TWI902142B - Multi-path current difference detection device - Google Patents

Abstract

A multi-path current difference detection device includes an induction component and a determination unit. The induction component induces a plurality of currents flowing through a plurality of paths, and calculates a net current value of a plurality of current values of the plurality of currents. The determination unit receives a current signal corresponding to the net current value, and provides a detection signal when determining that the current signal is greater than or equal to a current threshold.

Description

Multi-path current difference detection device

This invention relates to a current difference detection device, and more particularly to a multi-path current difference detection device.

Currently, the most common method for detecting different current directions in two or more paths is using a current transformer (CT). However, current transformers have disadvantages such as large size, complex wiring, and high cost. Furthermore, current transformers are susceptible to temperature variations and accuracy drift. Therefore, in addition to current transformers, Hall effect sensors are also used for current detection. However, a single Hall effect sensor can only detect current in a single path. Therefore, to detect different current directions in two or more paths, more Hall effect sensors must be used, which increases costs.

Therefore, designing a multi-path current difference detection device to solve the problems and technical bottlenecks of existing technologies is an important research topic for the inventors of this project.

One object of this invention is to provide a multi-path current difference detection device. The multi-path current difference detection device includes a sensing element and a judgment unit. The sensing element senses multiple currents flowing through multiple paths that are not in contact with the sensing element, and calculates the net current value of these multiple current values. The judgment unit receives a current signal corresponding to the net current value, and determines whether the current signal is greater than or equal to a current threshold, and provides a detection signal.

In one embodiment, the judgment unit includes a signal amplifier and a voltage follower. The signal amplifier receives and amplifies a current signal. The voltage follower is connected to the signal amplifier and receives the amplified current signal. The voltage follower provides a high-level detection signal when the amplified current signal is greater than or equal to a current threshold. The voltage follower provides a low-level detection signal when the amplified current signal is less than the current threshold.

In one embodiment, the current difference detection device is an integrated circuit.

In one embodiment, the current threshold corresponds to a current value of zero amperes.

In one embodiment, the currents are alternating currents, and the current threshold corresponds to a current value of 15 milliamperes.

In one embodiment, the currents are either alternating current (AC) or direct current (DC), and the corresponding current threshold is 6 milliamperes (DC).

In one embodiment, the inductive element is a Hall element, tunneling reluctance, anisotropic reluctance, giant reluctance, super-giant reluctance, or constant reluctance.

In one embodiment, the signal amplifier is an operational amplifier.

In one embodiment, the differential current detection device is disposed on a circuit board, and the circuit board is a multilayer board with a laminated structure. The paths are respectively disposed on different layers.

Another object of the present invention is to provide a multi-path current difference detection device. The multi-path current difference detection device includes a sensing element and a decision unit. The sensing element senses multiple currents flowing through multiple paths in contact with the sensing element. The decision unit receives multiple current signals corresponding to the multiple current values, calculates the net current of these current values, and determines that the net current signal corresponding to the net current is greater than or equal to a current threshold, thus providing a detection signal.

In one embodiment, the determination unit includes a complex signal amplifier, a complex voltage follower, and a calculation unit. The signal amplifiers respectively receive and amplify the current signals. The voltage followers are correspondingly connected to the signal amplifiers and respectively receive the amplified current signals. The calculation unit is connected to the voltage followers, receives the amplified current signals, and sums the current signals to generate a net current signal with a corresponding net current. Based on the net current signal being greater than or equal to the current threshold, the calculation unit provides a high-level detection signal. Based on the net current signal being less than the current threshold, the calculation unit provides a low-level detection signal.

In one embodiment, the current difference detection device is an integrated circuit.

In one embodiment, the current threshold corresponds to a current value of zero amperes.

In one embodiment, the currents are alternating currents, and the current threshold corresponds to a current value of 15 milliamperes.

In one embodiment, each current is either alternating current or direct current, and the current threshold corresponds to a current value of 6 milliamperes (DC).

In one embodiment, the sensing element is a Hall element, tunneling magnetoresistive element, anisotropic magnetoresistive element, giant magnetoresistive element, super-giant magnetoresistive element, constant magnetoresistive element, or shunt resistor.

In one embodiment, the signal amplifier is an operational amplifier.

In one embodiment, the differential current detection device is disposed on a circuit board, and the circuit board is a multilayer board with a laminated structure. The paths are respectively disposed on different layers.

