DESC:TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to circuit breakers. More particularly, the present invention provides a method and an apparatus for limiting the transient peak of passive filters. The present invention provides an easy to implement and cost efficient solution to the circuit breakers.

BACKGROUND AND THE PRIOR ART

A circuit breaker is a manually or automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. One variant of circuit breakers are microprocessor based circuit breakers. These circuit breakers make use of an electronic trip unit as the nucleus of sensing the fault condition. An electronic trip unit is an intelligent device that is used in conjunction with an electro-mechanical circuit breaker to measure system parameters such as voltage, current, power etc and protect the system against faults such as overload, short circuit, earth fault, etc and control the electro mechanical device in cases of occurrences of faults.

Most circuit breakers use the conventional core balance current transformer as the sensor to detect the current flowing through the system. However, due to drawbacks like saturation of the core and extended losses of the conventional core balance current transformer, the use of Air core sensors, preferably rogowski has progressed over the years.

While the output of the core balance current transformer is proportional to the input current, the output of the Rogowski is proportional to the first time derivative of primary current (di/dt).
E=L(di/dt)
Where,
“E” is the output voltage of the Rogowski coils measured in volts.
“L” is the mutual inductance of the Rogowski coil measured in Henry.
“i” is the primary current measured in Amperes.

Hence, the output of the Rogowski is fed to an integrator circuit. The integrator is used because the measured voltage is proportional to the first time derivative of the primary current. In order to obtain the equivalent value of current that is proportional to the primary current, the Rogowski output voltage is integrated.

Integrator Circuits can be broadly divided into two categories, Passive integrator and Active Integrator. First order Passive Integrator circuits use simple passive components like resistors and capacitors to integrate the input signal. Due to their simple construction, Passive integrators are preferred for most applications. However, there are certain inherent problems that are faced when the output of passive integrators is fed to consecutive circuitry.

The differentiated voltage output of the Rogowski, when fed to the passive integrator, gives an output with a reduced gain as the original signal. Hence, to make the signal equivalent to the original signal, the output of the passive integrator is transmitted through an operational amplifier circuit that compensates for the loss in the signal amplitude caused by the passive integrator. It is observed that an inherent problem of the passive integrator is an initial transient peak, caused by the charging of the capacitor within the R-C network of the passive integrator. This transient peak tends to get amplified when passed through the operational amplifier circuit, becoming instrumental in conveying incorrect signals to the microcontroller circuitry that follows the operational amplifier circuit.

Hence, a need for a device and mechanism to reduce the inherent peak of the passive filter, while ensuring that the original signal properties is not altered.

OBJECTS OF THE INVENTION

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 method for limiting the transient peak of the passive filters in circuit breakers.

Another object of the present invention is to provide an apparatus for limiting limit the transient peak of the passive filters in circuit breakers.

Another object of the present invention is to provide an easy to implement, cost efficient method providing minimal analog circuitry changes.

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 method and an apparatus to limit the transient peak of Passive Filters in Circuit Breakers using Air Core Sensors by capacitor compensation and the concepts are further described below in the detailed description. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.

Accordingly, in one implementation, a circuit breaker having an electronic trip unit to nullify an inherent peak is disclosed. The circuit breaker comprises of one or more air core sensor configured to measure an alternate current or high speed current pulses to generate an output; one or more passive low pass filter circuit configured to receive said output and integrate said output; one or more operational amplifier circuit comprising one or more gain setting resistors, and configured to amplify said output integrated, thereby accommodate said output integrated within a format readable by one or more analog to digital converter of one or more controller, and characterized by having one or more capacitor in a non-inverting terminal; and one or more trip mechanism; WHEREIN when a fault is detected, said controller feeds signal integrated within the format readable to said trip mechanism which comprises of an electromechanical device which in turn propagates a mechanical section of said circuit breaker to open the electrical circuit.

In one implementation, a method for nullifying an nullify an inherent peak produced by a passive low pass filter circuit or an integrator in a circuit breaker having an electronic trip unit is disclosed. The method comprises of:
· measuring, using one or more air core sensor, an alternate current or high speed current pulses to generate an output;
· receive, using one or more passive low pass filter circuit, said output and integrate said output;
· amplifying, using one or more operational amplifier circuit comprising one or more gain setting resistors, to amplify said output integrated;
· accommodate, using said using one or more operational amplifier circuit, said output integrated within a format readable by one or more analog to digital converter of one or more controller;
· CHARACTERIZED BY COMPRSING
· providing one or more capacitor in a non-inverting terminal of said operational amplifier circuit;
· nullifying, by said operational amplifier circuit, an inherent peak produced by said passive low pass filter circuit or said integrator.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The following drawings are illustrative of particular examples for enabling methods of the present invention, are descriptive of some of the methods, and are not intended to limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description.

