TECHNICAL FIELD

Embodiments of the present invention relate to electrical safety devices and more particularly to an anti-shock device for making an electrical supply shock proof during overload and overvoltage conditions.

BACKGROUND ART

Electricity is one of the major sources of power supply to domestic and industrial consumers. While, for most of domestic applications, the electricity is supplied in single phase at a rated voltage and frequency, industrial applications may require three or more phases at significantly high voltages. One of the major area of concern in all such applications is safety of industry personnel or domestic users which are regularly operating machinery or appliances, respectively, using the electricity. Any contact with the electricity, even for a very short duration, can cause anything from a minor injury to something as worse as death.

There are a number of safety standards and regulations to which any manufacturer of electrical machinery or appliances has to comply. Further, the designers of the machinery and the appliances take a number of precautions during design stage of such machinery and appliances, however the same are still far from being fool proof.

The machinery and the appliances are most prone to situations such as, overvoltage and overload, arising in a supply line. The overload happens when current in the supply line is significantly higher than what the supply line can handle. This may be caused due to the supply line being connected with a large number of the machinery or the appliances, the machinery or the appliances being simultaneously active. Overvoltage is a condition where a voltage in a circuit or a part of the circuit exceeds what the circuit is designed for. The overvoltage may be caused due to natural phenomena such as lightning, solar winds or solar flares. The overvoltage may also be caused due to man-made factors such as electromagnetic induction during switching of inductive loads.

During any of the situations involving the overload or the overvoltage, large amounts of the current may flow through circuits inside a house or a factory, resulting in electrical shocks to residents of the house or personnel in the factory. One solution in this regard is discussed below: IN0184/KOL/2011 discloses a shock proofing device. The device converts electric supply to shock free current, without cutting off the power supply, for protecting a person from receiving electrical shock by accidental touch on naked wires. The device includes at least one variable transformer and at least one relay for regulating voltage. The above mentioned solution may attempt to resolve the condition of overvoltage, but does not provide any solution to the condition of overload. Therefore there is a need in the art for an anti-shock device, which does not suffer from above mentioned discrepancies.

SUMMARY OF THE INVENTION Embodiments of the present invention aim to provide an anti-shock device. The device is capable of providing protection with respect to both the overload and the overvoltage conditions, using a servo dimmer, an overload relay and overvoltage relay. Further, the device comprises an alarm clock for raising an alarm during one or more of an overload condition or an overvoltage condition, allowing the authorities to take appropriate action. Also, the device is available in a plurality of KVA ratings making the device suitable for a number of applications. In accordance with an embodiment of the present invention, an anti-shock device comprises an input side and an output side, an overload protection circuit connected with the input side, the overload protection circuit having a primary overload winding, a secondary overload winding inductively coupled with the primary overload winding and an overload tripping circuit connected with the secondary overload winding, a servo dimmer having a dimmer input side and a dimmer output side, the dimmer input side being connected in series with the primary overload winding, and an overload relay connected with the overload tripping circuit and connected in series between the dimmer output side and the output side. Further, the overload tripping circuit is configured to detect an overload condition on basis of a voltage induced in the secondary overload winding and trip open the overload relay on detection of the overload condition.

In accordance with an embodiment of the present invention, the overload tripping circuit is configured to operate in a plurality of KVA ratings.

In accordance with an embodiment of the present invention, the an anti-shock device further comprises an overvoltage protection circuit connected with the dimmer output side, in parallel with respect to the overload relay, the overvoltage protection circuit having a primary overvoltage winding, a secondary overvoltage winding inductively coupled with the primary overload winding and an overvoltage tripping circuit connected with the secondary overvoltage winding and an overvoltage relay connected with the overvoltage tripping circuit and connected in series between the overload relay and the output side. Further, the overvoltage tripping circuit is configured to detect an overvoltage condition on basis of a voltage induced in the secondary overvoltage winding and trip open the overvoltage relay on detection of the overvoltage condition.

