Isolation current detection circuit

Abstract

The utility model relates to the technical field of detection circuits, and provides an isolation current detection circuit, which comprises an operational amplification circuit, a voltage-frequency conversion circuit and an optocoupler isolation transmission circuit, and is characterized in that the operational amplification circuit is electrically connected with the voltage-frequency conversion circuit and is used for receiving voltage signals of a shunt; the shunt voltage signal is amplified; the voltage-frequency conversion circuit is electrically connected with the optocoupler isolation transmission circuit and is used for converting the voltage signal into a frequency signal; and the optical coupler isolation transmission circuit is electrically connected with the voltage-frequency conversion circuit and is used for performing isolation transmission on the frequency signal. According to the utility model, the sensitivity and precision of current detection are improved, and the anti-interference capability and the signal isolation reliability are enhanced.

Description

Technical Field

[0001] This utility model relates to the field of detection circuit technology, and in particular to an isolation current detection circuit. Background Technology

[0002] As a core component of the power environment in communication equipment rooms, rectifier modules have stringent reliability requirements. Internally, the rectifier module needs to detect the output current; this state variable is a fundamental data acquisition signal used by the module to adjust output power and load distribution. Since base stations are often unattended, a malfunction in the output current detection could cause the base station to malfunction, affecting the stability and reliability of the communication network.

[0003] Chinese patent CN211527657U discloses a detection circuit based on a linear optocoupler-matched operational amplifier. It employs a temperature detection method using a cascaded linear optocoupler and operational amplifier, directly transmitting analog voltage signals via a linear optocoupler IL300, and performing signal processing through precision operational amplifier matching. However, due to the use of voltage signal transmission throughout, it suffers from insufficient anti-interference capability in communication power supply environments with significant electrical noise. The nonlinear characteristics of the linear optocoupler lead to signal distortion, and significant temperature drift results in unstable accuracy with varying operating environments. This makes it unsuitable for the high-precision current detection and load sharing requirements of communication base station rectifier modules. Utility Model Content

[0004] In view of this, this utility model proposes an isolated current detection circuit to solve the problems of insufficient anti-interference capability in communication power supply environments with large electrical noise interference due to the voltage signal transmission method in the existing technology, signal distortion caused by the nonlinear characteristics of the linear optocoupler, significant temperature drift, and unstable accuracy with changes in the operating environment, which cannot meet the requirements of high-precision current detection and load sharing of communication base station rectifier modules.

[0005] The technical solution of this utility model is implemented as follows: an isolation current detection circuit, which includes an operational amplifier circuit, a voltage-to-frequency conversion circuit, and an optocoupler isolation transmission circuit, wherein:

[0006] The operational amplifier circuit is electrically connected to the voltage-to-frequency conversion circuit and is used to receive the shunt voltage signal and amplify the shunt voltage signal.

[0007] The voltage-to-frequency conversion circuit is electrically connected to the optocoupler isolation transmission circuit and is used to convert the voltage signal into a frequency signal.

[0008] The optocoupler isolation transmission circuit is electrically connected to the voltage-to-frequency conversion circuit and is used for isolated transmission of frequency signals.

[0009] Based on the above technical solutions, preferably, the operational amplifier circuit includes an operational amplifier U1, a shunt R1, resistors R2-R4, and a capacitor C1.

[0010] Based on the above technical solution, preferably, the non-inverting input terminal of operational amplifier U1 is electrically connected to one end of resistor R2, the inverting input terminal of operational amplifier U1 is electrically connected to one end of resistor R3 and one end of resistor R4 respectively, the other end of resistor R2 is electrically connected to one end of shunt R1 and one end of capacitor C1 respectively, the other end of resistor R3 is electrically connected to the other end of capacitor C1 and the other end of shunt R1 respectively, the negative power supply terminal of operational amplifier U1 is input with a -5V voltage, the positive power supply terminal of operational amplifier U1 is input with a VCC voltage, and the output terminal of operational amplifier is electrically connected to the voltage-to-frequency conversion circuit.

[0011] Based on the above technical solutions, preferably, the operational amplifier U1 is a bipolar operational amplifier of model OP07.

[0012] Based on the above technical solutions, preferably, the voltage-frequency conversion circuit includes resistors R5-R10, potentiometer RP1, capacitors C2-C4, and voltage-frequency conversion chip U2.

