DESC:FIELD OF THE INVENTION

The present disclosure relates to household appliances and more particularly, to a system and a method for controlling a speed of a motor of a fan.

BACKGROUND

Generally, electrical appliances having a rotating function are equipped with an electric motor. The electric motor is connected to a power source to receive an input voltage for operating the electrical appliances. Further, a speed of the electric motor, such as an induction motor, varies based on fluctuations in the input voltage. Particularly, a drop or a rise in the input voltage may vary the speed of the electric motor which further impacts the performance of the electrical appliance and hamper a user’s experience. For example, the electrical appliance may be a table fan and/or pedestal fan equipped with an induction motor. The induction motor is further connected to a power source to receive an input voltage for operating the table fan at different speed levels. The speed levels of such table fans can be adjusted either manually or via a remote device, in accordance with the required comfort of the user.

Currently, the user can set the speed of the table fan at three fixed levels including a low-speed level, a medium-speed level, and a high-speed level. However, the speed of the induction motor-based fan is dependent on the input voltage. Thus, a drop or a rise in the input voltage impacts the operation of the induction motor which varies the speed of the table fan. The drop in the input voltage may reduce the speed of the table fan, and the rise in the input voltage may increase the speed of the table fan. Therefore, in a scenario of voltage fluctuations in the input voltage, the speed of the table fan varies irrespective of the speed level set by the user. Such uneven variations in the speed of the table fan impact the comfort of the user which ultimately hampers the user’s experience.

Moreover, the rise in the input voltage may deliver a high voltage to the induction motor which increases the temperature of motor windings of the induction motor. This causes burning of the motor winding which increases the overall maintenance and repair cost of the induction motor.

Therefore, in view of the above-mentioned problems, it is desirable to provide a system and a method that can eliminate one or more of the above-mentioned problems associated with the existing art.

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.

In an embodiment of the present disclosure, a system for controlling a speed of a motor is disclosed. The system includes a control unit in communication with the motor and monitors an input voltage supplied to the motor. The control unit further monitors a user input provided to operate the motor at a predefined speed level from among a plurality of speed levels. Herein, the user input corresponds to a selected predefined speed level of the motor. The control unit further analyse the input voltage with a predefined voltage required to operate the motor at the predefined speed level. Furthermore, the control unit generates a feedback signal based on the analysis. A chopper circuit is in communication with the control unit and the motor. The chopper circuit is operated to trim the input voltage to control the speed of the motor based on the generated feedback.

In an embodiment of the present disclosure, a method for controlling a speed of a motor is disclosed. The method includes monitoring an input voltage supplied to the motor. The method further includes monitoring a user input provided to operate the motor at a predefined speed level from among a plurality of speed levels. Herein, the user input corresponds to a selected predefined speed level of the motor. Further, the method includes analysing the input voltage with a predefined voltage required to operate the motor at the predefined speed level. Further, the method includes generating a feedback signal based on the analysis. Furthermore, the method includes trimming the input voltage for controlling the speed of the motor based on the generated feedback.

In the present disclosure, the implementation of the system and the method may prevent speed variation due to fluctuations in the input voltage and maintain a constant speed of the motor of a fan even if the input voltage rises or drops. This improves the user experience while using the fan. Further, the system provides the isolation between the high-voltage and the low-voltage to protect the microcontroller from high-voltage breakdown. This prevents the burning of the motor winding due to the high input voltage.

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 are 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 system for controlling a speed of a motor, according to an embodiment of the present disclosure;

Figure 2 illustrates a conversion of input AC into a rectified direct current (DC), according to an embodiment of the present disclosure;

Figure 3 illustrates a schematic of a chopper circuit of the system, according to an embodiment of the present disclosure; and

Figure 4 illustrates a flowchart depicting an exemplary method for controlling a speed of a motor, 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 the 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 does 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 a 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 the 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 system 100 for controlling a speed of a motor 114, according to an embodiment of the present disclosure. The system 100 may be adapted to control the speed of the motor 100 irrespective of the fluctuations in an input voltage supplied to the motor 114. In an embodiment, the system 100 may be implemented in a fan such as a table fan or a pedestal fan. In an embodiment, the motor 114 may be an induction motor. In another embodiment, the motor 114 may be any other motor, without departing from the scope of the present disclosure. Hereinafter, in the subsequent paragraphs, the motor 114 may be interchangeably referred to as the induction motor 114 within the scope of the present disclosure.