Figure 1 illustrates a block diagram of the electronic trip unit.

Figure 2 illustrates an exemplary two stage system consisting of alow pass passive filter, in combination with the operational amplifier gain stage.

Figure 3 illustrates the transient peak observed at the output of the Signal Conditioning Circuit.

Figure 4 illustrates the exemplary two stage system consisting of alow pass passive filter, in combination with the operational amplifier gain stage, along with the compensatory capacitor.

Figure 5 illustrates the waveforms observed at the output of the Signal Conditioning Circuit, with the compensatory Capacitor.

Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.

Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

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 provides a method and an apparatus for limiting the transient peak of passive filters using air core sensor, preferably rogowski rather than conventional core balance current transformer, achieved through analog circuitry. The invention uses a capacitor to compensate for the transient peak,

Figure 1 is a block diagram representation of the electronic trip unit, consisting of an air core sensor, Rogowski, which is a device that is used for measuring alternate current or high speed current pulses. The output of the Rogowski is proportional to the first time derivative of primary current (di/dt).
E=L(di/dt)
Where,
E is the output voltage of the Rogowski coils measured in volts.
L is the mutual inductance of the Rogowski coil measured in Henry.
I is the primary current measured in Amperes.

The output of the air core sensor of the individual phases namely R, Y ,B and N denoted by 101,104, 107,110 respectively is fed to the Passive Low Pass Filter Circuit, 102,105,108,111 respectively., whose functionality is similar to that of an integrator.

The integrator is used because the measured voltage is proportional to the first time derivative of the primary current. In order to obtain the equivalent value of current that is proportional to the primary current, the Rogowski output voltage is integrated. The cut off frequency of the passive low pass filter circuit is kept as low as possible. The integrator offers large impedance to high frequency signal and hence filters out the external noises that are high frequency in nature.

The output of the passive low pass filter circuit is fed to the operational amplifier circuit103, 106,109,112 in the R, Y, B, N phase respectively. The operational amplifier acts as an amplifier with the help of gain setting resistors. A DC offset is provided in order to accommodate the entire signal within Vcc and GND, a format that is readable by the ADC of the controller, 113.In case of a fault condition, the controller 113 gives an output signal to the trip mechanism114, which comprises of an electromechanical device which in turn propagates the mechanical section of the circuit breaker to open the electrical circuit.

The air core sensor, 101, 104, 107, 110, Passive Low Pass Filter Circuit, 102, 105, 108, 111, and operational amplifier circuit, 103,106,109,112 are best seen by referring to figure 2, which depicts a schematic illustrative of an embodiment of a passive low pass filter circuit , operational amplifier circuit, as depicted in figure 1. However, it will be appreciated if the schematic of figure 2 is for illustration purposes only, and that embodiments of the invention may be practiced using alternative arrangements of electronic components.

While figure 2 depict the signal path in only one phase of the circuit breaker, it will be appreciated and understood by one skilled in the art that similar schematics may be used for the other phases, and coupled appropriately at the output side.

In the given schematic of figure 2, the Passive Low Pass Filter Circuit201 has a -3db point at 15Hz with a -20db/decade roll-off. The Passive Low Pass Filter Circuit201 provides a steep slope, hence faster response to the input signal, with a cut-off frequency of 15Hz.

The Passive Low Pass Filter Circuit201, the operational amplifier gain stage 202 is defined by using the gain setting resistor R7 and the feedback resistor R6 represented by,
Av = -(R6/R7)

The output of the Passive Low Pass Filter Circuit 201 is coupled with the operational amplifier circuit 202and fed as input to the ADC of the micro controller, 113. The micro controller reads this value and checks whether the value exceeds the predefined fault pick up value and persist more than set duration. If so, the micro controller issues trip command to the trip mechanism, 114.

Figure 3 depicts the signal at the output of the Signal Conditioning Circuit of figure 2.Once the Signal Conditioning Circuit is powered ON, it takes 4ms for the Output to rise to its peak value of 1.74V and then it begins to drop, taking 20ms to settle to the 80% percent value of 1.65V. Hence the overall settling time calculated for the signal to reach 80% of the actual value results to 24ms. The ideal signal expected at the output of the Signal conditioning circuit of figure 2. would be a steep rise with 0ms rise time, becoming constant at the actual value of 1.65V, but due to the charging time of the capacitor, an initial rise time followed by settling time is seen.

