CLIAMS:1. A control circuit to control an electrically operating mechanism, the control circuit comprising:
at least one electro-mechanical relay; and
at least one actuator (1) further comprising
at least one micro-switch (2, 5, 6, 8, 9) arranged in a predefined logical sequence to enable the rotation of a motor in the electrically operating mechanism; and
at least one projection (4, 7).

2. The control circuit in accordance with claim 1, the electrically operating mechanism further comprises of a shaft (3) which is driven by the motor.

3. The control circuit in accordance with claim 1, further comprising
at least one holding contact to maintain the flow of current to the motor in electrically operating mechanism; and
at least one relay contact for maintaining transfer of control to the at least one holding contact.

4. The control circuit in accordance with claim 1, wherein the at least one motor switch (2, 5, 6, 8, 9) controls an operation of the motor.
,TagSPECI:TECHNICAL FIELD
The present subject matter described herein, in general relates to a control circuit of an electrically operating mechanism (EOM) and, more particularly, to a control circuit used in Electrically Operating mechanism (EOM) for Changeover Switch.

BACKGROUND

Changeover switches (CO) are widely used to switch between a primary and a backup power source. These switches comprises of two switch disconnectors (SD) connected back-to-back. Further, the changeover switches have three stable positions ON1, OFF, ON2. Electrically operating mechanism is used to operate the changeover switches using the electrical power that provides ease of operation to the user. EOM drives the shaft of the changeover switch through a gear train powered by a motor as the input. The electrical supply to EOM has to be controlled so that it does not drive the changeover switch after the stable position is reached. In addition, the control mechanism and the circuit involved have to also sense the position of the switch so that the supply is cut when the same input signal is given repeatedly. The invention described here provides a simple Control circuit which controls the supply to EOM so that the mechanism drives the CO-SD to its appropriate stable position.

Existing products use electronic components in their control circuit of EOM. These circuits have voltage regulator circuits and other protective devices for the safety of the electronic components being used. The electromagnetic relays being used in these circuits are also controlled by the electronic components. The presence of electronic components in the control circuit of EOM makes the design more complex and prone to satisfy additional requirements such as Electromagnetic Interference (EMI), and electromagnetic compatibility (EMC). This makes the control circuit complex and hence the size and cost becomes high.

So there exists a need to provide a solution to all the above mentioned problems, by providing a control circuit with only electrical components i.e. electromagnetic relays to control the switching and supply of the EOM. This control circuit avoids the need for additional electronic components to regulate the input supply.

OBJECTS

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 a control circuit with only electrical components i.e. electromagnetic relays to control the switching and supply of the EOM is provided.

Another object of the present invention is to eliminate the need for additional electronic components to regulate the input supply.

Another object of the present invention is to provide a simple electromechanical relay based circuit, which controls the rotation of motor in the desired direction till the desired position is reached.

Another object of the present invention is to provide dual functions of the micro switches.

Another object of the present invention is to provide a control circuit to control an electrically operating mechanism.

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

This summary is provided to introduce concepts related to a control circuit used in Electrically Operating mechanism (EOM) for changeover switch. This summary is not intended to identify essential features of the subject matter nor is it intended for use in determining or limiting the scope of the subject matter.

In one implementation, a control circuit with only electrical components i.e. electromagnetic relays to control the switching and supply of the EOM is provided.

In one implementation, control circuit avoids the need for additional electronic components to regulate the input supply.

In one implementation, the operation of EOM to drive the changeover switch is achieved through a simple electromechanical relay based circuit, which controls the rotation of motor in the desired direction till the desired position is reached.

In one implementation, the micro-switches are utilized to perform a dual function of limiting the supply at the required position as well as to know the state of the CO-SD. They also provide a control over repetition of input signal by not responding to the input signal of the current position of the Switch.

In one implementation, a control circuit to control an electrically operating mechanism is disclosed. The control circuit comprises of at least one electro-mechanical relay and at least one actuator. The at least one actuator further comprises of at least one micro-switch arranged in a predefined logical sequence to enable the rotation of a motor in the electrically operating mechanism and at least one projection.

In one implementation, the control circuit consists of a set of electro-mechanical relays, and an actuator mechanism with set of micro switches arranged in a predefined logical sequence to enable the rotation of motor in the desired direction of movement till the desired position is reached.

Further, there are two different set of contacts namely, holding contacts and relay contacts, there being two sets of holding contacts, one for each direction of rotation of motor. The holding contacts maintain the flow of current to the motor till the desired position is reached. The relay contact enables the transfer of control from one set of holding contacts to the other set of holding contacts.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.

