CN211856709U - Current detection circuit - Google Patents
Current detection circuit Download PDFInfo
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- CN211856709U CN211856709U CN201922250583.4U CN201922250583U CN211856709U CN 211856709 U CN211856709 U CN 211856709U CN 201922250583 U CN201922250583 U CN 201922250583U CN 211856709 U CN211856709 U CN 211856709U
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Abstract
The embodiment of the utility model discloses a current detection circuit, the circuit includes control switch, first sampling resistance, second sampling resistance and well accuse chip, control switch's input is connected with the output electricity of the circuit of waiting to detect, control switch's output is connected with the first end of first sampling resistance and the first end electricity of second sampling resistance respectively; the second end of the first sampling resistor and the second end of the second sampling resistor are grounded; the control end of the control switch is electrically connected with the central control chip; the central control chip is also electrically connected with the first sampling resistor and the second sampling resistor; the resistance value of the first sampling resistor is smaller than that of the second sampling resistor. The central control chip controls the control switch to select the first sampling resistor and the second sampling resistor or only the second sampling resistor to be connected to the output end of the circuit to be detected according to the current value flowing through the first sampling resistor, so that the current can be accurately tested under different conditions that the circuit to be detected outputs large current and small current.
Description
Technical Field
The embodiment of the utility model provides a relate to the current detection technique, especially relate to a current detection circuit.
Background
Along with the popularization of the fast-charging mobile phone, more and more mobile power supplies are available in the market. In the use process of the mobile power supply, the output current is an important parameter, the mobile power supply can be burnt due to too large output current of the mobile power supply, and the charged equipment can not be charged normally due to too small output current.
In the prior art, a current detection circuit of a mobile power supply cannot accurately test the output current of the mobile power supply.
SUMMERY OF THE UTILITY MODEL
An embodiment of the utility model provides a current detection circuit to realized treating the accurate test of detection circuitry output heavy current and output undercurrent, reached the accurate test to output current.
The embodiment of the utility model provides a current detection circuit, which comprises a control switch, a first sampling resistor, a second sampling resistor and a central control chip,
the input end of the control switch is electrically connected with the output end of the circuit to be detected, and the output end of the control switch is electrically connected with the first end of the first sampling resistor and the first end of the second sampling resistor respectively;
the second end of the first sampling resistor and the second end of the second sampling resistor are both grounded;
the control end of the control switch is electrically connected with the central control chip; the central control chip is also electrically connected with the first sampling resistor and the second sampling resistor;
the resistance value of the first sampling resistor is smaller than that of the second sampling resistor.
Optionally, the control switch includes a first transistor and a second transistor;
the control end of the first transistor and the control end of the second transistor are electrically connected with the central control chip;
the input end of the first transistor and the input end of the second transistor are electrically connected with the output end of the circuit to be detected;
the output end of the first transistor is electrically connected with the first end of the first sampling resistor; and the output end of the second transistor is electrically connected with the first end of the second sampling resistor.
Optionally, the first transistor and the second transistor are of the same conductivity type.
Optionally, the central control chip includes a first voltage detection unit and a second voltage detection unit; the first end of the first voltage detection unit is electrically connected with the first end of the first sampling resistor, and the second end of the first voltage detection unit is electrically connected with the second end of the first sampling resistor; the first end of the second voltage detection unit is electrically connected with the first end of the second sampling resistor, and the second end of the second voltage detection unit is electrically connected with the second end of the second sampling resistor.
Optionally, when the central control chip detects that the current value flowing through the first sampling resistor is smaller than a preset current value, the central control chip controls the control switch to connect the second sampling resistor to the output end of the circuit to be detected; when the central control chip detects that the current value flowing through the first sampling resistor is larger than a preset current value, the central control chip controls the control switch to connect the first sampling resistor and the second sampling resistor to the output end of the circuit to be detected.
The embodiment of the utility model provides an electric current detection circuit includes control switch, first sampling resistance, second sampling resistance and well accuse chip, and control switch's input is connected with the output electricity of circuit under test, and control switch's output is connected with the first end of first sampling resistance and the first end electricity of second sampling resistance respectively; the second end of the first sampling resistor and the second end of the second sampling resistor are grounded; the control end of the control switch is electrically connected with the central control chip; the central control chip is also electrically connected with the first sampling resistor and the second sampling resistor; the resistance value of the first sampling resistor is smaller than that of the second sampling resistor. According to the detection of the value of the current flowing through the first sampling resistor by the central control chip, the control switch is controlled to select the first sampling resistor and the second sampling resistor or only connect the second sampling resistor to the output end of the circuit to be detected, so that the current can be accurately tested under different conditions of large current and small current output by the circuit to be detected.
Drawings
Fig. 1 is a block diagram of a current detection circuit according to a first embodiment of the present invention;
fig. 2 is a block diagram of a current detection circuit according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
Example one
Fig. 1 is a block diagram of a current detection circuit according to an embodiment of the present invention, as shown in fig. 1, the current detection circuit includes a control switch 10, a first sampling resistor 20, a second sampling resistor 30, and a central control chip 40,
the input end of the control switch 10 is electrically connected with the output end of the circuit to be detected, and the output end of the control switch 10 is electrically connected with the first end of the first sampling resistor 20 and the first end of the second sampling resistor 30 respectively;
the second end of the first sampling resistor 20 and the second end of the second sampling resistor 30 are both grounded;
the control end of the control switch 10 is electrically connected with the central control chip 40; the central control chip 40 is also electrically connected with the first sampling resistor 20 and the second sampling resistor 30;
the resistance value of the first sampling resistor 20 is smaller than that of the second sampling resistor 30.
The central control chip 40 is connected to the first sampling resistor 20 and the second sampling resistor 30, and the central control chip 40 is electrically connected to the control terminal of the control switch 10. After the current detection circuit is electrically connected with the output end of the circuit to be detected, the central control chip 40 firstly controls the control switch 10 to conduct the output end of the circuit to be detected with the first sampling resistor 20, the central control chip 40 detects the voltage value of the first sampling resistor 20, and then the current value of the first sampling resistor 20 is obtained through calculation. If the detected current value of the first sampling resistor 20 is smaller than the preset current value, it indicates that the current output by the output terminal of the circuit to be detected is smaller. When the current is small, the mode of collecting the divided voltage and calculating the current by using the small resistor is inaccurate, so that the output end of the circuit to be detected is conducted with the second sampling resistor 30 by controlling the control switch 10 by the central control chip 40, and at the moment, the current output by the output end of the circuit to be detected is calculated by collecting the divided voltage value of the second sampling resistor 30, so that the current is more accurate.
If the detected current value of the first sampling resistor 20 is greater than the preset current value, it indicates that the output end of the circuit to be detected outputs a larger current. If the mode of collecting the divided voltage and calculating the current through the resistor easily causes the power consumption to be too high, the control switch 10 can be controlled by the central control chip 40 to conduct the output end of the circuit to be detected with the first sampling resistor 20 and the second sampling resistor 30, and at the moment, the first sampling resistor 20 and the second sampling resistor 30 are connected in parallel, so that the total sampling resistor is smaller than the resistance value of the first sampling resistor 20, and the power consumption can be saved while the output end of the circuit to be detected outputs a large current.
Example two
Fig. 2 is a block diagram of a current detection circuit provided in the second embodiment, and as shown in fig. 2, based on the second embodiment, further optimization is performed, optionally, the control switch includes a first transistor 11 and a second transistor 12;
the control end of the first transistor 11 and the control end of the second transistor 12 are both electrically connected with the central control chip 40;
the input end of the first transistor 11 and the input end of the second transistor 12 are both electrically connected with the output end of the circuit to be detected;
the output end of the first transistor 11 is electrically connected with the first end of the first sampling resistor 20; the output terminal of the second transistor 12 is electrically connected to a first terminal of a second sampling resistor 30.
Alternatively, the first transistor 11 and the second transistor 12 are of the same conductivity type.
It should be noted that, the control switch plays a role of switching into the first sampling resistor 20 and the second sampling resistor 30, and the type of the control switch is not limited here. Alternatively, the control switch may include a first transistor 11 and a second transistor 12, and the conductivity types of the first transistor 11 and the second transistor 12 are both P-type conductivity types or both N-type conductivity types. The control switch may also be a switch control chip.
With continued reference to fig. 2, optionally, the central control chip 40 includes a first voltage detection unit 41 and a second voltage detection unit 42; a first end of the first voltage detection unit 41 is electrically connected with a first end of the first sampling resistor 20, and a second end of the first voltage detection unit 41 is electrically connected with a second end of the first sampling resistor 20; a first end of the second voltage detecting unit 42 is electrically connected to a first end of the second sampling resistor 30, and a second end of the second voltage detecting unit 42 is electrically connected to a second end of the second sampling resistor 30.
When the central control chip 40 detects that the current value flowing through the first sampling resistor 20 is smaller than the preset current value, the control switch is controlled to connect the second sampling resistor 20 to the output end of the circuit to be detected, and at the moment, the condition that the output end of the circuit to be detected outputs small current is detected; when the central control chip 40 detects that the current value flowing through the first sampling resistor 20 is greater than the preset current value, the control switch 10 is controlled to connect both the first sampling resistor 20 and the second sampling resistor 30 to the output end of the circuit to be detected, and at this time, the condition that the output end of the circuit to be detected outputs a large current is detected.
Illustratively, the circuit to be detected may be an output circuit of a mobile power supply, the output circuit of the mobile power supply is electrically connected to the control switch, when the mobile power supply starts to have sufficient electric quantity, and when the mobile power supply discharges to an external terminal device, the output current in the output circuit of the mobile power supply is relatively large, the central control chip 40 is connected to the first sampling resistor 20, and the central control chip 40 detects the voltage value of the first sampling resistor 20 through the first voltage detection unit 41 and calculates to obtain a corresponding current value. Then, the central control chip 40 determines that the magnitude of the current value of the first sampling resistor 20 is detected.
When the current value of the first sampling resistor 20 is detected to be larger than the preset current value, the control switch is controlled to connect the first sampling resistor 20 and the second sampling resistor 30 into the output circuit of the mobile power supply, the output circuit of the mobile power supply is connected in parallel with the first sampling resistor 20 and the second sampling resistor 30, the impedance value of the output circuit is reduced after the output circuit is connected in parallel, and the power consumption during current detection can be reduced.
When the current value of the first sampling resistor 20 is detected to be smaller than the preset current value, the control switch is controlled to connect the second sampling resistor 30 into the output circuit of the mobile power supply, that is, the second sampling resistor 30 with a larger resistance value is switched to detect a small current so as to improve the accuracy of current detection.
The method solves the problems of increased heat loss, inaccurate voltage test and the like caused by the fact that a larger resistor is connected when a circuit to be detected outputs a larger current in the prior art; meanwhile, the problem that when the circuit to be detected outputs small current, if the small resistor is connected, voltage testing is inaccurate is solved, in the scheme, when the output current of the circuit to be detected is large, the first sampling resistor and the second sampling resistor which are connected in parallel are connected, when the output current of the circuit to be detected is small, the second sampling resistor is connected, and through connection switching of the sampling resistors, accurate testing of the output current of the circuit to be detected is achieved.
It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.
Claims (5)
1. A current detection circuit is characterized by comprising a control switch, a first sampling resistor, a second sampling resistor and a central control chip,
the input end of the control switch is electrically connected with the output end of the circuit to be detected, and the output end of the control switch is electrically connected with the first end of the first sampling resistor and the first end of the second sampling resistor respectively;
the second end of the first sampling resistor and the second end of the second sampling resistor are both grounded;
the control end of the control switch is electrically connected with the central control chip; the central control chip is also electrically connected with the first sampling resistor and the second sampling resistor;
the resistance value of the first sampling resistor is smaller than that of the second sampling resistor.
2. The current sensing circuit of claim 1, wherein the control switch comprises a first transistor and a second transistor;
the control end of the first transistor and the control end of the second transistor are electrically connected with the central control chip;
the input end of the first transistor and the input end of the second transistor are electrically connected with the output end of the circuit to be detected;
the output end of the first transistor is electrically connected with the first end of the first sampling resistor; and the output end of the second transistor is electrically connected with the first end of the second sampling resistor.
3. The current sensing circuit of claim 2, wherein the first transistor and the second transistor are of the same conductivity type.
4. The current detection circuit according to claim 1, wherein the central control chip comprises a first voltage detection unit and a second voltage detection unit; the first end of the first voltage detection unit is electrically connected with the first end of the first sampling resistor, and the second end of the first voltage detection unit is electrically connected with the second end of the first sampling resistor; the first end of the second voltage detection unit is electrically connected with the first end of the second sampling resistor, and the second end of the second voltage detection unit is electrically connected with the second end of the second sampling resistor.
5. The current detection circuit according to claim 1, wherein when the central control chip detects that the value of the current flowing through the first sampling resistor is smaller than a preset current value, the central control chip controls the control switch to connect the second sampling resistor to the output end of the circuit to be detected; when the central control chip detects that the current value flowing through the first sampling resistor is larger than a preset current value, the central control chip controls the control switch to connect the first sampling resistor and the second sampling resistor to the output end of the circuit to be detected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922250583.4U CN211856709U (en) | 2019-12-13 | 2019-12-13 | Current detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922250583.4U CN211856709U (en) | 2019-12-13 | 2019-12-13 | Current detection circuit |
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| CN211856709U true CN211856709U (en) | 2020-11-03 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112289273A (en) * | 2020-11-25 | 2021-01-29 | 未来汽车科技（深圳）有限公司 | Optical machine backlight dynamic range adjusting circuit and adjusting method |
| CN112834904A (en) * | 2020-12-31 | 2021-05-25 | 武汉光谷信息光电子创新中心有限公司 | Chip aging test system and method |
-
2019
- 2019-12-13 CN CN201922250583.4U patent/CN211856709U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112289273A (en) * | 2020-11-25 | 2021-01-29 | 未来汽车科技（深圳）有限公司 | Optical machine backlight dynamic range adjusting circuit and adjusting method |
| CN112834904A (en) * | 2020-12-31 | 2021-05-25 | 武汉光谷信息光电子创新中心有限公司 | Chip aging test system and method |
| CN112834904B (en) * | 2020-12-31 | 2024-10-11 | 武汉光谷信息光电子创新中心有限公司 | Chip aging test system and method |
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