Description:FIELD OF THE INVENTION

The present disclosure generally relates to a heat ventilation and air conditioning (HVAC) system, and more particularly, the present disclosure relates to a motor sensing system of a flap control system of an HVAC system of an automobile.

BACKGROUND

In the HVAC system for an automobile, flaps are typically used for controlling the passage of air entering from different positions into a cabin compartment. The controlling of the flaps is done to facilitate the change in the direction of the air to a passage of air as determined by occupants in the cabin compartment. For controlling the orientation of the flaps, a motor is coupled with the flaps. However, if the motor is stuck, or there is any problem in this motor such as but not limited to a breakage in the gear mechanism, jamming, or choking of the motor, the motor draws a large amount of current that may lead to the draining of the battery. In some cases, this may cause the overheating of the motor resulting in complete malfunctioning of the motor or any parts surrounding the motor. In worst cases situation, this may lead to a fire.

Therefore, there is a need for an improved system to control the operating parameters of the motor and detect any failure, fault, or stalling in the motor, thereby reducing the draining of the battery and the prevent any other component failure of the automobile.

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 is related to a system for detecting the stall condition of a motor. The system comprises a voltage source having a first terminal and a second terminal, a motor having a first terminal electrically coupled to the first terminal of the voltage source, and a second terminal electrically coupled to the second terminal of the voltage source. In addition, the system includes a first operational amplifier having a non-inverting terminal electrically coupled to the first terminal of the voltage source, an inverting terminal electrically coupled to the first terminal of the motor, a source input terminal, a ground terminal, and a first output terminal. Additionally, the system includes a second operational amplifier having a non-inverting terminal electrically coupled to the second terminal of the voltage source, an inverting terminal electrically coupled to the second terminal of the motor, a source input terminal, a ground terminal, and a second output terminal. The one of the first operational amplifier and the second operational amplifier is adapted to generate a first output signal of a pre-set voltage at one of the first output terminal and the second output terminal based on the direction of rotation of the motor. The one of the first operational amplifier and the second operational amplifier is adapted to generate a second output signal, indicative of a stall condition of the motor, at one of the first output terminal and the second output terminal. A magnitude of the second output signal is greater than a magnitude of the first output signal.

The system facilitates the detection of the Bi-directional stall current/condition when the motor is rotating in a clockwise (first direction) or anticlockwise direction (second direction). In addition, the combined output from the first operational amplifier and the second operational amplifier facilitates sensing the voltage of stall condition from a single output. The single output from the system facilitates low pin consumption of the controller, thereby enabling the controller to be used in the detection of many motors and detecting stalled conditions of the plurality of motors. The application of the first operational amplifier and the second operational amplifier in a differential mode configuration facilitates the cancelation of any noise from the system and facilitates the reduction of any external interference. Additionally, the first operational amplifier and the second operational amplifier are linear and are used for increasing the rejection mode which reduces the unwanted signals. In addition, the determination of the stalling condition of the motor prevents the overheating of the motor and further facilitates avoiding any drainage of any potential from the voltage source. In addition, a capacitor facilitates the filtering and stabilizing of a combined voltage. Additionally, a resistor facilitates in pulling down the combined voltage to sense at a pin of the controller.

To further clarify 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 circuit diagram of a motor operational current detection system when the motor is rotating in a first direction, in accordance with an embodiment of the present disclosure;
Figure 2 illustrates a circuit diagram of a motor operational current detection system when the motor is rotating in a second direction, in accordance with an embodiment of the present disclosure; and
Figure 3 illustrates a circuit diagram of a plurality of motor operational current detection systems configured together with a controller, in accordance with 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, one or more 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 this invention belongs. The system, methods, 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 one or more features or elements, unless otherwise stated. Further, such terms must not be taken to exclude the possible removal of one or more 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 “one or more features” or “one or more elements” or “at least one feature” or “at least one element.” Furthermore, the use of the terms “one or more” 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 one or more…” or “one or more 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 one or more 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, one or more particular features and/or elements described in connection with one or more 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 one or more 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.

A system 100 to facilitate the detection of any stalling condition of a motor 102 is shown in Figure 1 to Figure. 3. Specifically, Figure 1, illustrates a circuit diagram of the system 100 to determine/detect the stalling in the motor 102 when the motor 102 is rotating in a first direction (clockwise direction). Figure 2 illustrates a circuit diagram of the system 100 to determine/detect the stalling of the motor 102 when the motor is rotating in a second direction opposite to the first direction. Figure 3, illustrates a circuit diagram having more than one system adapted to detect the stalling of the motor in different directions.

As shown in Figure 1 and Figure 2, the system 100 to facilitate the detection of a stalling condition of a motor 102 is shown. The system 100 is adapted to be installed in an HVAC system (not shown) of an automobile (not shown). In addition, the motor 102 of the system 100 is adapted to control the movement of a one or more flaps (not shown) facilitating the flow of air into the passenger compartment of the automobile. The system 100 includes a voltage source 104 to facilitate the supply of electric current to the motor 102 to facilitate the rotation of the one or more flaps of the HVAC system, a first operational amplifier 106 to facilitate the determination of the potential difference across an end of the motor 102, a second operational amplifier 108 to facilitate the determination of the potential difference across an opposite end of the motor 102, and a controller 110 to facilitate the receiving of the output voltage from the system 100.

As shown, the voltage source 104 may be a battery or any other source of an automobile facilitating a continuous supply of electrical charge into the system 100. As shown, the voltage source 104 includes a first terminal 112 and a second terminal 114. Alternatively, the voltage source 104 can be a bi-polar voltage regulator.

Further, the motor 102 of the system 100 includes a first terminal 116 electrically coupled to the first terminal 112 of the voltage source 104, and a second terminal 118 electrically coupled to the second terminal 114 of the voltage source 104. In addition, the system 100 includes a first shunt resistor 120 having a first terminal 122 adapted to couple parallel with the first terminal 112 of the voltage source 104, and a second terminal 124 electrically coupled in series with the first terminal 116 of the motor 102. The first shunt resistor 120 facilitates the creation of a low resistance path for the current and further facilitates directing the current to the first terminal 116 of the motor 102.

Details of the first operational amplifier 106 are shown. The first operational amplifier 106 may be adapted to electrically couple in parallel connection to the first shunt resistor 120 to facilitate the determination of the potential difference across the first shunt resistor 120. The first operational amplifier 106 includes a non-inverting terminal 126 electrically coupled to the first terminal 112 of the voltage source 104, an inverting terminal 128 electrically coupled to the first terminal 116 of the motor 102, a source input terminal 130, a ground terminal 132, and a first output terminal 134 adapted to facilitate the exit of the voltage from the first operational amplifier 106. In addition, the first operational amplifier 106 is a closed-loop amplifier s to facilitate the cancelation of any noise in the system 100.

Additionally, the system 100 includes a resistor R1 having a first terminal 136 connected to a ground 137, and a second terminal 138 electrically coupled parallel to the non-inverting terminal 126 of the first operational amplifier 106. Additionally, the system 100 includes a resistor R2 having a first terminal 140 electrically coupled parallel with the first terminal 122 of the first shunt resistor 120, and a second terminal 142 electrically coupled parallelly to the second terminal 138 of the resistor R1. In addition, the second terminal 142 of the resistor R2 is coupled with the non-inverting terminal 126 of the first operational amplifier 106.

Further, the system 100 may include a resistor R3 having a first terminal 144 electrically coupled parallel with the second terminal 124 of the first shunt resistor 120, and a second terminal 146 electrically coupled parallel with the inverting terminal 128 of the first operational amplifier 106. Additionally, the system 100 includes a resistor R4 having a first terminal 148 parallelly coupled with the first output terminal 134 of the first operational amplifier 106, and a second terminal 150 parallelly coupled with the second terminal 146 of the resistor R3. In an example, the resistor R4 facilitates a feedback system or a closed loop arrangement of the first operational amplifier 106 making the first operational amplifier 106 work in a differential mode of actuation. Additionally, the system 100 includes a first diode 152 electrically coupled with the first output terminal 134 of the first operational amplifier 106 to facilitate the passing of an output voltage from the first diode 152.

Referring to Figure 1 and Figure 2, the second operational amplifier 108 is shown. The second operational amplifier 108 includes a non-inverting terminal 156 electrically coupled to the second terminal 114 of the voltage source 104, an inverting terminal 158 electrically coupled to the second terminal 118 of the motor 102, a source input terminal 160, a ground terminal 162, and a second output terminal 164 adapted to facilitate the exit of the voltage from the second operational amplifier 108. In addition, the second operational amplifier 108 is a closed-loop amplifier s to facilitate the cancelation of any noise in the system 100.

Further, system 100 includes a resistor R5 having a first terminal 168 electrically coupled with the ground 137, and a second terminal 170 electrically coupled parallelly with the non-inverting terminal 156 of the second operational amplifier 108. Further, the system 100 includes a resistor R6 having a first terminal 172 electrically coupled parallel with a first terminal 176 of a second shunt resistor 178, and a second terminal 180 parallelly coupled with the non-inverting terminal 156 of the second operational amplifier 108.

Furthermore, the system includes a resistor R7 having a first terminal 182 electrically coupled parallel with a second terminal 184 of the second shunt resistor 178, and a second terminal 186 electrically coupled parallelly with the inverting terminal 158 of the second operational amplifier 108. Additionally, the system 100 includes a resistor R8 adapted to electrically couple parallel to the second operational amplifier 108 including a first terminal 188 parallelly coupled with the second output terminal 164 of the second operational amplifier 108, and a second terminal 190 parallelly coupled with the second terminal 186 of the resistor R7. Additionally, the system 100 includes a second diode 192 electrically coupled with the second output terminal 164 of the second operational amplifier 108 to facilitate the passing of an output voltage from the second diode 192. The output from the first diode 152 and the output from the second diode 192 is combined and sent to a pin (Ao) of the controller 110. As shown, the controller 110 is operably coupled to the first output terminal 134 of the first operational amplifier 106 and the second output terminal 164 of the second operational amplifier 108. Additionally, the system 100 includes a capacitor 194 having a first end electrically coupled parallel with the first diode 152 and the second diode 192, and a second end coupled with the ground 137. In addition, the system 100 includes a resistor 196 having a first end electrically coupled parallel with the first end of the capacitor 194 and the controller 110, and a second end coupled with the ground 137.

The one of the first operational amplifier 106 and the second operational amplifier 108 is adapted to generate a first output signal of a pre-set voltage at one of the first output terminal 134 and the second output terminal 164 based on the direction of rotation of the motor. In addition, the one of the first operational amplifier 106 and the second operational amplifier 108 is adapted to generate a second output signal, indicative of a stall condition of the motor, at one of the first output terminal 134 and the second output terminal 164. A magnitude of the second output signal is greater than a magnitude of the first output signal.

Further, the controller 110 is adapted to compare the second output signal with a threshold signal and determine the stall condition when a magnitude of the second output signal is greater than a magnitude of the threshold signal. The magnitude of the threshold signal is equal to a magnitude of the first output signal. The one of the first operational amplifier 106 and the second operational amplifier 108 is adapted to generate a first output signal of a pre-set voltage at one of the first output terminals and the second output terminal based on the direction of rotation of the motor.

Referring to Figure 2, the system 100 with the polarity of the voltage source 104 is switched. The components, elements, positioning, and reference numerals of all the components are the same except for the polarity of the voltage source 104. So for the purpose of clarity and brevity, all the elements are retained at the same numerals only the polarity of the voltage source 104 is switched resulting in the switching in the direction of the spin of the motor 102.

Referring to Figure 3, a circuit diagram 500 to facilitate the detection of more than one motor is used. The circuit diagram includes the system 100 and a second system 300 having the same elements, as that of the system 100 explained above. The two systems 100, and 300 are connected with the controller 110 to facilitate the detection of the stalling condition of the two motors of the two systems 100, and 300.

The working of the system 100 is now explained. As mentioned in Figure. 1, the motor 102 rotates in a first direction (clockwise) when a positive voltage is at the first terminal 112 of the voltage source 104 and a negative voltage is at a second terminal 114. The voltage may be achieved by any motor driver IC, HEX Bridge driver, or voltage polarity reverse switch. In addition, the system 100 is designed to sense the current that passes through the motor 102, as shown by the arrows. The current passes through the first shunt resistor 120 and the second shunt resistor 178. The current increase with the load of the motor 102 in stall condition or any stuck/engaged position of the motor 102. The stalling/struck condition of the motor 102 increases the current and the voltage across the first shunt resistor 120 and the second shunt resistor 178. A voltage across the first shunt resistor 120 (VRsh1) having resistance (Rsh1) is VRsh1= I x Rsh1 and a voltage across the second shunt resistor 178 (VRsh2) having resistance (Rsh2) is VRsh2 = I x Rsh2. In an example, the resistances of the system 100 are R1=R4=R5=R8, and the resistances for the system 100 are R2=R3=R6=R7. In addition, the diodes are D1=D2, and the first operational amplifier 106 and the second operational amplifier 108 are similar in construction and working. In an embodiment, a capacitor C1 is used at an output side, and the resistance Ro is used at an output side. The controller 110 is used to read the analog voltage coming to the pin Ao of the controller 110.

In the first operational amplifier 106 when the voltage at the first terminal 112 of the voltage source 104 is positive and the motor 102 is adapted to rotate in a first direction. A voltage (V1+) at the first terminal 122 of the first shunt resistor 120 is greater than a voltage (V1-) at the second terminal 124 of the first shunt resistor 120. Accordingly, at the first operational amplifier 106, as per the output voltage formula for a differential amplifier the output voltage at the first operational amplifier 106 (Vo1) is Vo1= [ (V1+) - (V1-)] * R4/R3, and the resistances are R1=R4=R5=R8, R2=R3=R6=R7.

As shown, the V1+ is greater than V1- in the first direction of rotation of the motor 102. A positive voltage (Vo1) is obtained at the first output terminal 134 of the first operational amplifier 106 in normal operating conditions. However, in case of a stalled condition of the motor 102, the current across the first shunt resistor 120 increases, and the differential voltage V1+ & V1- also increased. In the stalled condition of the motor 102, the current across the first shunt resistor 120 (Rsh1) is increased and the corresponding voltage is also increased as the voltage across first shunt resistor 120 is VRsh1=I x Rsh1. In this manner, the output voltage (Vo1) at the first output terminal 134 of the first operational amplifier 106 also increases. The controller 110 senses the voltage increase at the pin A0 and a software algorithm in the controller 110 determines the stall condition when the magnitude of the first output voltage (Vo1) is greater than the magnitude of the threshold signal.

Simultaneously, in the second operational amplifier 108, a voltage V2- at the first terminal 176 of the second shunt resistor 178 and a voltage V2+ at the second terminal 184 of the second shunt resistor 178 are associated. As per the formula, the output voltage at the second output terminal 164 (VO2) is determined by Vo2= [ (V2+) - (V2-)] * R8/R7, and the resistances are R1=R4=R5=R8, R2=R3=R6=R7. As Vo2 is negative, the second operational amplifier 108 has the minimum voltage of ground reference from the ground terminal 162 which is 0 Volt. In this manner, the second operational amplifier 108 will give the output zero (Vo2) in the first direction of rotation of the motor 102. For, the stall condition of the motor the V2->V2+, the output voltage (Vo2) from the second operational amplifier 108 is zero volts or equivalent to the ground. In the rotation of the motor 102 in the first direction, the first operational amplifier 106 will give the voltage (V1+) at the first terminal 122 of the first shunt resistor 120 the (non-inverting terminal) is greater than the voltage (V1-) at the second terminal 114 of the first shunt resistor 120 at the inverting terminal 128. Simultaneously, the second operational amplifier 108 will always give zero V because the V2+ (non-inverting terminal) voltage is less than V2- (Inverting terminal voltage).

As shown in Figure. 2, the motor 102 of the system 100 is adapted to rotate in a second direction defining an opposite direction of rotation from the first direction. For so doing the polarity of the voltage source 104 is reversed and all the components are adapted to remain in the same state, configuration, and orientation. In this operation condition, a voltage (V1+) at the first terminal 122 of the first shunt resistor 120 is lower than a voltage (V1-) at the second terminal 114 of the first shunt resistor 120. Accordingly, at the first operational amplifier 106, as per the output voltage formula for a differential amplifier the output voltage at the first operational amplifier 106 Vo1= [ (V1+) - (V1-)] * R4/R3 and the resistances are R1=R4=R5=R8 and R2=R3=R6=R7. So, the Vo1 is a negative value. However, the minimum output voltage (Vo1) for the first operational amplifier 106 is in a grounded state so it becomes zero volts. For stall condition, V1+ < V1- and the first operational amplifier 106 outputs zero volts, such that the Vo1= 0, as the voltage across VRsh1=I x Rsh1.

Similarly, for the second operational amplifier 108, the condition is V2+ > V2-. As per the formula Vo2= [ (V2+) - (V2-)] * R8/R7, the resistances are R1=R4=R5=R8, and R2=R3=R6=R7. In this manner, the second operational amplifier 108 gives the positive voltage (Vo2). However, in a stalled condition of the motor 102, this voltage will increase. The increase in the voltage is due to the current across the Rsh2 being increased the corresponding voltage is also increased as the voltage across the second shunt resistor 178 is VRsh2=I x Rsh2. The controller 110 senses the voltage increase at the pin A0 and a software algorithm in the controller 110 determines the stall condition when the magnitude of the first output signal (Vo2) is greater than the magnitude of the threshold signal.

In this manner, the Vo1 & Vo2 is the output voltage comes from the first operational amplifier 106 and the second operational amplifier 108. The voltage Vo1 passes through diode D1 & the voltage Vo2 passes through diode D2 after that it combines to form a combined voltage Vo to sense at the pin Ao of the controller 110. This facilitates sensing and determining a stalled condition of the motor moving in a first direction and a second direction opposite to the first direction. Further, the capacitor 194 facilitates the filtering and stabilizing of the combined voltage Vo. Additionally, the resistor 196 facilitates in pulling down the combined voltage Vo to sense at the pin A0 of the controller 110.

The advantage of the system 100 is now explained. The system 100 facilitates the detection of the Bi-directional stall current/condition when the motor 102 is rotating in a clockwise (first direction) or anticlockwise direction (second direction). In addition, the combined output from the first operational amplifier 106 and the second operational amplifier 108 facilitates sensing the voltage of stall condition from a single output. The single output from the system 100 facilitates low pin consumption of the controller 110, thereby enabling the controller 110 to be used in the detection of many motors 102 and detecting stalled conditions of the plurality of motors 102. The application of the first operational amplifier 106 and the second operational amplifier 108 in a differential mode configuration facilitates the cancelation of any noise from the system 100 and facilitates the reduction of any external interference. Additionally, the first operational amplifier 106 and the second operational amplifier 108 are linear and are used for increasing the rejection mode which reduces the unwanted signals. In addition, the determination of the stalling condition of the motor 102 prevents the overheating of the motor 102 and further facilitates avoiding any drainage of any potential from the voltage source 104.

While specific language has been used to describe the present disclosure, 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) comprising:
a voltage source (104) having a first terminal (112) and a second terminal (114);
a motor (102) comprising:
a first terminal (116) electrically coupled to the first terminal (112) of the voltage source (104); and
a second terminal (118) electrically coupled to the second terminal (114) of the voltage source (104);
a first operational amplifier (106) comprising:
a non-inverting terminal (126) electrically coupled to the first terminal (112) of the voltage source (104), an inverting terminal (128) electrically coupled to the first terminal (116) of the motor (102), a source input terminal (130), a ground terminal (132), and a first output terminal (134);
a second operational amplifier (108) comprising:
a non-inverting terminal (156) electrically coupled to the second terminal (114) of the voltage source (104); an inverting terminal (158) electrically coupled to the second terminal (118) of the motor (102); a source input terminal (160); a ground terminal (162); and a second output terminal (164),
wherein
one of the first operational amplifier (106) and the second operational amplifier (108) is adapted to generate a first output signal of a pre-set voltage at one of the first output terminal (134) and the second output terminal (164) based on the direction of rotation of the motor (102), and
one of the first operational amplifier (106) and the second operational amplifier (108) is adapted to generate a second output signal, indicative of a stall condition of the motor (102), at one of the first output terminal (134) and the second output terminal (164), wherein
a magnitude of the second output signal is greater than a magnitude of the first output signal.

2. The system (100) as claimed in claim 1, comprising:
a controller (110) operably coupled to the first output terminal (134) and the second output terminal (164) and adapted to:
sense a combined voltage (Vo) from the first output terminal (134) (Vo1) and the second output terminal (164) (Vo2); and
determine the stall condition when the magnitude of the combined voltage (Vo) is greater than the magnitude of the threshold signal.

3. The system (100) as claimed in claim 2, wherein the magnitude of the threshold signal is equal to the magnitude of the first output signal (Vo1).

4. The system (100) as claimed in claim 1, wherein the first operational amplifier (106) and the second operational amplifier (108) are closed-loop amplifiers to facilitate the cancelation of any noise in the system.

5. The system (100) as claimed in claim 1, comprising a first shunt resistor (120) having a first terminal (122) adapted to electrically couple parallel with the first terminal (112) of the voltage source (104), and a second terminal (124) electrically coupled parallel with the first terminal (116) of the motor (102).

6. The system (100) as claimed in claim 1, comprising a second shunt resistor (178) having a first terminal (176) adapted to couple with the second terminal (114) of the voltage source (104), and a second terminal (184) electrically coupled with the second terminal (118) of the motor (102).

7. The system (100) as claimed in claim 1, comprising:
a resistor R1 having a first terminal (136) coupled to a ground (137), and a second terminal (138) electrically coupled parallel to the non-inverting terminal (126) of the first operational amplifier (106);
a resistor R2 having a first terminal (140) electrically coupled with the first terminal (122) of the first shunt resistor (120), and a second terminal (142) electrically coupled parallelly to the second terminal (138) of the resistor R1;
a resistor R3 having a first terminal (144) electrically coupled parallel with the second terminal (124) of the first shunt resistor (120), and a second terminal (146) electrically coupled parallel with the inverting terminal (128) of the first operational amplifier (106);
a resistor R4 adapted to electrically coupled parallel to the first operational amplifier (106) having a first terminal (148) parallelly coupled with the first output terminal (134) of the first operational amplifier (106), and a second terminal (150) parallelly coupled with the second terminal (146) of the resistor R3;
a resistor R5 having a first terminal (168) electrically coupled with the ground (137), and a second terminal (170) electrically coupled parallelly with the non-inverting terminal (156) of the second operational amplifier (108);
a resistor R6 having a first terminal (172) electrically coupled parallel with the first terminal (176) of the second shunt resistor (178), and a second terminal (180) parallelly coupled with the non-inverting terminal (156) of the second operational amplifier (108);
a resistor R7 having a first terminal (182) electrically coupled parallel with the second terminal (184) of the second shunt resistor (178), and a second terminal (186) electrically coupled parallelly with the inverting terminal (158) of the second operational amplifier (108); and
a resistor R8 adapted to electrically couple parallel to the second operational amplifier (108) having a first terminal (188) parallelly coupled with the second output terminal (164) of the second operational amplifier (108), and a second terminal (190) parallelly coupled with the second terminal (186) of the resistor R7.

8. The system (100) as claimed in claim 7, wherein the resistor R1, the resistor R4, the resistor R5, and the resistor R8 are of equal resistance.

9. The system (100) as claimed in claim 7, wherein the resistor R2, the resistor R3, the resistor R6, and the resistor R7 are of equal resistance.

10. The system (100) as claimed in claim 1, comprising a first diode (152) electrically coupled with the first output terminal (134) of the first operational amplifier (106), and a second diode (192) electrically coupled with the second output terminal (164) of the second operational amplifier (108).

11. The system (100) claimed in claim 10, comprising:
a capacitor (194) having a first end electrically coupled parallel with the first diode (152) and the second diode (192), and a second end coupled with the ground (137); and
a resistor (196) having a first end electrically coupled parallel with the first end of the capacitor (194) and the controller (110), and a second end coupled with the ground (137).