CN218938372U

CN218938372U - Step-type current analog quantity moment detection circuit

Info

Publication number: CN218938372U
Application number: CN202123443287.XU
Authority: CN
Inventors: 梅琦; 王卫兵; 李耀坤
Original assignee: Beijing Qibing Intelligent Technology Co ltd
Current assignee: Beijing Qibing Intelligent Technology Co ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2023-04-28
Anticipated expiration: 2031-12-31

Abstract

The utility model belongs to the technical field of detection circuits, and particularly relates to a stepped current analog quantity moment detection circuit. The utility model provides a novel stepping current analog quantity moment detection circuit, wherein a second weak current signal can carry out stepping acquisition according to actual measurement of load moment of different types of actuators and the proportional relation of the moment between different loads, so that moment output voltages of all load types can be controlled to be in a linear region, and the aim of accurate detection is fulfilled; meanwhile, the moment value is output in two paths, which respectively represent the anticlockwise direction and the clockwise direction of the load, so that the load power in the circuit can be accurately reflected. The detection circuit can be used in an actuator to detect the load moment of the motor, can also be applied to other equipment to measure the load power, has wide application range, and has high linearity and good accuracy of the obtained measurement result, and can provide reference for subsequent work.

Description

Step-type current analog quantity moment detection circuit

Technical Field

The utility model belongs to the technical field of detection circuits, and particularly relates to a stepped current analog quantity moment detection circuit.

Background

In instruments and industrial automation systems, various non-electric physical quantities such as temperature, pressure, speed, angle and density are generally required to be measured, and the non-electric physical quantities are required to be converted into analog electrical signals and then transmitted to a remote centralized control room, so that acquisition and monitoring are performed.

The Chinese patent with the publication number CN 213843388U discloses a current analog moment detection circuit which can directly output the analog quantity of power, but when weak current signals are collected, the resistance value of a sampling resistor is fixed, and only the moment of the same load type can be detected.

Disclosure of Invention

In order to solve the problems in the prior art, the utility model provides a novel stepping current analog quantity moment detection circuit.

The specific technical scheme of the utility model is as follows:

the utility model provides a stepped current analog moment detection circuit, which comprises a weak current signal output circuit, a voltage signal output circuit, a comparison circuit, a stepped weak current signal acquisition circuit, a power signal output circuit and an integral amplification circuit, wherein the weak current signal output circuit converts input three-phase electricity into a first weak current signal, the stepped weak current signal acquisition circuit acquires a second weak current signal in a stepped way, converts the second weak current signal into a second voltage signal and amplifies the second voltage signal to output the second voltage signal to the power signal output circuit, the voltage signal output circuit converts the first weak current signal into a first voltage signal and amplifies the first voltage signal to output the first voltage signal to the comparison circuit, and the comparison circuit compares the first voltage signal with an applied standard voltage and outputs a result; the power signal output circuit multiplies the signal output by the comparison circuit and the second voltage signal to output a power signal, and the integration amplifying circuit amplifies the power signal and outputs analog quantities respectively.

Further improved, the step weak current signal acquisition circuit comprises an interface JN2, an operational amplifier U4B, a dial switch JN4 and a dial switch JN5, wherein the interface JN2 is externally connected with a current transformer, the 2 pin is grounded, the 1 pin outputs a weak current signal HALL+ and is grounded through a diode D3, the weak current signal HALL+ is respectively input into the dial switch JN4 and the dial switch JN5 and is input into the 6 pin of the U4B through a resistor R3, the 2 pin, the 4 pin, the 6 pin, the 8 pin, the 10 pin and the 12 pin of the JN4 are connected in parallel and are connected with the 1 pin of the JN4 through a resistor R101, the 3 pin is grounded through a resistor R102, the 5 pin is grounded through a resistor R103, the 7 pin is grounded through a resistor R104, the 9 pin is grounded through a resistor R105, the 1 pin of the dial switch JN4 and the JN5 is grounded through a resistor R107, the 5 pin is grounded through a resistor R109, the 2 pin, the 8 pin and the 12 pin is grounded through a resistor R11 and the resistor R11 are connected with the resistor R11 in parallel, and the resistor R11 is connected with the resistor R11.

Further improved, the weak current signal output circuit comprises a current type voltage transformer U10 and an interface JN3, the interface JN3 is externally connected with a three-Phase power supply and outputs Phase-U, phase-W and Phase-V, pins 1 and 2 of the U10 are respectively input with three-Phase power, wherein pin 1 is connected with Phase-U through series resistors R51 and R52 and is connected with Phase-W through series resistors R55 and R56, pin 2 is connected with Phase-V, pin 3 is grounded, and pin 4 is used for outputting a first weak current signal CT.

