CN218865993U - Current detection circuit with protection - Google Patents
Current detection circuit with protection Download PDFInfo
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- CN218865993U CN218865993U CN202222782843.4U CN202222782843U CN218865993U CN 218865993 U CN218865993 U CN 218865993U CN 202222782843 U CN202222782843 U CN 202222782843U CN 218865993 U CN218865993 U CN 218865993U
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Abstract
The utility model discloses a current detection circuit of area protection is applied to on the electronic product, include: the power supply anode of the single chip microcomputer is connected with a power supply voltage; a first voltage-dividing resistor, wherein a first end of the first voltage-dividing resistor is connected with a power supply cathode of the singlechip and forms a first node; and a first end of the second voltage-dividing resistor is connected with a second end of the first voltage-dividing resistor to form a second node, the second node is connected with an AD sampling port of the singlechip, and the second end of the second voltage-dividing resistor is grounded. The overcurrent protection circuit is reasonable in design, can realize the current detection function of a product, can protect the single chip microcomputer from being damaged by large voltage, and can perform overcurrent protection on a load without depending on the instruction of the single chip microcomputer.
Description
Technical Field
The utility model relates to an electronic circuit technical field especially relates to a current detection circuit of area protection.
Background
At present, most of electronic products sample voltage through a power sampling resistor when detecting current, and then are directly connected to a pin of a singlechip in series to sample voltage. When the power sampling resistor is in poor open circuit, voltage can be directly loaded to a pin of the single chip microcomputer, and if the voltage exceeds the withstand voltage value of the single chip microcomputer, the single chip microcomputer can be damaged; if the single chip microcomputer is abnormal and the voltage cannot be sampled correctly, when the current flowing through the sampling resistor is too large, the single chip microcomputer cannot send an instruction to protect the load, and therefore overcurrent protection failure is caused.
Disclosure of Invention
The utility model discloses aim at solving one of the problems that exist among the prior art to a certain extent at least, for this reason, the utility model provides a current detection circuit of area protection, its reasonable in design can realize the current detection function of electronic product, also can protect the singlechip not damaged by big voltage, can also not rely on the instruction of singlechip and carry out the overcurrent protection of load simultaneously.
The above purpose is realized by the following technical scheme:
a current detection circuit with protection is applied to an electronic product and comprises:
the power supply anode of the single chip microcomputer is connected with a power supply voltage;
a first voltage-dividing resistor, wherein a first end of the first voltage-dividing resistor is connected with a power supply cathode of the singlechip and forms a first node;
and a first end of the second divider resistor is connected with a second end of the first divider resistor to form a second node, the second node is connected with the AD sampling port of the singlechip, and the second end of the second divider resistor is grounded.
In some embodiments, the device further comprises a filter capacitor, a first end of the filter capacitor is respectively connected with the second node and the AD sampling port of the single chip, and a second end of the filter capacitor is grounded.
In some embodiments, the self-healing fuse further comprises a first end connected to the first node and a second end connected to ground.
In some embodiments, the self-healing fuse is made of a positive temperature coefficient thermistor.
In some embodiments, the self-healing fuse has an impedance value of 50m Ω To 500m Ω 。
In some embodiments, a voltage value loaded on the AD sampling port of the single chip microcomputer is smaller than a preset withstand voltage value of the single chip microcomputer.
In some embodiments, the impedance of the first and second voltage-dividing resistors is 5K Ω to 50K Ω.
Compared with the prior art, the utility model discloses an at least including following beneficial effect:
1. the utility model discloses a current detection circuit, its reasonable in design can realize the current detection function of electronic product, also can protect the singlechip not damaged by the large voltage, can also not rely on the instruction of singlechip and carry out the overcurrent protection of load simultaneously.
Drawings
Fig. 1 is a schematic circuit diagram of a current detection circuit according to an embodiment of the present invention.
Detailed Description
The present invention is illustrated by the following examples, but the present invention is not limited to these examples. To the embodiment of the present invention, modify or replace some technical features, without departing from the spirit of the present invention, it should be covered in the technical solution scope of the present invention.
The embodiment is as follows:
as shown in fig. 1, the present embodiment provides a current detection circuit with protection, applied to an electronic product, including:
the positive electrode of the single chip microcomputer U1 is connected with a power supply voltage VDD;
a first end of the first divider resistor R1 is connected with a power supply cathode of the singlechip U1 and forms a first node a;
and a first end of the second divider resistor R2 is connected with a second end of the first divider resistor R1 to form a second node b, the second node b is connected with an AD sampling port of the singlechip U1, and a second end of the second divider resistor R2 is grounded.
In this embodiment, the single chip U1 may be equivalent to a load in an electronic product, an anode of the single chip U1 is connected to a supply voltage VDD so that the supply voltage VDD is loaded onto the anode of the single chip U1, thereby enabling the single chip U1 to operate, a cathode of the single chip U1 is connected to a first end of a first voltage-dividing resistor R1 and forms a first node a, a second end of the first voltage-dividing resistor R1 is grounded through a second voltage-dividing resistor R2, thereby enabling a current to flow from the anode of the single chip U1 onto the single chip U1, and then the current flows out through the cathode of the single chip U1 so that the current flows onto a circuit system, thereby enabling the whole circuit system to form a loop, thereby enabling the electronic product to operate normally, a voltage at the first node a is divided by the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, a voltage after voltage division is generated at the second node b, and the divided voltage is loaded onto an AD sampling port of the single chip U1, thereby achieving an over-voltage protection of the AD sampling port of the single chip U1 from damaging the single chip U1, which is reasonably designed, and a current detection function of the electronic product can be realized, and an overcurrent detection function of protecting the single chip U1 and a load of the single chip U1 can be protected without depending on an instruction of the load.
In addition, the current detection circuit in this embodiment is preferably applied to an electronic product, but is not limited to the electronic product, and may also be applied to other more suitable control circuits according to actual requirements.
Further, still include filter capacitor C1, filter capacitor C1 first end is connected with second node b, singlechip U1's AD sample connection respectively to filter capacitor C1 second end ground connection.
In this embodiment, a second node b is formed between the second voltage-dividing resistor R2 and the first voltage-dividing resistor R1, and the second node b is respectively connected to the first end of the filter capacitor C1 and the AD sampling port of the single chip microcomputer U1, specifically, the second node b is connected to the AD sampling port of the single chip microcomputer U1 through the network AD, the voltage at the first node a is divided by the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 to generate the divided voltage at the second node b, the sampled voltage signal at the second node b is filtered by the filter capacitor C1 and then is received at the AD sampling port of the single chip microcomputer U1 for sampling, and the conversion is performed to accurately sample the current value flowing through the single chip microcomputer U1 by the single chip microcomputer U1.
Preferably, a self-recovery fuse RP1 is further included, a first end of the self-recovery fuse RP1 is connected to the first node a, and a second end thereof is grounded.
Further, the self-recovery fuse RP1 is made of a positive temperature coefficient thermistor.
Specifically, the self-healing fuse has an impedance value of 50m Ω To 500m Ω 。
In the present embodiment, the resistance value of the self-healing fuse RP1 is relatively small, and is preferably 50m Ω To 500m Ω The first end of the self-recovery fuse RP1 is connected with the first node a, the second end of the self-recovery fuse RP1 is grounded, namely the negative electrode of the single chip microcomputer U1 is grounded through the self-recovery fuse RP1, and a first node a is formed between the self-recovery fuse RP1 and the negative electrode of the single chip microcomputer U1, because the impedance value of the self-recovery fuse RP1 is relatively small, when current flows through the self-recovery fuse RP1, the first node a has potential difference to the ground, the voltage at the first node a is divided through the first voltage dividing resistor R1 and the second voltage dividing resistor R2, the divided voltage is generated at the second node b, and the divided voltage is loaded to the AD sampling port of the single chip microcomputer U1, so that the overvoltage protection of the AD sampling port of the single chip microcomputer U1 is realized to avoid damaging the single chip microcomputer U1.
In this embodiment, when the single chip microcomputer U1 has a short circuit or an excessive current, a large current of the single chip microcomputer U1 flows through the self-recovery fuse RP1, and the self-recovery fuse RP1 is preferably made of a positive temperature coefficient thermistor, so that the temperature of the self-recovery fuse RP1 can rapidly rise, and the impedance value of the self-recovery fuse RP1 can also rapidly increase, so that the grounding on the loop of the single chip microcomputer U1 can be directly disconnected through the self-recovery fuse RP1, that is, the grounding of the negative electrode of the single chip microcomputer U1 is disconnected, so that the single chip microcomputer U1 stops working, and further, the overcurrent protection function of the electronic product load is realized.
In this embodiment, when the self-recovery fuse RP1 is broken or broken and damaged, the voltage on the single chip microcomputer U1 is directly loaded on the first node a, so that the voltage value at the first node a is relatively high, the voltage at the first node a is divided by the first voltage dividing resistor R1 and the second voltage dividing resistor R2 to generate the divided voltage at the second node b, the divided voltage value is relatively low, and the divided voltage generated at the second node b is loaded on the AD sampling port of the single chip microcomputer U1, so that the overvoltage protection of the AD sampling port of the single chip microcomputer U1 is realized, and the single chip microcomputer U1 is prevented from being damaged.
Further, the voltage value loaded by the AD sampling port of the single chip microcomputer is smaller than the preset withstand voltage value of the single chip microcomputer.
In particular, the impedance values of the first and second voltage-dividing resistors are 5K Ω to 50K Ω.
In this embodiment, whole current detection circuit, the accessible chooses for use the self-resuming fuse RP1 of different current protection gears, so can realize the load protection of different overcurrent protection points, through changing the resistance of first divider resistance R1 and second divider resistance R2, thereby can make the loaded voltage value of the AD sample connection of singlechip U1 be less than singlechip U1's the withstand voltage value of predetermineeing, the voltage value after producing the partial pressure in second node b department is less than singlechip U1's the withstand voltage value of predetermineeing, predetermineeing the maximum value of instantaneous voltage that withstand voltage value can bear for singlechip U1, and then realize the effect of protection singlechip U1. Further, the impedance values of the first and second voltage-dividing resistors R1 and R2 are relatively large, and the impedance values thereof are preferably 5K Ω to 50K Ω.
What has been described above are only some embodiments of the invention. For those skilled in the art, without departing from the inventive concept, several modifications and improvements can be made, which all fall within the scope of the invention.
Claims (7)
1. The utility model provides a current detection circuit of area protection, is applied to electronic product on, its characterized in that includes:
the power supply anode of the single chip is connected with a power supply voltage;
a first voltage-dividing resistor, wherein a first end of the first voltage-dividing resistor is connected with a power supply cathode of the singlechip and forms a first node;
and a first end of the second voltage-dividing resistor is connected with a second end of the first voltage-dividing resistor to form a second node, the second node is connected with an AD sampling port of the singlechip, and the second end of the second voltage-dividing resistor is grounded.
2. The current detection circuit with protection according to claim 1, further comprising a filter capacitor, wherein a first end of the filter capacitor is connected to the second node and an AD sampling port of the single chip microcomputer, respectively, and a second end of the filter capacitor is grounded.
3. The protected current detection circuit of claim 1, further comprising a self-healing fuse, wherein a first end of the self-healing fuse is connected to the first node and a second end of the self-healing fuse is connected to ground.
4. The protected current detection circuit according to claim 3, wherein the self-healing fuse is made of a positive temperature coefficient thermistor.
5. The protected current detection circuit of claim 3, wherein the self-healing fuse has an impedance value of 50m Ω To 500m Ω 。
6. The current detection circuit with protection according to any one of claims 1 to 5, wherein a voltage value loaded on an AD sampling port of the single chip microcomputer is smaller than a preset withstand voltage value of the single chip microcomputer.
7. The protected current detection circuit according to any one of claims 1 to 5, wherein the impedance values of the first voltage-dividing resistor and the second voltage-dividing resistor are in a range from 5K Ω to 50K Ω.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222782843.4U CN218865993U (en) | 2022-10-21 | 2022-10-21 | Current detection circuit with protection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222782843.4U CN218865993U (en) | 2022-10-21 | 2022-10-21 | Current detection circuit with protection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218865993U true CN218865993U (en) | 2023-04-14 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202222782843.4U Active CN218865993U (en) | 2022-10-21 | 2022-10-21 | Current detection circuit with protection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN218865993U (en) |
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2022
- 2022-10-21 CN CN202222782843.4U patent/CN218865993U/en active Active
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