Title of Invention

AN EQUIPMENT TO PROVIDE FREQUENCY CLEARING OF METALLISED PLASTIC FILM CAPACITOR

Abstract The present invention relates to the frequency clearing of a metallised plastic film capacitor by applying Alternating Current (AC) voltage in the form of pulses to clear conducting path of the metal plate of capacitor. Equipment to provide frequency of metallised plastic film capacitor is disclosed. The equipment comprises : an AC power supply unit, control unit, output unit and Alternating Current (AC) to Direct Current (DC) converter. An AC power supply unit generates 0 to 230 V variable AC power being further step up to 1250V AC variable in steps as per the requirement of voltage. The control unit provides a fixed number of pulses required for the frequency clearing operation, The control unit comprises : digital two digit counter which counts and allows desired number of sinewave cycles pulses at the output, settable from 1 to 99; a flip-fftvp having "SET" and "RESET" terminals, to start and reset the timer; a pair of monostable multivibrator for providing square wave pulse outputs for setting and resetting the flip flop; foot switch is connected to ''SET' terminal of the flip flop through one monostable multivibrator to start the counter; count over output is connected to reset terminal of the flip flop through the second monostable multivibrator to stop and reset the counter; solid state switch to ensure that only fixed number of pulses being decided by the control unit to be given to output unit. The output unit provides an amplitude controlled AC voltage pulses to the capacitor for frequency clearing purpose, said output unit is connected to control unit, said output unit consists of variable transformer unit for providing variable amplitude AC voltage pulses. The AC to DC converter is connected to AC power supply unit for providing DC power supply to control unit and output unit. Also a method of manufacturing a metallised plastic film capacitor with frequency clearing as one of the step is disclosed.
Full Text FORM 2
THE PATENTS ACT, 1970
(39 FO 1970)
&
PATENT RULES, 2003
PROVISIONAL/COMPLETE SPECIFICATION
(See section 10 and rule 13)

l. TITLE OF THE INVENTION : An Equipment and method to provide Frequency Clearing of Metallised Plastic Film Capacitor.
2. APPLICANT(S)
(a) Name : CTR Manufacturing Industries Ltd.(b) Nationality : Indian Company(c) Address : E 1, Chikalthana, (d) AURANGABAD-431210, MAHARASHTRA, INDIA
3. PREAMBLE TO THE DESCRIPTION :
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION
The present invention relates to the frequency clearing of a metallised plastic film capacitor by applying Alternating Current (AC) voltage in the form of pulses to the capacitor element to clear conducting path of the metal plate of capacitor. More particularly it relates to an equipment to provide frequency clearing of a metallised plastic film capacitor. It also relates to method of manufacturing a capacitor which includes frequency clearing as one of the step to achieve desired characteristics of the metallised plastic film capacitor.
PRIOR ART:
The self healing property of the metallised plastic film capacitor offers a distinct advantage over the film foil capacitors. This self healing property is a result of the extreme thinness of the metallised electrode material. Whereever a flow or weak spot in the dielectric results in a short condition, the stored electrons in the capacitor and the associated circuitry will immediately avalanche and cross at the shorted point. The election density concentration results in an extremely high current condition which in turn provides sufficient energy in the form of heat to vaporize the thin metallic electrode. The vaporized electrode forms a fairly concentric pattern away from the point of the short. As a result of the vaporization, the short condition is removed and the capacitor is again operational. This is known as "Clearing" which is the self healing process.
In short metallised plastic film capacitor having a property of self healing, means a pin hole on the metallised film created during its manufacturing process to be cleared or removed by applying Alternating Current (AC); Direct Current (DC) voltage in pulse form (i.e. shock treatment) after lead welding process of capacitor. Where improvement in performance, avoidance of premature failure of a metallised plastic film capacitor frequency clearing is a must.
2

