CN214473578U - High-end high-voltage current detection circuit - Google Patents
High-end high-voltage current detection circuit Download PDFInfo
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- CN214473578U CN214473578U CN202023026867.4U CN202023026867U CN214473578U CN 214473578 U CN214473578 U CN 214473578U CN 202023026867 U CN202023026867 U CN 202023026867U CN 214473578 U CN214473578 U CN 214473578U
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Abstract
The utility model provides a high-end high voltage current detection circuit, including sampling resistor, detection conditioning circuit, load. The sampling resistor and the load are connected in series in the main loop, the sampling resistor is arranged at the high end of the power supply input, the input port of the current detection conditioning circuit is respectively connected with the two ends of the sampling resistor, a voltage value with the ground as a reference point is output, and a corresponding current value can be calculated according to the voltage value. The circuit realizes high-end high-voltage current detection without introducing an additional power supply for detection, is built by adopting a discrete device and has low price.
Description
Technical Field
The utility model relates to a high-end current detection technical field, concretely relates to high-end high-voltage current detection circuit.
Background
The current detection is the basis of various protection circuits and control circuits. The current detection method is to connect a shunt (a resistor with small resistance and high precision) in series in the current loop to be detected, amplify the voltage difference between the two ends of the shunt by an operational amplifier and then output the amplified voltage, and then divide the amplified voltage by the product of the amplification factor and the resistance of the shunt to obtain the magnitude of the current to be detected.
The current divider can be arranged at the positive input end of the power supply and the negative input (ground) end of the power supply, and the corresponding current detection circuits are high-end current detection and low-end current detection, and each of the two circuits has advantages and disadvantages. The high-end current detection can detect the total current of the power supply input end, can judge the overcurrent and short-circuit faults of the subsequent loop and take corresponding protective measures, and is particularly suitable for a system adopting a multipoint grounding design.
At present, a plurality of special high-end current detection chips can output current values taking ground as reference points, but the application range of most high-end current chips is smaller than 36V, and higher voltage detection special chips are fewer and higher in cost.
SUMMERY OF THE UTILITY MODEL
To the not enough among the prior art, the utility model provides a high-end high voltage current detection circuit.
A high-end high-voltage current detection circuit comprises a sampling resistor R2, an amplifier U1 and a photoelectric coupler U2, wherein one end of the sampling resistor R2 is connected with a high-level power supply, and the other end of the sampling resistor R2 is connected with a load; the common end of the sampling resistor R2 and the high-level power supply is electrically connected with the forward input end of the amplifier U1 through a resistor R1, the common end of the sampling resistor R2 and a load is electrically connected with the reverse input end of the amplifier U1 through a resistor R5, a diode D2 and a diode D3 which are opposite in direction are connected in parallel between the forward input end and the reverse input end of the amplifier U1, the output end of the amplifier U1 is electrically connected with the anode of the emitter of the photocoupler U2 through a resistor R3, the cathode of the emitter of the photocoupler U2 is electrically connected with the cathode of a diode D4, the anode of the diode D4 is grounded, the cathode of the diode D4 is electrically connected with the negative power supply end of the amplifier U1, and the positive power supply end of the amplifier U1 is connected with the high-level power supply;
the C pole of the receiving end of the photoelectric coupler U2 is electrically connected with the positive pole end of a diode D1, the negative pole end of a diode D1 is electrically connected with the positive input end of the amplifier U1, the E pole of the receiving end of the photoelectric coupler U2 is grounded through an electric group R6, and the E pole of the receiving end of the photoelectric coupler U2 and the common end of the resistor R6 are used as the output end of the detection circuit after passing through an RC damping circuit.
Further: the diode D2 and the diode D3 are fast recovery diodes, and the diode D1 and the diode D4 are zener diodes.
Further: the amplifier U1 adopts a single power supply input rail-to-rail operational amplifier.
Further: the resistors R1 and R6 are high-precision resistors.
The utility model has the advantages that: the detection of high-end high-voltage current is realized under the condition of not introducing an additional power supply; the current change can be detected in real time according to the load change, and the output value takes the system ground as a reference point, so that the subsequent detection and control of the signal are facilitated.
Drawings
Fig. 1 is a schematic structural diagram of the present invention.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings. Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present invention, and should not be construed as limiting the present invention. The terms of left, middle, right, upper and lower directions in the examples of the present invention are only relative concepts or reference to the normal use status of the product, and should not be considered as limiting.
