FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
An encapsulated inductor
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTORS
Jaiswal Rajendra, Chaudhari Lokesh Kisan and Lohokare Yogesh, all of Crompton Greaves Ltd, Advanced Material & Process Technology Centre, CG Global R&D Centre, Kanjur Marg (East), Mumbai 400042, Maharashtra, India, all Indian nationals
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes this invention and the manner in which it is to be performed:

FIELD OF THE INVENTION
The invention relates to an encapsulated inductor.
BACKGROUND OF THE INVENTION
An inductor comprises an inductor coil and a magnetic core disposed within the coil. When a current passes through the coil, the inductor vibrates due to the flow of current in the coil and this creates noise. The intensity of vibration and noise level increases with the intensity of current flowing in the coil. This is not desirable and causes damage to the inductor over time which decreases the life of the inductor.
OBJECTS OF THE INVENTION
An object of the invention is to provide an encapsulated inductor having low noise level of operation.
Another object of the invention is to provide an encapsulated inductor which has a long life.
DETAILED DESCRIPTION OF THE INVENTION
Accordingly, the invention provides an encapsulated inductor comprising an inductor coil and a core disposed in the coil and encapsulated with an electrical grade nanocomposite comprising organically modified silicate nanoclay in an amount of 0.5% to 5% by weight blended with unsaturated polyester resin in an amount of 39% to 80% by weight in the presence of a reactive diluent in an amount of 19% to 60% by weight and a peroxide type

accelerator in an amount of 0.5% to 1.5 % by weight and optionally, upto 15% by weight of additives.
The organically modified silicate clay is obtained by modifying silicate clay by intercalation with organic modifiers as is already known in the art. The organic modifiers can be quarternary amines, long chain quaternary ammonium salts, tallow amines or combinations thereof. The unsaturated polyester resin can be selected from polyesters of maleic anhydride, isophthalic acid, phthalic anhydride or o-phthalic anhydride or copolyesters thereof. Preferably, the reactive diluent is styrene, methyl acrylate, methyl methacrylate, butyl acrylate, ethyl hexyl acrylate, ethyl acrylate, butyl methacrylate, ethyl hexyl methacrylate, ethyl methacrylate, or combinations thereof. Preferably, the accelerator is an organic peroxide compound. Preferably, the additives include flame retardants like aluminium trihydrate, coloring agents like titanium dioxide or combinations thereof.
The intensity of vibration of an encapsulated inductor is less as compared to the intensity of vibration of an un-encapsulated inductor. Therefore, the encapsulated inductor of the invention has a low noise level of operation. Further, low intensity of vibration during operation of the encapsulated inductor results in decreased damage to the inductor and an increase in the life of the inductor. The invention is thus advantageous in several respects.
The following example is illustrative of the invention: Example 1:

A motor (A) comprising an encapsulated inductor according to the invention, was tested against a motor (B) fitted with a commercially available un-encapsulated inductor. The noise generated was measured by a decibel meter at five positions relative to the motor position (the noise in dB at the five positions being denoted by PI, P2, P3, P4 and P5 respectively in the tables below). The noise generated by the motor with and without the load was studied. The ambient noise was 33.9dB, The results of these studies are compiled in the Tables below. Table 1 describes the noise generated by motor (B) wherein the motor is without load. Table 2 describes the noise generated by motor (B) wherein the motor is with load. Table 3 describes the noise generated by motor (A) wherein the motor is without load. Table 4 describes the noise generated by motor (A) wherein the motor is with load. Table 1
Voltage (in
Volts) Current
(in
Amperes) Power (in Watts) Frequency of rotation (in rpm) PI
in
dB P2
in
dB P3
in
dB P4
in
dB P5 in dB Average in dB
230 0.015 4.5 875 42.9 43 42.4 41.4 43.6 42.66
Table 2
Voltage
(in
Volts) Current
(in Amperes) Power (in Watts) Frequency of rotation (in rpm) PI
in dB P2
in
dB P3
in
dB P4
in
dB P5 in dB Average in dB
230 0.0144 36.1 360 56.1 56.6 57.1 56.1 59.9 57.16
Table 3
Voltage
(in
Volts) Current (in
Amperes) Power (in Watts) Frequency of rotation (in rpm) PI
in
dB P2
in
dB P3
in
dB P4
in
dB P5
in dB Average in dB
230 0.015 4.6 875 41.6 43.2 42.1 41 42.9 42.16
Table 4
Voltage
(in
Volts) Current
(in Amperes) Power
(in Watts) Frequency
of rotation (in rpm) PI
in
dB P2
in
dB P3
in
dB P4
in
dB P5 in dB Average in dB
230 0.0148 36.1 360 55 55 54.9 55 58 55.58

Tables 3 and 4 show that the average noise generated by motor (A) was lower than the noise generated by motor (B) as shown in Tables 1 and 2. It is obvious that the * encapsulated inductor is responsible for the lower noise level of operation of motor (A) as compared to motor (B).
The above example is non-limiting. The invention is defined by the claims that follow.

We claim:
1. An encapsulated inductor comprising an inductor coil and a core disposed in the coil and encapsulated with an electrical grade nanocomposite comprising organically modified silicate nanoclay in an amount of 0.5% to 5% by weight blended with unsaturated polyester resin in an amount of 39% to 80% by weight in the presence of a reactive diluent in an amount of 19% to 60% by weight and a peroxide type accelerator in an amount of 0.5% to 1.5 % by weight and optionally, upto 15% by weight of additives.
2. The encapsulated inductor as claimed in claim 1, wherein the unsaturated polyester resin is selected from polyesters of ma.leic anhydride, fumaric acid, isophthalic acid, phthalic anhydride or o-phthalic anhydride or copolyesters thereof.
3. The encapsulated inductor as claimed in claim 1 or 2, wherein the reactive diluent is styrene, methyl acrylate, methyl methacrylate, butyl acrylate, ethyl hexyl acrylate, ethyl acrylate, butyl methacrylate, ethyl hexyl methacrylate, ethyl methacrylate, or combinations thereof.
4. The encapsulated inductor as claimed in any one of claims 1 to 3, wherein the accelerator is an organic peroxide compound.

5. The encapsulated inductor as claimed in any one of claims 1 to 4, wherein the additives include flame retardants like aluminium trihydrate, coloring agents like titanium dioxide or combinations thereof.