The absence of frequency clearing while manufacturing leads to:
1. Non self healing of a capacitor
2. Impurities inside the capacitor
3. End spray metal on body which will reduce Insulation Resistance
4. Short circuit of capacitor
5. Erratic tan delta readings
6. More power loss
7. More capacitance loss
Currently available equipment and method for clearing of metallised plastic film capacitors involves technique of phase control to control power required to remove impurities and short circuit. In such case pulses i.e. waveform, which is used, is not purely sine wave; rather it is pulsating in nature. Further in such cases smooth control over power is difficult Also control of clearing voltage is not possible. Figure 1 shows the pulsating type of waveform with phase angle variation to control the power to be used for clearing purpose.
The above mentioned equipment and method of prior art discusses only frequency clearing done by phase control and not about the disadvantages such as premature failure, erratic change in tan delta, loss of power and electrical characteristics.
Thus the above mentioned equipment and method for dealing of a metallised plastic film capacitor along with aforementioned disadvantages associated with them makes it necessary to provide a system/ equipment/device which will overcome the above drawbacks of the prior art and provide frequency clearing of a metallised plastic film capacitor successfully.
3

OBJECTIVE OF THE INVENTION :
The main objective of the present invention is to provide an equipment, which eliminates the above said drawbacks associated with the prior equipment and method for providing frequency clearing of metallised film capacitor.
Another objective of the present invention is to provide an equipment of frequency clearing of a metallised plastic film capacitor by applying AC voltage in the form of pulses to remove impurities and to clear the conducting path of the metal plate (self healing properties) and to improve electrical characteristics
Yet another objective of the present invention is to provide an improved foolproof equipment and method for frequency clearing of a metallised plastic film capacitor resulting in prevention of premature failures:.
Yet another objective of the present invention is to provide and equipment an method for frequency clearing and improved self healing of a capacitor due to. impurities inside the capacitor, end spray metal on body of capacitor to prevent reduction of Insulation Resistance and short circuit of capacitor.
Yet another objective of the present invention is to reduce erratic change in tan delta readings, power loss and capacitance loss.
Yet another objective of the present invention is to enhance the life of a plastic film capacitor, improve reliability through better electrical characteristics of a metallised plastic film capacitor.
Yet another objective of the present invention is to provide an equipment and method for frequency clearing
which is economical and having simple operation.
4

STATEMENT OF THE INVENTION :
Accordingly in order to achieve the above mentioned objects, there is provided and equipment to provide
frequency clearing of a metallised plastic film capacitor, the said equipment comprises :
an AC power supply unit for generating 0 to 230V variable AC power being further stepped up to 1250 VAC
variable in steps as per the requirement of voltage;
.Control unit for providing a fixed number of pulses required for the frequency clearing operation, said control
unit comprises :
§ a digital two digit counter which counts and allows desired number of sinewave cycles pulses at the output, settable from 1 to 99;
§ a flip-flop having ""SET" and "RESET' terminals, to start and reset the timer;
§ a pair of monostable multivibrator for providing square wave pulse outputs for setting and resetting the flip flop;
§ a foot switch is connected to "SET” terminal of the flip flop through one monostable multivibrator to start the counter;
§ count over output is connected to reset terminal of the flip flop through the second monostable multivibrator to stop and reset the counter.
§ Solid state switch to ensure that only fixed number of pulses being decided by the control unit to be given to output unit, input of said solid state switch is connected to the output of the flip-flop;
Output unit to provide an amplitude controlled AC voltage pulses to the capacitor for frequency clearing purpose,-
said output unit is connected to and controlled by said control unit, said output unit consists of variable
transformer unit for providing variable amplitude AC voltage pulses; and
5

