The present invention relates to a Light Emitting Diodes LEDs based illumination system for vehicular application such as two-wheeler, bike, motorbike, scooter and the like.
BACKGROUND OF THE INVENTION:
A two-wheeler vehicle such as bike, motorbike, scooter and the like comprises a position indicating light, left & right winkers at the front, left & right winkers at the rear, a license plate illuminating light (located near a rear license plate), and a tail stop light associated with brakes.
In the prior art, the said lights incorporate incandescent bulbs. But as the automobile industry is evolving and moving towards replacing incandescent bulbs with the light emitting diode (LED) for the fact that LED has an extremely long lifespan and are energy efficient as compared to any other lighting technology. As LED is a constant current device, replacement of incandescent bulbs with LED necessitates use of some additional components such as buck/boost converter, current driver, power controller and the like.
By way of example, E.P. Patent no. 2538753 discloses a driver device for light-emitting diodes, comprising: - a controllable first power source configured to produce a first voltage at its output and a buck converter having an input coupled to the output of said first power source, and an output for coupling light-emitting diodes thereto. Further, the E.P. Patent discloses that same principle can be applied in cases where there are multiple buck converters that all receive their input voltages from a common controllable first power source. In such a case it may happen that different numbers of serially coupled LEDs are driven by different ones of the buck converters.
By way of example, Non- Patent Literature "LED Controllers and Switches Improve Matrix Lighting" as may be downloaded from https://www.planetanalog.com/author.asp7section id=3406&doc id=565004 discloses a led driving circuit with multiple buck converters. It has been felt that the use of multiple buck converters will increase the cost.
By way of example, U.S. Patent No. 20040155844 discloses a driver circuit for energizing a plurality of LEDs, said driver circuit comprising: a constant current source responsive to a

first input to produce a current and connectable to an emitter comprising a plurality of LEDs, said constant current source configured to monitor an electrical current through the plurality of LEDs and limit said current to said current; a controller programmed to; monitor the state of a synchronization input to the controller; provide said first input to said constant current source in a predetermined pattern, initiation of said pattern alternatively controlled by the controller or by a change of state of said synchronization input; and produce a synchronization output indicating initiation of said pattern by said controller; and a synchronization circuit electrically connected to a synchronization line, said synchronization circuit responsive to a change in the electrical potential present on the synchronization line from a first electrical potential to a second electrical potential to provide said synchronization input to the controller and responsive to said synchronization output from the controller to apply said second electrical potential to said synchronization line, wherein initiation of said pattern is triggered by the change of electrical potential on the synchronization line if said synchronization input is present before the controller produces said synchronization output and initiation of said pattern by said controller is triggered by the controller if said synchronization input is not present before the controller produces said synchronization output.
Thus, it has been felt that the existing LED-based illumination systems suffer from several disadvantages including high cost, large size, increased complexity, high heat dissipation etc. Therefore, a simpler and cost-efficient LED-based illumination system is required.
SUMMARY OF THE INVENTION:
This summary is provided to introduce a selection of concepts in a simplified format that is 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 control device (306) for providing
preconfigured constant driving currents to a plurality of LED-based devices (3041 n). In an
embodiment of the invention, the control device (306) comprises a buck converter (308)
configured to receive input voltage from a power source and generate a preconfigured driving
voltage. In an embodiment of the invention, the control dev ice (306) further comprises a
plurality of driver circuits (310i n) connected in parallel to each other and to an output of

