Description:FIELD OF THE INVENTION2

The present disclosure relates to electrical appliances and more particularly, relates to a system for determining earth condition in the electrical appliances.

BACKGROUND

Electrical equipment and appliances are devices that draw electricity power from a power supply. The electrical equipment can be of small size, such as a refrigerator, a microwave oven, or a washing machine, or big size, such as electric vehicle (EV) charging station. Such electrical equipment has three terminals that are connected to a live wire connection, a neutral wire connection, and an earth wire connection of the power supply, in which the live wire connection provides an electrical current, the neutral wire connection carries the return current to the power supply to complete electrical circuit(s) in the electrical equipment, and the earth wire connection creates a low-impedance path to Earth in case of insulation break of the electrical equipment. When the electrical equipment is coupled to the power supply by an operator, the terminals may be either be in normal configuration in which a live terminal is connected to the live wire connection or in a reverse configuration in which the live terminal is connected to the neutral wire connection. In either case, an earth terminal is connected to the earth wire connection. In general, such a configuration does not affect the working of the electrical equipment. However, the detection of the reverse configuration is important because the reverse configuration allows continuous electricity to flow in the electrical equipment even when a switch is OFF. Therefore, in case of isolation breakage, the electrical equipment accumulates current. Therefore, the user may experience shock that, in worst case, electrocute the person.

Further, in case where the earth terminal is not properly connected to the earth wire connection, such as when an earth wire is not connected to a nearby earth pit, the leakage current gets accumulated on the electrical equipment which poses a hazard to people who comes in contact with the electrical equipment. For instance, the person who accidentally touches the electrical equipment allows the leakage current to flow therethrough thereby resulting in an electrical shock, which some scenario, may electrocute the person.

Apart from the hazard risk, the accumulation of leakage current may affect the working of the electrical equipment. Various devices, such as a Residual Current Circuit Breaker (RCCB) have been developed to detect leakage current and cut off the power supply to reduce the leakage current. However, the RCCB is effective in both Normal and reverse configuration. The RCCB sense the current difference between live wire connection and the neutral wire connection. The RCCB is ineffective when there is rise in a voltage on the earth wire connection w.r.t. the neutral wire connection and a person who is standing on the earth which is at Zero potential. In this case, if the person touches the electrical equipment/appliance, the current will flow from the appliance to the Earth through the person and RCCB cannot detect it.

Hence, there is an immense need to provide a system to detect the reverse configuration and the bad earth connection and accordingly, warn the user about the hazard so that safety precautions may be taken to protect the user during the reverse configuration and the bad earth connection.
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SUMMARY

This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the invention. This summary is neither intended to identify key or essential inventive concepts of the invention and nor is it intended for determining the scope of the invention.

The present disclosure aims to provide a system to detect a reverse configuration and an earth condition to safeguard user from electrical shocks as generated in each of a normal configuration and the reverse configuration.

In an embodiment of the present disclosure, a system for determining an earth condition, that has, a receiving unit, a processing unit, at least one signal generating unit, and at least one hysteresis comparator unit, is disclosed. The receiving unit have a live wire connection, a neutral wire connection, and an earth wire connection. The live wire connection, the neutral wire connection, and the earth wire connection are connected to a power supply in one of a normal configuration and a reverse configuration. The processing unit is connected to the receiving unit. The processing unit is configured to generate an input reference voltage corresponding to a voltage across the live wire connection and the neutral wire connection. The processing unit is configured to generate an input sense voltage corresponding to a voltage across the earth wire connection and neutral wire connection. The at least one signal generating unit is configured to receive the input reference voltage and modify the received input reference voltage with a threshold voltage to generate a modified reference voltage. The at least one hysteresis comparator unit adapted to receive and compare the modified reference voltage and the input sense voltage. The at least one hysteresis comparator unit generates at least one output signal indicating one of a good earth condition and a bad earth condition based on the comparison.

The present disclosure ensures a configuration of the system for determining the earth condition along with input polarity, that is, the reverse configuration. Particularly, the at least one hysteresis comparator unit is adapted to generate the at least one output signal indicating the good earth condition and the bad earth condition. This configuration helps the user to operate an electrical appliance accordingly to avoid any electrical shock as generated by the bad earth condition in each of the normal configuration and the reverse configuration.

