or a power strip.
PCD Reader: A device or circuit that can read and/or write data from/to a PCD tag.
PCD Tag: A device containing data that can provide access to that data to a PCD reader when in close proximity. Effectively, a contactless memory storage device.
Plug: A set of connector pins or blades that provides a means to connect an attached electrical load device to a source of electrical power by way of a compatible receptacle.
Programmable: A device, storage means or data value is “programmable” if it can be adjusted, configured or changed.
Receptacle: A set of connector sockets that provides a means to connect an electrical load device equipped with a compatible plug to a source of electrical power.
Switch Device: A means to connect and disconnect the path of an electrical circuit.
In the attached drawings, like reference numerals designate corresponding elements throughout. Reference is first made to
It will be appreciated by those skilled in the art that the access information may include information regarding any suitable parameters. For instance, the access information may include time credit information 2 (
Alternatively, or in addition to the time credit information, the access information may include unique address information 4 (
Preferably, the preselected criteria are any suitable criteria. The preselected criteria in any particular application are determined according to the parameters utilized in the access information 30. For instance, where the access information 30 includes time credit information, the preselected criteria would include one or more criteria related to the time credit information. In this example, one such preselected criterion would be that there is a certain time period that is preauthorized (i.e., paid for in advance), according to the time credit information.
It will be understood that, when the reader determines whether the access information satisfies the preselected criteria, such criteria are only considered satisfied if all the preselected criteria are satisfied. Also, if any one of the preselected criteria is unsatisfied, then the preselected criteria are considered to be unsatisfied. In addition, it will be understood that, if the reader cannot read some or all of the access information, then the relevant preselected criteria are considered to be unsatisfied. That is, a lack of access information results in the preselected criteria being unsatisfied.
In one embodiment, another type of preselected criterion preferably is a group (or facility, or venue) code 6 (
In these circumstances, when the reader at a receptacle in the airport reads the access information, it is programmed to read the group code, and the time credit information. In this example, if the group code matches the group code that is required (or one of a number of preauthorized group codes, as the case may be), and if the time credit information satisfies the preselected criterion therefor, then all the preselected criteria are satisfied. If the receptacle is disconnected, then the connect signal is generated and transmitted, so that the receptacle is then connected to the source of electrical power 22.
However, in this example, if the user purchases the time credit information at a venue other than the airport, then the access information does not include the correct group code, if the user wishes to access the source of electrical power via a receptacle at the airport. In this case, when the reader reads the access information, the reader will determine that one of the preselected criteria (namely, a requirement that the access information includes a group code matching one or more preauthorized group codes in the reader's memory, e.g., a group code showing that the time credit was purchased at the airport) is not satisfied. As will be discussed below, if any one of the preselected criteria is unsatisfied, and if the receptacle is disconnected from the source of electrical power, then the receptacle remains disconnected. In this way, the owner/manager of the public area in which the receptacle(s) is located restricts access to the source of electrical power via the receptacle(s) to the users who purchased time credits at that venue.
The group code may be company-based, rather than location-based. For instance, a number of franchisees operating retail businesses (e.g., coffee shops) may offer time credits. When the user purchases time credits at one of the franchised retail businesses, the group code is added to the access information. Preferably, the group code satisfies the preselected criterion therefor at the receptacles (i.e., the readers) at any of the franchise chain's retail businesses, notwithstanding that the time credits may have been purchased at a different franchise business location.
Those skilled in the art will appreciate that the access information may contain such data related to selected parameters as is desired, and the reader may be programmed to read any such data, and to determine (by comparison to data in the reader's memory) whether the preselected criteria related to the selected parameters are satisfied by the data in the access information. For instance, and as will be described, in addition to the other parameters referred to above, the access information may include user identification information 8 and/or one or more preselected characteristics 10 of the electrical power provided by the source of electrical power. It will be understood that the parameters schematically illustrated in
Those skilled in the art will also appreciate that the reader 34 preferably reads the access information 30 in any suitable manner, and that there is a wide variety of methods and means that are suitable. For instance, the methods of reading the access information may include magnetic, RFID (i.e., PCD tags and readers), wireless radio, serial digital data, and parallel digital data. For the purposes of description herein, the system 20 including PCD tags read by PCD readers will be described. However, it will be understood that the system 20 may include any suitable method or means of storing the access information in the readable access information device, and any suitable method or means of reading the access information.