Further improved, the voltage signal output circuit comprises operational amplifiers U7A, 3 pins of U7A are grounded, 2 pins are connected with CT,1 pin outputs a first voltage signal and is connected with the comparison circuit, 4 pins are respectively connected with-5 VA and grounded through a capacitor C30, 8 pins are respectively connected with +5VA and grounded through a capacitor C31, and a capacitor C29 and a resistor R24 which are mutually connected in series are connected in parallel between the 1 pin and the 2 pin.

Further improved, the comparison circuit comprises an operational amplifier U6A, a 1 pin of the U6A is respectively connected with a multiplexer U9 and is connected with +5VA through a resistor R27, a 2 pin is connected with a triangular wave generation circuit through a resistor R25, a 4 pin is respectively connected with-5 VA and is grounded through a capacitor C33, a 8 pin is respectively connected with +5VA and is grounded through a capacitor C32, 1, 4, 8 and 11 pins of the multiplexer U9 are respectively grounded, a 7 pin is connected with-5 VA and a 14 pin is respectively connected with +5VA and is grounded through a capacitor C34, and 5, 6, 12 and 13 pins are connected in parallel and are connected with the 1 pin of the U6A, 2, 3, 9 and 10 pins and output signals to the power signal output circuit.

The triangular wave generating circuit is further improved, the triangular wave generating circuit comprises an operational amplifier U6B and U7B, the pin 6 of the U6B is grounded through a resistor R28, resistors R29 and R30 are connected in parallel on the pin 7, and a resistor R31 is connected between the pin 5 and the resistor R30 in parallel through the resistor R29;

the 5 pins of the operational amplifier U7B are grounded through a resistor R34, the 6 pins are connected with a resistor R32, a capacitor C35 is connected between the 6 pins and the 7 pins in parallel, the 7 pins are connected with resistors R33 and R26 in parallel, and the resistor R33 and the resistor R32 are respectively connected with two ends of the resistor R31 in parallel.

Further improved, the power signal output circuit comprises an operational amplifier U4A, a capacitor C16 is connected between the 1 pin and the 2 pin of the U4A in parallel, the 1 pin outputs a power signal to the integral amplifying circuit, the 2 pin is connected with I-W through a resistor R7, the 3 pin is connected with I-W through a resistor R5 and is connected with a multiplexer U9, the 4 pin is connected with-5 VA and is grounded through a capacitor C15, and the 8 pin is connected with +5VA and is grounded through a capacitor C14.

The integration amplifying circuit comprises an operational amplifier U5A, U5B, U A and U8B, wherein a 1 pin of the U5A is connected with a 6 pin of the U5B through a resistor R13, a capacitor C21 is connected in parallel between a 2 pin and the 1 pin, a 3 pin is respectively grounded through a capacitor C18 and connected with a 1 pin of the U4A through resistors R9 and R10 which are connected in series, a 4 pin is respectively connected with-5 VA and grounded through a capacitor C20, and an 8 pin is respectively connected with +5VA and grounded through a capacitor C19;

the 5 pins of the operational amplifier U5B are grounded through a resistor R12, a capacitor C22 and a resistor R14 which are mutually connected in parallel are connected between the 6 pins and the 7 pins in parallel, and the 7 pins are respectively connected with the 6 pins of the U8B through a resistor R16 and the 2 pins of the U8A through a resistor R20;

the 5 pin of the operational amplifier U8B is grounded through a resistor R15, the two ends of the resistor R15 are connected in parallel with a capacitor C23, the 6 pin and the 7 pin of the U8B are connected in parallel with a capacitor C24 and a resistor R17 which are connected in parallel with each other, the 7 pin outputs an analog quantity ZJ_OP through a resistor R18, and the negative electrode of the R18 is grounded through a diode D6;

the 3 pins of the operational amplifier U8A are grounded through a resistor R19, capacitors C25 are connected in parallel at two ends of the resistor R19, a capacitor C28 and a resistor R21 which are connected in parallel with each other are connected in parallel between the 2 pins and the 1 pins of the U8B, the 1 pin outputs analog quantity ZJ_CL through a resistor R22, the negative electrode of the R22 is grounded through a diode D7, the 4 pins of the U8A are respectively connected with-5 VA and grounded through a capacitor C27, and the 8 pins are respectively connected with +5VA and grounded through a capacitor C26.