To further clarify the advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

Figure 1 illustrates a block diagram of a power supply along with an electrical appliance having a system, according to an embodiment of the present disclosure;
Figure 2 illustrates a block diagram of the system, according to an embodiment of the present disclosure;
Figure 3A and 3B illustrates a schematic view of the system, according to an embodiment of the present disclosure;
Figure 3C illustrates a truth table of the system, according to an embodiment of the present disclosure; and
Figure 4 illustrates a method performed by the system, according to an embodiment of the present disclosure.

Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, a plurality of components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

DETAILED DESCRIPTION OF FIGURES

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled in the art to which invention belongs. The system and examples provided herein are illustrative only and not intended to be limiting.

For example, the term “some” as used herein may be understood as “none” or “one” or “more than one” or “all.” Therefore, the terms “none,” “one,” “more than one,” “more than one, but not all” or “all” would fall under the definition of “some.” It should be appreciated by a person skilled in the art that the terminology and structure employed herein is for describing, teaching, and illuminating some embodiments and their specific features and elements and therefore, should not be construed to limit, restrict or reduce the spirit and scope of the present disclosure in any way.

For example, any terms used herein such as, “includes,” “comprises,” “has,” “consists,” and similar grammatical variants do not specify an exact limitation or restriction, and certainly do not exclude the possible addition of a plurality of features or elements, unless otherwise stated. Further, such terms must not be taken to exclude the possible removal of the plurality of the listed features and elements, unless otherwise stated, for example, by using the limiting language including, but not limited to, “must comprise” or “needs to include.”

Whether or not a certain feature or element was limited to being used only once, it may still be referred to as “plurality of features” or “plurality of elements” or “at least one feature” or “at least one element.” Furthermore, the use of the terms “plurality of” or “at least one” feature or element do not preclude there being none of that feature or element, unless otherwise specified by limiting language including, but not limited to, “there needs to be plurality of…” or “plurality of elements is required.”

Unless otherwise defined, all terms and especially any technical and/or scientific terms, used herein may be taken to have the same meaning as commonly understood by a person ordinarily skilled in the art.

Reference is made herein to some “embodiments.” It should be understood that an embodiment is an example of a possible implementation of any features and/or elements of the present disclosure. Some embodiments have been described for the purpose of explaining plurality of the potential ways in which the specific features and/or elements of the proposed disclosure fulfil the requirements of uniqueness, utility, and non-obviousness.

Use of the phrases and/or terms including, but not limited to, “a first embodiment,” “a further embodiment,” “an alternate embodiment,” “one embodiment,” “an embodiment,” “multiple embodiments,” “some embodiments,” “other embodiments,” “further embodiment”, “furthermore embodiment”, “additional embodiment” or other variants thereof do not necessarily refer to the same embodiments. Unless otherwise specified, plurality of particular features and/or elements described in connection with plurality of embodiments may be found in one embodiment, or may be found in more than one embodiment, or may be found in all embodiments, or may be found in no embodiments. Although plurality of features and/or elements may be described herein in the context of only a single embodiment, or in the context of more than one embodiment, or in the context of all embodiments, the features and/or elements may instead be provided separately or in any appropriate combination or not at all. Conversely, any features and/or elements described in the context of separate embodiments may alternatively be realized as existing together in the context of a single embodiment.

Any particular and all details set forth herein are used in the context of some embodiments and therefore should not necessarily be taken as limiting factors to the proposed disclosure.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

Figure 1 illustrates a block diagram of a power supply 100 along with an electrical appliance 102 having a system 200, according to an embodiment of the present disclosure. In an embodiment, the power supply 100 may include a live terminal, a neutral terminal, and an earth terminal. The power supply 100 may be electrically connected with the electrical appliance 102 to supply electricity to the electrical appliance 102. For instance, a live wire connection 302 of the electrical appliance 102 may be electrically connected to the live terminal of the power supply 100 and a neutral wire connection 304 of the electrical appliance 102 may be connected with a neutral terminal of the power supply 100. This results in normal configuration of the electrical appliance 102 and the electrical appliance 102 receives optimum flow of voltage from the power supply 100.

In an embodiment, the power supply 100 for the electrical appliance 102 may be a socket, an electrical board, a charging panel, etc., without departing from the scope of the present disclosure. In an embodiment, the power supply 100 may be connected to AC mains supply. However, in some cases, the live wire connection 302 of the electrical appliance 102 may be connected with the neutral terminal of the power supply 100 and similarly, the neutral wire connection 304 of the electrical appliance 102 may be connected to the live terminal of the power supply 100. This results in a reverse configuration. Further, the electrical appliance 102, after receiving the voltage from the power supply 100 in both the configurations, operates different electrical appliances, for example, a fridge, an electric vehicle, and other electrical appliances.