PCD tags and PCD readers are described in U.S. Pat. No. 8,000,074, the entire specification and drawings of which are hereby incorporated herein by reference. Accordingly, a detailed description of the operation of the PCD tag and the PCD reader is unnecessary.
As noted above, it is preferred that the readable access information device 24 (and the access information 30) is associated with the electrical load device 26. In this context, “associated” means identified with, or related to. For instance, the electrical load device 26 may be a charging device, for charging a battery in a handheld device (not shown). Alternatively, the electrical load device may be a laptop computer or similar device (not shown). In one embodiment, the access information in or on the readable access information device 24 preferably includes time credit information, i.e., when read, the time credit information indicates that connection to the source of electrical power is authorized for a certain time period, which is prepaid, or authorized on some other basis.
Those skilled in the art will appreciate that the readable access information device 24 may be associated with the electrical load device 26 in any suitable manner. For example, and as will be described, the readable access information device 24 may be physically connected to, or included in, a plug 36 (
As noted above, the reader 34 is operably coupled with the switch device 32. The switch device 32 preferably is any suitable relay or switch which is adapted to receive signals from the reader. Preferably, the reader 34 is positioned proximal to the switch device 32, which in turn preferably is also positioned proximal to the receptacle 28. An embodiment of the receptacle 28, with the location of the reader 34 positioned proximal thereto, is illustrated in
An outlet 42, for use as a retrofit application, is illustrated in
Those skilled in the art would also appreciate that the access information preferably is encrypted, using any suitable type of encryption (e.g., public key cryptography), to discourage illicit utilization of electricity by unauthorized parties.
It will be appreciated by those skilled in the art that the invention preferably is implemented using any suitable hardware and software. For example, if PCD tags and PCD readers are utilized, then commercially available microprocessors, RFID reader chips, and RFID transponder chips may be used.
An unauthorized user may attempt to obtain illicit (i.e., unauthorized) access to the source of electrical power by, for example, removing the plug of a properly authorized electrical load device from a receptacle, and replacing that plug with the plug of an unauthorized electrical load device. In this way, the unauthorized user may attempt to utilize the access to the source of electrical power that an authorized user has paid for. Preferably, this possibility is addressed by the reader 34 reading the access information 30 at predetermined time intervals, because when the reader reads the access information, the reader also determines whether all of the preselected criteria are satisfied by the access information. In effect, when the reader reads the access information at the predetermined time intervals, the reader is checking, at the predetermined time intervals, whether the access information satisfies the preselected criteria.
In one embodiment, the reader 34 preferably reads the access information 30 at predetermined time intervals to determine, at the predetermined time intervals, whether the access information 30 satisfies one or more of the preselected criteria. Upon the reader 34 determining that the access information 30 satisfies all preselected criteria, and if the receptacle 28 is disconnected from the source of electrical power 22, the reader 34 generates the connect signal, which is transmitted to the switch device 32 for connection of the receptacle 28 to the source of electrical power 22. However, upon the reader 34 determining that one or more of the preselected criteria are unsatisfied by the access information 30 while the receptacle 28 is connected to the source of electrical power 22, the reader 34 generates the disconnect signal, which is transmitted to the switch device 32 for disconnection of the receptacle 28 from the source of electrical power 22.
The predetermined time interval may be any suitable time interval, and varies according to the application, and in particular varies depending on the type of access information which is stored and read. Preferably, the predetermined time interval is less than about 1 second, e.g., about 0.067 second.