[0013] Based on the above technical solution, preferably, pins 1 and 6 of the voltage-frequency conversion chip U2 and one end of capacitor C4 are all electrically connected to one end of resistor R9; the other end of resistor R9, the other end of capacitor C4, and one end of capacitor C3 are all grounded; pin 2 of the voltage-frequency conversion chip U2 is electrically connected to one end of potentiometer RP1; pin 3 of the voltage-frequency conversion chip U2 is electrically connected to the optocoupler isolation transmission circuit; pin 4 of the voltage-frequency conversion chip U2 and the other end of potentiometer RP1 are both grounded; and pin 5 of the voltage-frequency conversion chip U2 is connected to the other end of capacitor C3 and resistor R8 respectively. One end of the voltage-frequency converter chip U2 is electrically connected. Pin 7 of the voltage-frequency converter chip U2 is electrically connected to one end of capacitor C2 and one end of resistor R7. The other end of resistor R7 is electrically connected to one end of resistor R5 and one end of resistor R6. The other end of resistor R6 and the other end of capacitor C2 are both grounded. The other end of resistor R5 is electrically connected to the operational amplifier circuit. Pin 8 of the voltage-frequency converter chip U2 is electrically connected to the other end of resistor R8 and one end of resistor R10. The other end of resistor R10 is electrically connected to the optocoupler isolation transmission circuit. Pin 8 of the voltage-frequency converter chip U2 is input with VCC voltage.

[0014] Based on the above technical solutions, preferably, the voltage-frequency conversion chip U2 is a voltage-frequency conversion chip of model KA331.

[0015] Based on the above technical solutions, preferably, the optocoupler isolation transmission circuit includes optocoupler U3 and diode D1.

[0016] Based on the above technical solution, preferably, pin 1 of optocoupler U3 is electrically connected to the voltage-frequency conversion circuit, pin 2 of optocoupler U3 is electrically connected to the voltage-frequency conversion circuit, pin 3 of optocoupler U3 is electrically connected to the negative terminal of diode D1, and pin 4 of optocoupler U3 is electrically connected to the positive terminal of diode D1.

[0017] The isolation current detection circuit provided by this utility model has the following advantages compared with the prior art:

[0018] (1) The weak voltage signal generated by the shunt is amplified with high precision through the operational amplifier circuit, the voltage-to-frequency conversion circuit and the optocoupler isolation transmission circuit, and the analog voltage signal is effectively converted into a frequency signal. Then, the frequency signal is electrically isolated and safely transmitted through the digital optocoupler, which improves the sensitivity and accuracy of current detection, enhances anti-interference capability and signal isolation reliability.

[0019] (2) By combining potentiometers, resistors and capacitors, the conversion characteristics are finely adjusted, effectively compensating for device errors and changes in the external environment, ensuring that the voltage-frequency conversion chip outputs high-quality frequency signals under optimal working conditions, and improving the overall detection accuracy and anti-interference capability. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the system structure of an isolation current detection circuit according to the present invention;

[0022] Figure 2 This is a schematic diagram of the overall circuit of an isolation current detection circuit according to the present invention. Detailed Implementation

[0023] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0024] Please see Figure 1This utility model provides an isolation current detection circuit, which includes an operational amplifier circuit, a voltage-to-frequency conversion circuit, and an optocoupler isolation transmission circuit, wherein:

[0025] The operational amplifier circuit is electrically connected to the voltage-to-frequency conversion circuit and is used to receive the shunt voltage signal and amplify the shunt voltage signal.

[0026] The voltage-to-frequency conversion circuit is electrically connected to the optocoupler isolation transmission circuit and is used to convert the voltage signal into a frequency signal.

[0027] The optocoupler isolation transmission circuit is electrically connected to the voltage-to-frequency conversion circuit and is used for isolated transmission of frequency signals.

[0028] Specifically, this embodiment uses an operational amplifier circuit, a voltage-to-frequency conversion circuit, and an optocoupler isolation transmission circuit to amplify the weak voltage signal generated by the shunt with high precision, effectively convert the analog voltage signal into a frequency signal, and then use a digital optocoupler to achieve electrical isolation and safe transmission of the frequency signal, thereby improving the sensitivity and accuracy of current detection and enhancing anti-interference capability and signal isolation reliability.

