FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A wide input range Switching Mode Power Supply (SMPS)
equipment assembly
APPLICANT(S)
Crompton Greaves Limited, CG House, Dr. Annie Besant Road, Worli, Mumbai -400030, Maharashtra, India, an Indian Company
INVENTOR (S)
Sharma Vijay Ramsunder and Baviskar Ganesh Purushottam of Crompton Greaves Limited, Switchgear Division, A-3, M.I.D.C., Ambad, Nashik - 422010, Maharashtra, India, both Indian Nationals
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

FIELD OF THE INVENTION:
This invention relates to the field of electrical and electronic equipment.
Particularly, this invention relates to the field of Switching Mode Power Supply (SMPS) equipment.
Specifically, this invention relates to wide input range Switching Mode Power Supply (SMPS) equipment.
BACKGROUND OF THE INVENTION:
Electrical and electronic systems and equipment operate on electricity; either in the form of AC current or DC current or batteries or the like. In electrical appliance, a switched-mode power supply (switching-mode power supply, or SMPS) is an electronic power supply that incorporates a switching regulator in order to be highly efficient in the conversion of electrical power. Like other types of power supplies, an SMPS transfer's power from a source like the electrical power grid to a load (e.g., a personal computer) while converting voltage and current characteristics. An SMPS is usually employed to efficiently provide a regulated output voltage, typically at a level different from the input voltage.
A SMPS can be used in Meters, Measuring equipments, Protection Relays etc.
One feature of the SMPS is that it can operate at higher frequencies. A feedback from an output to a switching regulator of the SMPS aids in eliminating the need

for a separate inefficient series regulator on the voltage output used as the feedback reference.
Typically, a SMPS converts input DC voltage within a given range to a fixed stable pre-determined output.
According to the prior art, two different SMPS are used in order to incorporate a wide range typically from 18 V DC to 250 V DC. A first SMPS is used in order to cater to the input range of 18 - 52 V DC and a second SMPS is used in order to cater to the input range of 75 - 250 V DC.
Hence, it leads to a disadvantage that same product with two different power supply input ranges need to be maintained, thereby resulting in increase of inventory and cost.
OBJECTS OF THE INVENTION:
An object of the invention is to provide a wide-input-range SMPS equipment.
Another object of the invention is to reduce failure of SMPS due to overvoltage in the lower range of 18 to 52vdc.
Yet another object of the invention is to provide a common SMPS for all input requirement.
Still another object of the invention is to reduce cost in order to cater to a wide range of input supplies for SMPS features.

SUMMARY OF THE INVENTION:
According to this invention, there is provided a wide input range Switching Mode Power Supply (SMPS) equipment assembly comprises:
a. input means adapted to input a current of pre-defined voltage range;
b. transistorised constant current and voltage circuit mechanism for pulse width
modulated controller means adapted to receive input current to be given as a
further input to a pulse width modulation controller which controls the duty
cycle of a transformer adapted to provide output;
c. freewheeling and voltage clamping means adapted to provide a voltage
clamping threshold for said assembly;
d. Pulse Width Modulation controller adapted to receive said transistorised
constant current and voltage output, further adapted to receive feedback
from output of said assembly in order to provide modulated signals to a
drive mechanism which in turn provides drive signals to a high voltage high
frequency switching device; and
e. high frequency transformer adapted to receive switching signals from said
high voltage high frequency switching device in relation to said drive
signals and further adapted to receive voltage clamping threshold in order to
provide assembly voltage output;
characterised, in that, said duty cycle of the pulses for switching said transformer being varied from 10 to 90% for achieving said pre-determined (wide) input range.
Typically, said input means comprising surge protector means adapted to protect incoming surges / voltage spikes from the input line.

Typically, said input means comprising surge protector means adapted to protect incoming surges / voltage spikes from the input line, said input voltage being in the range of 18V to 250V.
Typically, said input means comprising Electromagnetic Interference (EMI) filter means adapted to bypass EMI or Radio Frequency (RF).
Typically, said input means comprising reverse polarity protection means adapted to protect said equipment assembly from backwards (or reverse) power connections.
Typically, said input means comprising inrush current limiter and DC filter means adapted to avoid gradual damage to components and avoid tripping the supply's fuse or circuit breaker and further adapted to provide output to each of said transistorised constant current and voltage circuit mechanism, said high frequency transformer, and said freewheeling and voltage clamping means.
Typically, said assembly comprising High Frequency Rectifier adapted to rectify said assembly voltage output.
Typically, said assembly comprising DC pi filter circuit means adapted to remove unwanted or undesired frequencies from said assembly voltage output.
Typically, said assembly comprising DC regulator means adapted to regulate said assembly voltage output.

Typically, said assembly comprising feedback circuit means adapted to provide feedback from said assembly voltage output to said Pulse Width Modulation controller means.
Typically, said assembly comprising feedback circuit means adapted to provide feedback from said assembly voltage output to said Pulse Width Modulation controller means through an isolator circuit means.
Preferably, said assembly is an 18 V DC to 250 V DC input equipment assembly.
Preferably, said assembly is a 5 V@l A fixed output equipment assembly.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
The invention will now be described in relation to the accompanying drawings, in which:
Figure 1 illustrates a schematic of the system.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
According to this invention, there is provided a wide input range Switching Mode Power Supply (SMPS) assembly.
Figure 1 illustrates a schematic of the system.

In accordance with an embodiment of this invention, there is provided a surge protector means (SPM) adapted to protect incoming surges / voltage spikes from the input line. A surge protector attempts to limit the voltage supplied to an electric device by either blocking or by shorting to ground any unwanted voltages above a safe threshold. The input voltage can typically be in the range of 18V to 250V.
In accordance with another embodiment of this invention, the surge protector means is further connected to an EMI filter means (EMIF). EMI relates to electromagnetic interference or radiofrequency interference. It is the disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. Hence, the use of the EMI filter means aids is bypassing EMI or improving RF immunity.
In accordance with yet another embodiment of this invention, the EMI filter means is further connected to a reverse polarity protection means (RPPM). This protects the system from backwards (or reverse) power connections.
In accordance with still another embodiment of this invention, the reverse polarity protection means further connects to an inrush current limiter and DC filter means (ICL-FM). An inrush current limiter is a component used to limit inrush current to avoid gradual damage to components and avoid tripping the supply's fuse or circuit breaker.
In accordance with an additional embodiment of this invention, output from the inrush current limiter and DC filer means (ICL-FM) is given to the following three components of the equipment:

i. Transistorised Constant Current cum Voltage Circuit for PWM Controller
Functionality means (TCVM); ii. Freewheeling and Voltage Clamping means (FVC); and iii. High Frequency Transformer designed for Wide Voltage Input Range (HFT).
The Transistorised Constant Current cum Voltage Circuit for PWM Controller Functionality means is further connected to a Pulse Width Modulation controller (PWM) which controls the duty cycle of the equipment of this invention.
The duty cycle D is defined as the ratio between the pulse duration (T) and the period (T) of a rectangular waveform, (pulse width modulated waveform).
According to this invention, the duty cycle of the pulses for switching the transformer is varied from 10 to 90% for achieving wide input range.
The freewheeling and voltage clamping means relates to the maximum amount of voltage that a surge protector will allow through itself before it will suppress the power surge. When the equipment reaches its clamping voltage, it blocks any further current from flowing through the device and into a computer system or other electronic device. The freewheeling portion of this component may be "freewheeling diode" which is put into the equipment in order to protect the switching device from being damaged by the reverse current of an inductive load.
Output from the Freewheeling and Voltage Clamping means is further given to the High Frequency Transformer designed for Wide Voltage Input Range.

Transformers are devices that transfer electrical energy from one circuit to another through inductively coupled conductors.
The High Frequency Transformer is connected to a High Voltage High Frequency Switching Device (HVHFSD), which in turn receives drive signals from a drive mechanism (DM) connected at the output of the Pulse Width Modulation controller through which it receives switching signals
The High Frequency Transformer is also further connected to a High Frequency Rectifier (HFR). The rectifier rectifies the output voltage. The rectified output is given to a DC pi filter circuit means (PFC) adapted to remove unwanted or undesired frequencies from a signal. This filtered signal is given to a DC regulator circuit (RC) in order to provide regulated output of the SMPS of this invention.
Output from the DC pi filter circuit means, in part, is also given to a feedback circuit means (FB) and further to an isolator circuit means (IC) before being finally given as input to the Pulse Width Modulation controller.
Preferably, the equipment of this invention provides a wide input range SMPS which works in the range of input from 18 C DC to 250 V DC with a fix output of 5 V@1A. This equipment converts the i/p dc in the above specified range to a fixed stable output of 5 V DC. The SMPS equipment is designed for a regular production of protection relays. This SMPS equipment is designed to meet all the range of input requirement of the customer for the protection relays. This SMPS equipment also reduces the inventory due to same components in the entire range of input. It also reduces the failure due to wrong input voltage given by the customer to the product while installed.