For instance, in the example set out above, one preselected criterion that is checked is whether the readable access information device 24, with the time credit information and other information contained therein that had authorized the current connection of the receptacle 28 to the source of electrical power, is still readable by the reader 34. If the access information 30 in such readable access information device 24 is not readable for whatever reason (e.g., if the readable access information device 24 was removed), then at least one of the preselected criteria is considered to be unsatisfied, and the reader generates the disconnect signal, resulting in the receptacle 28 being disconnected from the source of electrical power 22, as described above.
As noted above, in this example, the preselected criteria includes at least one preselected criterion in respect of the time credit information. The time credit information may include, for example, a preauthorized time period. The preselected criterion in respect of the time credit information is that there is a preauthorized time period, i.e., data in readable form confirming this. If it is determined in this example, initially, that the time credit information does not include data confirming a preauthorized time period, then at least one of the preselected criteria has not been satisfied. In this situation (i.e., if the receptacle 28 is disconnected from the source of electrical power 22, and any one of the preselected criteria is unsatisfied), then no signal is generated by the reader 34 for transmission to the switch device 32.
Those skilled in the art will appreciate that, in general, if any one of the preselected criteria is not satisfied by the access information 30, and if the receptacle is disconnected from the source of electrical power 22, then no signal is generated by the reader for transmission to the switch device, i.e., the receptacle remains disconnected. In an alternative embodiment, if any one of the preselected criteria is unsatisfied by the access information 30, and if the receptacle is disconnected from the source of electrical power, the reader generates a “non-connect” signal, which is transmitted to the switch device, resulting in the switch device not connecting the receptacle to the source of electrical power, i.e., the receptacle remains disconnected. The preselected criteria may be unsatisfied, for instance, if there is readable data in the access information 30 indicating that no preauthorized time period remains unused. As noted above, a lack of readable access information (i.e., for any data required to be read by the reader, for determining satisfaction or otherwise of any of the preselected criteria) also results in the preselected criteria being considered to be unsatisfied.
As described above, if all of the preselected criteria are satisfied by the access information 30, and if the receptacle is disconnected from the source of electrical power, then the reader generates the connect signal, which is transmitted to the switch device, and the switch device connects the receptacle to the source of electrical power. In one embodiment, if the receptacle is connected to the source of electrical power and the reader determines that all the preselected criteria are satisfied by the access information, then no signal is transmitted by the reader to the switch device, i.e., the receptacle remains connected. In an alternative embodiment, if the receptacle is connected to the source of electrical power and the reader determines that all of the preselected criteria are satisfied by the access information, the reader generates a “non-disconnect” signal, which is transmitted to the switch device, causing the switch device to keep the receptacle connected to the source of electrical power, i.e., the receptacle remains connected.
As another example, where the access information 30 preferably includes time credit information, upon the reader 34 determining that the time credit information satisfies one or more preselected criteria in respect thereof (and all preselected criteria are otherwise satisfied), and if the receptacle 28 is disconnected from the source of electrical power 22, the reader 34 generates the connect signal, which is transmitted to the switch device 32 for connection of the receptacle 28 to the source of electrical power 22. Also, upon the reader 34 determining that one or more of the preselected criteria (including those in respect of the time credit information) are unsatisfied by the time credit information while the receptacle 28 is connected to the source of electrical power 22, the reader 34 generates the disconnect signal, which is transmitted to the switch device 32 for disconnection of the receptacle 28 from the source of electrical power 22. Preferably, and as described above, the reader 34 reads the access information 30 (in this example, including time credit information) at predetermined time intervals, to determine at such time intervals whether the access information satisfies the preselected criteria.
The predetermined time interval is any suitable time interval. For example, where the access information 30 includes time credit information, it is preferred that the predetermined time interval is less than about one second.
As described above, it is preferred that the time credit information authorizes connecting the receptacle 28 to the source of electrical power 22 for up to a preauthorized time period while the preselected criteria are satisfied. Preferably, the reader 34 decrements the time credit information in preselected time decrement intervals while the receptacle 28 is connected to the source of electrical power 22, to decrease the preauthorized time period by the decremented time decrement intervals.