AC to DC converter/rectifier being connected to AC supply unit for providing DC power supply to said control unit and output unit
Also there is provided a method of manufacturing a metallised plastic film capacitor with frequency dealing as one of the step, said method comprising steps of
a. placing in a vacuum a plastic dielectric film and depositing a thin layer of metal alloy as an electrodes on it;
b. Winding a metallised film into a cylinder so that a metallised edge extends on each end of the wound
capacitor coil;
c. Spraying both ends with small droplets of molten metal that adhere along and make contact with the
metallisation on the film;
d. Soldering /welding the wire lead to this end sprayed metallised portion for making termination contact;
e. Applying amplitude controlled AC voltage in the form of pulses to the capacitor and thereby removing
impurities and clearing the conducting path of the metal film of the capacitor coil; and
f. Encapsulating and sealing said capacitor coil obtained in step (e).
BRIEF DESCRIPTION OF THE DRAWINGS :
Figure 1 : Shows the wave forms of a voltage pulse to be applied to the metallied plastic film capacitor for providing the frequency dealing available in prior art.
Figure 2 : Shows block diagram of an equipment to provide frequency of metallised plastic film capacitor in accordance to present invention.
Figure 3 : Shows the wave form of a voltage pulse to be applied to the metallised plastic film capacitor for
providing the frequency clearing in accordance to the present invention. Figure 4 : Shows wound capacitor coil
Figure 5 : Shows cross sectional area of wound capacitor coil
Figure 6 : Shows wound capacitor coil with end spray metallisation
6

Figure 7 : Shows capacitor coil with end spray metallisation and termination welded
Figure 8 : Shows wound capacitor coil with AC voltage applied across it for the purpose of frequency clearing
Figure 9 : Shows process flow chart for die said invented process of frequency clearing
DETAIL DESCRIPTION OF THE INVENTION :
The above, and the other objects, features and advantages of invention will become appaient from following description read in conjunction with the accompanying drawings.
Now referring to figure 2 and equipment to provide frequency clearing of metallised plastic film capacitor in 'accordance to present invention is shown. Basically the equipment provides and amplitude controlled AC voltage pulses across the capacitor for the purpose of frequency clearing. The equipment comprises and AC power supply unit (ACPS), control unit (CU), output unit (OU) and AC to DC converter (ADC).
An AC power supply unit (ACPS) is used for generating 0 to 230VAC power. This AC power is further step up to 0 to 1250VAC variable in steps as per the requirement of voltage. The control unit (CU) is used for providing a fixed number of pulses required for the frequency clearing operation. The control unit (CU) comprises a two digit digital counter (DTC). The external clock signal is applied to this digital counter (DTC) which counts the pulse upto 99. To this digital counter (DTC) a monostable multivibrator (MMV1) is connected. The output of the digital counter (DTC) is given to monostable multivibrator provides sqxiare wave output. The monostable multivibrator (MMV1) is followed by the flip flop (FF) having set (S) and reset ( R) terminals. The reset terminal (R) of the flip flop (FF) is connected to the digital counter (DTC) through monostable multivibrator (MMV1) and reset by the output there from. The set terminal (S) is connected to another monostable multivibrator (MMV2). This monostable multivibrator (MMV2) is getting the trigger signal from the foot switch (FS). The foot switch (FS) is connected to monostable multivibrator (MMV2) through opto-isolator (O11). The output of the flip flop
7

(FF) is connected to solid state switch (SSW) to ensure that only fixed number of pulses being decided by the control unit (CU) must be given to output unit (OU).
The output unit (OU) is connected to control unit (CU) through opto isolator (012). The output unit (OU) provides an amplitude controlled AC voltage pulses to the capacitor for frequency dealing purpose. The output unit (OU) consists of variable transformer unit (VT) for providing AC voltage pulses of variable amplitude. The amplitude of the AC voltage depends upon the various electrical characteristics of the capacitor like voltage, capacitor etc.
The AC to DC converter (ADC) is connected to AC power supply unit (ACPS) for providing DC power supply to control unit (CU) and output unit (OU).
According to second embodiment of the present invention, a plastic film capacitor is manufactured in which frequency clearing is one of the steps. Such capacitor is manufactured in which frequency is one of the steps. Such capacitor is manufactured by winding into a cylinder, any dielectric film and any electrode to form a capacitor. Fig 4 shows the wound coil (CC). As shown in Fig 5, electrodes (E) are placed between dielectric films (D). After winding, and end spray metallisation (ESM) is done for termination contact. Fig 6 shows the capacitor oil with end spray metallisation. Then the wire lead (L) is welded to this end spray for making termination contact Fig 7 shows the wound capacitor coil with end spray metallisation and termination welded. Basically the termination wire (L) and welding contact (WS) are shown in fig 7. After this as shown in fig. 8, and amplitude controlled AC voltage in the form of pulses is applied to the capacitor. Due to application of AC voltage across the capacitor impurities get removed and the conducting path of the metal film of the capacitor coil also eei« cleared. Then such capacitor coil is encapsulated and sealed.
All these above mentioned steps are shown in flowchart form in figure 9.
8