While this detailed description has disclosed certain specific embodiments of the present invention for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim,
1. A wide input range Switching Mode Power Supply (SMPS) equipment
assembly comprising:
a. input means adapted to input a current of pre-defined voltage range;
b. transistorised constant current and voltage circuit mechanism for pulse
width modulated controller means adapted to receive input current to be
given as a further input to a pulse width modulation controller which
controls the duty cycle of a transformer adapted to provide output;
c. freewheeling and voltage clamping means adapted to provide a voltage
clamping threshold for said assembly;
d. Pulse Width Modulation controller adapted to receive said transistorised
constant current and voltage output, further adapted to receive feedback
from output of said assembly in order to provide modulated signals to a
drive mechanism which in turn provides drive signals to a high voltage
high frequency switching device; and
e. high frequency transformer adapted to receive switching signals from
said high voltage high frequency switching device in relation to said
drive signals and further adapted to receive voltage clamping threshold in
order to provide assembly voltage output;
characterised, in that, said duty cycle of the pulses for switching said transformer being varied from 10 to 90% for achieving said pre-determined (wide) input range.
2. A wide input range Switching Mode Power Supply (SMPS) equipment
assembly as claimed in claim 1 wherein, said input means comprising surge

protector means adapted to protect incoming surges / voltage spikes from the input line.
3. A wide input range Switching Mode Power Supply (SMPS) equipment assembly as claimed in claim 1 wherein, said input means comprising surge protector means adapted to protect incoming surges / voltage spikes from the input line, said input voltage being in the range of 18V to 250V.
4. A wide input range Switching Mode Power Supply (SMPS) equipment assembly as claimed in claim 1 wherein, said input means comprising Electromagnetic Interference (EMI) filter means adapted to bypass EMI or Radio Frequency (RF).
5. A wide input range Switching Mode Power Supply (SMPS) equipment assembly as claimed in claim 1 wherein, said input means comprising reverse polarity protection means adapted to protect said equipment assembly from backwards (or reverse) power connections.
6. A wide input range Switching Mode Power Supply (SMPS) equipment assembly as claimed in claim 1 wherein, said input means comprising inrush current limiter and DC filter means adapted to avoid gradual damage to components and avoid tripping the supply's fuse or circuit breaker and further adapted to provide output to each of said transistorised constant current and voltage circuit mechanism, said high frequency transformer, and said freewheeling and voltage clamping means.

7. A wide input range Switching Mode Power Supply (SMPS) equipment assembly as claimed in claim 1 wherein, said assembly comprising High Frequency Rectifier adapted to rectify said assembly voltage output.
8. A wide input range Switching Mode Power Supply (SMPS) equipment assembly as claimed in claim 1 wherein, said assembly comprising DC pi filter circuit means adapted to remove unwanted or undesired frequencies from said assembly voltage output.
9. A wide input range Switching Mode Power Supply (SMPS) equipment assembly as claimed in claim 1 wherein, said assembly comprising DC regulator means adapted to regulate said assembly voltage output.
10. A wide input range Switching Mode Power Supply (SMPS) equipment assembly as claimed in claim 1 wherein, said assembly comprising feedback circuit means adapted to provide feedback from said assembly voltage output to said Pulse Width Modulation controller means.
11. A wide input range Switching Mode Power Supply (SMPS) equipment assembly as claimed in claim 1 wherein, said assembly comprising feedback circuit means adapted to provide feedback from said assembly voltage output to said Pulse Width Modulation controller means through an isolator circuit means.
12. A wide input range Switching Mode Power Supply (SMPS) equipment assembly as claimed in claim 1 wherein, said assembly is an 18 V DC to 250 V DC input equipment assembly.

13. A wide input range Switching Mode Power Supply (SMPS) equipment assembly as claimed in claim 1 wherein, said assembly is a 5 V@1A fixed output equipment assembly.