The manner in which the preauthorized time period is decremented in time decrement intervals is well known in the art, and therefore a detailed description of the process of decrementing is unnecessary. From the foregoing, it can be seen that, after the source of electrical power 22 has been connected for a certain period of time, during which period decrementing took place, the time credit information preferably includes a reduced preauthorized time period, i.e., the initial preauthorized time period as reduced by the decremented time intervals.
In another embodiment, where the access information 30 preferably includes time credit information, upon the reader 34 determining that the time credit information and any and all other access information satisfies the preselected criteria, and if the receptacle 28 is disconnected from the source of electrical power, the reader 34 generates the connect signal, which is transmitted to the switch device for connection of the receptacle 28 to the source of electrical power 22 for up to a preauthorized time period provided in the time credit information. Upon the reader 34 determining that one or more of the preselected criteria (including those in respect of the time credit information) is unsatisfied while the receptacle 28 is connected to the source of electrical power 22, the reader 34 generates the disconnect signal, which is transmitted to the switch device 32 for disconnection of the receptacle 28 from the source of electrical power 22.
In one embodiment, the access information 30 preferably includes time credit information for authorizing connection of the receptacle 28 to the source of electrical power 22 for up to a preauthorized time period. Upon the reader 34 determining that the time credit information satisfies one or more preselected criteria in respect thereof (and all other preselected criteria are otherwise satisfied), and if the receptacle 28 is disconnected from the source of electrical power 22, the reader 34 generates the connect signal, which is transmitted to the switch device 32 for connection of the receptacle 28 to the source of electrical power 22 for up to the preauthorized time period. As described above, while the receptacle 28 is connected to the source of electrical power 22, the reader 34 decrements the preauthorized time period in preselected time decrement intervals, to decrease the preauthorized time period by the decremented time decrement intervals. Upon the expiry of the preauthorized time period while the receptacle 28 is connected to the source of electrical power 22, the reader 34 determines that one or more of the preselected criteria in respect of the time credit information is unsatisfied, and the reader 34 generates the disconnect signal, which is transmitted to the switch device 32 for disconnection of the receptacle 28 from the source of electrical power 22.
In certain circumstances (discussed further below), it is advantageous to identify a particular electrical load device (or a number of electrical load devices, as the case may be) by a unique address therefor. One of the preselected criteria is that the unique address read by the reader matches a unique address in the reader's memory.
In another embodiment, the access information preferably includes a unique address associated with one or more electrical load devices. Preferably, the reader 34 reads the access information 30 at predetermined time intervals. Upon the reader 34 determining that the unique address satisfies one or more preselected criteria in respect thereof (and all other preselected criteria are otherwise satisfied), and if the receptacle 28 is disconnected from the source of electrical power 22, the reader 34 generates the connect signal, which is transmitted to the switch device 32 for connection of the receptacle 28 to the source of electrical power 22. Upon the reader 34 determining that one or more of the preselected criteria (including those in respect of the unique address) is unsatisfied in respect of the unique address while the receptacle 28 is connected to the source of electrical power 22, the reader 34 generates the disconnect signal, which is transmitted to the switch device 32 for disconnection of the receptacle 28 from the source of electrical power 22.
It will be appreciated that the frequent reading of the access information (i.e., at predetermined time intervals) provides security, to an extent, to the authorized user. For instance, if the predetermined time interval is set at less than about one second, then an unauthorized user (i.e., one who removes a plug for an electrical load device that is properly authorized, and inserts his (unauthorized) plug into that receptacle in an attempt to be connected to the source of electrical power 22) can only enjoy an unauthorized connection to the source of electrical power 22 for a maximum of the predetermined time interval, i.e., in this example, a time period that is less than about one second.
