FIELD OF INVENTION

[0001] The invention generally relates to electrical switches for controlling electrical appliances and more particularly to programmed switching devices for controlling electrical appliances.

BACKGROUND OF THE INVENTION

[0002] Electrical appliances used are generally controlled by two way switching circuits thereby enabling the user to operate the load (electrical appliance) from two different points. However  the two way switching circuits pose a restriction to the user by providing only two control points. Thus  such switching circuits do not facilitate multi point control for operating the electrical appliance thereby posing a limitation. Multi point control of the electrical appliance is desirable in situations where the utility/operation of the electrical appliance involves more than one party and yet the control of operation lies with a single party. In such situations  providing multi point control facilitates efficient use of resources.

[0003] Solutions provided in the prior art suggest using either multiple independent loads each with a two way switching circuit or a single load with multiple two way switching circuits. However  there is no solution suggested for providing multi point control of a single electrical appliance such as a water pump.

[0004] Another solution provided in the art describes a home automation system. One major limitation associated with such solutions is incompatibility of such devices with switches that are typically used in two-way switching circuits. Further  they are not economical and physical feel of the switch is missing

[0005] Hence there exists a need for providing a switching device that provides multi point control for operating an electrical appliance.

BRIEF DESCRIPTION OF THE INVENTION

[0006] The above-mentioned shortcomings  disadvantages and problems are addressed herein which will be understood by reading and understanding the following specification.

[0007] In one embodiment  a system for controlling operation of an electrical appliance is provided. The system comprises multiple switching units  each switching unit capable of independently controlling the operation of the electrical appliance  at least one switching means connected in series with the electrical appliance  the switching means capable of operating the electrical appliance and a control unit configured for monitoring state changes in a selected switching unit and further configured for operating the switching means based on the monitored state changes in the selected switching unit thereby controlling the operation of the electrical appliance. Further  at least one switching unit is coupled to the control unit. A method of controlling operation of an electrical appliance is also described

[0008] In another embodiment  a method of controlling operation of an electrical appliance is provided. The method comprises steps of monitoring state changes of a selected switching unit and controlling the operation of the electrical appliance based on the monitored state changes in the selected switching unit.

[0009] Systems and methods of varying scope are described herein. In addition to the aspects and advantages described in this summary  further aspects and advantages will become apparent by reference to the drawings and with reference to the detailed description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 shows a block diagram of a system for controlling operation of an electrical appliance as described one embodiment; and

[0011] FIG. 2 shows a flow chart depicting a method for controlling operation of an electrical appliance as described in one embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0012] In the following detailed description  reference is made to the accompanying drawings that form a part hereof  and in which is shown by way of illustration specific embodiments  which may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments  and it is to be understood that other embodiments may be utilized and that logical  mechanical  electrical and other changes may be made without departing from the scope of the embodiments. The following detailed description is  therefore  not to be taken in a limiting sense.

[0013] The system described in the invention overcomes the limitation in the prior art and provides simultaneous control of a load from multiple switches. This is achieved by using built in intelligence that monitors the intention of the user and controls the operation of the load accordingly.

[0014] To achieve the purpose of multi point control  the invention provides a system to integrate conventional switches with a control unit so as to eliminate the need for replacing the conventional switches. Each of the conventional switches is capable of overriding the appliance control as is done in a home automation system. Further  the control unit is configured with wired and wireless interfaces for receiving commands from any of the conventional switches and a remote control unit so as to provide the capability to the remote control unit to re-override the decision put forward by any of the switches. Therefore each of the switches and the remote control unit act as independent switches providing multi point control of a single load such that the load can be operated from the remote control unit as well as from the conventional switches. This eliminates the need for the user to replace existing switches and further allows the user to integrate the system with the conventional switches for their retrofit needs.

[0015] Accordingly  in one embodiment  as shown in FIG. 1  a system 100 for controlling operation of an electrical appliance 116 is provided. The system 100 is configured for mounting in a standard electrical wall switch box. The system 100 may either be connected between an outlet and an appliance to be controlled  or may replace a conventional switch. In one embodiment  the system 100 is designed to fit inside a standard electrical panel board co-habiting the electrical switch wall box with at least one conventional switching unit 102  104 and 106.

[0016] The system 100 comprises multiple switching units 102  104 and 106  each switching unit 102  104 and 106 capable of independently controlling the operation of the electrical appliance 116 and at least one switching means 114 connected in series with the electrical appliance 116  the switching means 114 capable of operating the electrical appliance 116. The switching means 114 comprises one of an electrical relays  TRIAC (Triode for Alternating Current) based switching system 100 and SCR (Silicon Controlled Rectifier) based switching system 100. Switching means 114 are well known in the art and hence will not be described in detail.

[0017] The switching means 114 can be operated based on transitions. Each of the switching unit 102  104 and 106 in the system 100 is capable of controlling the operation of the electrical appliance 116 irrespective of the state of the electrical appliance 116 and state of each of the other switching unit 102  104 and 106. Further  each of the multiple switching units 102  104 and 106 can be controlled by a user or an external device.

[0018] The system 100 comprises a control circuit for operating the electrical appliance 116 responsive to control commands received via the operation of the multiple switching units 102  104 and 106. Further the control unit 108 comprises a communication circuit for receiving control commands from a remote control unit 108. The remote control unit 108 can be a portable communication device such as a cordless device  a cellular phone  an internet enabled cellular phone  a personal digital assistant  a 4G portable device  a 3G portable device  a 2.5 G portable device  a laptop and the like.

[0019] The control unit 108 is coupled to each of the multiple switching units 102  104 and 106 via a wired interface including but not limited to RS232  RS422  RS485 and serial interface. Further  the control unit 108 is built in with wireless interfaces such as bluetooth  infrared  radiofrequency and ZigBee™ interfaces that enable the user to use wireless options to give instructions to switching means 114 to change the state of the load. Skilled artisans shall appreciate using other wireless communication means that can be employed to establish coupling between the remote control unit 108 and the control unit 108.

[0020] The control unit 108 comprises a conventional microcontroller/microprocessor and associated memory  the memory storing software to run the control unit 108. The memory unit 102  104 and 106 is further configured for storing event data depicting transitions of the electrical appliance 116. The control unit 108 is configured for monitoring state changes in a selected switching unit 102  104 and 106 and further configured for operating the switching means 114 based on the monitored state changes in the selected switching unit 102  104 and 106 thereby controlling the operation of the electrical appliance 116.

[0021] Accordingly  in another embodiment shown in FIG. 2  a method 200 of controlling operation of an electrical appliance 116 is provided. The method 200 comprises steps of monitoring state changes of a selected switching unit 102  104 and 106 at step 202 and controlling the operation of the electrical appliance 116 based on the monitored state changes in the selected switching unit 102  104 and 106 at step 204.

[0022] The control unit 108 is capable of monitoring state changes in the selected switching unit 102  104 and 106 operates the switching means 114 based upon the state changes of the switching unit 102  104 and 106.

[0023] In an exemplary embodiment  monitored state change of the selected switching unit 102  104 and 106 from a first position to a second position implies the intention of the user to switch ON the electrical appliance 116. In response to the monitored state change of the switching unit 102  104 and 106 the control unit 108 actuates ON transition of the electrical appliance 116.

[0024] On the other hand  when the state of the selected switching unit 102  104 and 106 is changed from the second position to the first position  the intention of the user is perceived to be to switch OFF the electrical appliance 116 and hence in response to the monitored state change of the selected switching unit 102  104 and 106  the control unit 108 actuates OFF transition of electrical appliance 116.

[0025] Accordingly  the control unit 108 is configured to actuate ON transition of the electrical appliance 116 upon monitoring change in the state of the selected switching unit 102  104 and 106 from a first position to a second position and is configured to actuate OFF transition of the electrical appliance 116 upon monitoring change in the state of the selected switching unit 102  104 and 106 from the second position to the first position.

[0026] The control unit 108 is configured to continuously monitor its ports for state changes and further to actuate the switching of switching means 114 accordingly. The logic is embedded into the micro operating system 100 framework that enables error checking and prevention of malfunction.

