FIELD OF INVENTION
The invention generally relates to a system and method for driving current-driven devices (loads) such as light emitting diodes (LEDs).
BACKGROUND
A light emitting diodes (LEDs) requires a driver arrangement/circuit to operate. The driver arrangement/Circuit controls the operation of LED. There are various known driver arrangement/Circuit for operating LEDs. One such arrangement/circuit is known as Quasi Continuous mode of Operation. The Quasi Continuous mode operates LEDs in such a way that the. power supply, is switched on/Off periodically for certain time intervals, which are short enough to reduce thermal effects significantly, but still long enough that the LED process is close to-steady state: Thexommercial drivers often employ power conversion topology to drive LED andhas a limitation of connecting number of LED's and its output drive current.
• Hence there is a need fora.system and method for driving light.emitting loads.
SUMMARY OF THE INVENTION
According to embodiments of the invention, a system and method for driving a light emitting load unit is disclosed. The disclosed system includes a central processing unit for generating a quasi-continuous waveform to drive the light emitting load, a system input and protection module for continuously monitoring health status and providing system health related feedbacks to central processing unit and a capacitor bank having plurality of capacitors to act as an energy storage bank and for supplying required energy for driving light emitting load. The system further includesa control module for controlling charging and discharging of the

capacitor bank based on the feedback from central processing unit and the charge available in
the capacitor bank.
BRIEF DESCRIPTION OF DRAWINGS
Other objects, features, and advantages of the invention will be apparent from the following description when read with reference to the accompanying drawings:
Figure I illustrates an exemplary block diagram of a system for driving a Lighting load
according to an embodiment of the invention Figure 2 illustrates an'exemplary system for driving a;Lighl emitting diode (LED)Lighting
unit according to an embodiment of the invention; and
Figure.3 illustrates anexemplary circuit for driving a LED Lighting unit according to.another embodiment of the invention.
DETAILED DESCRIPTION OF DRAWINGS
The following description with reference to the accompanying drawings is provided to assist in a comprehensive .understanding of exemplary embodiments. It. includes various specific details to assist in that understanding but these are regarded as merely exemplary.-Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
Figure 1 illustrates an exemplary block diagram for a system 100 for driving a light emitting load unit 102 according to an embodiment of the invention. The light emitting load unit 102

may include a plurality of light emitting diodes (LED's), organic light emitting diodes (OLEDs) or Laser diodes. The light emitting load may be so arranged to have a proper isolation and.efficient thermal management so as to maximize the lifecycle.
The system 100 further includes a central processing unit 104 for generating a quasi-continuous waveform to drive the light emitting load 102. The selection of central processing unit 104 may be based on the light emitting load 102 operating time, duty cycle & operating frequency etc. According to an embodiment, the central processing unit 104 is an integrated circuit (IC). The systenrTOO may.include one or. more sub component for addressing power, clock and reset
requirements .of the .central processing unit 104. -According to: an embodiment the central, processing unit 104 may have a timer and counter module (not shown), an Analog/ Digital
- module and-an Input/Output control modules (not shown).-The timer and;counter.module may¬be configured *o satisfy'the minimum timing requirement-of. light emitting load 102. The -: Analog/Digital module and the Input/output control module may define a safety thresholds of >the system 100. Based on the defined threshold limits.the-health of the system 100 may be' :
•monitored and controlled by the central processing-unit 104.
The system may further include a system input arid protection module; 106 for continuously monitoring input voltage and providing feedback to the central processing unit 104. The system input and protection module 106 may provide an external power interface and continuously monitor health status of the system 100 to avoid the risk of system 100 entering in to abnormal behaviour. According to another embodiment, the system 100 may further includes one or more protective features such as over current protection over voltage protection, charge current limit, discharge current limit, under voltage lock out, transient voltage suppressor,-short circuit protection etc.

The system 100 may further includes a capacitor bank. 108. According to an embodiment, the
capacitor bank 108 may have a plurality of capacitors to-act as an energy storage bank and for supplying required energy for driving the light emitting load 102. According to yet another, embodiment, the capacitor bank 108 may include a plurality of low equivalent series resistor (ESR) high density capacitors. The number/density of the capacitors in the capacitor bank 108 may depend on the type, number of light emitting load 102, drive current output, light output (Brightness), and the optical coverage area (Light Pattern). Proper isolation and thermal . management shall be planned to increase the capacitor lifecycle. According to embodiments of
the invention, -the.capacitor bank 1.08 may be scalable thereby enabling a- single driver circuit for various
lighting load applications. According to another embodiment the input power
source vbltage'may be.slightly higher than the output..voltage (load side) to avoid steady state'
behaviour of the capacitors.-
The system 100 further.includes a control module. L10 according to an;embodiment of the
invention: The. control module 1 10 may control the charging and:discharging of.the capacitor
bank-108'based on the feedback from central processing unit 104 and the charge available in
the.capacitor bankvl08. According to yet another embodiment* the control module 110 may .
include a charging control module for controlling the charging of the capacitor bank 108 at a
predefined charging rate and a discharge control module for .supplying predefined voltage &
current pulses across the light emitting load.
The charging control module may further include a high side driver module with closed loop feedback control mechanism and charging termination function to control the charging of the capacitor bank 108 in communication with the central processing unit 104. According to yet

another embodiment, the discharging control module may further include a low side driver module having control switch for discharging current from capacitor bank based on switching cycle of the light emitting load 102 and in communication with the central processing unit 104. According to another embodiment, the charging control module may include one or more resistors. The resistors may control the rate of charge of the capacitor bank 108 by adjusting charge current limit thresholds. According to another embodiment, the charging control module may have a feedback arrangement to ensure that the capacitor bank charges up to the recommended vollage and not to violate the pre-defined limits.
According.to an embodiment, the high side field effect transistor (FET.) and low side field effect
transistor (FET) switches may be operated through a high precision quasi continuous
waveforms from central processing'unit 104
Figure 2 illustrates an "exemplary-system for driving a Light emitting diode (LED) Lighting
unit according to an embodiment.of the invention and Figure 3 illustrates an .exemplary circuit
for driving a LED Lighting unit according to another embodiment of the invention.
"It is:understood that-the.above description is intended totbe illustrative, and not restrictive. It -
is intended to cover all alternatives, modifications and equivalents as may be included within
- the spirit and scope of the invention as defined . in the appended claims. Many other
embodiments will be apparent to those of skill in the art upon reviewing the above description.
The scope of the invention should, therefore, be determined with, reference to the appended
. claims, along with the full scope of equivalents to which such claims are entitled. In the
-appended claims, the terms "including" and "in which" are used as the plain-English
equivalents of the respective terms "comprising" and "wherein," respectively.

We claim:
1. A system 100 for driving a light emitting load unit 102, the system 100 comprises:
a central processing .unit 104 for generating a quasi-continuous waveform to drive the . light emitting load 102;
a system input and protection module 106 for continuously monitoring the health of the system 100 and providing feedback to the central processing unit 104;
a capacitor bank 108 having plurality of capacitors to act as an energy storage bank and for supplying required energy for driving light emitting load 102; and
a controLmodule 110 for controlling the charging and discharging of the capacitor bank.'based on.the feedback from central processing unit, and-the charge available.in the capacitor bank.
2. The system 100 as claimed in claim I, where in the control module 110 comprises:
.-!''' a charging control module.for controlling the charging of the capacitors.at a predefined
charging rate; arid.
.a discharge control module for supplying predefined-voltage'& current pulses across
the light emitting load.
3. The system 100 as claimed in claim 2, wherein the charging control module have a high
side driver module with closed loop feedback .control mechanism and charging
termination function in communication with the central processing unit.
4. The system 100 as claimed in claim 2, wherein the discharging module have a low side
driver module having control switch in communication with the central processing unit

for discharging current from capacitor bank based on switching cycle of the light
emitting load.
5. The system 100 as claimed in claim 3 or 4, wherein the switch are field effect transistor
(FET) switch.
6. .The system 100 as claimed in claim 1, wherein the central processing unit have a timer
and Counter module an Analog/Digital module and an Input/Output control module.
7.Thesystem 100 as.claime'd.in claim I, wherein the capacitors are low equivalent series resistor (ESR) high density capacitors.
8 .The system 100 as claimed.in claim 1, wherein the light emitting, load consist of light emittingdiodes.(L)EDs), Organic tight emiltingdiodes (OLEDs). or Laser diodes.