In an alternative embodiment, the access information 30 comprises one or more group codes associated with the electrical load device 26. Upon the reader 34 determining that one or more of the group codes satisfies one or more of preselected criteria in respect thereof (and all other preselected criteria are otherwise satisfied), and if the receptacle 28 is disconnected from the source of electrical power 22, the reader 34 generates the connect signal, which is transmitted to the switch device 32 for connection of the receptacle 28 to the source of electrical power 22. Upon the reader 34 determining that one or more of the preselected criteria is unsatisfied (including those in respect of the group code(s)) while the receptacle 28 is connected to the source of electrical power 22, the reader 34 generates the disconnect signal, which is transmitted to the switch device 32 for disconnection of the receptacle 28 from the source of electrical power 22.
It may be desirable to provide certain users with unfettered access to the source of electrical power, via the receptacles. In order to accommodate this, in one embodiment, the access information 30 preferably includes user identification information, to permit the reader to authorize access to the source of electrical power 22 for an authorized user upon the reader 34 detecting the user identification information in the access information 30. In this case, one of the preselected criteria is that the user identification information matches user identification information in the reader's memory.
In one embodiment, the access information 30 preferably includes user identification information for authorizing connection of the receptacle 28 to the source of electrical power 22 for the authorized user. Upon the reader 34 determining that the user identification information satisfies one or more preselected criteria in respect thereof (and all other preselected criteria are otherwise satisfied), and if the receptacle 28 is disconnected from the source of electrical power 22, the reader 34 generates the connect signal, which is transmitted to the switch device 32 for connection of the receptacle 28 to the source of electrical power 22. Upon the reader 34 determining that one or more of the preselected criteria (including those in respect of the user identification information) is unsatisfied while the receptacle 28 is connected to the source of electrical power 22, the reader 34 generates the disconnect signal and transmits the disconnect signal to the switch device 32 for disconnection of the receptacle 28 from the source of electrical power 22.
In this situation as well, it is advantageous to have the reader reading the access information (i.e., checking the user identification information) at predetermined time intervals, e.g., of 30 seconds each. In this way, the unauthorized user who attempts to take advantage of the authorized user's connection (e.g., by removing the authorized user's plug, and replacing it with the unauthorized user's plug) would be detected relatively rapidly, resulting in a prompt disconnection of the receptacle from the source of electrical power.
In another embodiment, the access information 30 preferably includes one or more preselected characteristics of electrical power provided by the source of electrical power 22. Preferably, the reader 34 reads the access information 30 at predetermined time intervals. Upon the reader determining that the preselected characteristic(s) satisfies one or more preselected criteria in respect thereof (and all preselected criteria are otherwise satisfied), and if the receptacle 28 is disconnected from the source of electrical power 22, the reader 34 generates and transmits the connect signal for connection of the receptacle 28 to the source of electrical power 22. Upon the reader 34 determining that one or more of the preselected criteria (including those in respect of the preselected characteristic of electrical power) is unsatisfied while the receptacle 28 is connected to the source of electrical power 22, the reader 34 generates the disconnect signal and transmits the disconnect signal to the switch device 32 for disconnection of the receptacle 28 from the source of electrical power 22.
Those skilled in the art will appreciate that the preselected characteristic(s) may be any suitable characteristic(s) of the electrical power. In one embodiment, the preselected characteristic is a line voltage associated with the electrical power provided by the source of electrical power at said at least one receptacle.
Preferably, where the access information includes line voltage, the reader checks the line voltage at relatively short predetermined time intervals. In this way, any significant problems with line voltage can be detected relatively promptly, minimizing the possibility of damage to the electrical load device.
It will be understood that, in another embodiment, the system 120 of the invention is for controlling access of an electrical load device 126 to the source of electrical power 22. The electrical load device 126 is directly connectable to the source of electrical power 22, i.e., such connection is not made via a receptacle. As can be seen in
The system 120 is for use where the electrical load device is “hardwired” to the source of electrical power, i.e., a substantially permanent connection is made between conductors. For example, the electrical load device 126 may be jets in a hot tub at a hotel. Because of the system 120, the jets in the hot tub are usable by a guest who has paid (or will pay, as the case may be) for such usage. As discussed above in connection with the access information 30 of the system 20, the access information 130 may include, for instance, time credit information, user identification information, or such other information as is desirable, depending on a preferred basis for control. The preferred basis for control may be, for example, time credit (i.e., a preauthorized time period paid for by the user in advance), user identification, or such other basis as is desirable or convenient, depending on the circumstances.