In a non-limiting embodiment, the system 100 may be implemented in any household appliance, for example, vacuum cleaners, blenders, mixers, and the like, that may be using the motor 114 to control one or more operations of the household appliance, without departing from the scope of the present disclosure.

In an embodiment, the fan may include, but is not limited to, the motor 114 adapted to be operated on different speed levels. The motor 114 may be connected to a power source to receive the input voltage. In an embodiment, the motor 114 may be adapted to be operated at a plurality of speed levels. In an embodiment, an operating speed level may be selected by a user from among the plurality of speed levels. The speed level may be adjusted by the user based on the conditions, such as a required temperature to be maintained within a region in which the fan is placed. The plurality of speed levels may include six levels defined between the highest speed and the lowest speed of the fan. Further, the motor 114 may be operated at different speeds to operate the fan at the plurality of speed levels.

The system 100 may include, but is not limited to, a rectifier 102, an analog-to-digital converter (ADC) 104, a level-shifting block 106, a control unit 108, a user interface 110, and a chopper circuit 112. Herein, the control unit 108 may have limitations in a voltage level, such that the control unit 108 may be operated within an operational range level of voltage and cannot read or understand if the voltage level is increased beyond the operational range level. In a non-limiting embodiment, the operational range level of the control unit 108 may be up to 3 Kilovolt (KV).

The rectifier 102 may be in communication with the power source and the control unit 108 via the ADC 104 and the level-shifting block 106. In an embodiment, the rectifier 102 may be adapted to convert an input alternating current (AC) to a rectified direct current (DC). In an embodiment, the rectifier 102 may be adapted to convert the input AC to the rectified DC to determine the input voltage supplied from the power source to the motor 114. Further, to determine the input voltage, the rectifier 102 may shift negative voltage to positive voltage by changing the sine voltage to a rectified sine wave pattern.

The ADC 104 may be in connection with the rectifier 102 and may be adapted to convert a high rectified voltage received from the rectifier 102 into a low rectified voltage. In an embodiment, the low rectified voltage may be a low rectified sine wave voltage within the scope of the present disclosure. In an embodiment, the ADC 104 may further be adapted to facilitate an isolation between the high rectified voltage and the low rectified voltage that may be supplied to the control unit 108. The facilitated isolation may protect the control unit 108 from high-voltage breakdown.

The level-shifting block 106 may be connected to the ADC 104. The level-shifting block 106 may be adapted to convert a rectified sine wave into a Pulse Width Modulation (PWM) signal corresponding to the input voltage. Further, the level-shifting block 106 may transmit the converted voltage in a digital form to the control unit 108.

The user interface 110 may be adapted to receive a command from a user corresponding to a predefined speed level of the motor 114 of the fan to be selected in accordance with the required comfort of the user. Further, the user interface 110, based on the received command, may determine the predefined speed level selected by the user. Further, the user interface 110 may transmit a signal to the control unit 108 based on the determination. In an embodiment, the user interface 110 may be manually operated by the user to select the speed of the motor 114 of the fan. In another embodiment, the user interface 110 may be wirelessly operated by the user via a remote device to select the speed of the motor 114 of the fan. Herein, the remote device may be in communication with the user interface 110 via a wireless network.

The control unit 108 may include, but is not limited to, a processor, memory, module(s), a database, and a display unit. The module(s) and the memory may be coupled to the processor. The processor may be a single processing unit or a number of units, all of which could include multiple computing units. The processor may be implemented as one or more microprocessors, microcomputers, control unit 108s, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. Among other capabilities, the processor is configured to fetch and execute computer-readable instructions and data stored in the memory. The memory may include any non-transitory computer-readable medium known in the art including, for example, volatile memory, 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 module(s), amongst other things, includes routines, programs, objects, components, data structures, etc., which perform particular tasks or implement data types. The module(s) may also be implemented as, signal processor(s), state machine(s), logic circuitries, and/or any other device or component that manipulates signals based on operational instructions. Further, the module(s) may be implemented in hardware, instructions executed by at least one processing unit, for e.g., the processor, or by a combination thereof. The processing unit may comprise a computer, a processor, a state machine, a logic array and/or any other suitable devices capable of processing instructions. The processing unit may be a general-purpose processor which executes instructions to cause the general-purpose processor to perform operations or, the processing unit may be dedicated to performing the required functions. In some examples, embodiments, the module(s) may be machine-readable instructions (software, such as web application, mobile application, program, etc.) which, when executed by a processor/processing unit, perform any of the described functionalities.

