Circuit for disconnection detection and circuit breaker

Abstract

The utility model provides a circuit for broken line detection and a circuit breaker, the circuit comprises a filtering assembly, a first capacitor, a diode, a first resistor, a second resistor and a second capacitor, the first end of the filtering assembly is configured to receive a first voltage signal associated with the voltage of a coil, and the second end of the filtering assembly is configured to receive a second voltage signal associated with the voltage of the coil; the second end of the filtering component is configured to be connected to the first capacitor, and the third end of the filtering component is configured to be grounded; the first capacitor is configured to be connected between the second end of the filtering assembly and the anode of the diode; the first resistor is configured to be connected between the anode of the diode and the ground; the cathode of the diode is connected to the first end of the second capacitor, the first end of the second resistor is connected between the cathode of the diode and the first end of the second capacitor, the second end of the second resistor is grounded, and the first end of the second capacitor is configured to output a second voltage signal indicating whether the coil is broken or not. The second end of the second capacitor is grounded.

Description

Technical Field

[0001] This utility model relates to electronic circuits, and in particular to a circuit and circuit breaker for detecting broken wires. Background Technology

[0002] Compact circuit breakers typically include multiple iron core coils. When one or more coils break, the circuit breaker will malfunction. Therefore, it is crucial to accurately detect whether a coil is broken.

[0003] Typically, coil breakage can be detected by measuring current or voltage. However, when using current measurement, a high-power shunt resistor and a high-precision operational amplifier are required in series with each coil. As the number of coils increases, this can lead to insufficient board space. Similarly, measuring coil voltage using resistor dividers to detect breakage can be inaccurate due to leakage current in the rectifier bridge. Furthermore, due to the unique power supply method of compact circuit breakers, the coil's energization time may be very short, making it difficult to detect coil energization and, consequently, coil breakage using either of these conventional methods.

[0004] To address the aforementioned problems, this disclosure proposes a circuit for detecting coil breakage. The circuit proposed in this disclosure satisfies component layout requirements without necessitating the placement of numerous components on a circuit board, and avoids interference from factors such as leakage current of the rectifier bridge on coil breakage detection, thereby accurately detecting whether the coil is broken. Utility Model Content

[0005] According to one aspect of the present invention, a circuit for detecting open circuit is provided, characterized in that it includes a filter component, a first capacitor, a diode, a first resistor, a second resistor, and a second capacitor, wherein: a first terminal of the filter component is configured to receive a first voltage signal associated with the voltage of a coil; a second terminal of the filter component is configured to be connected to the first capacitor; and a third terminal of the filter component is configured to be grounded; the first capacitor is configured to be connected between the second terminal of the filter component and the anode of the diode; the first resistor is configured to be connected between the anode of the diode and ground; the cathode of the diode is connected to the first terminal of the second capacitor; the first terminal of the second resistor is connected between the cathode of the diode and the first terminal of the second capacitor; the second terminal of the second resistor is grounded; the first terminal of the second capacitor is configured to output a second voltage signal indicating whether an open circuit has occurred in the coil; and the second terminal of the second capacitor is grounded.

[0006] For example, according to an embodiment of the present invention, the circuit is characterized in that the filtering component is configured to filter out AC interference signals included in the first voltage signal, the filtering component includes: a third resistor, a first end of the third resistor being configured to receive the first voltage, a second end of the third resistor being connected to the first capacitor, a third capacitor, a first end of the third capacitor being configured to be connected between the third resistor and the first capacitor, and a second end of the third capacitor being configured to be grounded.

[0007] For example, in a circuit according to an embodiment of the present invention, the first capacitor is configured to filter out DC interference signals in the first voltage signal.

[0008] For example, according to an embodiment of the present invention, the circuit is characterized in that, in response to the first voltage signal having a negative polarity, the first resistor is configured to transfer current from ground to the first capacitor.

[0009] For example, in a circuit according to an embodiment of the present invention, the second capacitor is configured to store the energy carried by the first voltage signal.