[0029] One embodiment of the isolation current detection circuit consists of an operational amplifier circuit, a voltage-to-frequency conversion circuit, and an optocoupler isolation transmission circuit.

[0030] Please see Figure 2 The operational amplifier circuit includes an operational amplifier U1, a shunt R1, resistors R2-R4, and a capacitor C1.

[0031] The non-inverting input of operational amplifier U1 is electrically connected to one end of resistor R2. The inverting input of operational amplifier U1 is electrically connected to one end of resistor R3 and one end of resistor R4. The other end of resistor R2 is electrically connected to one end of shunt R1 and one end of capacitor C1. The other end of resistor R3 is electrically connected to the other end of capacitor C1 and the other end of shunt R1. The negative power supply terminal of operational amplifier U1 receives a -5V voltage, and the positive power supply terminal of operational amplifier U1 receives a VCC voltage. The output terminal of operational amplifier U1 is electrically connected to the voltage-to-frequency conversion circuit.

[0032] The operational amplifier U1 is a bipolar operational amplifier of model OP07.

[0033] Specifically, the operational amplifier circuit in this embodiment consists of operational amplifier U1, shunt R1, resistors R2, R3, R4, and capacitor C1. Resistors R2, R3, R4, capacitor C1, and operational amplifier U1 form an operational amplifier circuit that amplifies the voltage drop generated by the load current flowing through VOUT- and CT across shunt R1.

[0034] Please see Figure 2 The voltage-to-frequency conversion circuit includes resistors R5-R10, potentiometer RP1, capacitors C2-C4, and voltage-to-frequency conversion chip U2.

[0035] Pins 1 and 6 of the voltage-to-frequency converter chip U2 and one end of capacitor C4 are all electrically connected to one end of resistor R9. The other end of resistor R9, the other end of capacitor C4, and one end of capacitor C3 are all grounded. Pin 2 of the voltage-to-frequency converter chip U2 is electrically connected to one end of potentiometer RP1. Pin 3 of the voltage-to-frequency converter chip U2 is electrically connected to the optocoupler isolation transmission circuit. Pin 4 of the voltage-to-frequency converter chip U2 and the other end of potentiometer RP1 are both grounded. Pin 5 of the voltage-to-frequency converter chip U2 is electrically connected to the other end of capacitor C3 and one end of resistor R8, respectively. Pin 7 of the frequency converter chip U2 is electrically connected to one end of capacitor C2 and one end of resistor R7. The other end of resistor R7 is electrically connected to one end of resistor R5 and one end of resistor R6. The other end of resistor R6 and the other end of capacitor C2 are both grounded. The other end of resistor R5 is electrically connected to the operational amplifier circuit. Pin 8 of the frequency converter chip U2 is electrically connected to the other end of resistor R8 and one end of resistor R10. The other end of resistor R10 is electrically connected to the optocoupler isolation transmission circuit. Pin 8 of the frequency converter chip U2 is input with VCC voltage.

[0036] The voltage-to-frequency conversion chip U2 is a KA331 voltage-to-frequency conversion chip.

[0037] Specifically, the voltage-to-frequency conversion circuit in this embodiment consists of resistors R5, R6, R7, R8, R9, and R10, potentiometer RP1, capacitors C2, C3, and C4, and voltage-to-frequency conversion chip U2. The voltage signal amplified by the operational amplifier is divided by resistors R5 and R6, input through resistor R7, and capacitor C2 acts as a filter. Capacitors C3 and C4, resistors R8 and R9, and potentiometer RP1 set the corresponding parameters for the operation of voltage-to-frequency conversion chip U2.

[0038] Please see Figure 2 The optocoupler-isolated transmission circuit includes optocoupler U3 and diode D1.

[0039] Pin 1 of optocoupler U3 is electrically connected to the voltage-to-frequency conversion circuit, pin 2 of optocoupler U3 is electrically connected to the voltage-to-frequency conversion circuit, pin 3 of optocoupler U3 is electrically connected to the negative terminal of diode D1, and pin 4 of optocoupler U3 is electrically connected to the positive terminal of diode D1.

[0040] Specifically, the optocoupler isolated transmission circuit in this embodiment consists of a resistor R10, an optocoupler U3, and a diode D1. R10 provides bias for the optocoupler U3, and the diode D1 acts as a clamp.

[0041] The workflow of an isolated current detection circuit in this embodiment is as follows: an operational amplifier amplifies the shunt voltage signal, a voltage-to-frequency conversion circuit converts the voltage signal into a frequency signal, an optocoupler isolation transmission circuit transmits the frequency signal in isolation, and a high-precision operational amplifier is used in conjunction with a digital optocoupler to convert the current signal into a frequency signal.

[0042] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An isolation current detection circuit, characterized in that, The isolation current detection circuit includes an operational amplifier circuit, a voltage-to-frequency conversion circuit, and an optocoupler isolation transmission circuit, wherein: The operational amplifier circuit is electrically connected to the voltage-to-frequency conversion circuit and is used to receive the shunt voltage signal and amplify the shunt voltage signal. The voltage-to-frequency conversion circuit is electrically connected to the optocoupler isolation transmission circuit and is used to convert the voltage signal into a frequency signal. The optocoupler isolation transmission circuit is electrically connected to the voltage-to-frequency conversion circuit and is used for isolated transmission of frequency signals.

2. The isolation current detection circuit as described in claim 1, characterized in that, The operational amplifier circuit includes an operational amplifier U1, a shunt R1, resistors R2-R4, and a capacitor C1.

3. The isolation current detection circuit as described in claim 2, characterized in that, The non-inverting input of operational amplifier U1 is electrically connected to one end of resistor R2. The inverting input of operational amplifier U1 is electrically connected to one end of resistor R3 and one end of resistor R4. The other end of resistor R2 is electrically connected to one end of shunt R1 and one end of capacitor C1. The other end of resistor R3 is electrically connected to the other end of capacitor C1 and the other end of shunt R1. The negative power supply terminal of operational amplifier U1 receives a -5V voltage, and the positive power supply terminal of operational amplifier U1 receives a VCC voltage. The output terminal of operational amplifier U1 is electrically connected to the voltage-to-frequency conversion circuit.

4. The isolation current detection circuit as described in claim 3, characterized in that, The operational amplifier U1 is a bipolar operational amplifier of model OP07.

5. The isolation current detection circuit as described in claim 1, characterized in that, The voltage-to-frequency conversion circuit includes resistors R5-R10, potentiometer RP1, capacitors C2-C4, and voltage-to-frequency conversion chip U2.

6. The isolation current detection circuit as described in claim 5, characterized in that, Pins 1 and 6 of the voltage-to-frequency converter chip U2 and one end of capacitor C4 are all electrically connected to one end of resistor R9. The other end of resistor R9, the other end of capacitor C4, and one end of capacitor C3 are all grounded. Pin 2 of the voltage-to-frequency converter chip U2 is electrically connected to one end of potentiometer RP1. Pin 3 of the voltage-to-frequency converter chip U2 is electrically connected to the optocoupler isolation transmission circuit. Pin 4 of the voltage-to-frequency converter chip U2 and the other end of potentiometer RP1 are both grounded. Pin 5 of the voltage-to-frequency converter chip U2 is electrically connected to the other end of capacitor C3 and one end of resistor R8, respectively. Pin 7 of the frequency converter chip U2 is electrically connected to one end of capacitor C2 and one end of resistor R7. The other end of resistor R7 is electrically connected to one end of resistor R5 and one end of resistor R6. The other end of resistor R6 and the other end of capacitor C2 are both grounded. The other end of resistor R5 is electrically connected to the operational amplifier circuit. Pin 8 of the frequency converter chip U2 is electrically connected to the other end of resistor R8 and one end of resistor R10. The other end of resistor R10 is electrically connected to the optocoupler isolation transmission circuit. Pin 8 of the frequency converter chip U2 is input with VCC voltage.

7. The isolation current detection circuit as described in claim 6, characterized in that, The voltage-to-frequency conversion chip U2 is a KA331 voltage-to-frequency conversion chip.

8. The isolation current detection circuit as described in claim 1, characterized in that, The optocoupler-isolated transmission circuit includes optocoupler U3 and diode D1.

9. The isolation current detection circuit as described in claim 8, characterized in that, Pin 1 of optocoupler U3 is electrically connected to the voltage-to-frequency conversion circuit, pin 2 of optocoupler U3 is electrically connected to the voltage-to-frequency conversion circuit, pin 3 of optocoupler U3 is electrically connected to the negative terminal of diode D1, and pin 4 of optocoupler U3 is electrically connected to the positive terminal of diode D1.

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