the buck converter (308), each of the plurality of driver circuits (310i n) being configured
to receive the preconfigured driving voltage as produced by the buck converter (308) and generate the preconfigured constant current for driving the plurality of LED-based devices
(304i n). In a further embodiment of the invention, the control device (306) further
comprises a processing unit (316) adapted to set an impairment flag if voltage (VOUT) at a location between output terminal of the buck converter (308) and a junction terminal (314) exceeds a preset threshold value (VOUTmax).
In an embodiment of the invention, the processing unit (316) is operably coupled to an over voltage signal generation device (312) and is configured to set the impairment flag on basis of an over voltage indicative signal (S) as received there-from. In an embodiment of the invention, the over voltage signal generation device (312) is configured to generate the over voltage indicative signal (S) if a voltage (VOUT) at a location between output terminal of the buck converter (308) and a junction terminal (314) exceeds a preset threshold value (VOUTmax).
In an embodiment of the invention, the over voltage signal generation device (312) comprises a comparator (318). In relation to the comparator (318), threshold value (VOUTmax) may be set by controlling Vcc (i.e. Comparator reference voltage).
In an embodiment of the invention, the processing unit (316) is operably coupled to a first voltage sensor (402) and is adapted to receive there-from a first voltage signal (VOUT). In a further embodiment of the invention, the processing unit (316) is operably coupled to a memory device (404) and is configured to retrieve there-from the threshold value (VOUTmax). In a furthermore embodiment of the invention, the processing unit (316) is configured to compare the first voltage signal (VOUT) with the threshold value (VOUTmax) and set the impairment flag if the first voltage signal (VOUT) exceeds the threshold value (VOUTmax).
In an embodiment of the invention, the processing unit (316) is operably coupled to a second voltage sensor (502) and is adapted to receive there-from a second voltage signal (VIN). In another embodiment of the invention, the processing unit (316) is configured to compare the first voltage signal (VOUT) as received from the first voltage sensor (402) with the second voltage signal (VIN) as received from the second voltage sensor and determine a difference voltage (VDIFF) there-between. In a further embodiment of the invention, the processing unit

(316) is configured to set the impairment flag if the difference voltage (VDIFF) is less than a threshold value (X).
In an embodiment of the invention, a plurality of driver circuit control switches (6021....n) are
placed in conjunction with the driver circuits (310i n) and the processing unit (316) is
further adapted to provide control signals (CSi....n) to each of the driver circuit control
switches (602i n), each of the control signals (CSi....n) being same or different, thereby
controlling the ON/OFF state of the driver circuit (310i n).
In an embodiment of the invention, the control unit comprises a driver circuit control switch
(702) placed in conjunction with the plurality of driver circuits (310i n) and the processing
unit (316) is further adapted to provide control signal (CS) to the driver circuit control switch
(602), thereby controlling the ON/OFF state of the driver circuit (310i n)-
In an embodiment of the invention, the processing unit (316) is further adapted to generate an error signal and provide the error signal to an error signal output device (802) or error signal storing unit (804).
In an embodiment of the invention, the control device further comprises a capacitor (806) to act as a backup in an event of non-availability of voltage from the power supply (302).
In a further embodiment of the invention, the control device further comprises a reverse protection device (808) provided in a path between the power source (302) and the capacitor (806).
To further clarify the advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS:
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the

accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Figure 1 demonstrates a circuit (100) for providing a constant current to a plurality of LED-based devices incorporated in a two-wheeled vehicle in accordance with the teachings of
Applicant's co-pending patent application NO. ;
Figure 2 demonstrates a circuit (200) for providing a constant current to a plurality of LED-based devices incorporated in a two-wheeled vehicle in accordance with the teachings of
Applicant's co-pending patent application NO. ;
Figure 3 demonstrates a circuit (300) for providing a constant current to a plurality of LED-
based devices incorporated in a two-wheeled vehicle, wherein the circuit comprises a over
voltage signal generation device in accordance with an embodiment of the present invention;
Figure 4 demonstrates a circuit for providing a constant current to a plurality of LED-based
devices incorporated in a two-wheeled vehicle, wherein the circuit comprises a first voltage
sensor in accordance with an embodiment of the present invention;
Figure 5 demonstrates a circuit for providing a constant current to a plurality of LED-based
devices incorporated in a two-wheeled vehicle, wherein the circuit comprises a first voltage
sensor and a second voltage sensor in accordance with an embodiment of the present
invention;
Figure 6 demonstrates a circuit for providing a constant current to a plurality of LED-based
devices incorporated in a two-wheeled vehicle, wherein the circuit comprises a plurality of
driver circuit control switches placed in conjunction with the driver circuits in accordance
with an embodiment of the present invention;
Figure 7 demonstrates a circuit for providing a constant current to a plurality of LED-based
devices incorporated in a two-wheeled vehicle, wherein the circuit comprises a single driver
circuit control switch placed in conjunction with the driver circuits in accordance with an
embodiment of the present invention; and
Figure 8 demonstrates a circuit for providing a constant current to a plurality of LED-based
devices incorporated in a two-wheeled vehicle, wherein the circuit comprises other elements
such error signal output device, error signal storing device, capacitor, and reverse protection
device in accordance with an embodiment of the present invention.
Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve

understanding of aspects of the present invention. 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 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.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are explanatory of the invention and are not intended to be restrictive thereof.
Reference throughout this specification to "an aspect", "another aspect" 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 present 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 or components proceeded by "comprises... a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other

components or additional devices or additional sub-systems or additional elements or additional structures or additional components.
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.
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
Referring to Figure 1, a two-wheeled vehicle may be provided with a circuit (100) that
comprises a power supply device (102), a plurality of LED-based devices (104i n), and a
power controller (106) connected between the power supply device (102) and the plurality of
LED-based devices (104i n). The power controller (106) is configured to receive input
voltage from the power supply device (102) and provide constant driving currents to each of
the plurality of the LED-based devices (104i n). As disclosed in Applicant's co-pending
patent application No. , complete contents of which are incorporated herein, the
power controller (106) comprises a buck converter (108) configured to receive the input voltage and generate the preconfigured driving voltage. The power controller (106) further
comprises a plurality of driver circuits (110i n) connected to the buck converter (108). The
plurality of driver circuits (110i n) being connected so as to be parallel to each other. Each
of the plurality of driver circuits (110i n) receives the preconfigured driving voltage as
produced by the buck converter (108) and generates preconfigured constant driving current
for supply to LED-based device (104i n) connected thereto. The power controller (106)
may additionally comprise a capacitor (112) to act as a backup in an event of non-availability of input voltage from the power supply device (102). A reverse protection device (114) is provided in the path between the power supply device (102) and the capacitor (112). The power controller (106) further comprises a plurality of diodes (116i...n) connected after a junction terminal (JT), wherein the junction terminal being located between the buck
converter (108) and the plurality of current drivers (110i n). The plurality of diodes
(116i...n) provide safeguard against "wire harness output short to power supply device condition".

However, in the circuit (100) it is not possible to detect the wire harness output short to power supply device condition as the junction terminal is prohibited from reaching a voltage which is substantially equal to the input voltage as being supplied by the power supply device. Thus, providing an error signal for example, on an instrument cluster (or a dashboard), which is generally beneficial for the end user, is not possible with the circuit (100). Also, by providing the plurality of diodes (116i...n), the minimum voltage required for the circuit to function increases. Since, the LED-based devices are incorporated in a two-wheeled vehicle having limited voltage, an increase in the minimum voltage required for the circuit to function is a substantial drawback.
Referring to Figure 2, an alternative construction of the power controller (206) is shown,
which is disclosed in Applicant's co-pending patent application No. , complete
contents of which are incorporated herein. Even this power controller comprises a buck converter (208) configured to receive the input voltage and generate a preconfigured driving
voltage, and a plurality of driver circuits (210i n) connected in parallel to each other and to
an output of the buck converter (208). Each of the plurality of driver circuits (210i n) is
configured to receive the preconfigured driving voltage as produced by the buck converter
(208) and generate the preconfigured constant driving currents along a plurality of current
flow paths (212i n) that are parallel to each other for providing to the plurality of LED-
based devices (2041 n) connected thereto. Each of the plurality of current flow paths
(212i n) is provided with an output voltage sensor or an over-voltage signal generation
device (214i n). The power controller (206) further comprises a control unit (216) adapted to
set an impairment flag based on the input from the output voltage sensor or an over-voltage
signal generation device (214i n).
While the power controller (206) as shown in Figure 2 addresses the problems as faced in the power controller (106) as shown in Figure 1, it has its own disadvantages including high cost, large size, increased complexity, etc. Accordingly, there exists a need to address the aforesaid disadvantages.
Referring to Figure 3, there is illustrated a circuit (300) for providing a constant current to a plurality of LED-based devices incorporated in a two-wheeled vehicle in accordance with an embodiment of the invention. The second circuit (300) comprises a power supply device
(302), a plurality of LED-based devices (304i n), and a power controller (306) connected
between the power supply device (302) and the plurality of LED-based devices (304i n).