[0010] For example, in a circuit according to an embodiment of the present invention, the second capacitor is configured to release the energy stored in the second capacitor through the second resistor.

[0011] For example, the circuit according to an embodiment of the present invention is characterized by further including a fourth resistor, which is connected between the cathode of the diode and the first end of the second capacitor.

[0012] For example, the circuit according to an embodiment of the present invention is characterized in that it further includes a voltage clamping component, wherein a first end of the voltage clamping component is connected to a first end of the second capacitor, and a second end of the voltage clamping component is connected to a clamping voltage source.

[0013] For example, according to an embodiment of the present invention, the circuit is characterized in that, assuming no breakage occurs in the coil, the first terminal of the second capacitor is configured to output a second voltage signal having at least a threshold number of pulses in each threshold time period, wherein the pulse width is at least greater than the threshold pulse width.

[0014] For example, according to an embodiment of the present invention, the circuit is characterized in that, in response to the coil being disconnected, the first terminal of the second capacitor is configured to output a second voltage signal having a voltage continuously below a threshold voltage.

[0015] According to one aspect of the present invention, a circuit breaker is provided, characterized in that it includes the circuit described above for detecting open circuits.

[0016] To address the aforementioned problems, this disclosure proposes a circuit for detecting coil breakage. The circuit proposed in this disclosure satisfies component layout requirements without necessitating the placement of numerous components on a circuit board, and avoids interference from factors such as leakage current of the rectifier bridge on coil breakage detection, thereby accurately detecting whether the coil is broken. Attached Figure Description

[0017] The above and other aspects, features, and advantages of specific embodiments of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0018] Figure 1 A block diagram of a circuit including the coil to be tested is shown.

[0019] Figure 2 A block diagram of a circuit for detecting coil breakage according to an embodiment of the present disclosure is shown.

[0020] Figure 3 A block diagram of another circuit for coil breakage detection according to an embodiment of the present disclosure is shown.

[0021] Figure 4 A circuit breaker according to an embodiment of the present disclosure is shown. Detailed Implementation

[0022] Before proceeding with the following detailed description, it may be advantageous to define certain words and phrases used throughout this invention. The terms “comprising” and “including” and their derivatives mean including but not limited to. The phrase “at least one”, when used with a list of items, means that different combinations of one or more of the listed items may be used, and that only one item in the list may be required. For example, “at least one of A, B, and C” includes any one of the following combinations: A, B, C, A and B, A and C, B and C, A and B and C.

[0023] Definitions of other specific words and phrases are provided throughout this invention. Those skilled in the art will understand that, in many, if not most, cases, such definitions apply to the prior and future use of the words and phrases thus defined.

[0024] The various embodiments of the principles of this invention described below in conjunction with the accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of the invention in any way. Those skilled in the art will understand that the principles of this invention can be implemented in any suitably arranged system or device. In some cases, the actions described in this invention can be performed in different orders and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific order or sequential sequence shown to achieve the desired result. In certain embodiments, multitasking and parallel processing may be advantageous.

[0025] The text and accompanying drawings are provided by way of example only to aid in understanding the present invention. They should not be construed as limiting the scope of the appended claims in any way. Throughout the drawings, the same reference numerals generally indicate the same elements. Although certain embodiments and examples have been provided, it will be clear to those skilled in the art, based on the content of this invention, that changes can be made to the illustrated embodiments and examples without departing from the scope of this invention.

[0026] As mentioned above, when detecting coil breakage by measuring current, a high-power shunt resistor and a high-precision operational amplifier need to be connected in series with each coil. As the number of coils increases, this leads to insufficient space on the circuit board. When measuring coil voltage using resistor divider to detect coil breakage, inaccurate detection is impossible due to leakage current in the rectifier bridge. Furthermore, due to the special power supply method of compact circuit breakers, the coil energization time may be very short. Therefore, the two conventional methods mentioned above may struggle to detect coil energization, and consequently, whether a coil breakage has occurred.

