Home automation module having externally powered communications port

[0001] The present invention relates generally to home automation products. More specifically, the present invention relates to home automation modules that have an externally powered communications port.

[0002] As part of an effort to make home life more convenient, safe, and entertaining, home automation products have been developed. These products enable the home owner to perform and monitor various tasks in an automated or semi-automated fashion. A wide range of tasks are feasible involving assorted systems of the home including the lighting, climate control, security, maintenance, and entertainment systems, among others. Home automation also enables the integration of systems that may not have historically been integrated and the remote control of systems that may not have historically been remotely controlled. For example, with proper equipment and set up, it would be possible with one push of a button to close the drapes if it was too bright outside, dim the lights if it was too bright inside, turn on the television if it was not already on, turn on the surround sound tuner if it was not already on, turn on the DVD player if it was not already on, place the television in the proper video mode, place the tuner in the proper audio mode, and start a DVD playing. Both less complicated and even more complicated examples also exist using the same or different systems individually or in combination.

[0003] Generally, a home automation system includes a central processor, a plurality of controllers, and some means of communicating between and among the central processor and the controllers. The controllers may also perform some data collection and processing. In one such system, the communication is carried over the power lines of the dwelling. This allows the system to be retrofitted into an existing structure with less inconvenience and expense. The central processor and controllers each form modules that are coupled to the power lines through the power receptacles of the residence. The modules communicate with one another by way of signals placed on the power lines. A communications protocol exists whereby transmitters transmit messages and receivers receive messages. Each module may be a transmitter, a receiver, or both. Each module may have at least some user interface. The user interface may be as simple as a power receptacle or a switch. By necessity, the user interface for the central processor may be much more complicated. It is also possible for a module to be connected to an external user interface such as a personal computer and the like. The computer may also perform command and control functions. Connecting the home automation system to the computer takes advantage of an existing and familiar user interface and the processing and connectivity power of the computer. The module may only be temporarily connected to the external user interface. The connection period may also be more prolonged depending on the circumstances.

[0004] Among the more conventional means of connecting a module to an external user interface such as a computer is through an industry standard often referred to as RS232. The RS232 communications protocol is a well known serial data link between devices. Despite this fact, it is not always followed exactly as presented by the Electronic Industries Association. Over the over thirty years since this standard was developed, the EIA has published three modifications with the most recent being the EIA232E standard introduced in 1991. Besides changing the name from RS232 to EIA232, some signal lines were renamed and various new ones were defined, including a shield conductor. The point of connection at each device is referred to as a communications port. The protocol does not include provisions for one device to supply any significant amount of power over the link to other devices to which it is connected. Consequently, each device must include an internally powered communications port. Traditionally, this has not presented a major obstacle in the home automation environment as each module was already connected to the power lines of the home for communication with other modules in the system. It is important to note however that the module power supply must be an isolated one to prevent potential electrical problems with the connection between the module and the computer. Other non-powered communications protocols similar to that of RS232/EIA232 exist as well.

[0005] A home automation module having an externally powered communications port is disclosed. The module includes an automation microprocessor for controlling the module, a communications port for enabling the module to draw power in limited quantities from an external source, a receiver/transmitter section, a power line carrier (PLC) coupler for enabling the transfer of signals between the module and a main while electrically isolating the module from the main, a zero-crossing detector for monitoring the phase of the power on the main while maintaining substantial electrical isolation of the module from the main, and a boost regulator for enabling the module to derive sufficient power from the communications port to drive the PLC coupler during signal transmissions from the module to the main. The detector maintains substantial electrical isolation through an opto-isolator. The boost regulator stores up power over time so that sufficient power will be available when the demand is made.

[0011] Various exemplary embodiments of the present invention are described herein in the context of home automation modules that have an externally powered communications port. Those of ordinary skill in the art will realize that the following detailed description of the present invention is illustrative only and is not intended to be in any way limiting. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. Reference will now be made in detail to exemplary implementations of the present invention as illustrated in the accompanying drawings. The same reference indicators will be used throughout the drawings and the following detailed descriptions to refer to the same or like parts.

[0012] In the interest of clarity, not all of the routine features of the exemplary implementations described herein are shown and described. It will of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the specific goals of the developer, such as compliance with application- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure.