A high-end high-voltage current detection circuit is shown in figure 1 and comprises a sampling resistor R2, an amplifier U1 and a photoelectric coupler U2, wherein one end of the sampling resistor R2 is connected with a high-level power supply, and the other end of the sampling resistor R2 is connected with a load; the common end of the sampling resistor R2 and the high-level power supply is electrically connected with the forward input end of the amplifier U1 through a resistor R1, the common end of the sampling resistor R2 and a load is electrically connected with the reverse input end of the amplifier U1 through a resistor R5, a diode D2 and a diode D3 which are opposite in direction are connected in parallel between the forward input end and the reverse input end of the amplifier U1, the output end of the amplifier U1 is electrically connected with the anode of the emitter of the photocoupler U2 through a resistor R3, the cathode of the emitter of the photocoupler U2 is electrically connected with the cathode of a diode D4, the anode of the diode D4 is grounded, the cathode of the diode D4 is electrically connected with the negative power supply end of the amplifier U1, and the positive power supply end of the amplifier U1 is connected with the high-level power supply;
the C pole of the receiving end of the photoelectric coupler U2 is electrically connected with the positive pole end of a diode D1, the negative pole end of a diode D1 is electrically connected with the positive input end of the amplifier U1, the E pole of the receiving end of the photoelectric coupler U2 is grounded through an electric group R6, and the E pole of the receiving end of the photoelectric coupler U2 and the common end of the resistor R6 are used as the output end of the detection circuit after passing through an RC damping circuit.
The diode D2 and the diode D3 are fast recovery diodes, and the diode D1 and the diode D4 are zener diodes. The amplifier U1 adopts a single-power-supply input rail-to-rail operational amplifier, and the resistors R1 and R6 adopt high-precision resistors.
The utility model discloses a theory of operation: the main loop current flowing through the load is I, and the current flowing through the resistor R1 is IR1Since the operational amplifier has the "virtual short, virtual break" characteristic, the voltages of the forward input terminal and the reverse input terminal of the operational amplifier U1 are equal, I × R2 = IR1X R1, because of 'virtual break', the current flowing through R1 is equal to the current flowing through R6, and the output end of the current detection conditioning circuit is IR1Xr 6= (I × R2 × R6)/R1, and the current I in the main loop can be calculated by detecting the voltage value at the output end of the conditioning circuit.
The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that the foregoing embodiments and descriptions are provided only to illustrate the principles of the present invention without departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (4)
1. A high-side high-voltage current sense circuit, characterized by: the sampling circuit comprises a sampling resistor R2, an amplifier U1 and a photoelectric coupler U2, wherein one end of the sampling resistor R2 is connected with a high-level power supply, and the other end of the sampling resistor R2 is connected with a load; the common end of the sampling resistor R2 and the high-level power supply is electrically connected with the forward input end of the amplifier U1 through a resistor R1, the common end of the sampling resistor R2 and a load is electrically connected with the reverse input end of the amplifier U1 through a resistor R5, a diode D2 and a diode D3 which are opposite in direction are connected in parallel between the forward input end and the reverse input end of the amplifier U1, the output end of the amplifier U1 is electrically connected with the anode of the emitter of the photocoupler U2 through a resistor R3, the cathode of the emitter of the photocoupler U2 is electrically connected with the cathode of a diode D4, the anode of the diode D4 is grounded, the cathode of the diode D4 is electrically connected with the negative power supply end of the amplifier U1, and the positive power supply end of the amplifier U1 is connected with the high-level power supply; the C pole of the receiving end of the photoelectric coupler U2 is electrically connected with the positive pole end of a diode D1, the negative pole end of a diode D1 is electrically connected with the positive input end of the amplifier U1, the E pole of the receiving end of the photoelectric coupler U2 is grounded through an electric group R6, and the E pole of the receiving end of the photoelectric coupler U2 and the common end of the resistor R6 are used as the output end of the detection circuit after passing through an RC damping circuit.
2. The high-side high-voltage current detection circuit according to claim 1, wherein: the diode D2 and the diode D3 are fast recovery diodes, and the diode D1 and the diode D4 are zener diodes.
3. The high-side high-voltage current detection circuit according to claim 1, wherein: the amplifier U1 adopts a single power supply input rail-to-rail operational amplifier.
4. The high-side high-voltage current detection circuit according to claim 1, wherein: the resistors R1 and R6 are high-precision resistors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202023026867.4U CN214473578U (en) | 2020-12-16 | 2020-12-16 | High-end high-voltage current detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202023026867.4U CN214473578U (en) | 2020-12-16 | 2020-12-16 | High-end high-voltage current detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214473578U true CN214473578U (en) | 2021-10-22 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202023026867.4U Active CN214473578U (en) | 2020-12-16 | 2020-12-16 | High-end high-voltage current detection circuit |
Country Status (1)
| Country | Link |
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| CN (1) | CN214473578U (en) |
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2020
- 2020-12-16 CN CN202023026867.4U patent/CN214473578U/en active Active
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