In accordance with an embodiment of the present invention, the overvoltage tripping circuit is configured to operate in a plurality of KVA ratings.

In accordance with an embodiment of the present invention, the an anti-shock device further comprises an alarm circuit configured to raise an alarm in case of one or more of the overload condition and the overvoltage condition.

In accordance with an embodiment of the present invention, an anti-shock device comprises an input side and an output side, an overload protection circuit connected with the input side, the overload protection circuit having a primary overload winding, a secondary overload winding inductively coupled with the primary overload winding and an overload tripping circuit connected with the secondary overload winding, a servo dimmer having a dimmer input side and a dimmer output side, the dimmer input side being connected in series with the primary overload winding, an overload relay connected with the overload tripping circuit and connected in series between the dimmer output side and the output side, an overvoltage protection circuit connected with the dimmer output side, in parallel with respect to the overload relay, the overvoltage protection circuit having a primary overvoltage winding, a secondary overvoltage winding inductively coupled with the primary overload winding and an overvoltage tripping circuit connected with the secondary overvoltage winding and an overvoltage relay connected with the overvoltage tripping circuit and connected in series between the overload relay and the output side. Further, the overload tripping circuit is configured to detect an overload condition on basis of a voltage induced in the secondary overload winding and trip open the overload relay on detection of the overload condition Also, the overvoltage tripping circuit is configured to detect an overvoltage condition on basis of a voltage induced in the secondary overvoltage winding and trip open the overvoltage relay on detection of the overvoltage condition. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may have been referred by embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawing illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. These and other features, benefits, and advantages of the present invention will become apparent by reference to the following text figure, with like reference numbers referring to like structures across the views, wherein:

Fig. 1 illustrates a circuit diagram of an anti-shock device, in accordance with an embodiment of the present invention; and

Fig. 2 illustrates a servo dimmer, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the present invention is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments of drawing or drawings described, and are not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated in certain figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claim. As used throughout this description, the word "may" is used in a permissive sense (i.e. meaning having the potential to), rather than the mandatory sense, (i.e. meaning must). Further, the words "a" or "an" mean "at least one" and the word "plurality" means "one or more" unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention.

In this disclosure, whenever a composition or an element or a group of elements is preceded with the transitional phrase "comprising", it is understood that we also contemplate the same composition, element or group of elements with transitional phrases "consisting of", "consisting", "selected from the group of consisting of, "including", or "is" preceding the recitation of the composition, element or group of elements and vice versa.

The present invention is described hereinafter by various embodiments with reference to the accompanying drawing, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only, and are not intended to limit the scope of the claims. In addition, a number of materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary, and are not intended to limit the scope of the invention.

Referring to the drawings, the invention will now be described in more detail. Figure 1 illustrates a circuit diagram of an exemplary anti-shock device 100, in accordance with an embodiment of the present invention. The anti-shock device 100 comprises an input side 110 and an output side 170. In accordance with an embodiment of the present invention, the input side 110 is connected with an electrical meter or a system of electrical meters and the output side 170 is connected with a Miniature Circuit Breaker (MCB) or a system of MCBs. The anti-shock device 100 further comprises an overload protection circuit 120 connected with the input side 110.