INDUSTRIAL APPLICABILITY:
The equipment and method to provide frequency of a metallised plastic film capacitor in accordance to present invention applies AC voltage in the form of pulses to the capacitor and thereby removes impurities, clears the conduction path of the metal plate of the capacitor (self healing properties) and improves electrical characteristics like high voltage withstanding, tan delta improvement and also performance of capacitor during operation. The metallised plastic film capacitor obtained by the equipment and method of the present invention is useful in electronic as well as electrical industries. It is useful in various electronic and electrical circuits where high voltage withstanding capacity as well as better current carrying capacity of the plastic film capacitor is required.
The present invention is not limited to the above described embodiments, and various alterations, modifications, and / or alternative applications of the invention may be possible, if desired, without departing from the scope and spirit of the invention, which can be read from the claims and the entire specification. All these possible alterations, modifications, and / or alternative applications of the invention are also intended to be within technical scope of the present invention.
9

WE CLAIM :
1. An equipment to provide frequency clearing of a metallised film capacitor, said equipment comprises: an AC power supply unit for generating 0 to 230V variable AC power being further step up to 1250 VAC variable in steps as per the requirement of voltage;
■ a control unit for providing a fixed number of pulses required for the frequency clearing
operation, said control unit comprises:
■ a digital two digit counter which counts and allows desired number of sinewave cycles pulses at the output, settable from 1 to 99;
■ a flip-flop having "SET' and "RESET' terminals, to start and reset the timer;
■ a pair of monostable multivibrator for providing square wave pulse outputs for setting and resetting the flip flop;
■ foot switch is connected to "SET' terminal of the flip flop through one monostable . multivibrator to start the counter,
■ count over output is connected to reset terminal of the flip flop through the second
monostable multivibrator to stop and reset the counter.
10

Solid state switch to ensure that only fixed number of pulses being decided by the control unit to be given to output unit, input of said solid state switch is connected to the output of the flip-flop;
Output unit to provide and amplitude controlled Alternating Current (AC) voltage pulses to the capacitor for frequency clearing purpose, said output unit is connected to and controlled by said control unit, said output unit consists of variable transformer unit for providing variable amplitude Alternating Current (AC) voltage pulses; and AC to DC converter being connected to said AC supply unit for providing DC power supply to said control unit and output unit.
2. An equipment to provide frequency clearing of metallised plastic film capacitor as claimed in claiml wherein said variable transformer unit is powered by AC power supply unit.
3. An equipment to provide frequency clearing of metallised plastic film capacitor as claimed in claim 1, where the said output unit and control unit are connected to each other through opto isolator.
4. A method of manufacturing manufacturing a metallised plastic film capacitor with frequency clearing as one of the steps, said the method comprising steps of:
a. placing in a vacuum a plastic dielectric film and depositing a thin layer of metal alloy as an
electrodes on it;
b. Winding a metallised film into a cylinder so that a metallised edge extends on each end of the
wound capacitor coil;
c. Spraying both ends with small droplets of molten metal that adhere along and make contact with
the metallisation on the film;
11

d. Soldering /welding the wire lead to this end sprayed metallised portion for making termination
contact;
e. Applying amplitude controlled Alternating Current (AC) voltage in the form of pulses to the
capacitor and thereby removing impurities and clearing the conducting path of the metal film of
the capacitor coil; and
f Encapsulating and sealing said capacitor coil obtained in step (e).
5. An equipment to provide frequency of metallised plastic film capacitor as herein described and illustrated with reference to accompanying drawings.
6. A method of manufacturing a metallised plastic film capacitor with frequency clearing as one of the step as herein described and illustrated with reference to accompanying drawings.