[0027] Figure 1 A block diagram of a circuit including the coil to be tested is shown.

[0028] like Figure 1 As shown, the circuit may include coils CT1 and CT2, rectifier modules 111 and 121, power supply module 131, shunt module 141, and feedback module 151.

[0029] Coils CT1 and CT2 can be connected to rectifier modules 111 and 121, respectively. Rectifier modules 111 and 121 can be connected to power supply module 131 and shunt module 141. Feedback module 151 can be connected between power supply module 131 and shunt module 141. It should be noted that although... Figure 1 Only coils CT1 and CT2 are shown, but more or fewer coils may be included, and other coils may be connected in the circuit in a similar manner to coils CT1 and CT2.

[0030] The operation of the shunt module 141 to enable or disable the power-drawing module 131 can be determined based on signals such as voltage obtained from the feedback module 151. For example, the shunt module 141 can short-circuit rectifier modules 111 and 121 to ground to disable the power-drawing module 131. Alternatively, the shunt module 141 can leave rectifier modules 111 and 121 un-short-circuited to ground to enable the power-drawing module 131 to draw power. The current output by CT1 and CT2 to rectifier modules 111 and 121 may be very large, so the power-drawing module 131 may not draw power most of the time and draw power only a small portion of the time.

[0031] When it is necessary to detect whether coils CT1 and CT2 are disconnected, the detection can be based on the voltage signals associated with coil CT1 and coil CT2, respectively. Typically, when the coils are not disconnected, the voltage signals associated with the coils can be AC ​​voltage signals. When the coils are disconnected, the voltage signals associated with the coils should be low-level signals or zero.

[0032] However, when the coil is like Figure 1 When the connection is made as shown, if coil CT1 is not disconnected but coil CT2 is disconnected, due to the leakage current that may exist in the path of coil CT1, as well as the influence of power supply module 131 and shunt module 141, even if coil CT2 is disconnected, a large voltage signal associated with coil CT2 may still be detected, which may lead to coil CT2 being misjudged as not disconnected. Similarly, when coil CT1 is disconnected but coil CT2 is not disconnected, for similar reasons, coil CT1 may still be misjudged as not disconnected. In addition, since the energization time of coils CT1 and CT2 may be very short when a large current flows through them, conventional processing equipment may have difficulty detecting whether the coil is energized, and thus difficult to detect whether the coil is disconnected. To solve the above problems, this disclosure proposes a circuit for coil disconnection detection. Unlike existing circuits for coil disconnection detection, the circuit for coil disconnection detection proposed in this disclosure can filter out interference signals in the voltage signal associated with the coil and broaden the voltage signal associated with the coil, thereby accurately detecting whether the coil is disconnected.

[0033] Figure 2 A block diagram of a circuit for detecting coil breakage according to an embodiment of the present disclosure is shown.

[0034] Figure 2 The open circuit detection circuit 100 shown can be a single circuit 100 for detecting whether a coil has broken. Those skilled in the art will understand that multiple coils can each be configured with a separate open circuit detection circuit. Figure 2 As shown, the open circuit detection circuit 100 may include a filter component 110, a first capacitor 120, a diode 130, a first resistor 140, a second resistor 150, and a second capacitor 160. The open circuit detection circuit 100 may receive a first voltage signal associated with the voltage of the coil and output a second voltage signal indicating whether an open circuit has occurred in the coil.

[0035] The first terminal of the filter component 100 can be configured to receive a first voltage signal associated with the voltage of the coil, the second terminal of the filter component 100 is configured to be connected to the first capacitor 120, and the third terminal of the filter component 100 is configured to be grounded. The filter component 100 can be configured to filter out AC interference signals included in the first voltage signal. For example, the filter component 100 can filter out high-frequency harmonic interference in the first voltage signal, thus being unaffected by power supply harmonics. In this way, the problem of pulses still existing even when the coil is broken due to high-frequency harmonic components, leading to missed detection of the breakage, can be solved or mitigated. The filter component 100 can enhance the anti-interference capability of the breakage detection circuit 100.