The power controller (306) is configured to receive the input voltage from the power supply
(302) and provide constant driving currents for illuminating each of the plurality of the LED-
based devices (3041 n).
In an embodiment of the invention, the power controller (306) comprises a buck converter (308) configured to receive the input voltage and generate a preconfigured driving voltage,
and a plurality of driver circuits (310i n) connected in parallel to each other and to an
output of the buck converter (308). Each of the plurality of driver circuits (310i n) is
configured to receive the preconfigured driving voltage as produced by the buck converter
(308) and generate the preconfigured constant current for driving the plurality of LED-based
devices (304i n).
The power controller (306) comprises an over-voltage signal generation device (312) disposed between output terminal of the buck converter (308) and a junction terminal (314), wherein the junction terminal (314) is located between the buck converter (308) and the
plurality of current drivers (310i n). The over voltage generation device (312) is adapted to
generate an over-voltage signal (S) if the voltage at a location between output terminal of the buck converter (308) and the junction terminal (314) (i.e. VOUT) exceeds a threshold value that has been preset (i.e. VOUTmax).
The power controller (306) further comprises a control unit (316) operably coupled to the over voltage generation device (312). The control unit (316) is adapted to set an impairment flag in response to receiving the over-voltage signal (S) from the over-voltage signal generation device (312). It may be noted that setting of the impairment flag, is indicative of "wire harness output short to power supply device condition", as only during "wire harness output short to power supply device condition" the voltage at a location between the output terminal of the buck converter (308) and the junction terminal (314) will go beyond the threshold value.
In an embodiment of the invention, the over voltage generation device (312) comprises a comparator (318). In relation to the comparator (318), threshold value (VOUTmax) may be set by controlling Vcc (i.e. voltage at the common-collector terminal).
Referring to Figure 4, in an alternative embodiment, the power controller (306) comprises a first voltage sensor (402) disposed between output terminal of the buck converter (308) and a

junction terminal (314), wherein the junction terminal (314) is located between the buck
converter (308) and the plurality of current drivers (310i n). The first voltage senor (402)
is adapted to sense the voltage at a location between output terminal of the buck converter (308) and the junction terminal (314) and produce a signal indicative thereof (VOUT).
In this embodiment, the power controller (306) further comprises a memory device (404) that stores a threshold value (VOUTmax). The control unit (316) is operably coupled to the first voltage sensor (402) and is adapted to receive the signal there-from (VOUT). The control unit (316) is further coupled to the memory device (404) and retrieve the threshold value there-from (VOUTmax). The control unit (316) is further adapted to compare the signal received from the first voltage sensor (402) with the threshold value retrieved from the memory device (404) (i.e. compare VOUT with VOUTmax) and in case the signal received from the first voltage sensor VOUT exceeds the threshold value VOUTmax, set the impairment flag.
One scenario which is commonly faced in a vehicle includes change in the input voltage over time. If the input voltage being supplied changes over time, and in particular, if the input voltage being supplied reduces over time, it may be advantageous to consider additional factors for setting the impairment flag.
For example, when (a) the power controller has 4 LED-based devices connected thereto with each of the LED-based device having a voltage requirement of about 7.5V; (b) the threshold value has been set as a constant value of about 9V; and (c) the power controller receives an input voltage of the order of about 9.0 to about 9.7V from the battery (instead of 12V); the voltage as available at a location between output terminal of the buck converter (308) and the junction terminal (314) (i.e. VOUT) does not exceed 9V (i.e. VOUTmax) even under "wire harness output short to power supply device condition" and hence, it may be advantageous to consider additional factors for setting the impairment flag.
In this regard, attention is drawn to Figure 5, wherein the power controller (306) is additionally provided with a second voltage sensor (502). The second voltage sensor (502) is connected before the buck converter (308) and hence, senses the voltage as being supplied by the power source (302) (i.e. VIN). In this embodiment, the power controller (306) is not provided with over-voltage signal generation device (312), and instead is provided with the first voltage sensor (402). In accordance with this embodiment of the invention, the control unit (316) is configured to receive first voltage (VOUT) as sensed by each the first voltage