However, a user is prone to get electrocuted in both the conditions, if an earth condition in the electrical appliance 102 is not proper because of loosening of the earth wire connection 306, etc. Particularly, the operation of the electrical appliance 102 may be impacted by the earth condition of the electrical appliance 102. The earth condition indicates a bad earth condition and a good earth condition. The good earth condition indicates that the electrical appliances are safely operating. However, the bad earth condition indicates that an earth wire connection 306 of the electrical appliances in each of the normal configuration and the reverse configuration is poor or lost entirely. In this case, a voltage difference between the earth wire and the neutral wire increases, may result in generation of electrical shocks, etc. The electrical shocks as generated may be lethal to the users using the electrical appliance 102 for operating the components. Further, the operation of the electrical appliance 102 by the user may be also impacted by the reverse configuration because the user may be prone to get electrocuted, when the reverse configuration is detected. The reverse configuration allows continuous electricity to flow in the electrical appliance 102 even when a switch is OFF. Therefore, in case of isolation breakage, the electrical appliance 102 accumulates current. Therefore, the user may experience shock that, in worst case, electrocute the person. Hence, to determine the earth condition in both the configurations, and to detect the reverse configuration the electrical appliance 102 has the system 200. The system 200 may be employed to determine the earth condition in the electrical appliance 102 during the normal configuration and the reverse configuration of the electrical appliance 102. Further, the system 200 may be able to detect the reverse configuration. Details of the system 200 will be provided with respect to the Figures 2, 3A, and 3B.

Figure 2 illustrates a block diagram of the system 200, according to an embodiment of the present disclosure. Figure 3A and 3B illustrates a schematic view of the system 200, according to an embodiment of the present disclosure. Figure 3C illustrates a truth table of the system 200, according to an embodiment of the present disclosure.

The system 200 may include different components that operate synergistically to detect bad earth connection. For instance, the system 200 may include a processor/controller 202, a memory 204, unit(s) 206, and data 208. The memory 204, in one example, may store the instructions to carry out the operations of the units 206. The units 206 and the memory 204 may be coupled to the processor 202.

The processor 202 can be a single processing unit or several units, all of which could include multiple computing units. The processor 202 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processor, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. Among other capabilities, the processor 202 is configured to fetch and execute computer-readable instructions and data stored in the memory 204. The processor 202 may include one or a plurality of processors. At this time, one or a plurality of processors may be a general-purpose processor 202, such as a central processing unit (CPU), an application processor 202 (AP), or the like, a graphics-only processing unit such as a graphics processing unit (GPU), a visual processing unit (VPU), and/or an AI-dedicated processor 202 such as a neural processing unit (NPU). The one or a plurality of processors control the processing of the input data in accordance with a predefined operating rule or artificial intelligence (AI) model stored in the non-volatile memory and the volatile memory. The predefined operating rule or machine learning model is provided through training or learning.

The memory 204 may include any non-transitory computer-readable medium known in the art including, for example, volatile memory 204, such as static random-access memory (SRAM) and dynamic random-access memory (DRAM), and/or non-volatile memory, such as read-only memory (ROM), erasable programmable ROM, flash memories, hard disks, optical disks, and magnetic tapes.

The units 206, amongst other things, include routines, programs, objects, components, data structures, etc., which perform particular tasks or implement data types. The units 206 may also be implemented as, signal processor 202(s), state machine(s), logic circuitries, and/or any other device or component that manipulates signals based on operational instructions.

Further, the units 206 can be implemented in hardware, instructions executed by a processing unit, or by a combination thereof. The processing unit can comprise a computer, a processor, such as the processor 202, a state machine, a logic array, or any other suitable devices capable of processing instructions. The processing unit can be a general-purpose processor 202 which executes instructions to cause the general-purpose processor 202 to perform the required tasks or, the processing unit can be dedicated to performing the required functions. In another embodiment of the present disclosure, the units 206 may be machine-readable instructions (software) which, when executed by a processor 202/processing unit, perform any of the described functionalities. Further, the data serves, amongst other things, as a repository for storing data processed, received, and generated by one or more of the units 206. The data 208 may include information and/or instruction to perform activities by the processor 202.