Figure 1 illustrates a complete control circuit is shown, in accordance with an embodiment of the present subject matter.

Figure2, Figure 3, and Figure 4 illustrate the basic construction of the actuator mechanism is shown, in accordance with an embodiment of the present subject matter.
Figure 5, Figure 6, and Figure 7 illustrate the working of the control circuit when the initial position is position- I (ON-I) and command is given to take the CO-SD to position-O (OFF) is shown, in accordance with an embodiment of the present subject matter.

Figure 8, Figure 9, and Figure 10 illustrate the working of the control circuit when the initial position is position- O (OFF) and command is given to take the CO-SD to position-I (ON-I) is shown, in accordance with an embodiment of the present subject matter.

Figure 11, Figure 12, Figure 13, Figure 14, and Figure 15 illustrate the working of the control circuit when the initial position is position- I (ON-I) and command is given to take the CO-SD to position-II (ON-II) is shown, in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION

Preferred embodiments of the present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

Accordingly, present invention is a control circuit used in electrically operating mechanism (EOM) for changeover switch is disclosed.

Construction of the connector assembly of the present invention is explained with reference to the accompanying figures.

1. Actuator (1)
2. Micro-switch (2, 5, 6, 8, 9)
3. Shaft (3)
4. Projection (4, 7)

The terms that may be frequently used in the description are as follows:

EOM: Electrically operated mechanism - Electrical power is used to operate the device.

Micro-switch: Small sized switches with contacts that can be closed/opened through an actuating lever/projection.

Normally Open (NO) contacts: These contacts will be open when the Micro-switch is not actuated mechanically and will close when actuated. Similar contacts are present in Electromagnetic relays which get actuated electrically.

Normally Closed (NC) contacts: These contacts will be closed when the Micro-switch is not actuated mechanically and will open when actuated. Similar contacts are present in Electromagnetic relays which get actuated electrically.

Electro-mechanical relays: These relays have a set of contacts which open/close in response to excitation of a control coil integrated into the same assembly.

Push button: A device that closes the circuit through the push of an actuator in it.

In one implementation, a control circuit to control an electrically operating mechanism is disclosed. The control circuit comprises of at least one electro-mechanical relay and at least one actuator (1). The at least one actuator further comprises of at least one micro-switch (2, 5, 6, 8, 9) arranged in a predefined logical sequence to enable the rotation of a motor in the electrically operating mechanism and at least one projection (4, 7).

In one implementation, the electrically operating mechanism may further include a shaft (3) which is driven by the motor.

In one implementation, the control circuit further comprises of at least one holding contact to maintain the flow of current to the motor in electrically operating mechanism. Further, the transfer of control to the at least one holding contact is maintained using at least one relay contact.
In one implementation, the at least one motor switch (2, 5, 6, 8, 9) controls an operation of the motor.

In one implementation, the control circuit consists of a set of electro-mechanical relays, and an actuator mechanism with set of micro switches arranged in a predefined logical sequence to enable the rotation of motor in the desired direction of movement till the desired position is reached.

Further, there are two different set of contacts namely, holding contacts and relay contacts, there being two sets of holding contacts, one for each direction of rotation of motor. The holding contacts maintain the flow of current to the motor till the desired position is reached. The relay contact enables the transfer of control from one set of holding contacts to the other set of holding contacts.

Referring now to figure 1 illustrates a complete control circuit is shown, in accordance with an embodiment of the present subject matter.

In one implementation, the control circuit consists of a set of Electro-mechanical relays, and an actuator mechanism with set of micro switches arranged in a predefined logical sequence to enable the rotation of motor in the desired direction of movement till the desired position is reached.

In further detail, there are two different set of contacts namely, holding contacts and relay contacts, there being two sets of holding contacts, one for each direction of rotation of motor. The holding contacts maintain the flow of current to the motor till the desired position is reached. The relay contact enables the transfer of control from one set of holding contacts to the other set of holding contacts.

Referring now to figure2, figure 3, and figure 4 illustrate the basic construction of the actuator mechanism is shown, in accordance with an embodiment of the present subject matter. In one implementation, the actuator mechanism consists of an actuator (1) with two sets of projecting ears and 4 Micro-switches (2). One set of projections in actuator along with one set of micro-switches control the supply.

During the ON to OFF operation of CO-SD whereas the other set of projections along with other set of micro-switches control the OFF to ON operation. ON operation can be to position ON 1 or ON 2 i.e. primary source connected or backup source connected. The micro-switches are placed in such a manner that its orientation and position meets the requirement i.e. supply cut-off at the desired angle of rotation.