sensor (402) and the second voltage (VIN) as sensed by the second voltage sensor (502). The control unit (316) is further configured to compare the first received voltage (VOUT) and the second received voltage (VIN) and to determine voltage difference therebetween (VDIFF). The control unit (316) is further configured to set the impairment flag if the voltage differences (VDIFF) is less than a threshold value (X). It may be noted that the control unit (316) is operably coupled to the memory unit (404) and is configured to extract there-from the threshold value (X).
The control unit (316) may be configured such that it first determines as to whether the first voltage is greater than the corresponding threshold value i.e. is VOUT > VOUTmax. In case the first voltage is greater than the corresponding threshold value VOUTmax, the control unit is configured to set the impairment flag. If however VOUT < VOUTmax, the control unit determines voltage difference (VDIFF) and in case VDIFF is less than the threshold value X, set the impairment flag.
In addition to setting the impairment flag (or in other words, detecting the wire harness output
short to power supply device condition), in an embodiment of the invention, the control unit
(316) may be further configured to control the ON/OFF state of the driver circuits (310i „)•
In an embodiment of the invention, the control unit (316) may selectively control the
ON/OFF state of the driver circuits (310i n) i.e. the control unit (316) may keep one or
more of the driver circuits in ON state while may keep the remaining of the driver circuits in OFF state. In a non-limiting example of the invention, the control unit (316) may selectively
control the ON/OFF state of the driver circuits (210i n) based on the nature of the load thus
connected. For instance, a driver circuit driving a predetermined type of LED-based device may be kept in ON state despite detection of the wire harness short to power supply device condition while the remaining driver circuits (i.e. the driver circuits that are NOT driving the predetermined type of LED-based device) may be kept in OFF state.
Referring to Figure 6, in an embodiment of the invention, to enable the control unit (316) to
selectively control the ON/OFF state of the driver circuits (310i n), each driver circuit is
provided with a dedicated driver circuit control switch (6021 n). In an embodiment of the
invention, the control unit (316) may generate control signals (CSi n) specific for each
driver circuit and provide the same to the associated driver circuit control switch.

In an alternative embodiment of the invention, the control unit (316) may uniformly control
the ON/OFF state of the driver circuits (310i n) i.e. the control unit (316) may keep all of
the driver circuits (310i n) in ON state or keep all of the driver circuits (310i n) in OFF
state.
It may be noted that even the power controller (306) as shown in Figure 6 may keep all of
the driver circuits (310i n) in ON state or keep all of the driver circuits (310i n) in OFF
state. For this purpose, the control unit (316) is merely required to generate a single control
signal and provide the single control signal to all of the dedicated driver circuit control switch
(602! n).
It may be noted that in an alternative embodiment as shown in Figure 7, a single driver
circuit control switch (702) is shared by of all the driver circuits (310i n)- The single driver
circuit control switch (702) is connected to the control unit (316). The control unit (316)
generates and provides a single control signal to the single driver circuit control switch (702)
and thus controls the ON/OFF state of all driver circuits (310i n).
In an embodiment of the invention, once the control unit (316) detects the wire harness output short to power source condition, the control unit (316) may be further configured to generate error signal. In an embodiment of the invention as shown in Figure 8, the power controller (306) may further comprise an error signal output device (802) and the control unit (316) may be further adapted to provide the error signal to the error signal output device (802). The error signal output device (802) may be a visual output providing device that may be disposed on the instrument cluster of the vehicle. Alternatively, the error signal output device (802) may be an audio output providing device that may be disposed at a suitable location on the vehicle.
The power controller (306) may further comprise an error signal storing unit (804) and the control unit (316) may be further adapted to provide the error signal to the error signal storing unit (804). The error signal thus stored on the error signal storing unit (804) may be used for diagnostic purposes.
In an embodiment of the invention, the power controller (306) may comprise a capacitor (806) to act as a backup in an event of non-availability of input voltage from the power supply device (302).