The unit(s) 206 may perform different functionalities which may include, but may not be limited to, receiving information to determine the earth condition. Accordingly, the unit(s) 206 may include a receiving unit 210, a processing unit 212, at least one signal generating unit 214, and at least one hysteresis comparator unit 216. In an embodiment, the at least one signal generating unit 214 may be interchangeably referred to as a signal generating unit 214 without departing from the scope of the present disclosure. In an embodiment, the at least one hysteresis comparator unit 216 may be interchangeably referred to as a hysteresis comparator unit 216 without departing from the scope of the present disclosure.

In an embodiment, the receiving unit 210 may include the live wire connection 302, the neutral wire connection 304, and the earth wire connection 306 connected to the power supply 100 (as shown in Figure 1) in one of the normal configuration and the reverse configuration. For instance, in the normal configuration, the live wire connection 302 may be connected to the live terminal of the power supply 100 and the neutral wire connection 304 may be connected to the neutral terminal of the power supply 100, respectively. Similarly, in the reverse configuration, the live wire connection 302 may be connected to the neutral terminal of the power supply 100 and the neutral wire connection 304 may be connected to the live terminal of the power supply 100. Further, the live wire connection 302 and the earth wire connection 306 along with the neutral wire connection 304 receive the voltage from the power supply 100. In an embodiment, the voltage of the earth wire connection 306 and the neutral wire connection 304 may be equal ideally, without departing from the scope of the present disclosure.

The voltage received from the power supply 100 may be transferred to the processing unit 212 through a protection unit 308. The protection unit 308 may be adapted to protect the processing unit 212 from one of an electrical surge and other abnormalities in one of the live wire connection 302, the neutral wire connection 304 and the earth wire connection 306. Particularly, the protection unit 308 may be adapted to protect the processing unit 212 from the electrical surge transients and all other abnormal conditions from the power supply in one of the live wire connection 302, the neutral wire connection 304, and the earth wire connection 306.

In an embodiment, an earth disconnection sense unit 318 may be adapted to determine one of a condition that the earth wire connection 306 may be connected to the earth terminal of the power supply 100, discontinuity of the earth wire connection 306 from the power supply 100, and discontinuity between the earth terminal of the power supply 100 and an earth pit. Particularly, the earth disconnection sense unit 318 may determine status of the earth connection wire 306 in case, where the earth connection wire 306 may be not connected or any discontinuity of the earth terminal (earth connection) from the power supply to the earth pit . Further, the receiving unit 210 may be connected with the processing unit 212 and transfer voltage received from the power supply 100 to the processing unit 212.

In an embodiment, the processing unit 212 may include a first rectifier with a step-down circuit 310, a first delay circuit 312, a first filter 314, a first buffer circuit 316, a second rectifier with a step-down circuit 320, a second delay circuit 322, a second filter 324 and a second buffer circuit 326. In another embodiment, the processing unit 212 may be an integrated circuit without departing from the scope of the present disclosure. The processing unit 212 may be configured to generate an input reference voltage 328 corresponding to the voltage across the live wire connection 302 and the neutral wire connection 304. Further, the processing unit 212 may be configured to generate an input sense voltage 330 corresponding to the voltage across the earth wire connection 306 and the neutral wire connection 304. Particularly, the voltage from the live wire connection 302 and the neutral wire connection 304 may be received by the first rectifier with the step-down circuit 310. The first rectifier with the step-down circuit 310 may be adapted to convert the voltage across the live wire connection 302 and the neutral wire connection 304 to a direct current (DC) reference voltage. Further, the first delay circuit 312 may be adapted to receive the DC reference voltage to generate a stable reference voltage. Further, the first filter 314 may be adapted to receive the stable reference voltage from the first delay circuit 312 and remove variation in voltage known as ‘noise’ from the stable reference voltage. Further, the first buffer circuit 316 may be adapted to receive the stable reference voltage, without the noise, and adapted to generate the input reference voltage 328.

Similarly, in an embodiment, the voltage from the earth wire connection 306 and the neutral wire connection 304 may be transferred to the second rectifier having the step-down circuit 320. The second rectifier with the step-down circuit 320 may be adapted to convert the voltage across the earth wire connection 306 and the neutral wire connection 304 to a direct current (DC) sense voltage. Further, the second delay circuit 322 may be adapted to receive the DC sense voltage to generate a stable sense voltage. Furthermore, the second filter 324 may be adapted to receive the stable sense voltage from the second delay circuit 322 and removes noise from the stable sense voltage. The second buffer circuit 326, connected to the second filter 324, may be adapted to receive the stable sense voltage, without the noise, and generate the input sense voltage 330.

