CN-224216773-U - Isolation current detection circuit

CN224216773UCN 224216773 UCN224216773 UCN 224216773UCN-224216773-U

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 optical coupler isolation transmission circuit, wherein the operational amplification circuit is electrically connected with the voltage-frequency conversion circuit and used for receiving a voltage signal of a shunt and amplifying the voltage signal of the shunt, the voltage-frequency conversion circuit is electrically connected with the optical coupler isolation transmission circuit and 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 used for carrying out isolation transmission on the frequency signal. The utility model improves the sensitivity and the precision of current detection and enhances the anti-interference capability and the signal isolation reliability.

Inventors

CHEN FENG
WAN QIANG
XU LEI
ZHU WENJUN
MA LEILEI
CHEN XIAOXIONG

Assignees

西藏洲际电讯科技有限公司

Dates

Publication Date: 20260508
Application Date: 20250604

Claims (9)

1. The utility model provides an isolation current detection circuit which characterized in that, isolation current detection circuit includes operational amplifier circuit, voltage-to-frequency conversion circuit and opto-coupler isolation transmission circuit, wherein: The operational amplifier circuit is electrically connected with the voltage-frequency conversion circuit and is used for receiving the shunt voltage signal and amplifying the shunt voltage signal; The voltage-frequency conversion circuit is electrically connected with the optocoupler isolation transmission circuit and is used for converting a voltage signal into a frequency signal; the optical coupling isolation transmission circuit is electrically connected with the voltage-frequency conversion circuit and is used for carrying out isolation transmission on frequency signals.
2. An isolated current sensing circuit as defined in claim 1, wherein the op-amp circuit comprises an op-amp U1, a shunt R1, resistors R2-R4, and a capacitor C1.
3. An isolated current detection circuit according to claim 2, wherein the non-inverting input terminal of the operational amplifier U1 is electrically connected to one end of the resistor R2, the inverting input terminal of the operational amplifier U1 is electrically connected to one end of the resistor R3 and one end of the resistor R4, the other end of the resistor R2 is electrically connected to one end of the shunt R1 and one end of the capacitor C1, the other end of the resistor R3 is electrically connected to the other end of the capacitor C1 and the other end of the shunt R1, the negative power supply terminal of the operational amplifier U1 inputs-5V voltage, the positive power supply terminal of the operational amplifier U1 inputs VCC voltage, and the output terminal of the operational amplifier is electrically connected to the voltage-to-frequency conversion circuit.
4. An isolated current sensing circuit according to claim 3, wherein said operational amplifier U1 is a bipolar operational amplifier of model OP 07.
5. An isolated current detection circuit according to claim 1, wherein the voltage-to-frequency conversion circuit comprises resistors R5-R10, a potentiometer RP1, capacitors C2-C4, and a voltage-to-frequency conversion chip U2.
6. The isolated current detection circuit according to claim 5, wherein a pin 1, a pin 6 and one end of a capacitor C4 of a voltage-to-frequency conversion chip U2 are electrically connected to one end of a resistor R9, the other end of the capacitor C4 and one end of the capacitor C3 are electrically grounded, a pin 2 of the voltage-to-frequency conversion chip U2 is electrically connected to one end of a potentiometer RP1, a pin 3 of the voltage-to-frequency conversion chip U2 is electrically connected to an optocoupler isolated transmission circuit, a pin 4 of the voltage-to-frequency conversion chip U2 and the other end of the potentiometer RP1 are both grounded, a pin 5 of the voltage-to-frequency conversion chip U2 is electrically connected to the other end of the capacitor C3 and one end of a resistor R8, a pin 7 of the voltage-to-frequency conversion chip U2 is electrically connected to one end of the capacitor C2 and one end of the resistor R7, the other end of the resistor R7 is electrically connected to one end of the resistor R5 and one end of the resistor R6, the other end of the resistor R6 and the other end of the resistor C2 are both grounded, the other end of the resistor R5 is electrically connected to an operational amplifier circuit, the other end of the voltage-to the pin 8 of the voltage-to-frequency conversion chip U2 is electrically connected to the other end of the resistor R8 and the resistor 10, and the other end of the voltage-to the resistor 10 is electrically isolated circuit is electrically connected to the voltage-to the resistor 10.
7. The isolated current detection circuit of claim 6, wherein the voltage-to-frequency conversion chip U2 is a voltage-to-frequency conversion chip of model KA 331.
8. An isolated current sensing circuit as defined in claim 1, wherein the optocoupler isolated transmission circuit comprises an optocoupler U3 and a diode D1.
9. The isolated current detection circuit of claim 8, wherein 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 electrode of diode D1, and pin 4 of optocoupler U3 is electrically connected to the positive electrode of diode D1.