It will be understood that the reader 134 and the switch device 132 are to be located wherever convenient.
In one embodiment, upon the reader 134 determining that at least one of the preselected criteria is unsatisfied, and if the electrical load device is disconnected from the source of electrical power 22, the reader does not generate a signal for transmission to the switch device 132. In an alternative embodiment, if any one of the preselected criteria is unsatisfied by the access information 30, and if the electrical load device is disconnected from the source of electrical power, the reader generates the “non-connect” signal, which is transmitted to the switch device, resulting in the switch device not connecting the electrical load device to the source of electrical power.
As described above, if all of the preselected criteria are satisfied by the access information 30, and if the electrical load device is disconnected from the source of electrical power, then the reader generates the connect signal, which is transmitted to the switch device, and the switch device connects the electrical load device to the source of electrical power. In one embodiment, if the electrical load device is connected to the source of electrical power and the reader determines that all the preselected criteria are satisfied by the access information, then no signal is transmitted by the reader to the switch device. In an alternative embodiment, if the electrical load device is connected to the source of electrical power and the reader determines that all of the preselected criteria are satisfied by the access information, the reader generates a “non-disconnect” signal, which is transmitted to the switch device, causing the switch device to keep the electrical load device connected to the source of electrical power.
For example, in one embodiment, the access information preferably includes time credit information. Upon the reader 134 determining that the time credit information satisfies one or more preselected criteria in respect thereof (and all preselected criteria are otherwise satisfied), and if the electrical load device 126 is disconnected from the source of electrical power 22, the reader 134 generates the connect signal, which is transmitted to the switch device 132 for connection of the electrical load device 126 to the source of electrical power 22. Upon the reader 134 determining that one or more of the preselected criteria (including those in respect of the time credit information) are unsatisfied while the electrical load device 126 is connected to the source of electrical power 22, the reader 134 generates the disconnect signal, which is transmitted to the switch device 132 for disconnection of the electrical load device 126 from the source of electrical power 22.
In another alternative embodiment, in the system 120, the access information preferably includes user identification information. Upon the reader 134 determining that the user identification information satisfies one or more preselected criteria in respect thereof (and all preselected criteria are otherwise satisfied), and if the electrical load device 126 is disconnected from the source of electrical power 22, the reader 134 generates the connect signal, which is transmitted to the switch device 132 for connection of the electrical load device 126 to the source of electrical power 22. Also, upon the reader 134 determining that one or more of the preselected criteria (including those in respect of the user identification information) is unsatisfied while the electrical load device 126 is connected to the source of electrical power 22, the reader 134 generates the disconnect signal, which is transmitted to the switch device 132 for disconnection of the electrical load device 126 from the source of electrical power 22.
In use, an embodiment of a method 250 of the invention preferably includes the steps of, first, providing the readable access information device 24 associated with electrical load device(s) 26 electrically connectable to the receptacle(s) 28, the readable access information device 24 including access information (step 252,
It will be appreciated by those skilled in the art that, although certain steps are shown in
As described above, the reader 34 preferably reads the access information 30 at predetermined time intervals. As can be seen in
As described above, in one embodiment, the access information 30 preferably includes time credit information. The method 450 of the invention, schematically illustrated in
It will be appreciated by those skilled in the art that, although certain steps are shown in
In one embodiment, the reader 34 preferably reads the access information 30 at decrement intervals. As illustrated in
It will be understood that, in practice, data related to other parameters in the access information (e.g., a group code), is also read, if present. For clarity of illustration, references to other parameters are omitted from
The decrement interval is the time period by which the preauthorized time period is decremented. The decrement interval preferably is any suitable time interval, selected based on the circumstances in which the time credits are to be utilized. For instance, where the readable access information device 24 is included in or mounted onto the plug 36, the decrement interval may be one minute. Preferably, the reader includes a timer that is set to equal the decrement interval. As can be seen in
As can be seen in
If the decrement interval is one minute, then, as described above, the result is that the timer “times out” once a minute, and the reader 34 checks (in steps 576, 578, 580) to determine whether the preselected criteria are satisfied. As noted above, this may be convenient where, e.g., the readable access information device 24 is mounted in or on the plug 36 of the electrical load device. In these circumstances, it is preferred that the decrement interval is relatively short because of the risk that an unauthorized user may attempt to connect via a receptacle which has been connected.