In an embodiment of the invention, the power controller (306) may further comprise a reverse protection device (808) provided in a path between the power supply device (302) and the capacitor (806).
In an embodiment of the invention, the output voltage sensors may be resistor connected in shunt with the current flow paths.
In an embodiment of the invention, each of the driver circuit control switch (602i....n) is a transistor.
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. Clearly, the invention may be otherwise variously embodied, and practiced within the scope of the following claims.

WE CLAIM:

1.A control device (306) for providing preconfigured constant driving currents to a
plurality of LED-based devices (3041 n), the control device comprising:
a buck converter (308) configured to receive input voltage from a power source and generate a preconfigured driving voltage;
a plurality of driver circuits (310i n) connected in parallel to each other and to an
output of the buck converter (308), each of the plurality of driver circuits (310i n)
being configured to receive the preconfigured driving voltage as produced by the buck converter (308) and generate the preconfigured constant current for driving the
plurality of LED-based devices (304i n); and
a control unit (316) adapted to set an impairment flag if voltage (VOUT) at a location between output terminal of the buck converter (308) and a junction terminal (314) exceeds a preset threshold value (VOUTmax).
2. The control device as claimed in claim 1, wherein the control unit (316) is operably coupled to an over voltage signal generation device (312) and is configured to set the impairment flag on basis of an over voltage indicative signal (S) as received there¬from.
3. The control device as claimed in claim 2, wherein the over voltage signal generation device is configured to generate the over voltage indicative signal (S) if the voltage (VOUT) at a location between output terminal of the buck converter (308) and a junction terminal (314) exceeds a preset threshold value (VOUTmax).
4. The control device as claimed in claim 1, wherein the control unit (316) is operably coupled to a first voltage sensor (402) and is adapted to receive there-from a first voltage signal (VOUT).
5. The control device as claimed in claim 1, wherein the control unit (316) is operably coupled to a memory device (404) and is configured to retrieve there-from the threshold value (VOUTmax).

6. The control device as claimed in any of claims 4-5, wherein the control unit (316) is configured to compare the first voltage signal (VOUT) with the threshold value (VOUTmax) and set the impairment flag if the first voltage signal (VOUT) exceeds the threshold value (VOUTmax).
7. The control device as claimed in claim 1, wherein the control unit (316) is operably coupled to a second voltage sensor (502) and is adapted to receive there-from a second voltage signal (VIN).
8. The control device as claimed in claim 7, wherein the control unit (316) is configured to compare the first voltage signal (VOUT) as received from the first voltage sensor (402) with the second voltage signal (VIN) as received from the second voltage sensor and determine a difference voltage (VDIFF) there-between; the control unit (316) is configured to set the impairment flag if the difference voltage (VDIFF) is less than a threshold value (X).
9. The control device as claimed in claim 1, comprising a plurality of driver circuit control switches (602i....n) that are placed in conjunction with the driver circuits
(310i n) and the control unit (316) is further adapted to provide control signals
(CSi....n) to each of the driver circuit control switches (602i n), each of the control
signals (CSi....n) being same or different, thereby controlling the ON/OFF state of the
driver circuit (310i n).
10. The control device as claimed in claim 1, comprising a driver circuit control switch
(702) placed in conjunction with the plurality of driver circuits (310i n) and the
control unit (316) is further adapted to provide control signal (CS) to the driver circuit control switch (702), thereby controlling the ON/OFF state of the driver circuit
(310l n).
11. The control device as claimed in claim 1, wherein the control unit (316) is further
adapted to generate an error signal and provide the error signal to an error signal
output device (802) or error signal storing unit (804).

12. The control device as claimed in claim 1, comprising a capacitor (806) to act as a backup in an event of non-availability of voltage from the power supply (302).
13. The control device as claimed in claim 1, comprising a reverse protection device (808) provided in a path between the power source (302) and the capacitor (806).