[0036] The first capacitor 110 can be configured to be connected between the second terminal of the filter component 110 and the anode of the diode 130. The first capacitor 110 can be a DC blocking capacitor. The first capacitor 110 can be configured to filter out DC interference signals in the first voltage signal. For example, the DC interference signal can be from... Figure 1 The leakage current interference of other rectifier modules is shown. In this way, the problem of missed detection of open circuits can be solved or mitigated when multiple channels (e.g., multiple coils and corresponding rectifier modules and open circuit detection circuits) are connected in parallel. This is because the channel where the coil is open may still have pulses due to leakage current from other channels, which may lead to missed detection of open circuits.

[0037] The first resistor 140 is configured to be connected between the anode of the diode 130 and ground. The first resistor 140 can be referred to as a charging resistor. The first resistor 140 can transfer current from ground to the first capacitor 120 when the polarity of the first voltage signal is negative. In this way, saturation of the first capacitor 120 can be avoided, thereby enabling the open circuit detection circuit 100 to continuously detect whether the coil is open.

[0038] The anode of diode 130 can be connected to the first capacitor 120 and the first resistor 140, and the cathode of diode 130 can be connected to the first terminal of the second capacitor 160. Diode 130 can be called a reverse-biased diode. Diode 130 can conduct current unidirectionally from the filter component 110 to the second capacitor 160. Diode 130 can prevent the energy stored in the second capacitor 160 from generating a reverse current flowing into the filter component 110 when the polarity of the first voltage signal is negative.

[0039] The first end of the second resistor 150 can be connected between the cathode of the diode 130 and the first end of the second capacitor 160, and the second end of the second resistor 150 can be grounded. The second resistor 150 can be called a discharge resistor. The second resistor 150 can cause the energy stored in the energy storage capacitor 160 to be released slowly, thereby widening the pulse width of the first voltage signal.

[0040] The second capacitor 160 can be configured to store the energy carried by the first voltage signal and slowly release the energy through the second resistor 150. The first terminal of the second capacitor 160 can output a second voltage signal indicating whether a coil has broken wire, and the second terminal of the second capacitor 160 can be grounded. That is, the second capacitor 160 and the second resistor 150 can broaden the pulse width of the first voltage signal to output the second voltage signal. As mentioned earlier, since the energization time of the coil may be very short when a large current flows through it, conventional processing devices may have difficulty detecting whether the coil is energized, and thus, whether a coil has broken wire. The wire breakage detection circuit 100 according to an embodiment of this disclosure can broaden the pulse width of the first voltage signal, thereby enabling the processing device receiving the second voltage signal to determine whether a coil has broken wire.

[0041] Figure 3 A block diagram of another circuit for coil breakage detection according to an embodiment of the present disclosure is shown.

[0042] Figure 3 The open circuit detection circuit 200 shown can be a single circuit for detecting whether a coil has broken wire. Those skilled in the art will understand that multiple coils can each be configured with a separate open circuit detection circuit. Figure 3 As shown, the disconnection detection circuit 200 may include a filter component 110, a first capacitor 120, a diode 130, a first resistor 140, a second resistor 150, a second capacitor 160, and a fourth resistor 230. Figure 3 Zhongyu Figure 2The same and similar components will not be described again. The open circuit detection circuit 200 can receive a first voltage signal associated with the voltage of the coil and output a second voltage signal indicating whether the coil has been disconnected.

[0043] Filter component 110 can be an RC filter. For example... Figure 3 As shown, the filter assembly 110 may include a third resistor 210 and a third capacitor 220. The first terminal of the third resistor may be configured to receive a first voltage, and the second terminal of the third resistor is connected to the first capacitor 120. The first terminal of the third capacitor 220 may be configured to be connected between the third resistor 210 and the first capacitor, and the second terminal of the third capacitor 220 may be configured to be grounded. Although Figure 3 The filter component 110 is illustrated with a specific RC filter, but those skilled in the art will understand that other structures of RC filters or other filters are possible, and this disclosure does not limit them.

