CN212622795U - Big and small double-circuit current detection circuit - Google Patents
Big and small double-circuit current detection circuit Download PDFInfo
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- CN212622795U CN212622795U CN202020948036.3U CN202020948036U CN212622795U CN 212622795 U CN212622795 U CN 212622795U CN 202020948036 U CN202020948036 U CN 202020948036U CN 212622795 U CN212622795 U CN 212622795U
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Abstract
The utility model relates to a big or small double-circuit current detection circuit, it includes: the analog quantity input end is used for acquiring a current value; a first operational amplifier circuit with high amplification factor; the second operational amplifier circuit with low amplification factor; the comparison circuit is connected with the analog quantity input end, compares a current value input by the analog quantity input end with a reference value and outputs a high or low level; a multiplexing switch; and the detection chip selects different operation coefficients to operate according to the high/low levels obtained by the I/O pin. The operational amplifier circuits with two different amplification factors are used for acquiring analog quantity, the input analog quantity is compared through the comparator, the input ends of the multiplexing switches are switched according to comparison results, switching of different operational amplifier circuits is achieved, meanwhile, the comparator is directly used for switching, software processing is omitted, automatic switching can be achieved, the optimal amplification factors can be guaranteed, current detection with different sizes can be met, and the circuit is simple.
Description
Technical Field
The utility model relates to a detect technical field, concretely relates to big or small double-circuit current detection circuit.
Background
In the design and detection of the circuit, current detection is one of the important detection contents. At present, one method for detecting current is to use resistance detection, which is a schematic diagram of resistance detection current. When the current to be detected flows through the detection resistor R, V ═ I × R can be obtained from ohm's law. When the resistance R is a fixed value, the change of the voltage V reflects the change of the circuit. The introduction of the detection resistor can increase the power consumption of the circuit, in order to reduce the power consumption, the value of the detection resistor needs to be reduced as much as possible, so that the voltage values at two ends of the resistor are very small, and in order to improve the detection accuracy, the operational amplifier is usually adopted to amplify the voltage signal, so that the signal reading is facilitated.
However, when the current variation is large and exceeds the detection range of a single current detection chip, a plurality of chips are needed for current detection, so that the detection circuit is too complex and is not favorable for the miniaturization development of products.
SUMMERY OF THE UTILITY MODEL
Not enough to prior art exists, the utility model aims to provide a big or small double-circuit current detection circuit.
In order to achieve the above purpose, the utility model provides a following technical scheme: a large and small two-way current detection circuit, comprising:
the analog quantity input end is used for acquiring a current value;
the first operational amplifier circuit with high amplification factor is connected with the analog input end and is used for small current detection;
one path of second operational amplifier circuit with low amplification factor is connected with the analog input end and used for detecting large current;
one path of comparison circuit is connected with the analog quantity input end, compares the current value input by the analog quantity input end with a reference value and outputs high or low level;
the input end of the multiplexing switch is respectively connected with the first operational amplifier circuit and the second operational amplifier circuit, the gating pin of the multiplexing switch is connected with the output end of the comparison circuit, and different input ends are switched according to different output levels of the comparison circuit;
the detection chip comprises a sampling pin and an I/O pin, different operational coefficients are arranged in the detection chip, the sampling pin is connected with the output end of the multiplexing switch, the I/O pin is connected with the output end of the comparison circuit, and the detection chip selects different operational coefficients to operate according to the high/low level acquired by the I/O pin.
And an AD sampling module is arranged between the output end of the multiplexing switch and the sampling pin of the detection chip.
The first operational amplifier circuit comprises a first operational amplifier, the positive input end of the first operational amplifier is connected with the analog input end, the negative input end of the first operational amplifier is grounded through a resistor R1, a resistor R2 is connected between the output end and the negative output end of the first operational amplifier in parallel, and the amplification coefficient of the first operational amplifier is adjusted through adjusting the resistance values of the resistor R1 and the resistor R2.
The second operational amplifier circuit includes the second operational amplifier, the positive input end and the analog input end that the second operational amplifier was put are connected, the negative input end that the second operational amplifier was put passes through resistance R3 ground connection, just parallelly connected resistance R4 between the output that the second operational amplifier was put and the negative output, and through the adjustment the amplification factor that the second operational amplifier was put is adjusted to resistance R3 and resistance R4.
The comparator circuit comprises a comparator, the positive input end of the comparator is connected with the analog input end, the negative input end of the comparator is respectively connected with the power VCC through the resistor R5 grounding and the resistor R6, and the comparison coefficient of the comparator is adjusted through the resistance values of the adjusting resistor R5 and the resistor R6.
The utility model has the advantages that: the operational amplifier circuits with two different amplification factors are used for acquiring analog quantity, the input analog quantity is compared through the comparator, the input ends of the multiplexing switches are switched according to comparison results, switching of different operational amplifier circuits is achieved, meanwhile, the comparator is directly used for switching, software processing is omitted, automatic switching can be achieved, the optimal amplification factors can be guaranteed, current detection with different sizes can be met, and the circuit is simple.
Drawings
Fig. 1 is a schematic circuit diagram of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
It should be noted that all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.
In the present application, unless expressly stated or limited otherwise, the terms "connected" and "fixed" are to be construed broadly, e.g., "fixed" may be fixedly connected or detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.
In addition, descriptions in the present application as to "first", "second", and the like are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit to the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.
As shown, a magnitude two-way current detection circuit, comprising:
the analog quantity input end is used for acquiring a current value;
the first operational amplifier circuit with high amplification factor is connected with the analog input end and is used for small current detection; the first operational amplifier circuit comprises a first operational amplifier, the positive input end of the first operational amplifier is connected with the analog input end, the negative input end of the first operational amplifier is grounded through a resistor R1, a resistor R2 is connected between the output end and the negative output end of the first operational amplifier in parallel, and the amplification coefficient of the first operational amplifier is adjusted through adjusting the resistance values of the resistor R1 and the resistor R2. The analog quantity is measured when the analog quantity value is small by adopting a high amplification factor.
One path of second operational amplifier circuit with low amplification factor is connected with the analog input end and used for detecting large current; the second operational amplifier circuit includes the second operational amplifier, the positive input end and the analog input end that the second operational amplifier was put are connected, the negative input end that the second operational amplifier was put passes through resistance R3 ground connection, just parallelly connected resistance R4 between the output that the second operational amplifier was put and the negative output, and through the adjustment the amplification factor that the second operational amplifier was put is adjusted to resistance R3 and resistance R4. The analog quantity is measured when the analog quantity value is larger by adopting a low amplification factor.
One path of comparison circuit is connected with the analog quantity input end, compares the current value input by the analog quantity input end with a reference value and outputs high or low level; the comparator circuit comprises a comparator, the positive input end of the comparator is connected with the analog input end, the negative input end of the comparator is respectively connected with the power VCC through the resistor R5 grounding and the resistor R6, and the comparison coefficient of the comparator is adjusted through the resistance values of the adjusting resistor R5 and the resistor R6.
The input end of the multiplexing switch is respectively connected with the first operational amplifier circuit and the second operational amplifier circuit, the gating pin of the multiplexing switch is connected with the output end of the comparison circuit, and different input ends are switched according to different output levels of the comparison circuit;
and an AD sampling module is arranged between the output end of the multiplexing switch and the sampling pin of the detection chip.
The detection chip comprises a sampling pin and an I/O pin, different operational coefficients are arranged in the detection chip, the sampling pin is connected with the output end of the multiplexing switch, the I/O pin is connected with the output end of the comparison circuit, and the detection chip selects different operational coefficients to operate according to the high/low level acquired by the I/O pin.
When the analog input value is small, the output of the comparator is low level, SEL gating of the multiplexing switch is connected with the SA path with the first operational amplifier circuit, the AD sampling module collects the voltage value of the first operational amplifier, and the input of an I/O pin of the detection chip is low level.
When the analog input value is large, the output of the comparator is high level, SEL gating of the multiplexing switch is connected with the SB circuit through the first operational amplifier circuit, the AD sampling module collects the voltage value of the second operational amplifier, and the input of an I/O pin of the detection chip is high level.
The detection chip calculates the input quantity by using different coefficients through high and low levels on the I/O pins, thereby meeting the requirements of current detection with different sizes.
The examples should not be construed as limiting the present invention, but any modifications made based on the spirit of the present invention should be within the scope of the present invention.
Claims (5)
1. A big double-circuit current detection circuit which is characterized in that: it includes:
the analog quantity input end is used for acquiring a current value;
the first operational amplifier circuit with high amplification factor is connected with the analog input end and is used for small current detection;
one path of second operational amplifier circuit with low amplification factor is connected with the analog input end and used for detecting large current;
one path of comparison circuit is connected with the analog quantity input end, compares the current value input by the analog quantity input end with a reference value and outputs high or low level;
the input end of the multiplexing switch is respectively connected with the first operational amplifier circuit and the second operational amplifier circuit, the gating pin of the multiplexing switch is connected with the output end of the comparison circuit, and different input ends are switched according to different output levels of the comparison circuit;
the detection chip comprises a sampling pin and an I/O pin, different operational coefficients are arranged in the detection chip, the sampling pin is connected with the output end of the multiplexing switch, the I/O pin is connected with the output end of the comparison circuit, and the detection chip selects different operational coefficients to operate according to the high/low level acquired by the I/O pin.
2. The big-small two-way current detection circuit according to claim 1, wherein: and an AD sampling module is arranged between the output end of the multiplexing switch and the sampling pin of the detection chip.
3. The big-small two-way current detection circuit according to claim 1, wherein: the first operational amplifier circuit comprises a first operational amplifier, the positive input end of the first operational amplifier is connected with the analog input end, the negative input end of the first operational amplifier is grounded through a resistor R1, a resistor R2 is connected between the output end and the negative output end of the first operational amplifier in parallel, and the amplification coefficient of the first operational amplifier is adjusted through adjusting the resistance values of the resistor R1 and the resistor R2.
4. The big-small two-way current detection circuit according to claim 1, wherein: the second operational amplifier circuit includes the second operational amplifier, the positive input end and the analog input end that the second operational amplifier was put are connected, the negative input end that the second operational amplifier was put passes through resistance R3 ground connection, just parallelly connected resistance R4 between the output that the second operational amplifier was put and the negative output, and through the adjustment the amplification factor that the second operational amplifier was put is adjusted to resistance R3 and resistance R4.
5. The big-small two-way current detection circuit according to claim 1, wherein: the comparator circuit comprises a comparator, the positive input end of the comparator is connected with the analog input end, the negative input end of the comparator is respectively connected with the power VCC through the resistor R5 grounding and the resistor R6, and the comparison coefficient of the comparator is adjusted through the resistance values of the adjusting resistor R5 and the resistor R6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020948036.3U CN212622795U (en) | 2020-05-29 | 2020-05-29 | Big and small double-circuit current detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020948036.3U CN212622795U (en) | 2020-05-29 | 2020-05-29 | Big and small double-circuit current detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212622795U true CN212622795U (en) | 2021-02-26 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020948036.3U Active CN212622795U (en) | 2020-05-29 | 2020-05-29 | Big and small double-circuit current detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN212622795U (en) |
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2020
- 2020-05-29 CN CN202020948036.3U patent/CN212622795U/en active Active
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