In an embodiment, the signal generating unit 214 may be adapted to receive the input reference voltage 328. Further, the signal generating unit 214 may be adapted to modify the received input reference voltage 328 with a variable threshold voltage to generate a modified reference voltage. Further, in the normal configuration, the at least one signal generating unit 214 may be a normal signal generating unit 336 and the variable threshold voltage may be a normal variable threshold voltage received from a control unit 360 of the system 200. The normal variable threshold voltage may be generated by the control unit 360 depending on the input reference voltage 328 sensed by an input AC voltage sense circuit 332. Particularly, the control unit 360 may generate the normal variable threshold voltage in the normal configuration corresponding to a fluctuation in the voltage across the live wire connection 302 and the neutral wire connection 304.

In one example, the normal variable threshold voltage may be added or subtracted from the input reference voltage 328, as per requirement, to generate the modified reference voltage. For example, in a scenario, if the user has installed the electrical appliance 102 in an area where the user is aware that the earth condition may be poor and the voltage of the earth wire connection 306 may be higher than a predetermined value with respect to the neutral wire connection 304, and where the predetermined value may be approximately 25V. In that case, the input reference voltage 328 may be modified by the normal signal generating unit 336. The modified reference voltage may be transferred to the hysteresis comparator unit 216. This configuration ensures a flexibility to incorporate the system 200 for different voltage range received by the electrical appliance 102.

Similarly, in the reverse configuration, the at least one signal generating unit 214 may be a reverse signal generating unit 338 and the variable threshold voltage may be a reverse variable threshold voltage received from the control unit 360. The reverse variable threshold voltage may be generated by the control unit 360 depending on the input reference voltage 328 sensed by the input AC voltage sense circuit 332. Particularly, the control unit 360 may generate the reverse variable threshold voltage in the reverse configuration corresponding to a fluctuation in the voltage across the live wire connection 302 and the neutral wire connection 304. Further, in an embodiment, the reverse variable threshold voltage may be added or subtracted from the input reference voltage 328, as per the requirement, to generate the modified reference voltage. Further, in a scenario of the reverse configuration, the voltage of the live wire connection 302 and the neutral connection 304 may also get reversed. For example, the neutral wire connection 304 may have 230V and the live wire connection 302 may have 0V. Further, the predetermined value of the voltage of the earth wire connection 306 may be 25V with respect to the neutral wire connection 304. In that case, the modified voltage of the earth wire connection 306 may be 205V. Further, the modified reference voltage may be transferred to the hysteresis comparator unit 216. This configuration ensures a flexibility to incorporate the system 200 for different voltage ranges received by the electrical appliance 102.

In an embodiment, the hysteresis comparator 216 receives the modified reference voltage and the input sense voltage 330 from the signal generating unit 214 and the processing unit 212, respectively. In another embodiment, the signal generating unit 214, and the hysteresis comparator unit 216 may be a main control unit with an analog-to-digital converter unit having an analog isolator circuit. This configuration ensures a reduced number of components to facilitate efficient operation of the system 200. Further, the hysteresis comparator 216 may be adapted to compare the modified reference voltage and the input sense voltage 330. Particularly, the hysteresis comparator unit 216 may be adapted to determine a difference value between the modified reference voltage and the input sense voltage 330. Further, the difference value, as determined, may be compared against a hysteresis range.

Based on the comparison, the hysteresis comparator unit 216 may generate at least one output signal 356 indicating one of a good earth condition and a bad earth condition. Further, the at least one output signal 356 may be generated when the difference value may be outside the hysteresis range. Particularly, in the normal configuration, the at least one hysteresis comparator unit 216 may be a normal hysteresis comparator unit 340. The normal hysteresis comparator unit 340 may be adapted to generate the at least one output signal 356 as a first digital signal 352.

In an embodiment, the normal hysteresis comparator unit 340 may be adapted to receive the modified reference voltage from the normal signal generating unit 336 and the input sense voltage 330 from the processing unit 212, respectively. The normal hysteresis comparator unit 340 determines the difference value between the modified reference voltage and the input sense voltage 330. Further, the normal hysteresis comparator unit 340 compares the difference value with the hysteresis range. The normal hysteresis comparator unit 340 provides the hysteresis range of approximately 3V from a predetermined value of a threshold voltage stored in the normal hysteresis comparator unit 340. The normal hysteresis comparator unit 340 generates the first digital signal 352, when the difference value may be outside the hysteresis range. For example, the normal hysteresis comparator unit 340 compares the difference value with the hysteresis range.