[0044] A fourth resistor 230 can be connected between the cathode of diode 130 and the first terminal of second capacitor 160. The fourth resistor 230 acts as a current limiter, restricting the current flowing into the second capacitor 160, thereby protecting the second capacitor 160 from damage when the amplitude of the first voltage signal is large. Although Figure 3 The fourth resistor 230 is shown as being connected between the first end of the second resistor 150 and the first end of the second capacitor 160, but this disclosure is not limited thereto. For example, the fourth resistor 230 may be connected between the cathode of the diode 130 and the first end of the second resistor 150.

[0045] A first terminal of the voltage clamping assembly 240 is connected to a first terminal of the second capacitor 160, and a second terminal of the voltage clamping assembly 240 can be connected to a clamping voltage source. The voltage of the clamping voltage source can be, for example, 3.3V. Those skilled in the art will understand that the voltage value of the clamping voltage source is merely an example, and this disclosure is not limited thereto. The voltage clamping assembly 240 can be configured to limit the voltage output of the second capacitor 160. For example, the voltage clamping assembly 240 can limit the amplitude of the second voltage signal to below the voltage value of the clamping voltage source, thereby protecting the processing equipment receiving the second voltage signal from damage.

[0046] As mentioned above, when a large current flows through the coil, the energization time of the coil may be very short, making it difficult for conventional processing equipment to detect whether the coil is energized, and consequently, whether a wire breakage has occurred. The wire breakage detection circuit 100 according to an embodiment of this disclosure can broaden the pulse width of the first voltage signal, thereby enabling the processing equipment receiving the second voltage signal to determine whether a wire breakage has occurred in the coil.

[0047] Specifically, in one embodiment, in response to no wire breakage in the coil, the first terminal of the second capacitor 160 can be configured to output a second voltage signal having at least a threshold number of pulses in each threshold time period, wherein the pulse width is at least greater than the threshold pulse width. According to one embodiment of this disclosure, the threshold time period can be 1 second, the threshold number can be 2, and the threshold pulse width can be 100 microseconds. Those skilled in the art will understand that the specific values ​​described above are merely examples, and other thresholds can be set for the wire breakage detection circuit 100 or 200 depending on specific usage requirements and settings.

[0048] In another embodiment, in response to a coil breakage, the first terminal of the second capacitor 160 can be configured to output a second voltage signal having a voltage continuously below a threshold voltage. According to one embodiment of this disclosure, the threshold voltage may be 0.7 volts. Those skilled in the art will understand that the specific values ​​described above are merely examples, and other thresholds may be set for the breakage detection circuit 100 or 200 depending on specific usage requirements and settings.

[0049] Figure 4 A circuit breaker according to an embodiment of the present disclosure is shown.

[0050] The open circuit detection circuit 410 may include one or more of the open circuit detection circuits 100 and 200 described above. The open circuit detection circuit 410 may receive a first voltage signal associated with the coil and output a second voltage signal to the processing device 420 that has been filtered out of interference signals (e.g., high-frequency and DC interference signals) and has a widened pulse width.

[0051] Processing device 420 can be connected to open circuit 410 to receive a second voltage signal. Processing device 420 may include a microcontroller unit (MCU), central processing unit (CPU), digital signal processor (DSP), single-chip microcomputer, or other processing unit with data processing and / or program execution capabilities, such as a field-programmable gate array (FPGA). Processing device 420 may include a general-purpose processor or a special-purpose processor and can perform the desired function. Although not shown, processing device 420 may include memory. Memory may include any combination of one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache. Non-volatile memory may include, for example, read-only memory (ROM), hard disk, erasable programmable read-only memory (EPROM), portable compact disc read-only memory (CD-ROM), USB memory, flash memory, etc. One or more computer program modules may be stored on the computer-readable storage medium, and one or more computer program modules may be run to implement the coil open circuit detection function. Various applications and data, as well as various data used and / or generated by applications, can also be stored in computer-readable storage media.