Considering only the passive low pass filter circuit, to analyze the cause of the initial peak, the output of the passive low pass filter can be computed as
Vout = [Xc/(Rc+Xc)]* Vin
Where Rc is the Integrator Resistor R8
Xc is the Equivalent Impedence of Capacitor C4 given by
Xc = 1/(2*p*f*C)
Where,
C is the capacitance in farad
f is the operating frequency in Hertz

Now, at time t=0+, the voltage across Capacitor C is 0, hence the initial gain (Vout/Vin) of the Passive Low pass Filter is 0. Since the DC analysis of the Signal Conditioning Circuit is carried out keeping two aspects in mind, the Passive Low pass filter as well as the Operational Amplifier Circuit, the DC offset of both the circuits plays a key role in deciding the output signal. Now, since at t=0+, the passive low pass filter gain is 0, the Operational Amplifier circuit tries to compensate for the loss faced in the integrator section, in turn corresponding to the initial peak. The Rogowski signal rides on this DC signal obtained. When the Rogowski signal rides on the peak, the controller senses the peak signal as a fault signal and issues a trip command to the trip mechanism, which in turn trips the circuit breaker. As such, a problematic situation of nuisance trip on power on arises for certain protection settings, which is highly undesirable.

To cater to this issue, a method is required to reduce the initial peak to an acceptable level. A method, depicted in figure 4, shows the peak can be nullified by making minimal changes in the already established circuit. In figure 4, it can be seen that majority of the signal conditioning circuit is kept intact, along with the component values. The only change that is performed is the addition of a Capacitor C7 401, in the non-inverting terminal of the operational Amplifier. The Passive integrator circuit lies in the inverting section of the Operational amplifier. By introducing a capacitor in the non- inverting leg, we purposefully create another charging curve, which is a replica of the curve generated by the charging of capacitor C8 in the Passive integrator section. When both the capacitor signals are fed into the operational amplifier, by the inherent property of the Operational Amplifier to bias the inputs received from the inverting terminal and non- inverting terminal, the charging curve formed by capacitor C7 tends to nullify the initial peak formed by C8 in the passive integrator section.

Although the method provides a stable approach to deal with the issue of initial peak of the passive integrator section, it comes with a drawback of increased rise time. The design demands sound consideration of the value of capacitor C7, as it inhibits a trade-off between rise time and the initial peak of the passive integrator section.

Figure 5 depicts the output waveform of the signal conditioning circuit with the addition of Capacitor C7 in the schematic. It is noteworthy that the addition of the capacitor C7 does not hamper the functionality of the circuit in any form as compared to the original circuit depicted in figure 3. AC analysis as well as DC analysis of the signal conditioning circuit depicts replicating results with an improvement of the initial peak obtained during DC analysis, to a great extent. It can be observed from figure 5 that the peak measured of the signal is at 1.66V as observed earlier of 1.74V. There is also an observed advantage of improved settling time from 24ms to 20ms; however, the rise time has deteriorated from 4ms to 18ms. The waveforms depict the reduced transient peak of the Passive integrator circuit.
Attribute Original Circuit Original Circuit + Capacitor C7 Unit
Initial Peak 1.74 1.66 V
Rise Time 4 18 ms
Settling Time 24 20 ms

The most prominent feature of the invention is that the inherent issue of a passive integrator circuit, of transient peak is reduced by simple means, by introducing a capacitor in the circuit. Hence a solution that is easy to implement, cost efficient and involving minimal analog circuitry changes is implemented. It is also noteworthy that this compensatory alteration made reduces the transient peak and does not interfere with the gain calculations of the signal conditioning circuit.

Accordingly, in one implementation, a circuit breaker having an electronic trip unit to nullify an inherent peak is disclosed. The circuit breaker comprises of one or more air core sensor configured to measure an alternate current or high speed current pulses to generate an output; one or more passive low pass filter circuit configured to receive said output and integrate said output; one or more operational amplifier circuit comprising one or more gain setting resistors, and configured to amplify said output integrated, thereby accommodate said output integrated within a format readable by one or more analog to digital converter of one or more controller, and characterized by having one or more capacitor in a non-inverting terminal; and one or more trip mechanism; WHEREIN when a fault is detected, said controller feeds signal integrated within the format readable to said trip mechanism which comprises of an electromechanical device which in turn propagates a mechanical section of said circuit breaker to open the electrical circuit.

In one implementation, a method for nullifying an nullify an inherent peak produced by a passive low pass filter circuit or an integrator in a circuit breaker having an electronic trip unit is disclosed. The method comprises of:
· measuring, using one or more air core sensor, an alternate current or high speed current pulses to generate an output;
· receive, using one or more passive low pass filter circuit, said output and integrate said output;
· amplifying, using one or more operational amplifier circuit comprising one or more gain setting resistors, to amplify said output integrated;
· accommodate, using said using one or more operational amplifier circuit, said output integrated within a format readable by one or more analog to digital converter of one or more controller;
· CHARACTERIZED BY the steps of:
· providing one or more capacitor in a non-inverting terminal of said operational amplifier circuit;
· nullifying, by said operational amplifier circuit, an inherent peak produced by said passive low pass filter circuit or said integrator.

In one implementation, said air core sensor is preferably a Rogowski sensor.

In one implementation, said output of said air core sensor is proportional to the first time derivative of primary current.

In one implementation, said output of said air core sensor is in an electrical resistivity of phases namely R, Y, B and N.

In one implementation, said passive low pass filter circuit is an integrator configured to integrate said output as to obtain an equivalent value of current that is proportional to the primary current.

In one implementation, said passive low pass filter circuit offers large impedance to high frequency signal and hence filters out said external noises that are high frequency in nature.

In one implementation, said output integrated is in is in an electrical resistivity of phases namely R, Y, B and N.

In one implementation, the system comprises a DC offset in order to accommodate said output integrated within Vcc and GND, said format readable by said ADC of said controller.

In one implementation, said passive low pass filter circuit is at an inverting terminal of said operational amplifier circuit.

In one implementation, said capacitor in said non-inverting terminal is configured to create a charging curve which is a replica of a curve generated by a charging of another capacitor in said passive low pass filter circuit.

In one implementation, said operational amplifier circuit is configured to receive inputs from said inverting terminal and said non-inverting terminal, thereby nullify an inherent peak produced by said passive low pass filter circuit.

Although a method and an apparatus to limit the transient peak of Passive Filters in Circuit Breakers using Air Core Sensors by capacitor compensation has been described in language specific to structural features and/or methods, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific features or methods or devices described. Rather, the specific features are disclosed as examples of implementations of a method and an apparatus to limit the transient peak of Passive Filters in Circuit Breakers using Air Core Sensors by capacitor compensation.

The method may be described in the general context of computer executable instructions. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, functions, etc., that perform particular functions or implement particular abstract data types. The method may also be practiced in a distributed computing environment where functions are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, computer executable instructions may be located in both local and remote computer storage media, including memory storage devices.

The order in which the method is described is not intended to be construed as a limitation, and any number of the described method steps can be combined in any order to implement the method or alternate methods. Additionally, individual steps may be deleted from the method without departing from the scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof. However, for ease of explanation, in the embodiments described below, the method may be considered to be implemented in the above described circuit breaker.

In interpreting the appended claims, it should be understood that:
a) the word “comprising” does not exclude the presence of other elements or acts than those listed in a given claim;
b) the word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements;
c) any reference signs in the claims do not limit their scope;
d) several “means” may be represented by the same item or hardware or software implemented structure or function;
e) any of the disclosed elements may be comprised of hardware portions (e.g., including discrete and integrated electronic circuitry), software portions (e.g., computer programming), and any combination thereof;
f) hardware portions may be comprised of one or both of analog and digital portions;
g) any of the disclosed devices or portions thereof may be combined together or separated into further portions unless specifically stated otherwise; and
h) no specific sequence of acts or steps is intended to be required unless specifically indicated.

Dedicated hardware implementations including, but not limited to, application specific integrated circuits, programmable logic arrays and other hardware devices can likewise be constructed to implement the methods described herein. Applications that may include the apparatus and systems of various embodiments broadly include a variety of electronic and computer systems. Some embodiments implement functions in two or more specific interconnected hardware modules or devices with related control and data signals communicated between and through the modules, or as portions of an application-specific integrated circuit. Thus, the example system is applicable to software, firmware, and hardware implementations.

A person of ordinary skill in the art may understand that, all or a part of the steps of the foregoing method embodiments may be implemented by a program instructing relevant hardware. The aforementioned program may be stored in a computer readable storage medium. When the program runs, the steps of the forgoing method embodiments are performed. The storage medium includes any medium capable of storing program code, such as a ROM, a RAM, a magnetic disk, or an optical disc.

Thus, although specific arrangements have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific arrangement shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments and arrangements of the invention. Combinations of the above arrangements, and other arrangements not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description. Therefore, it is intended that the disclosure not be limited to the particular arrangement(s) disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments and arrangements falling within the scope of the appended claims.

Finally, it should be noted that the foregoing embodiments are merely intended for describing the technical solutions of the present invention rather than limiting the present invention. Although the present invention is described in detail with reference to the foregoing embodiments, persons of ordinary skill in the art should understand that they may still make modifications to the technical solutions described in the foregoing embodiments, or make equivalent replacements to some or all the technical features thereof, as long as such modifications and replacements do not cause the essence of corresponding technical solutions to depart from the scope of the technical solutions of the embodiments of the present invention.
,CLAIMS:1. A circuit breaker having an electronic trip unit to nullify an inherent peak, said circuit breaker comprising:
one or more air core sensor configured to measure an alternate current or high speed current pulses to generate an output;
one or more passive low pass filter circuit configured to receive said output and integrate said output;
one or more operational amplifier circuit comprising one or more gain setting resistors, and configured to amplify said output integrated, thereby accommodate said output integrated within a format readable by one or more analog to digital converter of one or more controller, and characterized by having one or more capacitor in a non-inverting terminal; and
one or more trip mechanism; WHEREIN
when a fault is detected, said controller feeds signal integrated within the format readable to said trip mechanism which comprises of an electromechanical device which in turn propagates a mechanical section of said circuit breaker to open the electrical circuit.

2. The circuit breaker as claimed in claim 1, wherein said air core sensor is preferably a Rogowski sensor.

3. The circuit breaker as claimed in any of the preceding claims, wherein said output of said air core sensor is proportional to the first time derivative of primary current.

4. The circuit breaker as claimed in any of the preceding claims, wherein said output of said air core sensor is in an electrical resistivity of phases namely R, Y, B and N.

5. The circuit breaker as claimed in any of the preceding claims, wherein said passive low pass filter circuit is an integrator configured to integrate said output as to obtain an equivalent value of current that is proportional to the primary current.

6. The circuit breaker as claimed in any of the preceding claims, wherein said passive low pass filter circuit offers large impedance to high frequency signal and hence filters out said external noises that are high frequency in nature.

7. The circuit breaker as claimed in any of the preceding claims, wherein said output integrated is in is in an electrical resistivity of phases namely R, Y, B and N.

8. The circuit breaker as claimed in any of the preceding claims, comprises a DC offset in order to accommodate said output integrated within Vcc and GND, said format readable by said ADC of said controller.

9. The circuit breaker as claimed in any of the preceding claims, wherein said passive low pass filter circuit is at an inverting terminal of said operational amplifier circuit.

10. The circuit breaker as claimed in any of the preceding claims, wherein said capacitor in said non-inverting terminal is configured to create a charging curve which is a replica of a curve generated by a charging of another capacitor in said passive low pass filter circuit.

11. The circuit breaker as claimed in any of the preceding claims, wherein said operational amplifier circuit is configured to receive inputs from said inverting terminal and said non-inverting terminal, thereby nullify an inherent peak produced by said passive low pass filter circuit.

12. A method for nullifying an inherent peak produced by a passive low pass filter circuit or an integrator in a circuit breaker having an electronic trip unit, said method comprising:
measuring, using one or more air core sensor, an alternate current or high speed current pulses to generate an output;
receive, using one or more passive low pass filter circuit, said output and integrate said output;
amplifying, using one or more operational amplifier circuit comprising one or more gain setting resistors, to amplify said output integrated;
accommodate, using said using one or more operational amplifier circuit, said output integrated within a format readable by one or more analog to digital converter of one or more controller;
CHARACTERIZED BY the steps of:
providing one or more capacitor in a non-inverting terminal of said operational amplifier circuit;
nullifying, by said operational amplifier circuit, an inherent peak produced by said passive low pass filter circuit or said integrator.

13. The method as claimed in claim 12 comprises creating, by said capacitor in said non-inverting terminal, a charging curve which is a replica of a curve generated by a charging of another capacitor in said passive low pass filter circuit.

14. The method as claimed in any of the preceding claims comprises providing said passive low pass filter circuit is at an inverting terminal of said operational amplifier circuit.
15. The method as claimed in any of the preceding claims comprises receiving, by said operational amplifier circuit, inputs from said inverting terminal and said non-inverting terminal, thereby nullifying an inherent peak produced by said passive low pass filter circuit.

16. The method as claimed in any of the preceding claims, wherein when a fault is detected, said controller feeds signal integrated within the format readable to said trip mechanism which comprises of an electromechanical device which in turn propagates a mechanical section of said circuit breaker to open the electrical circuit.