In another embodiment, the decrement interval may be set at a longer time period, e.g., 30 minutes. This relatively long decrement interval is preferred, for example, where the readable access information device 24 is included in the command card or key fob 38. For instance, the card 38 may be purchased for one-time use, and disposable. The longer decrement interval is preferred for the user's convenience, i.e., the user only needs to position the card near the receptacle once every 30 minutes, in order to re-connect to the source of electrical power.
In another embodiment of the method 650 of the invention, first, the readable access information device 124 associated with one or more electrical load devices 126 is provided, the readable access information device including access information (step 652,
It will be appreciated by those skilled in the art that, although certain steps are shown in
Another embodiment of the method 750 of the invention is schematically illustrated in
It will be appreciated by those skilled in the art that, although certain steps are shown in
As described above, in one embodiment, the method of the invention includes determining whether one or more preselected characteristics of the electrical power provided by the source of electrical power 22 is within certain parameters. For example, one such preselected characteristic is line voltage. In an embodiment of the method 850 of the invention schematically illustrated in
Next, the reader 34 determines whether the readable access information device 24 is present (step 876). If it is, then in the next step, the reader 34 reads the readable access information device 24 (step 878). Preferably, in this step, the reader determines the balance of the preauthorized time period remaining, as well as the applicable decrement time interval for the time credit information, in the access information.
As will be described, in this embodiment, the access information preferably also includes a preselected characteristic of the electrical power provided by the source of electrical power, i.e., line voltage. It will be understood that, in practice, data related to other parameters in the access information (e.g., a group code) is also read, if present. For clarity of illustration, references to other parameters are omitted from
As described above, the decrement interval is the time period by which the preauthorized time period is decremented, and the decrement interval preferably is any suitable time interval, selected based on the circumstances in which the time credits are to be utilized. For instance, where the readable access information device 24 is included in or mounted onto the plug 36, the decrement interval may be one minute. Preferably, the reader includes a timer that is set to equal the decrement interval. As can be seen in
As can be seen in
Once the receptacle is connected, the line voltage is measured, to determine whether it is above the minimum threshold voltage (step 896). As can be seen in
If, in step 898, the line voltage is determined to be below the minimum threshold voltage, then the receptacle remains disconnected from the source of electrical power. As indicated by the loop in
If the voltage is checked and found to be above the minimum threshold voltage, then the receptacle is connected (steps 896, 899). While the timer has not expired, the receptacle remains connected. When the timer expires (i.e., if the decrement interval expires) (step 892), then the reader checks to determine whether the access information is present and readable, and also whether the preselected criteria are still satisfied (steps 876, 878, 880). If so, and if the balance of the preauthorized time period remaining is greater than zero (step 886), then the reader proceeds with the next steps (888, 890, 882) to connect the receptacle. However, as can be seen from the foregoing, if the access information 30 fails to meet any of the preselected criteria (step 880), then the receptacle is disconnected. (As described above, connection and disconnection of the receptacle are effected by the switch device in response to signals. For the purposes of illustration, the details of connection and disconnection have been omitted from
It will be appreciated by those skilled in the art that the invention can take many forms, and that such forms are within the scope of the invention as described above. The foregoing descriptions are exemplary, and their scope should not be limited to the preferred versions provided therein.
This application claims the benefit of U.S. Provisional Patent Application No. 61/390,677, filed Oct. 7, 2010, and incorporates such provisional application in its entirety by reference.
Number | Date | Country | |
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61390677 | Oct 2010 | US |