During OFF to ON-I operation (O-I), the motor drives the shaft (3) in clockwise direction and in turn the actuator also rotates in clockwise direction. After rotating to a particular angle, one set of projections (4) (NC actuator) in the actuator pushes the lever of the Micro-switch (5) (NC1 Micro-switch) thereby opening its Normally Closed (NC) contacts which cut the supply to the motor in EOM.

During ON1 to OFF operation (I-O), the motor drives the shaft (3) in Anti-clockwise direction and in turn the actuator also rotates in Anti-clockwise direction. Now, the other set of projections (7) (NO cam) in the Actuator releases the lever of the Micro-switch (8) (NO1 Micro-switch) thereby opening its Normally Open (NO) contacts which cut the supply to the motor in EOM.

Similarly, the OFF to ON2 (O-II) and ON2 to OFF (II-O) operation is carried out through the Micro-switches on the other side (6 and 9) (NC2 and NO2 Micro-switches).

Referring now to figure 5, figure 6, and figure 7 illustrate the working of the control circuit when the initial position is position- I (ON-I) and command is given to take the CO-SD to position-O (OFF) is shown, in accordance with an embodiment of the present subject matter. In one implementation, OFF command by closing of the OFF push button initiates the following:

Transfer relay R3 gets energized subsequently energizing holding relay R2 through the NO-I (7 and 8) contact of micro switch in actuator mechanism, which maintains the flow of current to motor even after removal of command. Flow of current to the motor is sustained till the NO-I contact (7 and 8) of micro switch in actuator mechanism opens, which happens, as explained before, after the toggle point of switch is reached.

Referring now to figure 8, figure 9, and figure 10 illustrate the working of the control circuit when the initial position is position- O (OFF) and command is given to take the CO-SD to position-I (ON-I) is shown, in accordance with an embodiment of the present subject matter. In one implementation, ON-I command by closing of the ON-I push button initiates the following:

Holding relay R1 gets energized, contact of the same is maintained through Normally Closed contact of transfer relay R3 and the NC-I (4and5) contact of micro switch in actuator, which results in maintaining the flow of current to motor even after removal of command. Flow of current to the motor is sustained till the NC-I (4 and 5) contact of micro switch in actuator opens, which happens, as explained before, after the toggle point of switch is reached.

Referring now to figure 11, figure 12, figure 13, figure 14, and figure 15 illustrate the working of the control circuit when the initial position is position- I (ON-I) and command is given to take the CO-SD to position-II (ON-II) is shown, in accordance with an embodiment of the present subject matter. In one implementation, ON-II command by closing of the ON-II push button initiates the following:

Transfer relay R3 gets energized subsequently energizing holding relay R2 through the NO-I (7 and 8) contact of micro switch in actuator, which maintains the flow of current to motor even after removal of command. Subsequently, holding relay R2remainsenergized; contact of the same is maintained through Normally Closed contact of transfer relay R3 and the NC-II (4 and6) contact of micro switch in actuator, which results in maintaining the flow of current to motor even after removal of command. Flow of current to the motor is maintained till the NC-II (4 and 6) switch in actuator opens, which happens, as explained before, after the toggle point of switch is reached.

Operations - OFF to ON-II, ON-II to OFF and ON-II to ON-I get executed in a similar fashion as described above.

Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features:

One feature of the invention is that, the proposed control circuit is highly flexible design that can adapt to varied requirements.

Another feature of the invention is that, the proposed control circuit implements a simple circuitry with reduced chances of failure.

Yet another feature of the invention is that, the proposed control circuit has an inbuilt precedence to ‘OFF’ command over other input commands.

Still another feature of the invention is that, the proposed control circuit is that the same design of the circuit can be extended to any area where bidirectional control is required.

Some other features of the proposed invention are listed below:
1. Control signal used for each position may be pulsed (momentary) as well as continuous.
2. Simple electromechanical relays are used in the construction of the circuitry, eliminating the need for complex electronics.
3. The inbuilt precedence to ‘OFF’ command over other input commands.
4. Alteration in cut-off points may be done by minor changes in the actuation mechanism.
5. The proposed circuit works with the same voltage level as the motor which is being controlled.

Although implementations for the control circuit used in Electrically Operating mechanism (EOM) for changeover switch have been described in language specific to structural features and/or the methods, it is to be understood that the appended claims are not necessarily limited to the specific features or methods described. Rather, the specific features are disclosed as examples of the control circuit used in Electrically Operating mechanism (EOM) for changeover switch.

It is intended that the disclosure and examples above be considered as exemplary only, with a true scope and spirit of disclosed embodiments being indicated by the following claims.