If the difference value exceeds the hysteresis range, then the normal hysteresis comparator generates the first digital signal 352. The normal hysteresis comparator unit 340 sends the first digital signal 352 to the control unit 360 through an isolator circuit 348 and an independent circuit 344. The control unit 360 receives the first digital signal 352 as an input in a Binary format that is 1.

When the difference value may be smaller than the hysteresis range, then the normal hysteresis comparator 340 generates the first digital signal 352. The normal hysteresis comparator unit 340 sends the first digital signal 352 to the control unit 360 through the isolator circuit 348 and the independent circuit 344. The control unit 360 receives the first digital signal 352 as an input in Binary format that is 0. Further, in an embodiment, the normal hysteresis comparator 340 may be adapted to hold the first digital signal 352 till the voltage of the earth wire connection 306 exceeds the hysteresis range of the normal hysteresis comparator 340.

Further, in the reverse configuration, the at least one hysteresis comparator unit 216 may be a reverse hysteresis comparator unit 342. The reverse hysteresis comparator unit 342 may be adapted to generate the at least one output signal 356 as a second digital signal 354.

In an embodiment, the reverse hysteresis comparator unit 342 may be adapted to receive the modified reference voltage from the reverse signal generating unit 338 and the input sense voltage 330 from the processing unit 212, respectively. The reverse hysteresis comparator unit 342 determines the difference value between the modified reference voltage and the input sense voltage 330. Further, the reverse hysteresis comparator unit 342 compares the difference value with the hysteresis range. The reverse hysteresis comparator unit 342 provides the hysteresis range of approximately 3V from a predetermined value of a threshold voltage stored in the reverse hysteresis comparator unit 342. The reverse hysteresis comparator unit 342 generates the second digital signal 354, when the difference value may be outside the hysteresis range. For example, the reverse hysteresis comparator unit 342 compares the difference value with the hysteresis range.

If the difference value exceeds the hysteresis range, then the reverse hysteresis comparator unit 342 generates the second digital signal 354. The reverse hysteresis comparator unit 342 sends the second digital signal 354 to the control unit 360 through an isolator circuit 350 and an independent circuit 346. The control unit 360 receives the second digital signal 354 as an input in a Binary format that is 1. Further, when the difference value may be smaller than the hysteresis range, then the reverse hysteresis comparator unit 342 generates the second digital signal 354.

The reverse hysteresis comparator unit 342 sends the second digital signal 354 to the control unit 360 through the isolator circuit 350 and the independent circuit 346. The control unit 360 receives the second digital signal 354 as an input in a Binary format that is 0. Further, in an embodiment, the reverse hysteresis comparator unit 342 may be adapted to hold the second digital signal 354 till the voltage of the earth wire connection 306 exceeds the hysteresis range of the reverse hysteresis comparator unit 342.

In an embodiment, the isolator circuit 348, 350 may be adapted to receive the at least one output signal 356 and separate an AC voltage from the at least one output signal 356 before relaying the at least one output signal 356 to the control unit 360. Particularly, the isolator circuit 348 may be adapted to receive the first digital signal 352 and separate an AC voltage from the first digital signal 352 before relaying the first digital signal 352 to the control unit 360. Similarly, the isolator circuit 350 may be adapted to receive the second digital signal 354 and separate an AC voltage from the second digital signal 354 before relaying the second digital signal 354 to the control unit 360.

In an embodiment, the control unit 360 may be adapted to receive the at least one output signal 356 from the at least one hysteresis comparator unit 216. Further, the control unit 360 may be responsible to operate the system 200 to determine the earth condition based on the inputs provided by the at least one hysteresis comparator 216. In another embodiment, the at least one signal generating unit 214, the at least one hysteresis comparator unit 216, and the control unit 360 form a main control unit without departing from the scope of the present disclosure. This configuration ensures a reduced number of components required to maintain operation of the system 200.

Particularly, in an embodiment, the control unit 360 may be adapted to receive the first digital signal 352 and the second digital signal 354. The control unit 360 compares the first digital signal 352 and the second digital signal 354 with each other. When the control unit 360 determines that the first digital signal 352 and the second digital signal 354 may be equal, then the control unit 360 generates one of an aural alert and a visual alert indicating the bad earth condition. Further, when the control unit 360 determines that the first digital signal 352 and the second digital signal 354 may be unequal, then the control unit 360 generates one of an aural alert and a visual alert indicating the good earth condition. Particularly, referring to Figure 3C, when the first digital signal 352 may be greater than the second digital signal 354, then the control unit 360 may indicate the good earth condition. Similarly, when the first digital signal 352 may be smaller than the second digital signal 354, then the control unit 360 may again indicate the good earth condition.