Description

Isolation current detection circuit Technical Field The utility model relates to the technical field of detection circuits, in particular to an isolated current detection circuit. Background The rectifying module is used as core equipment of a power environment of a communication machine room and has strict requirements on reliability. The output current is required to be detected in the rectifying module, the state quantity belongs to a basic acquisition signal of the rectifying module, and the rectifying module adjusts the output power and equally divides the load according to the signal. Because the base station is often in an unattended state, once the output current detection fails, the base station may not work normally, and the stability and reliability of the communication network may be affected. The Chinese patent with the publication number of CN211527657U discloses a detection circuit based on linear optocoupler matching operational amplifier, adopts temperature detection based on cascade connection of a linear optocoupler and an operational amplifier, directly transmits an analog voltage signal by using a linear optocoupler IL300, and realizes signal processing by precise operational amplifier matching. However, the whole process adopts a voltage signal transmission mode, so that the anti-interference capability is insufficient in a communication power supply environment with large electric noise interference, the signal distortion is caused by the nonlinear characteristic of the linear optocoupler, the temperature drift is obvious, the precision is unstable along with the change of the use environment, and the requirements of high-precision current detection and load balancing of the communication base station rectifying module cannot be met. Disclosure of utility model In view of this, the utility model provides an isolation current detection circuit, which is used for solving the problems that the prior art adopts a voltage signal transmission mode, the anti-interference capability is insufficient in a communication power supply environment with larger electric noise interference, the signal distortion is caused by the nonlinear characteristic of a linear optocoupler, the temperature drift is obvious, the precision is unstable along with the change of the use environment, and the requirements of high-precision current detection and load sharing of a communication base station rectification module cannot be met. The technical scheme of the utility model is realized in such a way that the isolation current detection circuit comprises an operational amplifier circuit, a voltage-frequency conversion circuit and an optical coupling isolation transmission circuit, wherein: The operational amplifier circuit is electrically connected with the voltage-frequency conversion circuit and is used for receiving the shunt voltage signal and amplifying the shunt voltage signal; The voltage-frequency conversion circuit is electrically connected with the optocoupler isolation transmission circuit and is used for converting a voltage signal into a frequency signal; the optical coupling isolation transmission circuit is electrically connected with the voltage-frequency conversion circuit and is used for carrying out isolation transmission on frequency signals. On the basis of the above technical scheme, preferably, the operational amplifier circuit comprises an operational amplifier U1, a shunt R1, resistors R2-R4 and a capacitor C1. On the basis of the above technical scheme, preferably, the non-inverting input end of the operational amplifier U1 is electrically connected with one end of the resistor R2, the inverting input end of the operational amplifier U1 is electrically connected with one end of the resistor R3 and one end of the resistor R4, the other end of the resistor R2 is electrically connected with one end of the shunt R1 and one end of the capacitor C1, the other end of the resistor R3 is electrically connected with the other end of the capacitor C1 and the other end of the shunt R1, the negative power supply end of the operational amplifier U1 inputs-5V voltage, the positive power supply end of the operational amplifier U1 inputs VCC voltage, and the output end of the operational amplifier is electrically connected with the voltage-to-frequency conversion circuit. On the basis of the above technical solution, preferably, the operational amplifier U1 is a bipolar operational amplifier with a model OP 07. On the basis of the above technical scheme, preferably, the voltage-frequency conversion circuit comprises resistors R5-R10, a potentiometer RP1, capacitors C2-C4 and a voltage-frequency conversion chip U2. On the basis of the above technical solution, preferably, the pin 1, the pin 6 and one end of the capacitor C4 of the voltage-to-frequency conversion chip U2 are all electrically connected with one end of the resistor R9, the other end of the capacitor C4 and one end of the capacitor C3 are all