The overload protection circuit 120 comprises a primary overload winding 1202 and a secondary overload winding 1204. The primary overload winding 1202 is inductively coupled with the secondary overload winding 1204. In other words, change in current through the primary overload winding 1202 induces a voltage in the secondary overload winding 1204, through electromagnetic induction. Further, an overload tripping circuit 1206 is connected with the secondary overload winding 1204. The overload tripping circuit 1206 is configured to detect an overload condition on basis of the voltage induced in the secondary overload winding 1204. The overload tripping circuit 1206 is in turn connected with an overload relay 140. The overload tripping circuit 1206 is configured to trip open the overload relay 140 on detection of the overload condition. Further, a servo dimmer 130 is connected in series of the primary overload winding 1202. Figure 2 illustrates the exemplary servo dimmer 130, in accordance with an embodiment of the present invention. The servo dimmer 130 comprises a primary dimmer winding 1304 connected with a dimmer input side 1302 of the servo dimmer 130. In accordance with an embodiment, a phase of the dimmer input side 1302 is connected with the primary overload winding 1202 and a neutral of the dimmer input side 1302 is connected with a neutral of the input side 110. Further, the servo dimmer 130 comprises a secondary dimmer winding 1306 inductively coupled with the primary dimmer winding 1304. Further, a dimmer output side 1308 is connected with the secondary dimmer winding 1306. In accordance with an embodiment of the present invention, the servo dimmer 130 further comprises an electronically controlled motor (not shown), configured to change position and/or orientation of the secondary dimmer winding 1306 in order to adjust an output voltage of the servo dimmer 130. The presence of the electronically controlled motor allows adjustment of the output voltage of the servo dimmer 130 up to 50% with a good stability. The primary dimmer winding 1304 and the secondary dimmer winding 1302 allow non-contact type connection between the input side 110 and the output side 170 of the anti-shock device 100. Due to the non-contact type connection, voltage on the output side 170 may be independently regulated with respect to voltage on the input side 110.

The dimmer output side 1308 is connected with the overload relay 140 and an overvoltage protection circuit 160. In accordance with an embodiment, the overload relay 140 is connected in series between the phase of the dimmer output side 1308 and the output side 170 of the anti-shock device 100. In accordance with an embodiment, the overvoltage protection circuit 160 is in parallel connection with respect to the overload relay 140. The overvoltage protection circuit 160 comprises a primary overvoltage winding 1602 and a secondary overvoltage winding 1604. In accordance with an embodiment, the primary overvoltage winding 1602 is directly connected between a phase of the dimmer output side 1308 and a phase of the output side 170. Further, a neutral of the dimmer output side 1308 is also connected with the phase of the output side 170.

The primary overvoltage winding 1602 is inductively coupled with the secondary overvoltage winding 1604. In other words, change in current through the primary overvoltage winding 1602 induces a voltage in the secondary overvoltage winding 1604, through electromagnetic induction. Further, an overvoltage tripping circuit 1606 is connected with the secondary overvoltage winding 1604. The overvoltage tripping circuit 1606 is configured to detect an overvoltage condition on basis of the voltage induced in the secondary overvoltage winding 1604. The overvoltage tripping circuit 1606 is in turn connected with an overvoltage relay 150. The overvoltage tripping circuit 1606 is configured to trip open the overvoltage relay 150 on detection of the overvoltage condition. The overvoltage relay 150 is connected in series between the overload relay 140 and further a neutral of the output side 170 is connected in series of the overvoltage relay 150. Thus tripping of any one of the overload relay 140 and the overvoltage relay 150 will render the anti-shock device 100 open, thereby disconnecting an electrical supply passing through the anti-shock device 100, in case of one or more of the overload condition and the overvoltage condition. It is to be noted here that the electrical supply is an Alternating Current (AC) electrical supply.

In accordance with an embodiment of the present invention, the anti-shock device 100 further comprises an alarm circuit (not shown) configured to raise an alarm in case of one or more of the overload condition and the overvoltage condition. For example, if someone touches a live wire, the alarm is raised by the alarm circuit. This ensures that a concerned responsible authority is informed and the situation is remedied as soon as possible.

In accordance with an embodiment of the present invention, the anti-shock device 100 is available in a plurality of KVA ratings. In that manner, the overload tripping circuit 1206 and the overvoltage tripping circuit 1606 are configured to operate in a plurality of KVA ratings. Thus the anti-shock device 100 with different ratings may be chosen for different applications, like domestic, industrial, high voltage, medium voltage and high voltage etc.

Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but is to be providing broadest scope of consistent with the principles and the novel and inventive features disclosed or suggested herein. Accordingly, the invention is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present invention and appended claim.