Further, when the first digital signal 352 may be equal to the second digital signal 354, then the control unit 360 may indicate the bad earth condition. In another embodiment, logic of the first digital signal 352 and the second digital signal 354 may vary with reference to an implementation of the system 200 without departing from the scope of the present disclosure. This configuration ensures the determination of the earth condition in both the configurations. Further, the present system 200 as disclosed may be also compatible with various input voltage range, thus providing flexibility to use the system 200.

The present disclosure also relates to a method 400 for determining the earth condition by the system 200. The order in which the method steps are described below is not intended to be construed as a limitation, and any number of the described method steps can be combined in any appropriate order to execute the method or an alternative method. Additionally, individual steps may be deleted from the method without departing from the spirit and scope of the subject matter described herein.

The method 400 can be performed by programmed computing devices, for example, based on instructions retrieved from non-transitory computer readable media. The computer readable media can include machine-executable or computer-executable instructions to perform all or portions of the described method. The computer readable media may be, for example, digital memories, magnetic storage media, such as a magnetic disks and magnetic tapes, hard drives, or optically readable data storage media.

The method 400 is explained in conjunction with Figure 4. The method 400 begins at block 402, including connecting the live wire connection 302, the neutral wire connection 304, and the earth wire connection 306 of the receiving unit 210 to the power supply 100 in one of the normal configuration and the reverse configuration.

At block 404, the method includes determination by the earth disconnection sense unit 318, one of a condition that the earth wire connection 306 may be connected to the earth terminal of the power supply 100, discontinuity of the earth wire connection 306 from the power supply 100, and discontinuity between the earth terminal of the power supply 100 and an earth pit. Particularly, the earth disconnection sense unit 318 may determine status of the earth connection wire 306 in case, where the earth connection wire 306 may be not connected or any discontinuity of the earth terminal (earth connection) from the power supply 100 to the earth pit.

At block 406, the method includes connecting the processing unit 212 to the receiving unit 210. The processing unit 212 may be configured to generate the input reference voltage 328 corresponding to the voltage across the live wire connection 302 and the neutral wire connection 304 and generate the input sense voltage 330 corresponding to the voltage across the earth wire connection 306 and the neutral wire connection 304.

At block 408, the method includes configuring the at least one signal generating unit 214 to receive the input reference voltage 328 and modify the received input reference voltage 328 with the variable threshold voltage to generate the modified reference voltage.

At block 410, the method includes receiving and comparing the modified reference voltage and the input sense voltage by the at least one hysteresis comparator unit 216, where the at least one hysteresis comparator unit 216 generates the at least one output signal 356 indicating one of the good earth condition and the bad earth condition based on the comparison.

As would be gathered, the present disclosure ensures a configuration of the system 200 to determine the earth condition in each of the normal configuration and the reverse configuration. This configuration ensures safety of the user while using the electrical appliance 102 as the control unit 360 detects the earth condition, that is, the good earth condition and the bad earth condition beforehand. Further, the system 200 as disclosed may be compatible with the electrical appliance 102 having various input reference voltages, thus ensuring flexibility of use of the system 200. Further, the earth disconnection sense unit 318 as disclosed in the present disclosure detects connection or any discontinuity of the earth wire connection 306 with the earth terminal of the power supply 100 and also detects any discontinuity of the earth terminal of the power supply 100 to the earth pit. Thus, this configuration ensures smooth operation of the system 200. Further, the system 200 as disclosed also detects the reverse configuration, ensuring safety of the user while using the electrical appliance 102, even in the reverse configuration.

While specific language has been used to describe the present subject matter, any limitations arising on account thereto, are not intended. As would be apparent to a person in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein. The drawings and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. , Claims:1. A system (200) for determining an earth condition, comprising:
a receiving unit (210) having a live wire connection (302), a neutral wire connection (304), and an earth wire connection (306) connected to a power supply (100) in one of a normal configuration and a reverse configuration;
a processing unit (212) connected to the receiving unit (210) and configured to:
generate an input reference voltage (328) corresponding to a voltage across the live wire connection (302) and the neutral wire connection (304);
generate an input sense voltage (330) corresponding to a voltage across the earth wire connection (306) and the neutral wire connection (304);
at least one signal generating unit (214) configured to:
receive the input reference voltage (328);
modify the received input reference voltage (328) with a variable threshold voltage to generate a modified reference voltage; and
at least one hysteresis comparator unit (216) adapted to receive and compare the modified reference voltage and the input sense voltage (330), wherein the at least one hysteresis comparator unit (216) generates at least one output signal (356) indicating one of a good earth condition and a bad earth condition based on the comparison.