The control unit 108 may be in communication with the motor 114. In an embodiment, the control unit 108 may be configured to monitor the input voltage supplied to the motor 114 based on the PWM signal received from the level-shifting block 106. In an embodiment, the control unit may be adapted to monitor the input voltage once every 10 milliseconds of time duration. In an embodiment, the control unit may be adapted to monitor the input voltage at any other dime duration within the scope of the present disclosure. Further, the control unit 108 may be configured to monitor the user input provided to operate the motor 114 at a predefined speed level, selectable from a plurality of speed levels, where the user input corresponds to the selected predefined speed level of the motor 114.

Further, the control unit 108 may include predefined data including a table of pre-determined or user-selectable values for each of a predefined speed level, selectable from a plurality of speed levels. In an embodiment, the pre-determined or user-selectable values may be defined as the revolutions per minute (RPM) of the motor 114 of the fan at a particular speed and a particular voltage associated with the particular speed. In an embodiment, the particular voltage may correspond to a predefined voltage required to operate the motor 114 at the predefined speed level.

Further, the control unit 108 may be configured to analyse the input voltage with the predefined voltage required to operate the motor 114 at the predefined speed level. In an embodiment, to analyse the input voltage with the predefined voltage, the control unit 108 may be configured to compare the input voltage with the predefined voltage required to operate the motor 114 at the predefined speed level. Further, the control unit 108 may be configured to determine a deviation between the input voltage and the required predefined voltage, based on the comparison. Furthermore, the control unit 108 may be configured to generate a feedback signal based on the analysis. Accordingly, the feedback signal may indicate the deviation of the input voltage from the predefined voltage required to operate the motor 114 at the predefined speed level.

The chopper circuit 112 may be in communication with the control unit 108 and the motor 114. The feedback signal transmitted by the control unit 108 may be received by the chopper circuit 112 to adjust the determined deviation based on the generated feedback. Further, the chopper circuit 112 may be adapted to be operated to trim the input voltage to adjust the determined deviation based on the generated feedback of the control unit 108. Further, the chopper circuit 112 may be adapted to trim the input voltage supplied to the motor 114 to maintain the predefined speed level of the motor 114.

Accordingly, the chopper circuit 112 may adjust the deviation in the monitored input voltage and predefined voltage required corresponding to the current selected predefined speed level, to maintain the speed of the motor 114 of the fan at the selected predefined speed level.

Therefore, the control unit 108, based on the input received from the user interface 110, may eliminate any deviation resulting from the variation in the input voltage and may adjust the speed of the motor 114 of the fan corresponding to the selected predefined speed level based on the required comfort of the user.

The control unit 108, based on the feedback signal may be configured to adjust the PWM signal at a chopper level. Further, when the input voltage rises and crosses the predefined voltage required corresponding to the current selected predefined speed level, the control unit 108 may determine a deviation between the input voltage and the required predefined voltage the speed and the input voltage and then trigger the chopper circuit 112 to chop/trim a Root Mean Square (RMS) voltage. Accordingly, the RPM of the motor 114 of the fan may be controlled when the high input voltage is supplied. Moreover, the control unit 108 may be configured to provide an indication signal to the user to indicate that there has been a rise in the input voltage. In an embodiment, the indication signal may be at least one of a visual warning and an audio warning.

Figure 2 illustrates a conversion of input AC into a rectified direct current (DC), according to an embodiment of the present disclosure. A plotted line 202 may indicate an input sinewave corresponding to the input alternating current (AC), as received from the power source to the motor 114 and the rectifier 102. The rectifier 102 may convert the received input AC and convert it to the rectified direct current (DC). A plotted line 204 may indicate a rectified sinewave corresponding to the rectified direct current (DC) transmitted by the rectifier 102. In case of high rectified voltage, the rectified direct current (DC) may further be converted by the analog-to-digital converter (ADC) 104 into the low rectified voltage. Further, the level-shifting block 106 may be adapted to convert the rectified sine wave into the Pulse Width Modulation (PWM) signal corresponding to the input voltage. Therefore, the conversion of input AC to the PWM signal may ensure that the appropriate voltage within the operational range level of the control unit 108 is supplied to the control unit 108 corresponding to the input voltage.

Figure 3 illustrates a schematic of the chopper circuit 112 of the system 100, according to an embodiment of the present disclosure. As shown in Figure 3, the chopper circuit 112 may be configured to chop/trim the RMS voltage to control the speed of the motor 114 based on the feedback received from the control unit 108, such that the speed of the motor 114 may be controlled and a constant speed for the selected predefined speed level is maintained. In a non-limiting embodiment, the chopper circuit 112 may include a feedback device and a controlling device in communication with the feedback device. The feedback device may be adapted to receive the feedback from the control unit. In an embodiment, at terminal 302, the chopper circuit 112 may receive the feedback signal from the control unit 108. The feedback device may include a light emitting diode (LED) and a transistor. The feedback device may be adapted to provide isolation. The PWM signal received by the feedback device corresponding to the feedback signal and the LED and the transistor may be actuated based on the received feedback signal. In an embodiment, the transistor may be actuated in response to the actuation of the LED, such that for a duration of the actuation of the LED, the voltage may flow through the chopper circuit 112.

At terminal 304, the chopper circuit 112 may be connected to the power source adapted to supply live AC current to the chopper circuit 112. At terminal 306, the motor 114 may be connected to the chopper circuit 112. Accordingly, the motor 114 may be connected to the power source in a series loop.

Further, the feedback device may activate the controlling device to control the speed of the motor based on the feedback received from the control unit 108. In an embodiment, the controlling device may be adapted to conduct and insulate in response to the feedback received by the feedback device. Therefore, allowing the flow of voltage for the predetermined duration to the motor. For example, for 50Hz frequency, there may be a 20-millisecond time duration for the input voltage cycle, and every 10 milliseconds may be monitored by the control unit 108. Accordingly, the chopper circuit 112 may control a duration for which the voltage is supplied to the motor 114. In an embodiment, a gate may provide, such that, the actuation of the gate for a predetermined duration may allow the voltage to be supplied to the motor 114 through the chopper circuit 112. For example, actuating the gate for 5 milliseconds instead of 20 milliseconds may reduce the voltage supplied to the motor 114.

In an embodiment, a bridge may be provided between the controlling device of the chopper circuit 112 and the control unit 108. The bridge may be adapted to provide isolation between the controlling device of the chopper circuit 112 and the control unit 108. The provided isolation may advantageously protect the control unit 108 from surges and spikes in the input voltage supply, thereby preventing hazardous situations.

Accordingly, the speed of the motor may be maintained at a predefined speed level that may be preset by the user, such that the user comfort is maintained, and the user experience is not hampered. The controlling device may be activated with 3KV isolation between the control unit 108 and the input voltage. This protects the control unit 108 from a high-voltage breakdown.

Further, the control unit 108 may provide the indication signal to the user to indicate that there is a rise in the input voltage. In an embodiment, the indication signal may be a visual warning. Moreover, the system 100 provides isolation between the high-voltage and the low-voltage to protect the control unit 108 from high-voltage breakdown. This prevents the burning of the motor 114 windings due to the high input voltage.

Figure 4 illustrates a flowchart depicting an exemplary method for controlling a speed of a motor, according to an embodiment of the present disclosure. For the sake of brevity, the constructional and operational features of the system 200 that are already explained in the description of Figure 1, Figure 2, and Figure 3, are not explained in detail in the description of Figure 4.

The method 400 may begin with step 402 which may include monitoring, by a control unit 108, an input voltage supplied to the motor 114. In an embodiment, the control unit may be adapted to monitor the input voltage once every 10 milliseconds of time duration. In an embodiment, the control unit may be adapted to monitor the input voltage at any other dime duration within the scope of the present disclosure.

At 404, the method 400 may include monitoring, by the control unit 108, a user input provided to operate the motor 114 at a predefined speed level from among a plurality of speed levels. In an embodiment, the user input corresponds to a selected predefined speed level of the motor 114. In an embodiment, the selected predefined speed level of the motor 114 may be selected by the user corresponding to a predefined speed level of the motor 114 of a fan to be selected in accordance with the required comfort of the user.

At 406, the method 400 may include analysing, by the control unit 108, the input voltage with a predefined voltage required to operate the motor 114 at the predefined speed level. In an embodiment, for analysing the input voltage with a predefined voltage, the method 400 may include comparing, by the control unit 108, the input voltage with a predefined voltage required to operate the motor 114 at the predefined speed level. Further, the method 400 may include determining, by the control unit 108, a deviation between the input voltage and the predefined voltage, based on the comparison.

In an embodiment, the control unit 108 may include predefined data including a table of pre-determined or user-selectable values for each of a predefined speed level, selectable from a plurality of speed levels. In an embodiment, the pre-determined or user-selectable values may be defined as the revolutions per minute (RPM) of the motor 114 at a particular speed and a particular voltage associated with the particular speed. In an embodiment, the particular voltage may correspond to the predefined voltage required to operate the motor 114 at the predefined speed level.

At 408, the method 400 may include generating, by the control unit 108, a feedback signal based on the analysis. Accordingly, the feedback signal may indicate a deviation of the input voltage from the predefined voltage required to operate the motor 114 at the predefined speed level based on the analysis. In an embodiment, the feedback signal may be transmitted to a chopper circuit 112.

At 410, the method 400 may include trimming, by the chopper circuit 112, the input voltage for controlling the speed of the motor 114 based on the generated feedback. In an embodiment, the chopper circuit 112 may be in communication with the control unit 108 and the motor 114.

In an embodiment, the method 400 may further include maintaining the predefined speed level of the motor 114 by trimming the input voltage supplied to the motor 114. Accordingly, the chopper circuit 112 may adjust the deviation in the monitored input voltage and predefined voltage required corresponding to the current selected predefined speed level, to maintain the speed of the motor 114 of the fan at the selected predefined speed level.

In an embodiment, the method 400 may further include converting, by a rectifier 102, an input alternating current (AC) to a rectified direct current (DC) to determine the input voltage supplied from the power source to the motor 114. Further, to determine the input voltage, the rectifier 102 may shift negative voltage to positive voltage by changing a sine voltage to a rectified sine wave pattern.

In an embodiment, the method 400 may further include converting, an analog-to-digital converter (ADC) 104, a high rectified voltage into a low rectified voltage received from the rectifier 102. In an embodiment, the low rectified voltage may be a low rectified sine wave voltage within the scope of the present disclosure.

In an embodiment, the method 400 may further include isolation, by the ADC 104, between the high rectified voltage and the low rectified voltage supplied to the control unit 108. The facilitated isolation may protect the control unit 108 from high-voltage breakdown.

In an embodiment, the method 400 may further include converting, by a level-shifter 106, a rectified sine wave into a Pulse Width Modulation (PWM) signal corresponding to the input voltage. Further, the method 400 may include transmitting, by the level-shifting block 106, the converted voltage in a digital form to the control unit 108.

The present disclosure may further include several advantages over the existing techniques. For example, the system 100 may be configured to monitor the input voltage and the predefined speed level selected by the user in accordance with the required comfort, and may adjust the deviation in the monitored input voltage and predefined voltage required corresponding to the current selected predefined speed level, to maintain the speed of the motor 114 of the fan at the selected predefined speed level. This may ensure that the user experience may not be hampered when there is an unwanted spike in the input voltage. Further, this may ensure that the user will get a constant speed of the motor 114 of the fan even in the voltage variation at the Line or Input side. Thus, the implementation of the system 100 may prevent speed variation due to the fluctuation in the input voltage and maintain the constant speed of the motor 114 of the fan even if the input voltage rises or drops. This improves the user experience while using the fan.

Further, the system 100, on determination of the deviation in the monitored input voltage and predefined voltage required corresponding to the current selected predefined speed level, may trim the input voltage to adjust the determined deviation based on the generated feedback. This may advantageously protect the motor 114 from the burning of the motor windings due to high input voltage. Thereby eliminating frequent repair due to burning of the motor windings and enhancing the life of the motor 114.

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 (100) for controlling a speed of a motor (114), the system (100) comprising:
a control unit (108) in communication with the motor (114) and configured to:
monitor an input voltage supplied to the motor (114);
monitor a user input provided to operate the motor (114) at a predefined speed level from among a plurality of speed levels, wherein the user input corresponds to a selected predefined speed level of the motor (114);
analyse the input voltage with a predefined voltage required to operate the motor (114) at the predefined speed level; and
generate a feedback signal based on the analysis; and
a chopper circuit (112) in communication with the control unit (108) and the motor (114), wherein the chopper circuit (112) is adapted to be operated to trim the input voltage to control the speed of the motor (114) based on the generated feedback.

2. The system (100) as claimed in claim 1, wherein the chopper circuit (112) is adapted to trim the input voltage supplied to the motor (114) to maintain the predefined speed level of the motor (114).

3. The system (100) as claimed in claim 1, wherein to analyse the input voltage with a predefined voltage, the control unit (108) is configured to:
compare the input voltage with the predefined voltage required to operate the motor (114) at the predefined speed level; and
determine a deviation between the input voltage and the predefined voltage, based on the comparison.

4. The system (100) as claimed in claim 1, comprising a rectifier (102) connected with a power source and the control unit (108) and adapted to convert an input alternating current (AC) to a rectified direct current (DC) to determine the input voltage supplied from the power source.

5. The system (100) as claimed in claim 4, comprising an analog-to-digital converter (ADC) (104) connected with the rectifier (102) and adapted to convert a high rectified voltage into a low rectified voltage received from the rectifier (102).

6. The system (100) as claimed in claim 5, wherein the ADC (104) is adapted to facilitate an isolation between the high rectified voltage and the low rectified voltage supplied to the control unit (108).

7. The system (100) as claimed in claim 6, comprising a level-shifter (106) connected with the ADC (104) and adapted to convert a rectified sine wave into a Pulse Width Modulation (PWM) signal corresponding to the input voltage.

8. A method (400) for controlling a speed of a motor (114), the method (400) comprising:
monitoring (402) an input voltage supplied to the motor (114);
monitoring (404) a user input provided to operate the motor (114) at a predefined speed level from among a plurality of speed levels, wherein the user input corresponds to a selected predefined speed level of the motor (114);
analysing (406) the input voltage with a predefined voltage required to operate the motor (114) at the predefined speed level;
generating (408) a feedback signal based on the analysis; and
trimming (410) the input voltage for controlling the speed of the motor (114) based on the generated feedback.

9. The method (400) as claimed in claim 8, comprising maintaining the predefined speed level of the motor (114) by trimming the input voltage supplied to the motor (114).

10. The method (400) as claimed in claim 8, wherein analysing the input voltage with a predefined voltage comprises:
comparing the input voltage with a predefined voltage required to operate the motor (114) at the predefined speed level;
determining a deviation between the input voltage and the predefined voltage, based on the comparison; and
analysing the input voltage with a predefined voltage comprises based on the determination.

11. The method (400) as claimed in claim 8, comprising converting, by a rectifier (102), an input alternating current (AC) to a rectified direct current (DC) to determine the input voltage supplied from the power source.

12. The method (400) as claimed in claim 11, comprising converting, an analog-to-digital converter (ADC) (104), a high rectified voltage into a low rectified voltage received from the rectifier (102).

13. The method (400) as claimed in claim 12, comprising isolating, by the ADC (104), between the high rectified voltage and the low rectified voltage supplied to the control unit (108).

14. The method (400) as claimed in claim 13, comprising converting, by a level-shifter (106), a rectified sine wave into a Pulse Width Modulation (PWM) signal corresponding to the input voltage.