[0052] The open circuit detection circuit and circuit breaker according to embodiments of this utility model can meet the component layout requirements without arranging a large number of components on the circuit board, and can avoid interference from factors such as leakage current of the rectifier bridge on coil open circuit detection, thereby accurately detecting whether the coil is open. Furthermore, the open circuit detection circuit according to embodiments of this disclosure adopts a low-power, compact design. The open circuit detection circuit uses all passive components, requiring no chip power supply, thus simplifying the device and further saving power and space. Moreover, even when a large current flows through the coil and the coil's energization time may be very short, since the open circuit detection circuit according to embodiments of this disclosure can broaden the pulse width of the first voltage signal and output a second voltage signal, the processing device receiving the second voltage signal can determine whether the coil is open based on the second voltage signal.

[0053] Although the present invention has been described with reference to exemplary embodiments, various changes and modifications may be suggested to those skilled in the art. The present invention is intended to cover such changes and modifications that fall within the scope of the appended claims.

[0054] Any description in this invention should not be construed as implying that any particular element, step, or function is an essential element that must be included within the scope of the claims. The scope of the patent subject matter is defined only by the claims.

Claims

1. A circuit for detecting broken wires, characterized in that, It includes a filter component, a first capacitor, a diode, a first resistor, a second resistor, and a second capacitor, wherein: The first end of the filter component is configured to receive a first voltage signal associated with the voltage of the coil, the second end of the filter component is configured to be connected to a first capacitor, and the third end of the filter component is configured to be grounded. The first capacitor is configured to be connected between the second terminal of the filter assembly and the anode of the diode; The first resistor is configured to be connected between the anode of the diode and ground; The cathode of the diode is connected to the first terminal of the second capacitor. The first terminal of the second resistor is connected between the cathode of the diode and the first terminal of the second capacitor, and the second terminal of the second resistor is grounded. The first terminal of the second capacitor is configured to output a second voltage signal indicating whether the coil has been disconnected, and the second terminal of the second capacitor is grounded.

2. The circuit according to claim 1, characterized in that, The filtering component is configured to filter out AC interference signals included in the first voltage signal, and the filtering component includes: A third resistor, wherein a first terminal of the third resistor is configured to receive the first voltage, and a second terminal of the third resistor is connected to the first capacitor. A third capacitor, wherein a first terminal of the third capacitor is configured to be connected between the third resistor and the first capacitor, and a second terminal of the third capacitor is configured to be grounded.

3. The circuit according to claim 1, characterized in that, The first capacitor is configured to filter out DC interference signals in the first voltage signal.

4. The circuit according to claim 1, characterized in that, In response to the first voltage signal being negative, the first resistor is configured to transfer current from ground to the first capacitor.

5. The circuit according to claim 1, characterized in that, The second capacitor is configured to store the energy carried by the first voltage signal.

6. The circuit according to claim 1, characterized in that, The second capacitor is configured to release the energy stored in the second capacitor through the second resistor.

7. The circuit according to claim 1, characterized in that, It also includes a fourth resistor connected between the cathode of the diode and the first terminal of the second capacitor.

8. The circuit according to claim 1, characterized in that, It also includes a voltage clamping assembly, wherein a first end of the voltage clamping assembly is connected to a first end of the second capacitor, and a second end of the voltage clamping assembly is connected to a clamping voltage source.

9. The circuit according to claim 1, characterized in that, In response to the absence of a break in the coil, the first terminal of the second capacitor is configured to output a second voltage signal having at least a threshold number of pulses in each threshold time period, wherein the pulse width is at least greater than the threshold pulse width.

10. The circuit according to claim 1, characterized in that, In response to a break in the coil, the first terminal of the second capacitor is configured to output a second voltage signal having a voltage continuously below a threshold voltage.

11. A circuit breaker, characterized in that, Includes the circuit for wire break detection as described in any one of claims 1-10.

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