Therefore, the multi-path current difference detection device proposed in this invention has the following features and advantages: 1. The current difference detection device of this invention can be implemented by a packaged integrated circuit, thus significantly reducing its size and space; 2. The current difference detection device of this invention can implement multi-path current difference detection in a non-contact or contact manner; 3. The current difference detection device of this invention can be used for AC or DC current detection; 4. In a preferred embodiment, 15 milliamperes can be accurately detected. The above-mentioned AC current difference can accurately detect DC current differences of 6 mA or more; 5. Electromagnetic interference can be avoided through the spacing design of different current paths; 6. The detection time of the current difference detection of this invention can be less than 1 second; 7. The detection accuracy of the current difference detection of this invention is higher than 95% (i.e., error less than 5%); 8. The current difference detection device of this invention can operate in environments higher than 150°C; 9. The spacing of the multiple layers of the circuit board with the stacked structure of this invention can be designed to be 0.4 ± 0.1 mm.

To gain a further understanding of the techniques, means, and effects employed by this invention to achieve its intended purpose, please refer to the following detailed description and accompanying drawings. It is believed that the purpose, features, and characteristics of this invention will be understood in depth and in detail from these references. However, the accompanying drawings are for reference and illustration only and are not intended to limit the scope of this invention.

100: Current difference detection device

11: Sensing Element

12: Judgment Unit

Pi1: First Path

Pi2: Second Path

i1: First current

i2: Second current

Sin: Current signal

Sdet: Detection signal

121: Signal Amplifier

122: Voltage Follower

200: Current difference detection device

21: Sensing Element

22: Judgment Unit

Sin1: First current signal

Sin2: Second current signal

221-1: First Signal Amplifier

221-2: Second Signal Amplifier

222-1: First Voltage Coupling

222-2: Second Voltage Coupling

223: Calculation Unit

L1~L6: First to sixth floor panels

Figure 1: A schematic diagram of an existing current comparator used for current detection.

Figure 2: A block diagram of a first embodiment of the multi-path current difference detection device of the present invention.

Figure 3: A circuit block diagram of a first embodiment of the multi-path current difference detection device of the present invention.

Figure 4: This is a first schematic diagram of an integrated circuit implementation of a first embodiment of the multi-path current difference detection device of the present invention.

Figure 5: This is a second schematic diagram illustrating the first embodiment of the multi-path current difference detection device of the present invention, implemented using an integrated circuit.

Figures 6A-6C are schematic diagrams showing the application of the multi-path current difference detection device of the present invention to a multilayer circuit board.

Figure 7: A block diagram of a second embodiment of the multi-path current difference detection device of the present invention.

Figure 8: A circuit block diagram of a second embodiment of the multi-path current difference detection device of the present invention.

Figure 9: A schematic diagram illustrating the second embodiment of the multi-path current difference detection device of the present invention implemented using an integrated circuit.

The technical content and detailed description of this invention are explained below with reference to the accompanying drawings.

The following specific examples illustrate the implementation of this invention. Those skilled in the art can easily understand the other advantages and effects of this invention from the content disclosed in this specification. This invention can also be implemented or applied through other different specific examples, and the various details in this specification can be modified and changed based on different viewpoints and applications without departing from the spirit of this invention.

It should be understood that the structures, proportions, sizes, and number of components illustrated in the accompanying diagrams are solely for the purpose of illustrating the content of this manual and for those skilled in the art to understand and read. They are not intended to limit the implementation of this invention and therefore have no substantive technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this invention, should fall within the scope of the technical content disclosed herein.

Please refer to Figure 2, which is a block diagram of a first embodiment of the multi-path current difference detection device of the present invention. As shown in Figure 2, "multi-path" means multiple paths through which current can flow, and the direction of current flow in each path is not restricted, as explained below.

The multi-path current difference detection device 100 of the first embodiment shown in Figure 2 includes sensing elements 11 and a judgment unit 12. Each sensing element 11 has the function of sensing current to generate a magnetic field, thus generating an electrical signal (e.g., but not limited to a voltage signal) based on the magnitude of the sensed current and the corresponding change in the magnetic field. Therefore, based on the magnitude of the electrical signal, the magnitude of all currents sensed in the multi-path, or the net current magnitude, can be determined. In this invention, each of the sensing elements 11 is a Hall element, tunnel magnetoresistance (TMR), anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), colossal magnetoresistance (CMR), ordinary magnetoresistance (OMR), or a shunt resistor. However, this invention is not limited to these specific elements. Any element that can achieve the aforementioned functions and purposes can be used as the sensing element 11, and all such elements should fall within the scope of the technical content disclosed in this invention.

It is worth mentioning that the current difference detection device 100 is an integrated circuit (IC), meaning that the current difference detection device 100 can be implemented by a packaged integrated circuit, thus significantly reducing its size and space usage.

The sensing element 11 is used to sense complex currents i1, i2 flowing through multiple paths Pi1, Pi2. As shown in Figure 2, taking two paths, namely the first path Pi1 and the second path Pi2, as an example, the sensing element 11 can be used to sense the magnitude of the first current i1 flowing through the first path Pi1 and the magnitude of the second current i2 flowing through the second path Pi2. In this invention, the sensing element 11 can also be used to sense the magnitude of currents in more than two paths, which will not be elaborated here. Based on the magnitude of the first current i1 and the magnitude of the second current i2, the sensing element 11 calculates the net current value |i1-i2| of the complex current values of these currents i1, i2. This means that the net current calculated by sensing element 11 is |i1-i2| or |i2-i1|, indicating that the net current value only considers the magnitude of the net current and does not consider the direction of the first current i1 and the second current i2. Incidentally, if the net current of three currents is calculated, then the net current is |i1-i2-i3| or the absolute value of the difference between the three currents.

The determination unit 12 is connected to the sensing element 11, receives the current signal Sin corresponding to the net current value |i1-i2|, and determines that the current signal Sin is greater than or equal to a current threshold, providing a detection signal Sdet. Specifically, the net current value |i1-i2| is the actual current value. Therefore, the sensing element 11 converts the actual current value into the corresponding current signal Sin. In other words, the larger the current signal Sin, the larger the net current value |i1-i2|, and vice versa. Therefore, the determination unit 12 receives the current threshold and compares the current signal Sin with the current threshold. If the judgment unit 12 determines that the current signal Sin is greater than or equal to the current threshold, it provides the detection signal Sdet.

Incidentally, sensing element 11 can be used to sense alternating current or direct current. Therefore, in one embodiment, the current threshold corresponds to a current value of zero amperes. That is, when the current signal Sin is greater than or equal to zero amperes (i.e., the current threshold), the determination unit 12 outputs the detection signal Sdet, indicating that the net current value |i1-i2| between the first current i1 and the second current i2 is not zero, thus determining that there is a non-zero DC or AC current difference between the paths Pi1 and Pi2.

In another embodiment, if the first current i1 and the second current i2 are alternating currents, and the current threshold corresponding to the current value is 15 milliamperes, then when the current signal Sin is greater than or equal to 15 milliamperes (i.e., the current threshold), the determination unit 12 outputs the detection signal Sdet, indicating that the net current value |i1-i2| of the first current i1 and the second current i2 is greater than or equal to 15 milliamperes. Therefore, it can be determined that there is an alternating current difference greater than or equal to 15 milliamperes between the paths Pi1 and Pi2.

Similarly, in another embodiment, if the first current i1 and the second current i2 are alternating currents or direct currents, and the corresponding current threshold is 6 milliamperes (mA), then when the current signal Sin is greater than or equal to 6 mA (i.e., the current threshold), the determination unit 12 outputs the detection signal Sdet, indicating that the net current value |i1-i2| of the first current i1 and the second current i2 is greater than or equal to 6 mA. Therefore, it can be determined that there is a DC current difference greater than or equal to 6 mA between the paths Pi1 and Pi2.

Please refer to Figure 3, which is a circuit block diagram of a first embodiment of the multi-path current difference detection device of the present invention. Figure 3 further reveals and explains an embodiment of the judgment unit 12. As shown in Figure 3, the judgment unit 12 includes a signal amplifier 121 and a voltage follower 122. The signal amplifier 121 receives and amplifies the current signal Sin. In one embodiment, the signal amplifier 121 is an operational amplifier (OPA). Therefore, the signal amplifier 121, operating as an operational amplifier, receives the current signal Sin and amplifies it to generate a corresponding voltage signal. The voltage follower 122 is connected to the signal amplifier 121 and receives the amplified current signal Sin, that is, it receives the voltage signal generated by the signal amplifier 121.

The judgment unit 12 is based on the amplified current signal Sin being greater than or equal to the current threshold, and the voltage follower 122 provides a high-level detection signal Sdet. Corresponding to the above description, if the current value corresponding to the current threshold is zero amperes, and the voltage follower 122 outputs a high-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is not zero, and therefore it can be determined that there is a non-zero DC or AC current difference in the paths Pi1 and Pi2. If the current threshold corresponds to a current value of 15 mA, and the voltage follower 122 outputs a high-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is greater than or equal to 15 mA. Therefore, it can be determined that there is an AC current difference greater than or equal to 15 mA in the paths Pi1 and Pi2. If the current threshold corresponds to a current value of 6 mA, and the voltage follower 122 outputs a high-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is greater than or equal to 6 mA. Therefore, it can be determined that there is a DC current difference greater than or equal to 6 mA in the paths Pi1 and Pi2.

Conversely, if the amplified current signal Sin is less than the current threshold, the voltage follower 122 provides a low-level detection signal Sdet. Corresponding to the aforementioned description, if the current value corresponding to the current threshold is zero amperes, and the voltage follower 122 outputs a low-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is zero. Therefore, it can be determined that there is no DC or AC current difference between the paths Pi1 and Pi2. If the current threshold corresponds to a current value of 15 mA, and the voltage follower 122 outputs a low-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is less than 15 mA. Therefore, it can be determined that there is no AC current difference greater than or equal to 15 mA in the paths Pi1 and Pi2. If the current threshold corresponds to a current value of 6 mA, and the voltage follower 122 outputs a low-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is less than 6 mA. Therefore, it can be determined that there is no DC current difference greater than or equal to 6 mA in the paths Pi1 and Pi2.

However, this is not limited to determining that the net current value |i1-i2| is greater than or equal to the current threshold using the high-level detection signal Sdet, or determining that the net current value |i1-i2| is less than the current threshold using the low-level detection signal Sdet. In other words, the relationship between the net current value |i1-i2| and the current threshold can also be determined using the opposite signal level. For example, if the current threshold is set to zero amperes and the voltage follower 122 outputs a low-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is not zero; conversely, if the voltage follower 122 outputs a high-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is zero.

Please refer to Figure 4, which is a first schematic diagram of the first embodiment of the multi-path current difference detection device of the present invention implemented in an integrated circuit. As mentioned above, the current difference detection device 100 can be implemented as a packaged integrated circuit. Therefore, in Figure 4, the current difference detection device 100 is an integrated circuit for multi-path current difference detection. The current difference detection device 100 is disposed on the first path Pi1 and the second path Pi2 in a non-contact manner, wherein the first path Pi1 and the second path Pi2 can be a bus (or busbar, bus bar) or a trace on a printed circuit board (PCB). As shown in Figure 4, taking a bus as an example, the bottom view (top view) of Figure 4 shows that the current difference detection device 100 is disposed in a non-contact manner on the first path Pi1 and the second path Pi2 of the bus. The sensing element 11 senses the first current i1 flowing through the first path Pi1 and the second current i2 flowing through the second path Pi2. Furthermore, the sensing element 11 calculates the net current value |i1-i2| of the first current i1 and the second current i2. Then, the determination unit 12 receives the current signal Sin corresponding to the net current value |i1-i2|, and determines that the current signal Sin is greater than or equal to the current threshold, providing a detection signal Sdet. As shown in Figure 4, the current difference detection device 100 can output the detection signal Sdet as the output voltage Vout through an output pin Out. Furthermore, the current difference detection device 100 can be powered by an externally supplied voltage Vcc.

Please refer to Figure 5, which is a second schematic diagram of the first embodiment of the multi-path current difference detection device of the present invention implemented in an integrated circuit. As shown in Figure 5, taking a bus as an example, the bottom view (top view) shown in Figure 5 shows that the current difference detection device 100 is disposed in a non-contact manner on the first path Pi1 and the second path Pi2 of the bus. The sensing element 11 senses the first current i1 flowing through the first path Pi1 and the second current i2 flowing through the second path Pi2. Furthermore, the sensing element 11 calculates the net current value |i1-i2| of the first current i1 and the second current i2. Then, the determination unit 12 receives the current signal Sin corresponding to the net current value |i1-i2|, and determines that the current signal Sin is greater than or equal to the current threshold, providing a detection signal Sdet. As shown in Figure 5, the current difference detection device 100 can output this detection signal Sdet as an output voltage Vout through an output pin Out. Furthermore, the current difference detection device 100 can be powered by an externally supplied voltage Vcc.

Please refer to Figures 6A-6C, which are schematic diagrams of the application of the multi-path current difference detection device of the present invention on a multilayer circuit board. It should be noted that the content shown in Figures 6A-6C is mainly to clearly and conveniently present the schematic diagram of the application of the current difference detection device 100 on a multilayer circuit board, as explained below. The current difference detection device 100 is disposed on a circuit board, and the circuit board is a plurality of multilayer boards with a multilayer structure, wherein the paths Pi1, Pi2 are respectively disposed on different layers. As shown in Figure 6A, the circuit board has two layers: a first layer L1 and a second layer L2. A first path Pi1 is disposed on the first layer L1, and a second path Pi2 is disposed on the second layer L2. The current difference detection device 100 is disposed on the first path Pi1 and the second path Pi2 in a non-contact manner and is electrically connected to the first layer L1 of the circuit board. Therefore, using the aforementioned technical means, multi-path current difference detection is achieved by the sensing element 11 and the judgment unit 12, which will not be elaborated further here.

As shown in Figure 6B, the circuit board has four layers: a first layer L1, a second layer L2, a third layer L3, and a fourth layer L4. The first path Pi1 is disposed on the second layer L2, and the second path Pi2 is disposed on the third layer L3. However, this is not a limitation, and the number of multiple paths and their layer positions are not restricted. The current difference detection device 100 is disposed on the first path Pi1 and the second path Pi2 in a non-contact manner and is electrically connected to the first layer L1 of the circuit board. Therefore, through the aforementioned technical means, multi-path current difference detection is achieved using the sensing element 11 and the judgment unit 12, which will not be elaborated further here.

As shown in Figure 6C, the circuit board has six layers: a first layer L1, a second layer L2, a third layer L3, a fourth layer L4, a fifth layer L5, and a sixth layer L6. A first path Pi1 is disposed on the second layer L2, a second path Pi2 on the third layer L3, a third path Pi3 on the fourth layer L4, and a fourth path Pi4 on the fifth layer L5. However, this is not a limitation, and the number of paths and their placement on the layers are not restricted. The current difference detection device 100 is disposed non-contactly on the first path Pi1, the second path Pi2, the third path Pi3, and the fourth path Pi4, and is electrically connected to the first layer L1 of the circuit board. Therefore, using the aforementioned technical means, multi-path current difference detection is achieved through the sensing element 11 and the judgment unit 12, which will not be elaborated upon here.

Please refer to Figure 7, which is a block diagram of a second embodiment of the multi-path current difference detection device of the present invention. The multi-path current difference detection device 200 of the second embodiment shown in Figure 7 includes a sensing element 21 and a judgment unit 22. Compared with the non-contact detection method of the first embodiment shown in Figure 2, the current difference detection device 200 of this embodiment performs detection in a contact manner, and therefore uses the sensing element 21 to directly sense the current magnitude in a contact manner. In this invention, each of the sensing elements 21 is a Hall element, tunnel magnetoresistance (TMR), anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), colossal magnetoresistance (CMR), or ordinary magnetoresistance (OMR), but is not limited to these elements.

It is worth mentioning that the current difference detection device 200 is an integrated circuit (IC), meaning that the current difference detection device can be implemented using a packaged integrated circuit, thus significantly reducing its size and space requirements.

Sensing element 21 receives complex currents i1, i2 flowing through multiple paths Pi1, Pi2. Taking the two paths shown in Figure 7 as an example, sensing element 21 receives the magnitude of the first current i1 flowing through the first path Pi1 and the magnitude of the second current i2 flowing through the second path Pi2. In this invention, sensing element 21 can also be used to receive the magnitude of currents from more than two paths, which will not be elaborated here.

The determination unit 22 is connected to the sensing element 21 and receives complex current signals Sin1 and Sin2 corresponding to the complex current values i1 and i2. In other words, the determination unit 22 receives a first current signal Sin1 corresponding to the current value of the first current i1 and a second current signal Sin2 corresponding to the current value of the second current i2. Further, the determination unit 22 calculates a net current |i1-i2| between the current values of the first current i1 and the second current i2. That is, the net current calculated by the determination unit 22 is either |i1-i2| or |i2-i1|, indicating that the net current value only considers the magnitude of the net current value and does not consider the direction of the flow of the first current i1 and the second current i2.

The determination unit 22 determines if a net current signal corresponding to the net current |i1-i2| is greater than or equal to a current threshold and provides a detection signal Sdet. Specifically, the sensing element 21 converts the actual first current i1 into a corresponding first current signal Sin1, meaning that the larger the first current signal Sin1, the larger the first current i1, and vice versa; and converts the actual second current i2 into a corresponding second current signal Sin2, meaning that the larger the second current signal Sin2, the larger the second current i2, and vice versa, and provides this to the determination unit 22. Therefore, the determination unit 22 calculates the net current of the first current i1 and the second current i2 based on the first current signal Sin1 and the second current signal Sin2. Therefore, the determination unit 12 receives the current threshold value and compares the net current signal of the corresponding net current |i1-i2| with the current threshold value. If the determination unit 12 determines that the net current signal is greater than or equal to the current threshold value, it provides a detection signal Sdet.

Incidentally, sensing element 21 can be used to sense alternating current or direct current. Therefore, in one embodiment, the current threshold corresponds to a current value of zero amperes. That is, when the net current signal is greater than or equal to zero amperes (i.e., the current threshold), the determination unit 22 outputs the detection signal Sdet, indicating that the net current value |i1-i2| between the first current i1 and the second current i2 is not zero, thus determining that there is a non-zero DC or AC current difference between the paths Pi1 and Pi2.

In another embodiment, if the first current i1 and the second current i2 are alternating currents, and the corresponding current threshold is 15 milliamperes, then when the net current signal is greater than or equal to 15 milliamperes (i.e., the current threshold), the determination unit 22 outputs the detection signal Sdet, indicating that the net current value |i1-i2| of the first current i1 and the second current i2 is greater than or equal to 15 milliamperes. Therefore, it can be determined that there is an alternating current difference greater than or equal to 15 milliamperes between the paths Pi1 and Pi2.

Similarly, in another embodiment, if the first current i1 and the second current i2 are alternating currents or direct currents, and the corresponding current value of the current threshold is 6 milliamperes (mA), then when the net current signal is greater than or equal to 6 mA (i.e., the current threshold), the determination unit 22 outputs the detection signal Sdet, indicating that the net current value |i1-i2| of the first current i1 and the second current i2 is greater than or equal to 6 mA. Therefore, it can be determined that there is a DC current difference greater than or equal to 6 mA between the paths Pi1 and Pi2.

Please refer to Figure 8, which is a circuit block diagram of a second embodiment of the multi-path current difference detection device of the present invention. Figure 8 further reveals and explains the embodiment of the judgment unit 22. As shown in Figure 8, the judgment unit 22 includes complex signal amplifiers 221-1 and 221-2, complex voltage copiers 222-1 and 222-2, and a calculation unit 223. The complex signal amplifiers 221-1 and 221-2 respectively receive the current signals Sin1 and Sin2, and respectively amplify the current signals Sin1 and Sin2. In one embodiment, each of the signal amplifiers is an operational amplifier (OPA). Therefore, the first signal amplifier 221-1 operates as an operational amplifier to receive and amplify the first current signal Sin1; the second signal amplifier 221-2 operates as an operational amplifier to receive and amplify the second current signal Sin2.

Multiple voltage couplers 222-1 and 222-2 are correspondingly connected to signal amplifiers 221-1 and 221-2, and respectively receive the amplified current signals Sin1 and Sin2. Specifically, the first voltage coupler 222-1 is connected to the first signal amplifier 221-1 and receives the amplified first current signal Sin1; the second voltage coupler 222-2 is connected to the second signal amplifier 221-2 and receives the amplified second current signal Sin2.

Calculation unit 223 is connected to voltage couplers 222-1 and 222-2, receiving amplified current signals Sin1 and Sin2 respectively, and summing these current signals to generate a net current signal corresponding to the net current. Specifically, calculation unit 223 is connected to the first voltage coupler 222-1 and the second voltage coupler 222-2, receiving amplified first current signal Sin1 and amplified second current signal Sin2 respectively, and further summing the amplified first current signal Sin1 and amplified second current signal Sin2 to generate a net current signal corresponding to the net current |i1-i2|.

The judgment unit 22 is based on the net current signal being greater than or equal to the current threshold, and the calculation unit 223 provides a high-level detection signal Sdet. Corresponding to the above description, if the current value corresponding to the current threshold is zero amperes, and the calculation unit 223 outputs a high-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is not zero, and therefore it can be determined that there is a non-zero DC or AC current difference in the paths Pi1 and Pi2. If the current threshold corresponds to a current value of 15 mA, and the calculation unit 223 outputs a high-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is greater than or equal to 15 mA. Therefore, it can be determined that there is an AC current difference greater than or equal to 15 mA in the paths Pi1 and Pi2. If the current threshold corresponds to a current value of 6 mA, and the calculation unit 223 outputs a high-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is greater than or equal to 6 mA. Therefore, it can be determined that there is a DC current difference greater than or equal to 6 mA in the paths Pi1 and Pi2.

Conversely, if the net current signal is less than the current threshold, the calculation unit 223 provides a low-level detection signal Sdet. Corresponding to the foregoing description, if the current value corresponding to the current threshold is zero amperes, and the calculation unit 223 outputs a low-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is zero. Therefore, it can be determined that there is no DC or AC current difference between the paths Pi1 and Pi2. If the current threshold corresponds to a current value of 15 mA, and the calculation unit 223 outputs a low-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is less than 15 mA. Therefore, it can be determined that there is no AC current difference greater than or equal to 15 mA in the paths Pi1 and Pi2. If the current threshold corresponds to a current value of 6 mA, and the calculation unit 223 outputs a low-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is less than 6 mA. Therefore, it can be determined that there is no DC current difference greater than or equal to 6 mA in the paths Pi1 and Pi2.

However, this is not limited to determining that the net current value |i1-i2| is greater than or equal to the current threshold using the high-level detection signal Sdet, or determining that the net current value |i1-i2| is less than the current threshold using the low-level detection signal Sdet. In other words, the relationship between the net current value |i1-i2| and the current threshold can also be determined using the opposite signal level. For example, if the current threshold is set to zero amperes and the calculation unit 223 outputs a low-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is not zero; conversely, if the calculation unit 223 outputs a high-level detection signal Sdet, it indicates that the net current value |i1-i2| of the first current i1 and the second current i2 is zero.

Please refer to Figure 9, which is a schematic diagram of the second embodiment of the multi-path current difference detection device of the present invention implemented in an integrated circuit. As mentioned above, the current difference detection device 200 can be implemented as a packaged integrated circuit. Therefore, in Figure 9, the current difference detection device 200 is an integrated circuit for multi-path current difference detection. The current difference detection device 200 is disposed on the first path Pi1 and the second path Pi2 in a contact manner, wherein the first path Pi1 and the second path Pi2 can be a bus (or busbar, bus bar) or a trace on a printed circuit board (PCB). Specifically, the integrated circuit pins of the current difference detection device 200 are directly electrically connected to the first path Pi1 and the second path Pi2, thus receiving the first current i1 and the second current i2 through the integrated circuit pins. The sensing element 21 and the judgment unit 22, located within the integrated circuit, perform current reception, net current calculation, judgment of the net current signal and current threshold, and output of the detection signal Sdet, thereby realizing multi-path current difference detection in a contact manner. Further details are omitted here. As shown in Figure 9, the current difference detection device 200 can output the detection signal Sdet as the output voltage Vout through an output pin Out. Furthermore, the current difference detection device 200 can be powered by an externally supplied voltage Vcc.

In summary, the present invention has the following features and advantages:

1. The current difference detection device of this invention can be implemented as a packaged integrated circuit, thus significantly reducing its size and space requirements.

2. The current difference detection device of this invention can achieve multi-path current difference detection in either a non-contact or contact manner.

3. The current difference detection device of this invention can be used for detecting alternating current or direct current.

4. In a preferred embodiment, an AC current difference of 15 milliamperes or more can be accurately detected, or a DC current difference of 6 milliamperes or more can be accurately detected.

5. Electromagnetic interference can be avoided through the spacing design of different current paths.

6. The detection time of the current difference detection in this invention can be less than 1 second.

7. The detection accuracy of the current difference detection method of this invention is higher than 95% (i.e., the error is lower than 5%).

8. The current difference detection device of this invention can operate in environments above 150°C.

9. The spacing between the multiple layers of the circuit board with a laminated structure in this invention can be designed to be 0.4 ± 0.1 mm.

The above description and drawings are merely detailed examples of preferred embodiments of the present invention. However, the features of the present invention are not limited thereto and are not intended to limit the invention. The scope of the present invention shall be determined by the following patent application. All embodiments that conform to the spirit of the patent application and similar variations thereof shall be included within the scope of the present invention. Any variations or modifications that can be readily conceived by one skilled in the art within the field of the present invention shall be covered by the following patent application.

100: Current difference detection device

11: Sensing Element

12: Judgment Unit

Pi1: First Path

Pi2: Second Path

i1: First current

i2: Second current

Sin: Current signal

Sdet: Detection signal

Claims (16)

A multi-path current difference detection device is disposed on a circuit board, and the circuit board is a multilayer board with a laminated structure. The multi-path current difference detection device includes: a sensing element for sensing multiple currents flowing through multiple paths that are not in contact with the sensing element, and calculating a net current value of the multiple current values of the currents; wherein the paths are respectively disposed on different layers; and a judgment unit for receiving a current signal corresponding to the net current value, and determining that the current signal is greater than or equal to a current threshold, and providing a detection signal. The current difference detection device as described in claim 1, wherein the determination unit comprises: a signal amplifier for receiving and amplifying the current signal; and a voltage follower connected to the signal amplifier for receiving the amplified current signal; wherein the voltage follower provides a high-level detection signal based on the amplified current signal being greater than or equal to the current threshold; and wherein the voltage follower provides a low-level detection signal based on the amplified current signal being less than the current threshold. The current difference detection device as described in claim 1, wherein the current difference detection device is an integrated circuit. The current difference detection device as described in claim 1, wherein the current threshold corresponds to a current value of zero amperes. The current difference detection device as described in claim 1, wherein each current is an alternating current and the current threshold corresponds to a current value of 15 milliamperes. The current difference detection device as described in claim 1, wherein each current is an alternating current or a direct current, and the current threshold corresponding to the current value is a direct current of 6 milliamperes. The current difference detection device as described in claim 1, wherein the sensing element is a Hall element, a tunneling magnetoresistive element, an anisotropic magnetoresistive element, a giant magnetoresistive element, a super-giant magnetoresistive element, or a constant magnetoresistive element. The current difference detection device as described in claim 2, wherein the signal amplifier is an operational amplifier. A multi-path current difference detection device is disposed on a circuit board, and the circuit board is a multilayer board with a laminated structure. The multi-path current difference detection device includes: a sensing element for receiving multiple currents flowing through multiple paths in contact with the sensing element; wherein the paths are respectively disposed on different layers; and a judgment unit for receiving multiple current signals corresponding to the multiple current values of the multiple currents, calculating a net current of the multiple current values, and determining that the net current signal corresponding to the net current is greater than or equal to a current threshold, and providing a detection signal. The current difference detection device as described in claim 9, wherein the determination unit comprises: a complex signal amplifier, which receives the current signals and amplifies the current signals respectively; a complex voltage collector connected to the signal amplifier and receiving the amplified current signals respectively; and a calculation unit connected to the voltage collector, which receives the amplified current signals respectively and sums the current signals to generate a net current signal corresponding to the net current; wherein the calculation unit provides a high-level detection signal based on the net current signal being greater than or equal to the current threshold; wherein the calculation unit provides a low-level detection signal based on the net current signal being less than the current threshold. The current difference detection device as described in claim 9, wherein the current difference detection device is an integrated circuit. The current difference detection device as described in claim 9, wherein the current threshold corresponds to a current value of zero amperes. The current difference detection device as described in claim 9, wherein each current is an alternating current and the current threshold corresponds to a current value of 15 milliamperes. The current difference detection device as described in claim 9, wherein each current is an alternating current or a direct current, and the current threshold corresponding to the current value is a direct current of 6 milliamperes. The current difference detection device as described in claim 9, wherein the sensing element is a shunt resistor. The current difference detection device as described in claim 10, wherein each of the signal amplifiers is an operational amplifier.