Date of 10th August, 2007
12

ABSTRACT
The present invention relates to the frequency clearing of a metallised plastic film capacitor by applying Alternating Current (AC) voltage in the form of pulses to clear conducting path of the metal plate of capacitor. Equipment to provide frequency of metallised plastic film capacitor is disclosed. The equipment comprises : an AC power supply unit, control unit, output unit and Alternating Current (AC) to Direct Current (DC) converter. An AC power supply unit generates 0 to 230 V variable AC power being further step up to 1250V AC variable in steps as per the requirement of voltage. The control unit provides a fixed number of pulses required for the frequency clearing operation, The control unit comprises : digital two digit counter which counts and allows desired number of sinewave cycles pulses at the output, settable from 1 to 99; a flip-fftvp having "SET" and "RESET" terminals, to start and reset the timer; a pair of monostable multivibrator for providing square wave pulse outputs for setting and resetting the flip flop; foot switch is connected to 'SET' terminal of the flip flop through one monostable multivibrator to start the counter; count over output is connected to reset terminal of the flip flop through the second monostable multivibrator to stop and reset the counter; solid state switch to ensure that only fixed number of pulses being decided by the control unit to be given to output unit. The output unit provides an amplitude controlled AC voltage pulses to the capacitor for frequency clearing purpose, said output unit is connected to control unit, said output unit consists of variable transformer unit for providing variable amplitude AC voltage pulses. The AC to DC converter is connected to AC power supply unit for providing DC power supply to control unit and output unit. Also a method of manufacturing a metallised plastic film capacitor with frequency clearing as one of the step is disclosed.
13

Documents:

1550-MUM-2007-ABSTRACT(9-5-2011).pdf

1550-mum-2007-abstract.doc

1550-mum-2007-abstract.pdf

1550-MUM-2007-CLAIMS(AMENDED)-(9-5-2011).pdf

1550-mum-2007-claims.doc

1550-mum-2007-claims.pdf

1550-MUM-2007-CORRESPONDENCE(6-6-2011).pdf

1550-mum-2007-correspondence(ipo)-(12-5-2010).pdf

1550-mum-2007-correspondence-received.pdf

1550-mum-2007-description (complete).pdf

1550-MUM-2007-DRAWING(6-6-2011).pdf

1550-MUM-2007-DRAWING(9-5-2011).pdf

1550-mum-2007-drawings.pdf

1550-MUM-2007-FORM 1(9-5-2011).pdf

1550-MUM-2007-FORM 2(TITLE PAGE)-(9-5-2011).pdf

1550-mum-2007-form 2(title page)-(complete)-(10-8-2007).pdf

1550-MUM-2007-FORM 3(9-5-2011).pdf

1550-mum-2007-form-1.pdf

1550-mum-2007-form-18.pdf

1550-mum-2007-form-2.doc

1550-mum-2007-form-2.pdf

1550-mum-2007-form-3.pdf

1550-mum-2007-form-9.pdf

1550-MUM-2007-REPLY TO EXAMINATION REPORT(9-5-2011).pdf

1550-MUM-2007-SPECIFICATION(AMENDED)-(9-5-2011).pdf

abstract1.jpg


Patent Number 248104
Indian Patent Application Number 1550/MUM/2007
PG Journal Number 25/2011
Publication Date 24-Jun-2011
Grant Date 17-Jun-2011
Date of Filing 10-Aug-2007
Name of Patentee CTR MANUFACTURING INDUSTRIES LTD.
Applicant Address E 1, CHIKALTHANA, AURANGABAD
Inventors:
# Inventor's Name Inventor's Address
1 ANIL RAGHUNATH RANE CTR MFG IND. LTD. E 1, CHIKALTHANA, AURANGABAD 431006
PCT International Classification Number G11B27/00,G11B20/10
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA