CN210015156U - A current detection circuit, device and electrical product - Google Patents

Abstract

The utility model discloses a current detection circuit, a device and an electrical product. Current shunt, surge absorption circuit, low-pass filter circuit, anti-aliasing filter circuit and analog-to-digital converter, collect the current to be measured and convert it into a voltage signal, filter the collected voltage signal, and then convert it into a digital signal for Sampling, get the current value of the current to be measured, and set the temperature detection circuit to collect the ambient temperature information, compensate the sampling result according to the collected ambient temperature information, and improve the detection accuracy; In the prior art, the floating charging current of the battery pack is not easy to detect. The scheme of using a shunt and a small current transformer to detect the floating charging current has problems such as the current transformer returning to zero after being hit by a large current and requiring power failure and transformation, which achieves direct utilization. The original shunt can detect the technical effect of the float current.

Description

A current detection circuit, device and electrical product

technical field

The utility model relates to the technical field of current detection, in particular to a current detection circuit, a device and an electrical product.

Background technique

At present, substations, communication base stations, power plants and other places use DC power as backup power. Due to the needs of the working environment, the battery, the core component of the DC power supply, is continuously connected to the circuit, and it has been in a floating state for a long time. With the increase of time, the capacity gradually decreases, and the leakage current increases accordingly, which in turn causes the increase of the float current, which causes the battery to heat up and overcharge, accelerate the aging of the battery, and overcharge. The battery loses its power supply capability and even causes a safety accident.

At present, most power stations and base stations are unattended stations, and the equipped battery meters cannot measure the floating current. The existing technology for measuring the floating current mainly uses shunts and small current transformers. However, this solution has a cost of transformation. The problem that the high and current transformers will return to zero after being impacted by a large current and cannot be retrofitted and upgraded without shutting down.

Utility model content

The main purpose of the utility model is to provide a current detection circuit, which aims to provide a low-cost current detection circuit that can detect the floating current by using the original shunt without shutting down.

In order to achieve the above purpose, the current detection circuit proposed by the present utility model includes a current shunt, a surge absorption circuit, a low-pass filter circuit, an anti-aliasing filter circuit and an analog-to-digital converter; the current shunt and the surge absorption circuit circuit connection, the surge absorption circuit is connected with the low-pass filter circuit, the low-pass filter circuit is connected with the anti-aliasing filter circuit, and the anti-alias filter circuit is connected with the analog-to-digital converter; in,

The current shunt is used to convert the current signal to be measured into a first voltage signal;

The surge absorbing circuit is configured to receive the first voltage signal converted by the current shunt, absorb the surge voltage in the first voltage signal, and obtain a second voltage signal;

The low-pass filter circuit is configured to receive the second voltage signal, filter the second voltage signal, filter out the high-frequency signal in the second voltage signal, and obtain a low-frequency voltage signal;

The anti-aliasing filter circuit is configured to receive the low-frequency voltage signal, and reduce the aliasing frequency in the low-frequency voltage signal to obtain a filtered voltage signal;

The analog-to-digital converter is used to receive the filtered voltage signal, perform analog-to-digital conversion on the filtered voltage signal to obtain a digital signal, and obtain a current value to be measured according to the digital signal and the parameters of the current shunt.

Preferably, the current detection circuit further comprises a temperature detection circuit and a single-chip microcomputer; the single-chip microcomputer is connected to the analog-to-digital converter, and the temperature detection circuit is connected to the single-chip microcomputer; wherein,

The temperature detection circuit is used to detect the ambient temperature and generate a temperature signal;

The single-chip microcomputer is used for receiving the temperature signal and the current value to be measured sent by the analog-to-digital converter, and compensating the current value to be measured according to the temperature signal to obtain a high-precision current value.

Preferably, the surge absorption circuit includes a first resistor, a second resistor, a third resistor and a gas discharge tube; wherein,

The first end of the first resistor is connected to the first end of the current shunt, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the current The second end of the shunt is connected, the first end of the gas discharge tube is connected to the first end of the second resistor, the second end of the gas discharge tube is connected to the equipotential, and the first end of the third resistor is connected to the The first end of the first resistor is connected to the first end of the third resistor, the second end of the third resistor is connected to the second end of the second resistor; the first end of the third resistor is connected to the first end of the low-pass filter circuit, and the first end of the third resistor is connected to the first end of the low-pass filter circuit. The second end of the three resistors is connected to the second end of the low-pass filter circuit.

Preferably, the low-pass filter circuit includes a first capacitor and a fourth resistor; wherein,

The first end of the first capacitor and the first end of the fourth resistor are connected to the first end of the surge absorbing circuit, and the second end of the first capacitor and the second end of the fourth resistor are connected to the surge absorbing circuit. The second end of the wave absorption circuit is connected; the first end of the fourth resistor is also connected to the first end of the anti-aliasing filter circuit, and the second end of the fourth resistor is also connected to the second end of the anti-aliasing filter circuit connect.

Preferably, the anti-aliasing filter circuit includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a second capacitor and a third capacitor; wherein,

The first end of the fifth resistor is connected to the first end of the low-pass filter circuit, the second end of the fifth resistor is connected to the first end of the sixth resistor, and the second end of the sixth resistor is connected to the The second end of the low-pass filter circuit is connected, the second end of the sixth resistor is also connected to the first end of the seventh resistor, the second end of the seventh resistor is connected to the second end of the third capacitor, and the second end of the seventh resistor is connected to the second end of the third capacitor. The first end of the third capacitor is connected to the second end of the second capacitor, the first end of the second capacitor is connected to the second end of the eighth resistor, and the first end of the eighth resistor is connected to the fifth resistor the first end is connected, the second end of the fifth resistor is also connected to the second end of the second capacitor, the second end of the second capacitor is grounded; the first end of the second capacitor is connected to the analog-to-digital converter The non-inverting input end is connected, and the second end of the third capacitor is connected with the inverting input end of the analog-to-digital converter.

Preferably, the temperature detection circuit includes a current source circuit, a temperature sensor, a conversion circuit and a filter circuit; the current source circuit is connected to the temperature sensor, the temperature sensor is connected to the conversion circuit, and the conversion circuit is connected to the temperature sensor. The single-chip microcomputer is connected, and the filter circuit is connected with the conversion circuit; wherein,

the current source circuit for powering the temperature sensor;

The temperature sensor is used to collect the ambient temperature and output the corresponding analog signal;

the filter circuit for filtering the analog signal;

The conversion circuit is used to convert the analog signal collected by the temperature sensor into a digital signal.

Preferably, the current source circuit includes a ninth resistor, a tenth resistor, a fourth capacitor, a Zener diode and an operational amplifier; wherein,

The first end of the ninth resistor is connected to the input end of the circuit to be tested, the second end of the ninth resistor is connected to the negative electrode of the Zener diode, the positive electrode of the Zener diode is connected to the output end of the circuit to be tested, and the voltage regulator diode is connected to the output terminal of the circuit to be tested. The positive electrode of the voltage regulator diode is also connected to the second end of the first capacitor, the negative electrode of the voltage regulator diode is also connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is also connected to the first end of the tenth resistor. The first terminal of the fourth capacitor is also connected to the inverting input terminal of the operational amplifier, the second terminal of the tenth resistor is also connected to the non-inverting input terminal of the operational amplifier, and the second terminal of the tenth resistor is also connected to the non-inverting input terminal of the operational amplifier. It is also connected to the temperature detection circuit, and the output end of the operational amplifier is connected to the temperature detection circuit.

Preferably, the conversion circuit includes an eleventh resistor, a twelfth resistor, a thirteenth resistor, a sixth capacitor and a second operational amplifier; wherein,

The first end of the twelfth resistor is connected to the temperature detection circuit, the second end of the twelfth resistor is connected to the reverse input end of the second operational amplifier, and the first end of the eleventh resistor is connected to the connected to the temperature detection circuit, the second end of the eleventh resistor is connected to the non-inverting input end of the second operational amplifier, the output end of the second operational amplifier is connected to the microcontroller, and the first end of the thirteenth resistor is connected is connected to the non-inverting input terminal of the second operational amplifier, the second terminal of the thirteenth resistor is connected to the output terminal of the second operational amplifier, the second terminal of the thirteenth resistor is also connected to the analog ground terminal, and the The first end of the sixth capacitor is connected to the first end of the thirteenth resistor, and the second end of the sixth capacitor is connected to the second end of the thirteenth resistor.

The present invention also provides a current detection device, which includes the above-mentioned current detection circuit.

The utility model also provides an electrical product, the electrical product includes the current detection device as described above.

The technical scheme of the utility model forms a current detection circuit by adopting a current shunt, a surge absorption circuit, a low-pass filter circuit, an anti-aliasing filter circuit and an analog-to-digital converter. Among them, the current shunt collects the current to be measured, and is filtered by the surge absorption circuit, the low-pass filter circuit and the anti-aliasing filter circuit, and then converted and sampled by the analog-to-digital converter to obtain the sampling result, and set the temperature The detection circuit, according to the current ambient temperature detected by the temperature detection circuit, compensates the sampling results, further improves the detection accuracy of the current detection circuit, and makes it meet the detection conditions of the floating current. It can be installed immediately, and the detection accuracy is improved at a lower cost, so that the floating charging current of the battery can be detected, effectively alleviating the aging and overcharging of the battery, further strengthening the safety and stability of the battery, and prolonging the battery life. The working life of the backup power supply reduces the cost of use.

Description of drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are just some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained based on the structures shown in these drawings without any creative effort.

1 is a functional block diagram of an embodiment of a current detection circuit of the present invention;

2 is a schematic circuit diagram of an embodiment of a current detection circuit of the present invention;

3 is a functional block diagram of another embodiment of the current detection circuit of the present invention;

FIG. 4 is a schematic circuit diagram of another embodiment of the current detection circuit of the present invention.

Description of reference numbers:

label name label name 100 Surge Absorption Circuit R1～R14 The first resistor to the fourteenth resistor 200 low pass filter circuit C1～C6 The first capacitor to the sixth capacitor 300 Anti-aliasing filter circuit R15 Temperature Sensor 400 current source circuit D1 Zener diode 500 temperature detection circuit U1, U2 Operational Amplifier, Second Operational Amplifier 600 filter circuit GDT Gas discharge tube GDT 700 conversion circuit

The realization, functional characteristics and advantages of the purpose of the present utility model will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, not all of them. Example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the difference between the various components under a certain posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly.

In addition, the descriptions involving "first", "second", etc. in the present invention are only for description purposes, and should not be understood as indicating or implying their relative importance or implicitly indicating the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exists, and is not within the protection scope required by the present utility model.

1, the present utility model proposes a current detection circuit, the current detection circuit includes a current shunt, a surge absorption circuit 100, a low-pass filter circuit 200, an anti-aliasing filter circuit 300 and an analog-to-digital converter; the The current shunt is connected to the surge absorption circuit 100, the surge absorption circuit 100 is connected to the low-pass filter circuit 200, the low-pass filter circuit 200 is connected to the anti-aliasing filter circuit 300, and the The anti-aliasing filter circuit 300 is connected to the analog-to-digital converter; wherein,

The current shunt is used to convert the current signal to be measured into a first voltage signal;

The surge absorption circuit 100 is configured to receive the first voltage signal converted by the current shunt, absorb the surge voltage in the first voltage signal, and obtain a second voltage signal;

The low-pass filter circuit 200 is configured to receive the second voltage signal, filter the second voltage signal, filter out the high-frequency signal in the second voltage signal, and obtain a low-frequency voltage signal;

The anti-aliasing filter circuit 300 is configured to receive the low-frequency voltage signal, and reduce the aliasing frequency in the low-frequency voltage signal to obtain a filtered voltage signal;

The analog-to-digital converter is used to receive the filtered voltage signal, perform analog-to-digital conversion on the filtered voltage signal to obtain a digital signal, and obtain a current value to be measured according to the digital signal and the parameters of the current shunt.

It should be noted that, in this embodiment, the current shunt uses a high-precision resistor with a very small resistance value, and the current value to be measured can be obtained by measuring the voltage across the resistor, that is, the current signal to be measured is converted. is the voltage to be measured.

It is worth emphasizing that the surge absorption circuit 100 , the low-pass filter circuit 200 and the anti-aliasing filter circuit 300 are all used for filtering voltage signals. The surge absorption circuit 100 is mainly used for absorbing surge voltage. The voltage is caused by the switching circuit and cannot reflect the size of the floating current, so it needs to be filtered; and the low-pass filter circuit 200 is mainly used to filter the high-frequency signal that exceeds the threshold. charging current, and the high-frequency signal that exceeds the threshold is largely caused by interference, so the signal that exceeds the range of the floating charging current is filtered; The aliasing frequency components are reduced to the extent that they do not affect the final detection result, and the detection accuracy is improved.

It is easy to understand that the analog signal after the above filtering step is finally converted into a digital signal by an analog-to-digital converter, and the signal is sampled by the analog-to-digital converter to obtain the current value of the line installed by the current shunt.

In this embodiment, a current detection circuit is formed by using a current shunt, a surge absorption circuit 100 , a low-pass filter circuit 200 , an anti-aliasing filter circuit 300 and an analog-to-digital converter. The current to be measured is collected by the current shunt, filtered by the surge absorption circuit 100, the low-pass filter circuit 200 and the anti-aliasing filter circuit 300, and then converted and sampled by an analog-to-digital converter to obtain the sampling result. The technical solution of the utility model can be installed without shutting down, and the detection accuracy is improved at a lower cost, so that the floating charge current of the battery can be detected, effectively alleviating the aging and overcharging of the battery, and further enhancing the battery life. Safety and stability, prolong the working life of the battery as a backup power source, and reduce the cost of use.

As shown in FIG. 3 , the current detection circuit further includes a temperature detection circuit 500 and a single-chip microcomputer; the single-chip microcomputer is connected to the analog-to-digital converter, and the temperature detection circuit 500 is connected to the single-chip microcomputer; wherein,

The temperature detection circuit 500 is used to detect the ambient temperature and generate a temperature signal;

The single-chip microcomputer is used for receiving the temperature signal and the current value to be measured sent by the analog-to-digital converter, and compensating the current value to be measured according to the temperature signal to obtain a high-precision current value.

It is easy to understand that since the ambient temperature will change the performance of some electronic components, small changes in the measurement results will reduce the measurement accuracy, so a temperature detection circuit 500 is added to detect the ambient temperature to compensate the measurement results, so as to further improve the current detection. The detection accuracy of the circuit.

The technical scheme of the present invention forms a current detection circuit by using a current shunt, a surge absorption circuit 100, a low-pass filter circuit 200, an anti-aliasing filter circuit 300 and an analog-to-digital converter. The current to be measured is collected by the current shunt, filtered by the surge absorption circuit 100, the low-pass filter circuit 200 and the anti-aliasing filter circuit 300, and then converted and sampled by an analog-to-digital converter to obtain the sampling result, and A temperature detection circuit 500 is provided, and according to the current ambient temperature detected by the temperature detection circuit 500, the sampling result is compensated, and the detection accuracy of the current detection circuit is further improved to meet the detection conditions of the floating current. The technical scheme of the present invention is as follows: It can be installed without downtime, and the detection accuracy is improved at a lower cost, so that the floating charge current of the battery can be detected, effectively alleviating the aging and overcharging of the battery, and further enhancing the safety and stability of the battery , extending the working life of the battery as a backup power supply and reducing the cost of use.

As shown in FIG. 2 , the surge absorption circuit 100 includes a first resistor R1, a second resistor R2, a third resistor R3 and a gas discharge tube GDT; wherein,

The first end of the first resistor R1 is connected to the first end of the current shunt, the second end of the first resistor R1 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is connected with the second end of the current shunt, the first end of the gas discharge tube GDT is connected with the first end of the second resistor R2, the second end of the gas discharge tube GDT is connected with the equipotential, the third The first end of the resistor R3 is connected to the first end of the first resistor R1, the second end of the third resistor R3 is connected to the second end of the second resistor R2; the first end of the third resistor R3 is connected to the The first end of the low-pass filter circuit 200 is connected, and the second end of the third resistor R3 is connected to the second end of the low-pass filter circuit 200 .

It should be noted that, in order to meet the high-precision measurement requirements, the surge absorption circuit 100 is connected to the current shunt using the above connection method, and a gas discharge tube GDT is installed inside the circuit, which is connected to the equipotential to protect the surge. The absorption circuit 100 prevents the surge absorption circuit 100 from being damaged by a high-energy voltage signal, thereby affecting the detection result of the product and causing misjudgment.

Specifically, the low-pass filter circuit 200 includes a first capacitor C1 and a fourth resistor R4; wherein,

The first end of the first capacitor C1 and the first end of the fourth resistor R4 are connected to the first end of the surge absorbing circuit 100 , and the second end of the first capacitor C1 and the fourth resistor R4 are second The terminal is connected to the second terminal of the surge absorption circuit 100; the first terminal of the fourth resistor R4 is also connected to the first terminal of the anti-aliasing filter circuit 300, and the second terminal of the fourth resistor R4 is also connected to the The second end of the anti-aliasing filter circuit 300 is connected.

It is easy to understand that the above-mentioned low-pass filter circuit 200 is composed of a capacitor and a resistor connected in parallel, and is a simple filter circuit. The isolation of the two prevents the surge absorbing circuit 100 from affecting the anti-aliasing filter circuit 300 during the filtering process.

Specifically, the anti-aliasing filter circuit 300 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a second capacitor C2 and a third capacitor C3; wherein,

The first end of the fifth resistor R5 is connected to the first end of the low-pass filter circuit 200, the second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6, and the sixth resistor R6 The two terminals are connected to the second terminal of the low-pass filter circuit 200, the second terminal of the sixth resistor R6 is also connected to the first terminal of the seventh resistor R7, and the second terminal of the seventh resistor R7 is connected to the first terminal of the seventh resistor R7. The second end of the three capacitors C3 is connected, the first end of the third capacitor C3 is connected to the second end of the second capacitor C2, the first end of the second capacitor C2 is connected to the second end of the eighth resistor R8, The first end of the eighth resistor R8 is connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is also connected to the second end of the second capacitor C2, and the second capacitor C2 Two terminals are grounded; the first terminal of the second capacitor C2 is connected to the non-inverting input terminal of the analog-to-digital converter, and the second terminal of the third capacitor C3 is connected to the inverting input terminal of the analog-to-digital converter.

It is worth noting that, since the influence of the ambient temperature on the anti-aliasing filter circuit 300 is relatively large, it is difficult to improve the accuracy of the anti-aliasing filter under normal circumstances. Next, the design made by the anti-aliasing filter circuit 300 to improve the precision is suitable for a special working environment.

In this embodiment, a current detection circuit is formed by using a current shunt, a surge absorption circuit 100 , a low-pass filter circuit 200 , an anti-aliasing filter circuit 300 and an analog-to-digital converter. The current to be measured is collected by the current shunt, filtered by the surge absorption circuit 100, the low-pass filter circuit 200 and the anti-aliasing filter circuit 300, and then converted and sampled by an analog-to-digital converter to obtain the sampling result. The technical solution of the utility model can be installed without shutting down, and the detection accuracy is improved at a lower cost, so that the floating charge current of the battery can be detected, effectively alleviating the aging and overcharging of the battery, and further enhancing the battery life. Safety and stability, prolong the working life of the battery as a backup power source, and reduce the cost of use.

As shown in FIG. 4 , the temperature detection circuit 500 includes a current source circuit 400, a temperature sensor R15, a conversion circuit 700 and a filter circuit; the current source circuit 400 is connected to the temperature sensor R15, and the temperature sensor R15 is connected to the temperature sensor R15. The conversion circuit 700 is connected, the conversion circuit 700 is connected to the single-chip microcomputer, and the filter circuit 600 is connected to the conversion circuit 700; wherein,

The current source circuit 400 is used to supply power to the temperature sensor R15;

The temperature sensor R15 is used to collect the ambient temperature and output the corresponding analog signal;

The filtering circuit 600 is used for filtering the analog signal;

The conversion circuit 700 is configured to convert the analog signal collected by the temperature sensor R15 into a digital signal.

It should be noted that, in this embodiment, since the temperature sensor R15 measures the ambient temperature by measuring the resistance value of the temperature sensitive resistor, the current source circuit 400 needs to be used to supply power to the temperature sensor R15. Accurate temperature information is obtained only by measuring the magnitude of the voltage.

It is easy to understand that since the required accuracy is relatively high, a filter circuit is added to filter the voltage signal to be measured. Considering that the temperature will not fluctuate violently in a very short period of time, the voltage signal filtered by the filter circuit is largely All are interference voltages, and after filtering is completed, they are converted into digital signals by the conversion circuit 700 to facilitate subsequent use of temperature data for calculation.

Specifically, the current source circuit 400 includes a ninth resistor R9, a tenth resistor R10, a fourth capacitor C4, a Zener diode D1 and an operational amplifier U1; wherein,

The first end of the ninth resistor R9 is connected to the input end of the circuit to be tested, the second end of the ninth resistor R9 is connected to the negative electrode of the zener diode D1, and the positive electrode of the zener diode D1 is connected to the output end of the circuit to be tested. , the positive pole of the Zener diode D1 is also connected to the second end of the first capacitor, the negative pole of the Zener diode D1 is also connected to the first terminal of the fourth capacitor C4, and the second terminal of the fourth capacitor C4 is also connected It is connected to the first end of the tenth resistor R10, the first end of the fourth capacitor C4 is also connected to the inverting input end of the operational amplifier U1, and the second end of the tenth resistor R10 is also connected to the operational amplifier U1. The non-inverting input terminal is connected, the second terminal of the tenth resistor R10 is also connected to the temperature detection circuit 500 , and the output terminal of the operational amplifier U1 is connected to the temperature detection circuit 500 .

It should be noted that the Zener diode D1 acts as a current reference in this circuit. Here, the circuit is connected to form a simple reference current source. When the voltage fluctuates, the current size remains unchanged, making the current size easy to use. Measurement.

Specifically, the conversion circuit 700 includes an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a sixth capacitor C6 and a second operational amplifier U2; wherein,

The first end of the twelfth resistor R12 is connected to the temperature detection circuit 500, the second end of the twelfth resistor R12 is connected to the reverse input end of the second operational amplifier U2, and the eleventh resistor R11 The first end is connected to the temperature detection circuit 500, the second end of the eleventh resistor R11 is connected to the non-inverting input end of the second operational amplifier U2, and the output end of the second operational amplifier U2 is connected to the single-chip microcomputer, The first end of the thirteenth resistor R13 is connected to the non-inverting input end of the second operational amplifier U2, the second end of the thirteenth resistor R13 is connected to the output end of the second operational amplifier U2, and the thirteenth resistor R13 is connected to the output end of the second operational amplifier U2. The second end of the resistor R13 is also connected to the analog ground terminal, the first end of the sixth capacitor C6 is connected to the first end of the thirteenth resistor R13, and the second end of the sixth capacitor C6 is connected to the thirteenth resistor Connect the second end of R13.

It is easy to understand that since the operational amplifier U1 cannot amplify the current, it is necessary to convert the current signal into a voltage signal first, and then amplify the voltage signal. Due to the characteristics of the current source circuit 400, if there is no interference , the converted voltage signal should have a corresponding relationship with the current signal output by the current source, and since the current signal is stable, if the current signal is a constant value, the voltage signal should also be a constant value at this time, that is, the voltage signal here is convenient measured.