[0027] Each of the switching unit 102  104 and 106 is configured to communicate the state change via a wired serial interface. The control unit 108 in the control unit 108 is configured to continuously monitor the state changes in each of the switching unit 102  104 and 106 in order to accordingly control the operation of the electrical appliance 116. The system 100 is configured to receive state change inputs from any of the multiple switching units 102  104 and 106 and the remote control unit 108 and yet provide option to override the existing states.

[0028] In one exemplary embodiment  the state of the switching unit 102  104 and 106 may be toggled twice to obtain a desired state of the electrical appliance 116. For example  when a user wishing to switch ON the electrical appliance 116 may discover that the switching unit 102  104 and 106 is already in the second position  This does not confirm that the state of electrical appliance 116 is ON as the state of the electrical appliance 116 is not dependent on state of the individual switching unit 102  104 and 106. Hence  the state of the switching unit 102  104 and 106 needs to be toggled twice to confirm ON state of the electrical appliance 116.

[0029] In one embodiment  the control unit 108 is capable of comparing the state of the electrical appliance 116 and the state of the selected switching unit 102  104 and 106 prior to actuating a transition of the electrical appliance 116. Accordingly  actuating ON transition of the electrical appliance 116 may not result in operation of the switching means 114. The control unit 108 may compare the present state of the electrical appliance 116 with the monitored state change of the selected switching unit 102  104 and 106 and in a scenario where the two state match  the operation of the switching means 114 may not be commissioned.

[0030] In the event of the control unit 108 failure  the system 100 is configured such that the switching unit 102  104 and 106 physically coupled to the control unit 108 continues to operate like a typical switch.

[0031] It is to be noted that each block and combination of blocks can be implemented by special purpose hardware-based systems which perform the specified functions or steps  or combinations of special purpose hardware and computer instructions.

[0032] Skilled artisans shall appreciate that the system and method described herein for providing control are not restricted to the operation of an electrical appliance and can as well be used in operating any powered electrical  mechanical or electronic appliance.

[0033] This written description uses examples to describe the subject matter herein  including the best mode  and also to enable any person skilled in the art to make and use the subject matter. The patentable scope of the subject matter is defined by the claims  and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims  or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

CLAIMS
What is claimed is:

1. A system for controlling operation of an electrical appliance  the system comprising:
multiple switching units  each switching unit capable of independently controlling the operation of the electrical appliance;
at least one switching means connected in series with the electrical appliance  the switching means capable of operating the electrical appliance; and
a control unit configured for monitoring state changes in a selected switching unit and further configured for operating the switching means based on the monitored state changes in the selected switching unit thereby controlling the operation of the electrical appliance;
wherein at least one switching unit is coupled to the control unit.

2. The system of claim 1  wherein each of the switching unit is operated by one of a user and an external device.

3. The system of claim 1  wherein the control unit comprises wired and wireless interfaces for receiving commands for controlling the operation of the electrical appliance.

4. The system of claim 1  configured for mounting in a standard electrical wall switch box along with at least one of the multiple switching units.

5. The system of claim 1  wherein the control unit is configured to actuate ON transition of the electrical appliance upon monitoring change in the state of the selected switching unit from a first position to a second position.

6. The system of claim 1  wherein the control unit is configured to actuate OFF transition of the electrical appliance upon monitoring change in the state of the selected switching unit from a second position to a first position.

7. A method of controlling operation of an electrical appliance  the method comprising:
monitoring state changes of a selected switching unit; and
controlling the operation of the electrical appliance based on the monitored state changes in the selected switching unit.

8. The method of claim 7  wherein controlling the operation comprises actuating ON transition of the electrical appliance upon monitoring change in the state of the selected switching unit from a first position to a second position.

9. The method of claim 7  wherein controlling the operation comprises actuating OFF transition of the electrical appliance upon monitoring change in the state of the selected switching unit from a second position to a first position.

10. The method of claim 7  further comprising wirelessly controlling the operation of the electrical appliance using IEEE 802.11 standard of communication.