[0013] Turning first to FIG. 1, a block diagram according to the present invention of a home automation module 10 having an externally powered communications port is shown. In this instance, the externally powered communications port is a universal serial bus (USB) port 12. Other externally powered communications ports exist and can be treated similarly. The USB protocol is well known and includes provisions for one device to supply a defined amount of power over the link to other devices to which it is connected. The amount of power is limited however. In this instance, the module 10 is drawing power from the USB port 12. The module 10 is coupled twice to a main 14 having a hot and a neutral. The first coupling is through the power line carrier (PLC) coupler 16. The PLC coupler 16 enables the transfer of signals between the module 10 and the main 14. The PLC coupler 16 also electrically isolates the module 10 from the main 14. The second coupling is through the zero-crossing detector 18 which will be discussed in greater detail below. The detector 18 monitors the phase of the power on the main 14 while maintaining substantial electrical isolation of the module 10 from the main 14. Shown connected to the PLC coupler 16 is a receiver/transmitter (R/T) section 20. The R/T section 20 is a general depiction of what in practice may include a receiver, a transmitter, a combination receiver/transmitter, or both a receiver and a transmitter. It is also possible that the receiver and transmitter may be separate blocks rather than one as shown. The exact configuration of the R/T section 20 will depend on the circumstances. In any event, the R/T section 20 transfers signals between the module 10 and the main 14 through the PLC coupler 16. The USB port 12, the detector 18, and the R/T section 20 are in turn connected to an automation microprocessor 22. The microprocessor 22 receives various signals from and transmits various signals to the assorted components of the module 10. The microprocessor 22 is the primary command and control component of the module 10. In one embodiment, the microprocessor 22 is an eight bit micro-chip. As shown, the microprocessor 22 may require various external support components such as a clock crystal 24 and a power filter 26. The exact configuration and requirements of the microprocessor 22 will depend on the circumstances. Also connected to the microprocessor 22 is a boost regulator 28 which will be discussed in greater detail below. The boost regulator 28 enables the module 10 to derive enough power from the USB port 12 to drive the PLC coupler 16 during signal transmissions from the module 10 to the main 14. The module 10 may also include other components that are not shown.

[0014] Turning now to FIG. 2, a schematic diagram of an embodiment according to the present invention of the zero-crossing detector 18 of FIG. 1 is shown. The various electrical components are connected as illustrated. As noted above, the detector 18 monitors the phase of the power on the main 14 of FIG. 1 while maintaining substantial electrical isolation of the module 10 of FIG. 1 from the main 14. As is known by one of ordinary skill in the art, the power phase is used by the module 10 to determine when to transfer signals between itself and the main 14. The detector 18 maintains substantial electrical isolation of the module 10 through an opto-isolator U1. Electrical components depicted to the left of the opto-isolator U1 are powered by the main 14 and electrical components depicted to the right of opto-isolator U1 are powered by the module 10. Based on the circuit represented, the amount of power drawn from the main 14 is relatively insignificant. This is especially so by comparison to a conventional module that has an internally powered communications port.

[0015] Turning now to FIG. 3, a schematic diagram of an embodiment according to the present invention of the boost regulator 28 of FIG. 1 is shown. The various electrical components are connected as illustrated. As noted above, the boost regulator 28 enables the module 10 of FIG. 1 to derive enough power from the USB port 12 of FIG. 1 to drive the PLC coupler 16 of FIG. 1 during signal transmissions from the module 10 to the main 14 of FIG. 1. As further noted above, the USB port 12 is capable of supplying a defined amount of power but the amount of power is limited. Under certain circumstances the amount of power available is not sufficient to directly drive the PLC coupler 16 and simultaneously power the other various components of the module 10. To offset this, the boost regulator 28 stores up power over time so that sufficient power will be available when the demand is made by the module 10. In the embodiment illustrated, the boost regulator 28 charges capacitor C6 upon initial start up and then recharges it from then on to compensate for discharging that occurs. The recharging may be constant, random, periodic, on demand, partial, complete, or some combination of these, among others. The boost regulator 28 is controlled at least in part, if hot in substantial part, by the microprocessor 22 of FIG. 1.

[0016] While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art having the benefit of this disclosure that many more modifications than mentioned above are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims.