The invention generally relates to an electronic control unit for vehicles. More particularly, the invention relates to a system for providing automatic start stop functionality in a vehicle.
BACKGROUND
Over the years, there has been continuous increase in number of vehicles in every part of the country. Therefore, issues like rising fuel consumption and air pollution caused by vehicles have become more serious. Various attempts have been made to mitigate such effects. One of such attempts is development of an automatic start and stop system that automatically shuts the engine of a vehicle while idling in traffic (e.g. a traffic light stop)and turns it on as and when the rider actuates throttle of the vehicle with brake, thereby economising the usage of vehicle by preventing unnecessary fuel consumption and reducing emissions.
However, the aforesaid mechanism still falls short of substantially curbing unnecessary fuel consumption within the vehicle, especially while the vehicle is being driven. Although the mechanism triggers automatically switching on/off the engine as a step towards the same, however the engine's operation during the driving proceeds normally and remains unaffected by the presence of such automatic start-stop mechanisms. Accordingly, during the driving state, an additional control mechanism is always required to optimize the fuel consumption, thereby leaving the problem of fuel consumption only partially solved through these automatic start-stop mechanisms. Considering the fact that these automatic start-stop mechanisms are implemented through an embedded system within the vehicle and accordingly add to the manufacturing costs, the same proves cost-inefficient in the long run owing to limited problem solution.
Accordingly, there lies a need for a system that can not only automatically starts or stops the vehicle based on sensing the vehicle's state, but also simultaneously contributes to an engine's operation during the driving state of the vehicle.
Applicant's co-pending application No. 201611004609 may be referred which discloses a system and a method for providing automatic start stop functionality. Although, the system disclosed in Applicant's co-pending application No. 201611004609 provides

satisfactory results, a need to reduce the cost of the product and improve its performance has been felt.
SUMMARY OF THE INVENTION
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.
Accordingly, the present invention provides a system (126) for providing automatic start stop functionality in a vehicle, the system (126) comprising a plurality of sensing circuits (103, 104, 105, 106, 107, 108, 109, 110, 127, 128) for sensing a set of control parameters, the plurality of sensing circuits being selected from a group comprising of a battery voltage, a battery less condition, actuation of a brake switch, actuation of a self-switch, actuation of a clutch switch, a crank signal, a speed indicating signal, state of a control switch, state of a neutral switch, and state of a throttle switch. The system (126) further comprises a microcontroller (111) operably coupled to the plurality of sensing circuits, the microcontroller being configured to process the control parameters thus sensed by the plurality of sensing circuits and generate a set of control instructions. The system (126) further comprises a plurality of control circuits operably coupled to the microcontroller, the plurality of control circuits being adapted to receive a control instruction from the microcontroller (111) and perform a corresponding control function; the plurality of control circuits including a first control circuit (113) adapted to control an ignition coil (123) and an ignition timing thereof, a second control circuit (114) adapted to control a starter relay (124), and a third control circuit (112) adapted to control a battery status indicator (125). In a particular embodiment of the invention, the first control circuit (113) comprises a first capacitor (C5) acting as a biasing capacitor; plurality of transistors (Q15, Q3, Ql & Q2) adapted to cause generation of a spark; a second capacitor (C48) adapted to prevent occurrence of wrong spark; and a plurality of resistors (R2, R3, R4, R6& R5) adapted to drive the first control circuit (113).
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 ACCOMPANYING 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 schematic diagram of a system for providing automatic start stop functionality in a vehicle, in accordance with an embodiment of the invention;
Figure 2 illustrates an exemplary circuit diagram of a first reverse voltage protection circuit within the system of Fig. 1, in accordance with an embodiment of the invention;
Figure 3 illustrates an exemplary circuit diagram of a second reverse voltage protection circuit within the system of Fig. 1, in accordance with an embodiment of the invention;
Figure 4 illustrates an exemplary circuit diagram of a first sensing circuit (for battery voltage) within the system of Fig. 1, in accordance with an embodiment of the invention;
Figure 5 illustrates an exemplary circuit diagram of a second sensing circuit (for Battery less case) within the system of Fig. 1, in accordance with an embodiment of the invention;
Figure 6 illustrates an exemplary circuit diagram of a third sensing circuit (Brake switch sense) within the system of Fig. 1, in accordance with an embodiment of the invention;
Figure 7 illustrates an exemplary circuit diagram of a fourth sensing circuit (for self-switch) within the system of Fig. 1, in accordance with an embodiment of the invention;
Figure 8 illustrates an exemplary circuit diagram of a fifth sensing circuit (Crank Signal sense) within the system of Fig. 1, in accordance with an embodiment of the invention;

Figure 9 illustrates an exemplary circuit diagram of a sixth sensing circuit (Speed Signal Sense) within the system of Fig. 1, in accordance with an embodiment of the invention;
Figure 10 illustrates an exemplary circuit diagram of a seventh sensing circuit (Control switch sense) within the system of Fig. 1, in accordance with an embodiment of the invention;
Figure 11 illustrates an exemplary circuit diagram of an eighth sensing circuit (Throttle switch) within the system of Fig. 1, in accordance with an embodiment of the invention;
Figure 12 illustrates an exemplary circuit diagram of a power supply circuit within the system of Fig. 1, in accordance with an embodiment of the invention;
Figure 13 illustrates an exemplary circuit diagram for a microcontroller interface and its Peripheral circuit, in accordance with an embodiment of the invention;
Figure 14 illustrates an exemplary circuit diagram of a Transistor based Ignition circuit within the system of Fig. 1, in accordance with an embodiment of the invention;
Figure 15 illustrates an exemplary circuit diagram of a MOSFET based starter relay driver circuit within the system of Fig. 1, in accordance with an embodiment of the invention;
Figure 16 illustrates an exemplary circuit diagram of a MOSFET based battery indicator driver circuit within the system of Fig. 1, in accordance with an embodiment of the invention; and
Figure 17 illustrates an exemplary complete circuit diagram of the system for providing automatic start and stop functionality in a vehicle, in accordance with an embodiment of the invention.
It may be noted that to the extent possible, like reference numerals have been used to represent like elements in the drawings. Further, those of ordinary skill in the art will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help to improve understanding of aspects of the invention. Furthermore, the one or more elements 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 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.
DEATILED DESCRIPTION
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.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof. Throughout the patent specification, a convention employed is that in the appended drawings, like numerals denote like components.
Reference throughout this specification to “an embodiment”, “another embodiment” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, appearances of the phrase “in an embodiment”, “in another embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures proceeded by "comprises... a" does not, without more constraints, preclude the existence of other devices or other sub-systems.
Embodiments of the invention will be described below in detail with reference to the accompanying drawings.
6

Figure 1 illustrates a schematic diagram of a system 126 for providing automatic start stop functionality in a vehicle (not shown). In one embodiment, the system 126 comprises sensing circuits 103-110 and 127-128, reverse voltage protection circuit 101-102, a microcontroller 111, and control circuits 112-114. Each of the sensing circuits 103-110 and 127-128 senses a control parameter associated with the vehicle. The microcontroller 111 processes the sensed control parameter received from each of the sensing circuits 103-110 and 127-128, and accordingly provides control instructions to the control circuits 112-114 in order to automatically switch-on or switch-off an engine (not shown) of the vehicle and vary an ignition timing map thereof.
In said embodiment,101 and 102 are used for reverse voltage protection of a battery 116 of the vehicle, the sensing circuits 103-110 and 127-128 may include a first sensing circuit 103 for sensing battery voltage in the vehicle, a second sensing circuit 104 for sensing battery-less condition in the vehicle, a third sensing circuit 105 for sensing a state of a Brake switch 120, a fourth sensing circuit 106 for sensing a state of a self-start switch 121, a fifth sensing circuit 107 sensing crank signal received from a crank sensor (not shown in the figure) mounted on an AC generator 115 of the vehicle, a sixth sensing circuit 108 for sensing the speed, a seventh sensing circuit 109 for sensing a state of a controller switch 118, an eighth sensing circuit 110 for sensing a state of a throttle switch 119, a ninth sensing circuit 127 for sensing a state of a clutch switch 129 and a tenth sensing circuit 128 for sensing a state of a neutral switch 130. Further, the control circuits 112-114 may include a first control circuit 112 to control an ignition coil 123 as well as change an ignition timing map associated thereto, a second control circuit 113 for controlling a starter relay 124, and a third control circuit 114 for controlling the battery status indicator 125 that indicates a battery status such as a battery healthy battery level, a low battery level and a battery less condition in the vehicle.
The self-start switch 121 turns into an ON state upon actuation by a user, and a brake switch 120 turns ON/OFF upon depressing or releasing a brake lever, respectively. The controller switches 118 is manually turned ON or OFF by a user for activating or deactivating the “automatic start/stop” mode of operation in the vehicle. Further, the ignition coil 123 upon having been provided a large amount of voltage, through transistor occurring in the first control circuit 112, produces a spark. The first control circuit 112 is controlled by the microcontroller 111 not only to cause such spark generation, but also time generation of the spark. Further, the starter relay 113 actuates a starter motor of the vehicle to crank the engine,
7

as a part of starting the vehicle through the ‘self-start’ mechanism. The battery status indicator 114 indicates the battery level (e.g. healthy, low) or a battery-less condition in the vehicle.
In another embodiment, the system 126 further comprises an inbuilt power supply circuit 100 to supply regulated power, such as 5V supply to the microcontroller 111. The power supply circuit 100 derives power from the vehicle (either from the vehicle’s AC power generator 115 through reverse protection 101,102 or the vehicle’s battery 116) and connected component under reverse voltage conditions.
Figure 2 illustrates the reverse first voltage protection circuit for reverse protection for whole circuit 126, in accordance with an embodiment of the invention. The first reverse voltage protection circuit, 101 further includes a first capacitor C12 that acts as a voltage stabilizer at input terminal of the Ignition coil input & C12 use as a polarised capacitor. The first reverse voltage protection circuit 101 further includes a diode D1, which acts as a reverse protection diode.
Figure 3 illustrates the second reverse voltage protection circuit for reverse protection for microcontroller circuit 111, in accordance with an embodiment of the invention. The second reverse voltage protection circuit, 102 further includes a first capacitor C53 that acts as a voltage stabilizer at input terminal of the 5V voltage regulator & C53 use as a polarised capacitor. The second reverse voltage protection circuit, 102 further includes a diode D22, which acts as a reverse protection diode.
In an embodiment of the invention, the first reverse voltage protection circuit (101) & the second reverse voltage protection circuit (102) may be replaced by the reverse voltage protection as shown in Indian Application No. 201611004609.
Figure 4 illustrates the first sensing circuit 103, in accordance with an embodiment of the invention, which senses voltage of the battery 116 of the vehicle when the battery 116 is connected through an electrical fuse 117. The first sensing circuit 103 acts as an interface between the battery 116 and an ADC pin of the microcontroller 111. As shown, the first sensing circuit 103 comprises a combination of resistors R23 and R25 as a voltage divider for converting the voltage of the battery 116 to a digital equivalent to a pre-defined value for the ADC pin of the microcontroller 111. R23 may have a resistance of about 20 K (i.e. kilo ohm). R25 may have the resistance of about 3.6 K. The first sensing circuit 103 further includes a
8

Zener diode Z2 for clamping the sensed battery voltage to the suitable voltage, such as 5.1V, in order to protect the ADC pin of the microcontroller. The first sensing circuit 103 further includes a capacitor C49 that is used as a filter and as a voltage stabilizer at the ADC pin of the microcontroller 111. C49 may have a capacitance of about 10nF and a working-voltage of about 50 V.
Figure5 illustrates the second sensing circuit 104, in accordance with an embodiment of the invention, which senses battery-less condition in the vehicle in such cases, the second sensing circuit 104 acts as an interface between the AC-DC converter 122 and the microcontroller 111. The second sensing circuit 104 converts pulses received from the AC-DC converter 122 to a suitable voltage, such as 5 volt pulses, for the microcontroller 111. These 5V pulses are used as an interrupt for the microcontroller 111. In an implementation, in order to confirm battery less condition, number of interrupts as produced may be more than ‘one’ in a single rotation of the AC power generator 115.
As shown, the second sensing circuit 104 includes a first diode D7 for reverse voltage protection of the second sensing circuit 104, takes input from regulated Battery 6-24 DC and pulses of 18-22 V peak in case of battery disconnected. The second sensing circuit 104 further includes a transistor Q12 that acts as a digital switch to generate interrupts for the microcontroller 111. Q12 may be an NPN transistor. The second sensing circuit 104 also includes a series combination of a Zener diode Z7 to clamp voltage for the transistor Q12. The second sensing circuit 104 also includes a plurality of resistors R21, R62, R63, R74, and R75 as current limiting and biasing resistors for the transistor Q12. R21 may have a resistance in the range of about 22K. R62 may have the resistance of about 47K. R63 may have the resistance of about 10K. R74 may have the resistance of about 1K. R75 may have the resistance of about 47K.Z7 may have the clamping the 8.2V.
The second sensing circuit 104 also includes a plurality of capacitors C33 and C39 for filtering noise signal at base and collector terminals of the transistor Q12. C33 may have a capacitance of about 10nF and a working-voltage of about 50 V, while C39 may have a capacitance of about 2.2nF and a working-voltage of about 50V.
In an alternative embodiment, the battery less condition sensing circuit as shown and described in Indian Application No. 201611004609 may be adopted.
9

Figure 6 illustrates the third sensing circuit 105, in accordance with the embodiment of the invention, which senses the brake signal from the Switch 120 in order to determine whether the vehicle is in Brake. The third sensing circuit 105 acts as an interface between Brake signal sensors mounted on wheel and the microcontroller 111. The sensing circuit 105 includes D19 for reverse voltage protection to the third sensing circuit 105. Brake voltage sensed at the input of the third sensing circuit 105 may be sensed using resistor-divider logic. For example, in case of brake voltage up to 195 ohms. Accordingly, brake voltage sensed at microcontroller with combination of resistor R80 & R81 for third sensing circuit 105. R80 may have about 20K & R81 may have about 3.6K, Z10 may be a Zener diode for clamping the voltage to about 5.1 V & C51 may have a capacitance of about 10nF and a working-voltage of about 50 V & use for noise filtering. In an implementation, to reduce power dissipation and heat across leakage-resistor, R86 has an effective leakage resistance of about 195 ohm.
Figure 7 illustrates the fourth sensing circuit 106, in accordance with an embodiment of the invention, which senses ON and OFF states of the self-switch 121, which may be connected to the battery 116. The fourth sensing circuit 106 acts as an interface between the self-switch 121 and the microcontroller 111.
As shown, the fourth sensing circuit 106 includes a diode D9 for reverse voltage protection to the fourth sensing circuit 106. Self switch sense at the input of the fourth sensing circuit 106 may be sensed using resistor-divider logic. Accordingly, the fourth sensing circuit 106 also includes a combination of resistor R67 and a Zener diode Z8 to protect false triggering of the fourth sensing circuit 106, for example, in case of self switch sense up to 195 ohms. Z8 may be a Zener diode for clamping the voltage to about 3.3 V. In an implementation, to reduce power dissipation and heat across leakage-resistor, R67 has an effective leakage resistance of about 195 ohm.
The fourth sensing circuit 106 also includes a plurality of capacitors C34 and C40 for filtering noise signal.C34 may have a capacitance of about 100nF and a working-voltage of about 50 V, while C40 may have a capacitance of about 10nF and a working-voltage of about 50 V. The fourth sensing circuit 106 also includes a transistor Q4 that is used as an electronic switch to generate interrupt signal for the microcontroller 111. Q4 may be an NPN transistor. The fourth sensing circuit 106 further includes a plurality of resistors R68, R30, and R76 as biasing resistors for the transistor Q4. R68 may have the resistance of about 2.2 K. R30 may
10

have the resistance of about 10K. R76 may also have the resistance of about 10K. If the self-switch 121 is in the OFF state, the transistor Q4 remains in a cut-off condition and applies a suitable voltage, such as 5V, to the microcontroller 111. If the self-switch 121 is in the ON state, the transistor Q4 becomes ON and applies 0V to the microcontroller 111. For this purpose, the microcontroller 111 may be configured in the interrupt mode for the fourth sensing circuit 106, such that the microcontroller 111 senses this high to low transition to sense the state of the self-switch 121.
Accordingly, Self-voltage also sensed at microcontroller with combination of resistor R77 & R78 for Fourth sensing circuit 106. R77 may have about 20K & R78 may have about 3.6K, Z9 may be a Zener diode for clamping the voltage to about 5.1 V. C50 may have a capacitance of about 10nF and a working-voltage of about 50 V.
In an alternative embodiment, the self switch sensing circuit as shown and described in Indian Application No. 201611004609 may be adopted.
Figure 8 illustrates the fifth sensing circuit 107 in accordance with an embodiment of the invention, which senses crank signal or speed of the AC generator 115 in order to determine whether the vehicle is running or idling or stopped. The fifth sensing circuit 107 acts as an interface between the crank signal sensor mounted on the AC generator 115 and the microcontroller 111. Further, the fifth sensing circuit 107 converts positive and negative pulses received from the crank signal sensor mounted on the AC generator 115 to pulses of pre-determined voltage ratings, such as 5V pulses, for the microcontroller 111. As shown, the fifth sensing circuit 107 includes a capacitor C16 as a filter to provide protection against ignition noise. C16 may have the capacitance of about 15nF and may be associated with a working voltage of about 50V. The fifth sensing circuit 107 also includes transistors Q10 and Q11 used as an electronic switch to generate interrupt signal. Both Q10 and Q11 may be an epitaxial type NPN transistor. The fifth sensing circuit 107 also includes a plurality of resistors R35, R37, R39, R44, R47, R46, R45 as biasing resistors for the transistor Q10 and Q11. R35 may have the resistance of about 1.2 K. R37 may have the resistance of about 30K. R39 may also have the resistance of about 30K. R44 may have the resistance of about 47K. R47 may have the resistance of about 1K. R46 may have the resistance of about 1K. R45 may have the resistance of about 47K. In addition, R37 and R39 are connected in parallel with capacitors C17 and C19, respectively. C17 and C19 may be polarized capacitors having the
11

capacitance of about 2.2 micro-farad and may be associated with a working voltage of about 50V.
Further includes a plurality of capacitors C18, C20, C25, and C26 for filtering noise signal at base and collector terminals of the transistor Q10 and Q11. C18 may have the capacitance of about 10nF and may be associated with a working voltage of about 50V. C20 may also have the capacitance of about 10nF and may be associated with a working voltage of about 50V. C25 may have the capacitance of about 2.2nF and may be associated with a working voltage of about 50V. C26 may also have the capacitance of about 2.2nF and may be associated with a working voltage of about 50V. The fifth sensing circuit 107 also includes a plurality of Zener diodes Z4 and Z5 to clamp voltage across biasing circuit of the transistor Q10 and Q11. Z4 and Z5 may be associated with a working voltage of about 8.2V.
Figure 9 illustrates the sixth sensing circuit 108 in accordance with an embodiment of the invention, which senses the speed of the input signal. The sixth sensing circuit 108 acts as an interface between the Speed and the Interrupt pin of the microcontroller 111 The sixth sensing circuit includes a capacitor C52 for filtering noise at the input of the sixth sensing circuit 108. C52 may have the capacitance of about 15nF and may be associated with a working voltage of about 50V.The sixth sensing circuit 108 also includes a set of resistors R84 and R85 as current limiting resistors for the microcontroller 111. R84 may have the resistance of about 4.7K. R85 may also have a resistance of about 4.7K. The sixth sensing circuit 108 also includes a diode D20 for over and under voltage protection at the ADC pin of the microcontroller 111.
Figure 10 illustrates the seventh sensing circuit 109in accordance with an embodiment of the invention, which senses ON and OFF state of the controller switch 118.As aforesaid the controller switch 118 is manually operable by a user to activate the “automatic start/stop” functionality within the vehicle. The seventh sensing circuit 109 acts as an interface between the controller switch 118 and the ADC pin of microcontroller 111.The seventh sensing circuit 109 includes a resistor R33, it behaves as a voltage divider circuit in the seventh sensing circuit 109. R33 may have the resistance of about 750ohm. The seventh sensing circuit 109 also includes a resistor R34, which behaves as a current liming resistor for microcontroller 111. R34 may have a resistance about of 4.7K. The seventh sensing circuit 109 also includes a capacitor C46 for filtering noise at the output of the seventh sensing circuit 109.C46 may have the capacitance of about 10nF and may be associated with a working voltage of 50V.
12

The seventh sensing circuit 109 also includes a diode D12 for the reverse voltage protection circuit for the Controller switch circuit 109. The seventh sensing circuit 109 also includes a diode D21 for over and under voltage protection at the ADC pin of the microcontroller 111.
In an alternative embodiment, the control switch sensing circuit as shown and described in Indian Application No. 201611004609 may be adopted.
Figure 11 illustrates the eighth sensing circuit 110 in accordance with an embodiment of the invention, which senses ON and OFF states of the throttle switch 119 As aforesaid, the throttle switch 119 is manually operable by a user to activate the “automatic start/stop” functionality” within the vehicle. The eighth sensing circuit 110 acts as an interface between the throttle switch 119 and the ADC pin of the microcontroller 111.The eighth sensing circuit 110 also includes a plurality of capacitors C31 and C32 for filtering noise at the input of the eighth sensing circuit 110.C31 may have the capacitance of about 15nF and may be associated with a working voltage of about 50V, while C32 may also have the capacitance of about 15nF and may be associated with a working voltage of about 50V.The eighth sensing circuit 110 also includes a first set of resistors R58 and R59 as current limiting resistors for the microcontroller 111. R58 may have the resistance of about 4.7K. R59 may also have the resistance of about 4.7K. The eighth sensing circuit 110 also include a resistor R56 at ADC pin of the microcontroller 110. R56 may have the resistance of about 1K. The eighth sensing circuit 110 also include a resistor R55 to provide power to external Throttle circuit in the vehicle. R55 may have the resistance of about 100 ohms (High Wattage). The eighth sensing circuit 110 also includes a diode D14 for over and under voltage protection at the ADC pin of the microcontroller 111.
If the throttle switch 119 is in the OFF state, then voltage 5V applies to the ADC pin of the microcontroller 111. However, if the throttle switch 119 is in the ON state (Normal condition), then 0V applies to the ADC pin of the microcontroller 111.
In an alternative embodiment, the throttle switch sensing circuit as shown and described in Indian Application No. 201611004609 may be adopted.
The ninth sensing circuit 127 may be a clutch switch sensing circuit having a construction as shown and described in Indian Application No. 201611004609.
The tenth sensing circuit 128 may be a neutral switch sensing circuit having a construction as shown and described in Indian Application No. 201611004609.
13

Figure 12 illustrates 5V regulated power supply circuit, such as 5V regulated power supply, to various circuits and components of the system 126. The 5V regulated power supply circuit 100 receives as an input from battery protection circuit 2. As shown, the 5V power supply circuit 100 includes a voltage regulator U2 having load dump protection and may be selected as to provide 5V for Min. 6V battery voltage.C15 used as a voltage stabilizer at the output terminal of the voltage regulator U2.C15 may be polarized capacitor and may have the capacitance of about 470 micro farads and may be associated with a working voltage of about 16 V. The 5V regulated power supply circuit 100 further includes a capacitor C13 and another capacitor C14 for filtering noise signal at the input and output of the voltage regulator U2, respectively. C13 may have the capacitance of about 47nF and may be associated with a working voltage of about 50V. C14 may have the capacitance of about 100nF and may be associated with a working voltage of about 50V. The 5V regulated supply circuit 100 further includes a resistor R41 for discharging of the capacitor C15 when there is no voltage at the input terminal of the voltage regulator U2. R41 may have the resistance of about 47K. The 5V regulated supply circuit 100 further includes a diode D8, which acts as a switching diode, to provide path for reverse current which protects the voltage regulator U2 from damage.
Figure 13 illustrates the microcontroller 111 and associated circuit components, in accordance with an embodiment of the invention. In one implementation, the microcontroller 111 is a 16-bit microcontroller that performs the automatic start-stop functionality in a vehicle by causing spark-generation through the ignition coil 123 and further schedules the spark-generation at appropriate instants of time that are calculated while the engine is operating. In an example, the time-interval between any two generated sparks at a high RPM of the engine is different from a low RPM. In other words, apart from triggering the spark-generation, the microcontroller 111 also changes an ignition-timing map of the vehicle.
In present implementation, all unused pins of the microcontroller 111 may be configured as output low. Further, the status of the brake switch 105, the self-switch 106, and the controller switch 118, the voltage of the battery 116, and the status of the throttle switch 119 is sensed by the ADC pins of the microcontroller 111. Further, Crank Signal 107, vehicle speed 108, battery-less condition in the vehicle and the status of self-switch 121 is sensed as an interrupt by the microcontroller 111. As shown, a combination of a first diode D10, a resistor R42, and a first capacitor C21 may be used for a RESET pin of the microcontroller
14

111. D10 may be a small signal switching diode having a working voltage of about 100 V. R42 may have the resistance of about 4.7K. C21 may have the capacitance of about 100nF and may be associated with a working voltage of about 50V. Further, a second capacitor C23 may be used as a filter for noise signal at a REGC pin of the microcontroller 111.C23 may have the capacitance of about 470nF and may be associated with a working voltage of about 50V. Further, a third capacitor C24 may be used as a filter for noise signal and as a voltage stabilizer at a VDD pin of the microcontroller 111. C24 may have the capacitance of about 1 micro farad and a working-voltage of about 25V. Further, a connector J1 is used for microcontroller programming.
In an embodiment of the invention, if the system is provided in a vehicle having gears for transmission purposes, all of the above described sensing circuits may be adopted or at least some of the sensing circuits as described may be adopted. In case the system is provided in a vehicle having CVT based transmission system (in which neutral is absent and clutch is absent), the neutral switch sensing circuit and the clutch switch sensing circuit may be absent and the microcontroller may receive input from the remaining sensors and perform the desired functionality.
Figure 14 illustrates the first control circuit 112, in accordance with an embodiment of the invention, which controls the ignition coil 123 for Transistor Controlled ignition (TCI) within the vehicle’s engine. The first control circuit 112 acts as a switch between Ignition coil & ground. In addition, the first control circuit 112 also varies the ignition timing map through at-least utilizing the input from the crank signal as sensed by the fifth sensing circuit 107.
The timing of ignition may be calculated by the microcontroller 111 based on various factors such as crank signal as sensed by the fifth sensing circuit 107 etc. Likewise, the first control circuit 112 or the ignition control circuit 112 may be actuated by the microcontroller 111 to charge the ignition coil 123 based on various factors such as battery voltage sensing 103, state of the self-switch 106, the controller switch 109, and the crank signal state as received from the fifth sensing circuit 107.
As shown, the first control circuit 112 also includes a transistor Q1 which is used as a switch providing a voltage for further ignition circuit. It also includes a resistor R3 and capacitor C5. R3 may have the resistance of about 10K and C5 may have the capacitance of about 10nF and may have associated with a working voltage of about 50V. The first control circuit 112 also includes a transistor Q2 and resistor R2. Q2 is used as an ignition control
15

transistor and R2 is used as a collector current limiting current for transistor Q2. R2 may have the resistance of about 3.3K. The first control circuit 112 also includes two transistors Q3 and Q15 where Q3& Q15 use in ignition control circuit. The first control circuit 112 also includes a set of resistors R4 and R5 which is used as a collector current limiting resistors for transistor Q3. R4 may have the value of about 240ohm and R5 may have value of about 100 ohms. The first control circuit 112 also includes a resistor R6 use as a base current limiting resistor for transistor Q15. R6 may have the resistance of about 10 ohms. The first control circuit 112 also includes a second capacitor C48; it helps to slowly turn off the transistor Q15 for waste spark. C48 may have the capacitance of about 10micro farad and may be associated with a working voltage of about 16v.
Figure 15 illustrates the second control circuit 113 in accordance with an embodiment of the invention. The second control circuit 113 controls the starter relay 124 of the vehicle. Further, the second control circuit 113 acts as a switch between the primary coil of the starter relay 124 and ground. As shown, the second control circuit 113 includes a MOSFET Q13 used as low ON state resistance switch, that is, the MOSFET Q13 may be selected such that it will turn ON for low voltages also, say at VGS < 2.2V. In one implementation, the MOSFET Q13 provides overvoltage and as well as short circuit protection to the second control circuit 113.
As shown, the second control circuit 113 also includes a first capacitor C35 as a filter for noise signal at the drain terminal of the MOSFET Q13. While Q13 may be an N channel power FET, C35 may have a capacitance of about 10nF and may be associated with a working voltage of about 250V. The second control circuit 113 also includes a second capacitor C44 as a filter for noise signal at input of the second control circuit 113. C44 may have a capacitance of about 1nF and may be associated with a working voltage of about 50V. The second control circuit 113 also includes a plurality of resistors R31 and R32 for biasing of the MOSFET Q13. R31 may have a resistance of about 1K. R32 may have a resistance of 10K.The second control circuit 113 also includes a first diode D17 for reverse voltage protection for the primary coil of the starter relay 124. The second control circuit 113 also includes a second diode D16 as a freewheeling diode for the primary coil of the starter relay 124. A third capacitor C36 is provided for filtering noise signal at the gate of the MOSFET Q13, such that said MOSFET Q13 acts as the ON/OFF switch for the starter relay 124. C36 may have a capacitance of about 10nF and may be associated with a working voltage of about 50V.
16

Figure 16 illustrates the third control circuit 114 in accordance with an embodiment of the invention. The third control circuit 114 controls the battery status indicator 125 to indicate the battery level (e.g. healthy, low) or a battery-less condition in the vehicle. Further, the third control circuit 114 acts as a switch between the battery status indicator 125 and the ground. As shown, the third control circuit 114 includes a MOSFET Q14 used as low ON state resistance switch, this is, the MOSFET Q14 may be selected such that it will turn ON for low voltages also, say at VGS < 2.2V. In one implementation, the MOSFET Q14 provides overvoltage and as well as short circuit protection to the third control circuit 114.
The third control circuit 114 also includes a first capacitor C38 as a filter for noise signal at the drain terminal of the MOSFET Q14. While Q14 may be an N channel power MOSFET, C38 may have a capacitance of about 10nF and may be associated with a working voltage of about 250V.The third control circuit 112 also includes a second capacitor C45 as a filter for noise signal at input of the third control circuit 114.C45 may have a capacitance of about 1nF and may be associated with a working voltage of about 50V. The third control circuit 114 also includes a plurality of resistors R70 and R71 for biasing of the MOSFET Q14.R70 may have a resistance of about 1K. R71 may have a resistance of 10K.A third capacitor C37 is provided for filtering noise signal at gate of the MOSFET Q14. C37 may have a capacitance of about 10nF and may be associated with a working voltage of about 50V. A diode D18 is provided for reverse voltage protection for the battery status indicator 125, wherein such indicator 125 may be an illuminating device such as bulb or LED. The MOSFET Q14 acts as an ON/OFF for the battery status indicator 125.
Figure 17 illustrates a complete circuit for the system 126. As shown, the sensing circuits 103-110 the microcontroller 111, control circuits 112-114, the power supply circuit 100, and the reverse voltage protection circuit 101,102 may be connected with each other with help of couplers and connectors and other connection means.
At least by virtue of aforesaid embodiments, the present subject matter describes a multi-functional system 126 that leads to a substantial control over the vehicle’s engine -operation while the vehicle is being driven, while still switching the engine ON and OFF automatically based on various sensed parameters. Such discreet functionalities as exhibited by the system 126 leads to substantial fuel conservation at least by optimization of the fuel consumption during the driven state of the vehicle and prevention of fuel consumption at unnecessary situations.
17

Moreover, the system 126 incorporates a simpler arrangement of electronic/electrical components, thereby being durable and easily installable within the vehicle's chassis. Moreover, owing to being multi-functional in nature, the system 126 proves cost-efficient in the long run.
While certain present preferred embodiments of the invention have been illustrated and described herein, it is to be understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims.

We claim:

A system (126) for providing automatic start stop functionality in a vehicle, the system (126) comprising:
a plurality of sensing circuits (103, 104, 105, 106, 107, 108, 109, 110, 127 & 128) for sensing a set of control parameters, the plurality of sensing circuits being selected from a group comprising of a battery voltage, a battery less condition, actuation of a brake switch, actuation of a self-switch, actuation of a clutch switch, a crank signal, a speed indicating signal, state of a control switch, state of a neutral switch, and state of a throttle switch;
a microcontroller (111) operably coupled to the plurality of sensing circuits, the microcontroller being configured to process the control parameters thus sensed by the plurality of sensing circuits and generate a set of control instructions; and
a plurality of control circuits operably coupled to the microcontroller, the plurality of control circuits being adapted to receive a control instruction from the microcontroller (111) and perform a corresponding control function; the plurality of control circuits including a first control circuit (113) adapted to control an ignition coil (123) and an ignition timing thereof, a second control circuit (114) adapted to control a starter relay (124), and a third control circuit (112) adapted to control a battery status indicator (125);
characterized in that the first control circuit (112) comprises: a first capacitor (C5) acting as a biasing capacitor; plurality of transistors (Q15, Q3, Ql & Q2) adapted to cause
generation of a spark;
a second capacitor (C48) adapted to prevent occurrence of wrong
spark; and
a plurality of resistors (R2, R3, R4, R6& R5) adapted to drive the first
control circuit (113).
The system as claimed in claim 1, further comprising a first voltage protection circuit (101) connected to a DC line (117), the first voltage protection circuit being adapted to provide a stabilized driving voltage to an ignition coil (123), the first voltage protection circuit comprising a combination of a diode (Dl) and a capacitor (C12), the

capacitor (C12) being configured to provide the stabilized driving voltage and the diode (Dl) being configured to provide protection against a reverse voltage.
The system as claimed in claim 1, further comprising a power supply circuit (100) connected to a DC line (117) through a second voltage protection circuit (102), the second voltage protection circuit (102) being adapted to provide a stabilized input voltage to the power supply circuit (100), the second protection circuit (102) comprising a combination of a diode (D22) and a capacitor (C53), the capacitor (C53) being configured to provide the input voltage to the power supply circuit (100) and the diode (D22) being configured to provide protection against a reverse voltage.
The system as claimed in any of claims 2 or 3, wherein the DC line (117) receives DC output from the battery (116) as provided in the vehicle or DC output from an AC-DC converter (122) as provided in the vehicle, and wherein the AC-DC converter (122) converts AC output received from an AC generator (115) of the vehicle into the DC output.
The system as claimed in claim 1, wherein the plurality of sensing circuits comprises a first sensing circuit (103) for sensing a battery voltage level connected to the second voltage protection circuit (102), the first sensing circuit being adapted to sense the stabilized input voltage as provided by the second voltage protection circuit (102).
The system as claimed in claim 5, wherein the first sensing circuit (103) for sensing a battery voltage level comprises a combination of resistors (R23, R25) acting as a voltage divider for converting battery voltage to a pre-defined value, a Zener diode (Z2) for clamping sensed battery voltage, and a capacitor (C49) adapted to filter and provide stabilized voltage to the microcontroller (111).
The system as claimed in claim 1, wherein the plurality of sensing circuits comprises a second sensing circuit (104) directly connected to the DC line (117), the second sensing circuit (104) comprises a first diode (D7) for reverse voltage protection, a transistor (Q12) as a digital switch to generate interrupts for the microcontroller (111), a Zener diode (Z7) to clamp voltage for the transistor (Q12), a plurality of resistors (R21, R62, R63, R74, and R75) as current limiting and biasing resistors for the

transistor (Q12), and a plurality of capacitors (C33, C39) for filtering noise signal at base and collector terminals of the transistor (Q12).
The system as claimed in claim 1, wherein the plurality of sensing circuits comprises a third sensing circuit (105) adapted to sense actuation of a brake switch, the third sensing circuit (105) comprises a diode (D19) for reverse voltage protection to the third sensing circuit (105), a plurality of resistors (R80, R81) as voltage divider resistors for microcontroller (111), and a capacitor (C51) for filtering noise signal & Zener Diode (Z10) for protection of the microcontroller and R86 is high power dissipation resistance for leakage current.
The system as claimed in claim 1, wherein the plurality of sensing circuits comprises a fourth sensing circuit (106) adapted to sense actuation of a self-switch, the fourth sensing circuit comprises a diode (D9) for reverse voltage protection to the fourth sensing circuit (106), a resistor (R68) and a Zener diode (Z8) to protect false triggering of the Fourth sensing circuit (106), a transistor (Q4) used as a switch to generate interrupt signal for the microcontroller (111), a plurality of resistors (R68, R30, and R76) as biasing resistors for the transistor (Q4), a plurality of capacitors (C34, C40) for filtering noise signal, R67 a high power dissipation resistance for leakage current, a combination of resistors (R77, R78) as a voltage divider for converting self-switch voltage to a pre-defined value, a Zener diode (Z9) for clamping sensed self-switch voltage, and a capacitor (C50) as a filter and as a voltage stabilizer for the microcontroller (111).
The system as claimed in claim 1, wherein the plurality of sensing circuits comprise a fifth sensing circuit (107) adapted to sense a crank signal, the fifth sensing circuit comprises a capacitor (CI6) as a filter to provide protection against ignition noise, at least one transistor (Q10 and Ql 1) used as a switch to generate interrupt signal for the microcontroller (111), a plurality of resistors (R35, R37, R39, R44, R47, R46, R45)as biasing resistors for said transistors (Q10 and Ql 1), a plurality of capacitors (CI8, C20, C25, C26) for filtering noise signal at base and collector terminals of said transistors (Q10 and Ql 1), and a plurality of Zener diodes (Z4 and Z5) to clamp voltage across biasing circuit of said transistors (Q10 and Ql 1).

The system as claimed in claim 1, wherein the plurality of sensing circuits comprise a sixth sensing circuit (108) adapted to sense a speed indicating signal as received from a speed sensor disposed on the vehicle, the sixth sensing circuit (108) comprises a capacitor (C52) as a input filtering at the input of sixth sensing circuit(108), resistors (R84 & R85) as a current limiting resistor for the microcontroller (111), a diode (D20) as over and under voltage protection at an interrupt pin of the microcontroller (111).
The system as claimed in claim 1, wherein the plurality of sensing circuits comprise a seventh sensing circuit (109) adapted to detect status of a control switch, the seventh sensing circuit comprises a capacitor (C46) as a filter and as a voltage stabilizer for the microcontroller (111), a first resistor (R34) as a current limiting resistor for the microcontroller (111), a second resistor (R33) as a voltage pull up resistor for the microcontroller (111), a first diode (D21) as over and under voltage protection for the microcontroller (111), and a second diode (D12) for reverse voltage protection for the microcontroller (111).
The system as claimed in claim 1, wherein the plurality of sensing circuits comprise an eighth sensing circuit (110) adapted to detect status of a throttle switch, the eighth sensing circuit comprises plurality of capacitors (C31, C32) for filtering noise at the input of the Eight sensing circuit (110), a first set of resistors (R58 and R59) as current limiting resistors for the microcontroller (111), a resistor (R56) to provide voltage to the microcontroller (111), a resistor (R55) provide power to external throttle circuit in the vehicle and a diode (D14) for over and under voltage protection to the microcontroller (108).
The system as claimed in claim 1, wherein the second control circuit (113) comprises a MOSFET (Q13) as an ON/OFF switch for the starter relay (124), a first capacitor (C35) as a filter for noise signal at a drain terminal of the MOSFET (Q13), a second capacitor (C44) as a filter for noise signal at input of the second control circuit (113), a plurality of resistors (R31, R32) for biasing of the MOSFET (Q13), a first diode (D17) for reverse voltage protection for primary coil of the starter relay (124), and a second diode (D16) as a freewheeling diode for primary coil of the starter relay (124), and a third capacitor (C36) for filtering noise signal at the gate of the MOSFET (Q13).

The system as claimed in claim 1, wherein the third control circuit (114) comprises: a MOSFET (Q14) acting as an ON/OFF switch for the battery status indicator (125); a first capacitor (C38) as a filter for noise signal at a drain terminal of the MOSFET (Q14);
a second capacitor (C45) as a filter for noise signal at input of the third control circuit
(114);
a plurality of resistors (R70, R71) for biasing of the MOSFET (Q14);
a third capacitor (C37) for filtering noise signal at gate of the MOSFET (Q14); and
a diode (D18) for reverse voltage protection for the battery status indicatorl25
provided at the output of the third control circuit (114).
The system as claimed in claim 1, wherein the microcontroller (111) is a 16-bit microcontroller, wherein a combination of a first diode (DIO), a resistor (R42), and a first capacitor (C21) is used for RESET pin of the microcontroller (111), wherein a second capacitor (C23) is used as a filter for noise signal at a REGC pin of the microcontroller (111), wherein a third capacitor (C24)may be used as a filter for noise signal and as a voltage stabilizer at a VDD pin of the microcontroller (111), and wherein a connector (Jl) is used for microcontroller programming.
The system as claimed in claim 1, wherein the first transistor (Ql) forming part of the first control circuit has an emitter terminal coupled to the voltage supply circuit, a base terminal being connected to the voltage supply circuit via a parallel combination of a first capacitor (C5) and a first resistor (R3), and an collector terminal, the first transistor (Ql) acting as a switch and provide input voltage to a remaining components of the first control circuit (112).
The system as claimed in claim 1, wherein the second transistor (Q2) forming part of the first control circuit has a base terminal adapted to receive an ignition control signal as provided by the microcontroller (111); an emitter terminal being connected to a ground terminal, and a collector terminal being connected to the base terminal of the first transistor (Ql) via a current limiting resistor (R2), the second transistor (Q2) acting as ignition controlling element.

The system as claimed in claim 1, wherein the third transistor (Q3) forming part of the first control circuit has a base terminal adapted to receive an ignition timing control signal from the microcontroller (111); an emitter terminal being connected to a ground, and a collector terminal being connected to the collector terminal of the first transistor (Ql) via a series combination of current limiting resistors (R5 and R4).
The system as claimed in claim 1, wherein the fourth transistor (Q15) forming part of the first control circuit has a base terminal connected to a collector terminal of the third transistor (Q3) via a current limiting resistor (R6), an emitter terminal connected to a ground terminal and a collector terminal acts as output terminal.
The system as claimed in claim 1, wherein the first capacitor (C5) forming part of the first control circuit acts as a biasing capacitor.
The system as claimed in claim 1, wherein the second capacitor (C48) forming part of the first control circuit is adapted to slowly turn OFF the fourth transistor (Q15) for a waste spark.