FORM2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title of the invention. - ILLUMINATION DEVICE FOR DISTRIBUTION BOARD
2. Applicant(s)

(a) NAME: LARSEN & TOUBRO LIMITED
(b) NATIONALITY: An Indian Company.
(c) ADDRESS: L & T House, Ballard Estate, Mumbai 400 001,
State of Maharashtra, India
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed:

TECHNICAL FIELD OF THE INVENTION
Present invention relates generally to an illuminating device and more particularly the present invention relates to an illumination device for distribution board to operate modular devices in dark.
BACKGROUND AND THE PRIOR ART
The Distribution Boards contains modular devices which are operated manually to turn ON or OFF the load. Many a times, one needs to operate these modular devices present in the distribution board in dark. Due to darkness the person may turn ON an unintended load. The presence of light would help avoid the unnecessary operation of the modular devices; otherwise in dark one may need to make many trials to make the intended switch ON because he would be unable to see the modular device and also the label on the modular device of the individual loads.
Thus, there is a need to overcome the problems of the prior art. There is a need to avoid the wrong operation of the modular devices in dark. The present invention therefore provides an arrangement for illumination in distribution board to operate the modular devices in dark. It would avoid unnecessary operation of the modular devices in distribution board thereby avoiding the unintended operation of the loads.
OBJECTS OF THE INVENTION
A basic object of the present invention is to overcome the disadvantages/drawbacks of the known art.
Another object of the present invention is to provide an illumination arrangement in a distribution board to operate the modular devices in dark.

Another object is to provide illumination depending on the illumination present inside the distribution board.
These and other advantages of the present invention will become readily apparent from the following detailed description read in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
There is provided an illumination device for distribution board to operate modular devices in dark.
According to one embodiment of the present invention, there is provided an electronic circuit coupled on a printed circuit board to sense illumination inside distribution board, said electronic circuit comprising a light dependent resistor connected in series with said LEDs.
Other embodiment of the present invention provides a reflector that diverts light of LEDs to distribution board.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
In the appended drawings:
Fig 1 illustrates a general view of an arrangement of the illumination unit in to the distribution board.
Fig 2 illustrates a detailed view of an arrangement of the illumination unit in to the distribution board.

Fig 3 illustrates a side view of an arrangement of the illumination unit in to the distribution board.
Fig 4 illustrates an overview of electronic circuit.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The following drawings are illustrative of particular examples for enabling methods of the present invention, are descriptive of some of the methods, and are not intended to limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description.
Reference is first invited to Fig 1 where the distribution board with the illumination device is shown. It shows door of the distribution board, switch etc.
Fig. 2 shows a reflector reflecting light emanating from said LED's to the distribution board. It shows a protection shield coupled with said distribution board for housing the illumination device, a printed circuit board etc.
Fig. 3 shows the path of reflection of light emanating from LEDs and reflected by a flap shaped reflector directing the light towards different modules of the distribution board.
Fig. 4 shows the arrangement of electronic circuitry coupled on the printed circuit board. It comprises a full wave rectifier, an operational amplifier, a plurality of LEDs, light dependent resistors, transistor etc.
The invented system is thus an illumination device for distribution board to operate modular devices in dark.
DETAILED DESCRIPTION OF THE INVENTION

Accordingly the present invention provides an improved arrangement for illumination in distribution board to operate the modular devices in dark. Figure 1 shows the general arrangement of the installation of the invented illumination unit (1) in the distribution board (2). Unit is installed on the protection shield (3) of the distribution box. Door (4) operates the switch (S1) on the unit which will provide illumination to group of the modular devices (5) present in the distribution box.
Figure 2 shows the detailed view of the arrangement to install illumination unit in to the distribution box, it is having a flap shaped reflector (6) having reflective surface to divert light of light emitting diodes - LEDs (7) in to the intended direction to illuminate the complete distribution box. It also shows the PCB (8). The PCB can be easily fitted in the arrangement.
Figure 3 shows the side view of the arrangement of the figure 2 showing the LEDs (7) and reflector flap (6). The light of the LEDs will reflect on the reflector (6) and it will provide the illumination in complete distribution board. Figure 4 gives the overview of the circuit used in this invention.
The distribution board contains the modular devices like MCB, RCCB and RCBOs which are used for the protection of the loads and to make the loads ON or OFF. The MCB goes for the individual loads. Sometimes the MCB contains the labels which show the name of the loads to avoid the confusion to the person that which switch to make on. But in dark the user unable to see the modular devices also the name on the labels hence he may turn on the unnecessary loads.
To overcome above drawbacks, this invention describes the arrangement to view the modular devices in the dark. The Light Emitting Diodes are fitted in the projection as shown in figure 2. The projection on shield of the distribution board is such that all LEDs will give the light on to the modular devices to make it

visible. All LEDs are connected in series with the circuit containing LDR (Light Dependent Resistor).
The power supply to the electronic circuit will come from the main incoming side of the distribution board. It is first full wave rectified by the diode rectifier using diodes D1, D2, D3 and D4. In first half cycle diodes D1 and D3 will be in forward bias. The capacitor C1 acts as a filter and it will minimize the DC ripples in the waveform. Then it will be given to the regulator IC 1. The output is divided by the voltage divider so that it will be suitable for the operational amplifier IC2. The resistors R2 and R3 acting as a voltage divider. The values of R2 and R3 are kept constant so as to fix the voltage at non inverting terminal 1 of the operational amplifier.
The other end of the op-amp is connected to the Light Dependant Resistor (LDR) with resistor R4. The resistor R4 and LDR acting as another voltage divider circuit to give the voltage at the inverting input 2 of the OPAMP. The LDR resistance is dependent on light. In dark the LDR resistance is increases. In normal condition (i.e. during the day time), the LDR resistance is low (i.e. of the order of few Kilo Ohms). The value of the resistance R4 is adjusted such that the voltage at pin 2 will not exceed the voltage at pin L Hence the output of OP AMP is low. Due to low output of op-amp, the transistor Q1 will not get the proper base to emitter voltage and hence Q1 will not conduct. So LEDs L1, L2, L3 and L4 remain in off condition.
In dark, the resistance of LDR increases i.e. in the order of 50 Kilo Ohm. It will increase the voltage at pin 2. It will cross the voltage at pin 1 and output of OPAMP will turn to high. Hence the transistor Q1 becomes ON and current will starts flowing through the LEDs. The LEDs will give sufficient illumination to view the modular devices in the distribution board. The resistor R4 is variable to tune the circuit depending upon the light. Resistor R5 and R6 provides proper

base voltage to the transistor Q1. The resistor R7 limits the current through the LEDs.
But the LDR should sense the darkness only in case when distribution board's door is open. For this one push to off switch S1 is connected as shown in figure 1 and figure 4. When door of distribution boards is close, the door will push the switch S1 and the switch become open hence there will be no power supply to the circuit. When the door is open then the switch S1 becomes close. Hence the circuit will receive the power supply and the circuit will work accordingly as explained above.
ADVANTAGES
1. Avoiding unnecessary operation of the modular device in distribution board thereby avoiding the unintended operation of the loads
2. Increasing the life of the modular device in distribution board as it avoids the unnecessary operation.
3. Easy to install in a distribution board through push and slide arrangement.
Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the embodiments herein with modifications. However, all such modifications are deemed to be within the scope of the claims.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the embodiments described herein and all the statements of the scope of the embodiments which as a matter of language might be said to fall there between.

WE CLAIM:
1. An illumination device for use in a distribution board, said illumination
device comprising:
a protection shield coupled with said distribution board, said protection shield defining a housing for the illumination device;
switching means operatively connected to door of said distribution board;
a plurality of LEDs connected in series;
a reflector to divert light of said LEDs to said distribution board; and
an electronic circuit coupled to a printed circuit board to sense illumination inside said distribution board, said electronic circuit comprising a light dependent resistor connected in series with said LEDs.
2. Device as claimed in claim 1 wherein said switching means is a push to off switch supplying power to said electronic circuit.
3. Device as claimed in claim 1 wherein said electronic circuit further comprising operational amplifiers.
4. Device as claimed in claim 1 wherein said electronic circuit further comprising a full wave rectifier connected to a capacitor filter to minimize DC ripples in the waveform.
5. Device as claimed in claim 4 wherein said capacitor filter is adapted to be connected to a voltage divider via a regulator.
6. Device as claimed in claim 5 wherein said voltage divider comprising a duality of resistors kept constant to fix the voltage at non-inverting terminal of the operational amplifier.

7. Device as claimed in claim 6 wherein inverting terminal of said operational amplifier is connected to a variable resistor (R4) and said light dependent resistor.
8. Device as claimed in claim 7 wherein said variable resistor is substantially adjustable to tune the circuit depending upon the light.
9. Device as claimed in claim 3 wherein said operational amplifier is operatively coupled to a transistor for turning said LEDs ON/OFF.
10. Device as claimed in claim 6 wherein duality of resistors (R5 and R6) are connected to said transistor to provide substantially operable base voltage.
11. Device as claimed in claim 1 wherein said electronic circuit comprise a resistor (R7) connected in series with said LEDs to limit the incoming current in said LEDs.
12. Device as claimed in claim 1 wherein said reflector is a flap type reflector reflecting light emanating from said LED's to the distribution board.
13. An illumination device for distribution board to operate modular devices in dark as herein substantially described and illustrated with reference to the accompanying drawings.