2. The system (200) as claimed in claim 1, wherein the normal configuration is a configuration in which the live wire connection (302) is connected to a live terminal of the power supply (100) and the neutral wire connection (304) is connected to a neutral terminal of the power supply (100), and wherein:
the at least one signal generating unit (214) is a normal signal generating unit (336) and the variable threshold voltage is a normal variable threshold voltage; and
the least one hysteresis comparator unit (216) is a normal hysteresis comparator unit (340) adapted to generate the at least one output signal (356) as a first digital signal (352).

3. The system (200) as claimed in claim 1, wherein the reverse configuration is a configuration in which the live wire connection (302) is connected to a neutral terminal of the power supply (100) and the neutral wire connection (304) is connected to a live terminal of the power supply (100), and wherein:
the at least one signal generating unit (214) is a reverse signal generating unit (338) and the variable threshold voltage is a reverse variable threshold voltage; and
the least one hysteresis comparator unit (216) is a reverse hysteresis comparator unit (342) adapted to generate the at least one output signal (356) as a second digital signal (354).

4. The system (200) as claimed in any of the preceding claims, comprising a control unit (360) adapted to receive the at least one output signal (356) from the at least one hysteresis comparator unit (216) and adapted to:
generate one of an aural alert and a visual alert indicating the bad earth condition when the first digital signal (352) and the second digital signal (354) are equal; and
generate one of an aural alert and a visual alert indicating the good earth condition when the first digital signal (352) and the second digital signal (354) are unequal.

5. The system (200) as claimed in any of the preceding claims, comprising a control unit (360) adapted to receive the at least one output signal (356) from the at least one hysteresis comparator unit (216), wherein the control unit (360) is adapted to:
generate the normal variable threshold voltage in the normal configuration corresponding to a fluctuation in the voltage across the live wire connection (302) and the neutral wire connection (304); and
generate the reverse variable threshold voltage in the reverse configuration corresponding to a fluctuation in the voltage across the live wire connection (302) and the neutral wire connection (304).

6. The system (200) as claimed in claim 5, comprising an isolator unit (348, 350) adapted to receive the at least one output signal (356) and separate an AC voltage from the at least one output signal (356) before relaying the at least one output signal (356) to the control unit (360).

7. The system (200) as claimed in claim 1, wherein the at least one hysteresis comparator unit (216) is adapted to:
determine a difference value between the modified reference voltage and the sense voltage;
compare the difference value against a hysteresis range; and
generate the at least one output signal (356) when the difference value is outside the hysteresis range.

8. The system (200) as claimed in claim 1, comprising:
an earth disconnection sense unit (318) adapted to determine one of a condition that:
the earth wire connection (306) connected to an earth terminal of the power supply (100);
discontinuity of the earth wire connection (306) from the power supply (100);
discontinuity between the earth terminal of the power supply (100) and an earth pit; and
a protection unit (308) adapted to protect the processing unit (212) from one of an electrical surge and other abnormalities in one of the live wire connection (302), the neutral wire connection (304) and the earth wire connection (306).

9. The system (200) as claimed in claim 1, wherein the processing unit (212) comprises:
a first rectifier with a step-down circuit (310) adapted to convert the voltage across the live wire connection (302) and the neutral wire connection (304) to a direct current (DC) reference voltage;
a first delay circuit (312) adapted to receive the DC reference voltage to generate a stable reference voltage;
a first buffer circuit (316) adapted to receive the stable reference voltage and generate the input reference voltage (328);
a second rectifier with a step-down circuit (320) adapted to convert the voltage across the earth wire connection (306) and the neutral wire connection (304) to a direct current (DC) sense voltage;
a second delay circuit (322) adapted to receive the DC sense voltage to generate a stable sense voltage; and
a second buffer circuit (326) adapted to receive the stable reference voltage and generate the input sense voltage (330).

10. The system (200) as claimed in claim 1, wherein the at least one signal generating unit (214), and the at least one hysteresis comparator unit (216) is a main control unit with an analog to digital converter unit having an analog isolator circuit.

11. The system (200) as claimed in claim 1, wherein the at least one signal generating unit (214), and the at least one hysteresis comparator unit (216), and the control unit (360) form a main control unit.