In this embodiment, a current detection circuit is formed by using a current shunt, a surge absorption circuit 100 , a low-pass filter circuit 200 , an anti-aliasing filter circuit 300 and an analog-to-digital converter. The current to be measured is collected by the current shunt, filtered by the surge absorption circuit 100, the low-pass filter circuit 200 and the anti-aliasing filter circuit 300, and then converted and sampled by an analog-to-digital converter to obtain the sampling result, and A temperature detection circuit 500 is provided, and according to the current ambient temperature detected by the temperature detection circuit 500, the sampling result is compensated, and the detection accuracy of the current detection circuit is further improved to meet the detection conditions of the floating current. The technical scheme of the present invention is as follows: It can be installed without downtime, and the detection accuracy is improved at a lower cost, so that the floating charge current of the battery can be detected, effectively alleviating the aging and overcharging of the battery, and further enhancing the safety and stability of the battery , extending the working life of the battery as a backup power supply and reducing the cost of use.

The present invention also proposes a current detection device, which includes the above-mentioned current detection circuit and the current to be measured. The specific structure of the current detection circuit refers to the above-mentioned embodiment, because the current detection device adopts all the above-mentioned implementations. All the technical solutions of the above-mentioned embodiments have at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, and will not be repeated here. The current to be measured may be the floating charge current of the battery pack.

The utility model also proposes an electrical product, which includes the current detection device as described above. The specific structure of the current detection device refers to the above-mentioned embodiments. Since the electrical product adopts all the technical solutions of all the above-mentioned embodiments, Therefore, there are at least all the beneficial effects brought about by the technical solutions of the above embodiments, which are not repeated here.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Any equivalent structural transformations made by using the contents of the description and drawings of the present invention under the inventive concept of the present invention, or Direct/indirect applications in other related technical fields are included in the scope of patent protection of the present invention.

Claims (10)

1. A current detection circuit is characterized by comprising a current shunt, a surge absorption circuit, a low-pass filter circuit, an anti-aliasing filter circuit and an analog-to-digital converter; the current shunt is connected with the surge absorption circuit, the surge absorption circuit is connected with the low-pass filter circuit, the low-pass filter circuit is connected with the anti-aliasing filter circuit, and the anti-aliasing filter circuit is connected with the analog-to-digital converter; wherein,

the current divider is used for converting a current signal to be measured into a first voltage signal;

the surge absorption circuit is used for receiving the first voltage signal converted by the current divider, absorbing surge voltage in the first voltage signal and obtaining a second voltage signal;

the low-pass filter circuit is used for receiving the second voltage signal, filtering the second voltage signal, and filtering a high-frequency signal in the second voltage signal to obtain a low-frequency voltage signal;

the anti-aliasing filter circuit is used for receiving the low-frequency voltage signal and reducing aliasing frequency in the low-frequency voltage signal to obtain a filter voltage signal;

the analog-to-digital converter is used for receiving the filtering voltage signal, performing analog-to-digital conversion on the filtering voltage signal to obtain a digital signal, and obtaining a current value to be measured according to the digital signal and parameters of the current divider.

2. The current detection circuit of claim 1, wherein the current detection circuit further comprises a temperature detection circuit and a single chip; the single chip microcomputer is connected with the analog-to-digital converter, and the temperature detection circuit is connected with the single chip microcomputer; wherein,

the temperature detection circuit is used for detecting the ambient temperature and generating a temperature signal;

the single chip microcomputer is used for receiving the temperature signal and the current value to be measured sent by the analog-to-digital converter, and compensating the current value to be measured according to the temperature signal to obtain a high-precision current value.

3. The current sensing circuit of claim 1, wherein the surge absorption circuit comprises a first resistor, a second resistor, a third resistor, and a gas discharge tube; wherein,

the first end of the first resistor is connected with the first end of the current divider, the second end of the first resistor is connected with the first end of the second resistor, the second end of the second resistor is connected with the second end of the current divider, the first end of the gas discharge tube is connected with the first end of the second resistor, the second end of the gas discharge tube is connected with the same potential, the first end of the third resistor is connected with the first end of the first resistor, and the second end of the third resistor is connected with the second end of the second resistor; the first end of the third resistor is connected with the first end of the low-pass filter circuit, and the second end of the third resistor is connected with the second end of the low-pass filter circuit.

4. The current sensing circuit of claim 1, wherein the low pass filter circuit comprises a first capacitor and a fourth resistor; wherein,

the first end of the first capacitor and the first end of the fourth resistor are connected with the first end of the surge absorption circuit, and the second end of the first capacitor and the second end of the fourth resistor are connected with the second end of the surge absorption circuit; the first end of the fourth resistor is further connected with the first end of the anti-aliasing filter circuit, and the second end of the fourth resistor is further connected with the second end of the anti-aliasing filter circuit.

5. The current sensing circuit of claim 1, wherein the anti-aliasing filter circuit comprises a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a second capacitor, and a third capacitor; wherein,

the first end of the fifth resistor is connected with the first end of the low-pass filter circuit, the second end of the fifth resistor is connected with the first end of the sixth resistor, the second end of the sixth resistor is connected with the second end of the low-pass filter circuit, the second end of the sixth resistor is also connected with the first end of the seventh resistor, the second end of the seventh resistor is connected with the second end of the third capacitor, the first end of the third capacitor is connected with the second end of the second capacitor, the first end of the second capacitor is connected with the second end of the eighth resistor, the first end of the eighth resistor is connected with the first end of the fifth resistor, the second end of the fifth resistor is also connected with the second end of the second capacitor, and the second end of the second capacitor is grounded; the first end of the second capacitor is connected with the non-inverting input end of the analog-to-digital converter, and the second end of the third capacitor is connected with the inverting input end of the analog-to-digital converter.

6. The current sensing circuit of claim 2, wherein the temperature sensing circuit comprises a current source circuit, a temperature sensor, a conversion circuit, and a filter circuit; the current source circuit is connected with the temperature sensor, the temperature sensor is connected with the conversion circuit, the conversion circuit is connected with the single chip microcomputer, and the filter circuit is connected with the conversion circuit; wherein,

the current source circuit is used for supplying power to the temperature sensor;

the temperature sensor is used for collecting the ambient temperature and outputting a corresponding analog signal;

the filter circuit is used for filtering the analog signal;

the conversion circuit is used for converting the analog signals collected by the temperature sensor into digital signals.

7. The current sense circuit of claim 6, wherein the current source circuit comprises a ninth resistor, a tenth resistor, a fourth capacitor, a zener diode, and an operational amplifier; wherein,

the first end of the ninth resistor is connected with the input end of a circuit to be detected, the second end of the ninth resistor is connected with the cathode of the voltage stabilizing diode, the anode of the voltage stabilizing diode is connected with the output end of the circuit to be detected, the anode of the voltage stabilizing diode is also connected with the second end of the first capacitor, the cathode of the voltage stabilizing diode is also connected with the first end of the fourth capacitor, the second end of the fourth capacitor is also connected with the first end of the tenth resistor, the first end of the fourth capacitor is also connected with the reverse input end of the operational amplifier, the second end of the tenth resistor is also connected with the in-phase input end of the operational amplifier, the second end of the tenth resistor is also connected with the temperature detection circuit, and the output end of the operational amplifier is connected with the temperature detection circuit.

8. The current sensing circuit of claim 6, wherein the converting circuit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor, a sixth capacitor, and a second operational amplifier; wherein,

the first end of the twelfth resistor is connected with the temperature detection circuit, the second end of the twelfth resistor is connected with the reverse input end of the second operational amplifier, the first end of the eleventh resistor is connected with the temperature detection circuit, the second end of the eleventh resistor is connected with the in-phase input end of the second operational amplifier, the output end of the second operational amplifier is connected with the single chip microcomputer, the first end of the thirteenth resistor is connected with the in-phase input end of the second operational amplifier, the second end of the thirteenth resistor is connected with the output end of the second operational amplifier, the second end of the thirteenth resistor is further connected with an analog ground terminal, the first end of the sixth capacitor is connected with the first end of the thirteenth resistor, and the second end of the sixth capacitor is connected with the second end of the thirteenth resistor.

9. A current sensing device, characterized in that it comprises a current sensing circuit according to any one of claims 1-8.

10. An electric product characterized by comprising the current detection device according to claim 9.

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