Further improved, the detection circuit also comprises a power supply circuit, wherein the power supply circuit converts the input power supply voltage into a power supply voltage to supply power for each circuit; the power supply circuit comprises an interface JN1, a rectifier bridge U3, a first voltage stabilizer U2 and a second voltage stabilizer U1, wherein the interface JN1 is externally connected with power supply voltage and load, pins 1-3 of the JNI are respectively input into AV_1, AV_2 and DV_B1+, pins 4 are grounded, and

pins

5 and 6 respectively output analog quantities ZJ_OP and ZJ_CL;

the 1 pin of the rectifier bridge U3 is connected with the AV_1, the 2 pin is connected with the AV_2, the 4 pin outputs DV_B1-, the 3 pin is grounded, and a capacitor C3 is connected between the 4 pin and the 3 pin in parallel;

the 1 pin of the first voltage stabilizer U2 is respectively connected with DV_B1+ and is grounded through a capacitor C11 and is grounded through a capacitor C10, the 2 pin is grounded, the 3 pin is respectively output by +5VA and is grounded through a capacitor C9, is grounded through a capacitor C12 and is grounded through a diode D2;

the pin 2 of the second voltage stabilizer U1 is respectively connected with DV_B1-and grounded through a capacitor C5 and grounded through a capacitor C7, the pin 3 is grounded, the pin 1 is respectively output to-5 VA and grounded through a capacitor C8, grounded through a capacitor C6 and grounded through a diode D1.

The beneficial effects of the utility model are as follows:

the utility model provides a novel stepping current analog quantity moment detection circuit, wherein a second weak current signal can carry out stepping acquisition according to actual measurement of load moment of different types of actuators and the proportional relation of the moment between different loads, so that moment output voltages of all load types can be controlled to be in a linear region, and the aim of accurate detection is fulfilled; meanwhile, the analog quantity is output in two paths, which respectively represent the anticlockwise direction and the clockwise direction of the load, so that the load power in the circuit can be accurately reflected. The detection circuit can be used in an actuator to detect the load moment of the motor, can also be applied to other equipment to measure the load power, has wide application range, and has high linearity and good accuracy of the obtained measurement result, and can provide reference for subsequent work.

Drawings

FIG. 1 is a block diagram of a step-by-step current analog quantity moment detection circuit of the present utility model;

FIG. 2 is a circuit diagram of a stepped weak current signal acquisition circuit according to the present utility model;

FIG. 3 is a circuit diagram of a weak current signal output circuit according to the present utility model;

FIG. 4 is a circuit diagram of a voltage signal output circuit, a comparison circuit, a power signal output circuit and an integrating amplifying circuit according to the present utility model;

fig. 5-8 are circuit diagrams of the power supply circuit of the present utility model.

Detailed Description

The utility model will be described in further detail with reference to the accompanying drawings and the following examples.

As an embodiment, the present utility model provides a stepped current analog moment detection circuit, as shown in fig. 1, a weak current signal output circuit, a voltage signal output circuit, a comparison circuit, a stepped weak current signal acquisition circuit, a power signal output circuit and an integral amplification circuit, wherein the weak current signal output circuit converts input three-phase electricity into a first weak current signal, the stepped weak current signal acquisition circuit acquires a second weak current signal in a stepped manner, converts the second weak current signal into a second voltage signal and amplifies and outputs the second voltage signal to the power signal output circuit, the voltage signal output circuit converts the first weak current signal into a first voltage signal and amplifies and outputs the first voltage signal to the comparison circuit, and the comparison circuit compares the first voltage signal with an applied standard voltage and outputs a result; the power signal output circuit multiplies the signal output by the comparison circuit and the second voltage signal to output a power signal, and the integration amplifying circuit amplifies the power signal and outputs analog quantities respectively.

As shown in fig. 2, the step weak current signal collection circuit in this embodiment includes an interface JN2, an operational amplifier U4B (model LM 2904D), a dial switch JN4 and JN5, the interface JN2 is externally connected to a current transformer, and pin 2 is grounded, pin 1 outputs a weak current signal hall+ and is grounded through a diode D3 (model P6KE 10A), the weak current signal hall+ is respectively input to the dial switch JN4, JN5 and through 6 pins of a resistor R3 (10 k),

pins

2,4, 6, 8, 10, 12 of the JN5 are all connected in parallel and connected with pins hall+, pin 1 of JN4 is grounded through a resistor R101 (1Ω), pin 3 is grounded through a resistor R102 (5Ω), pin 7 is grounded through a resistor R104 (20Ω), pin 9 is grounded through a resistor R105 (R11), and is grounded through a resistor R11, and is connected through a resistor R11 (2Ω), and is connected with

pins

1,2, 8, 10, 12 pins (C) are connected with

pins

1, and 11, and 150 q (C) are connected in parallel with each other through a resistor R101 (1Ω), and are connected with

pins

1,2, 7 q (2Ω) and are connected with pins 1, and are connected with each other through a resistor R11, and with pins 1

q

2, 7, and with pins 11 q (2Ω) and with pins 1 q) are connected with pins 1 through resistor (1Ω).

As shown in fig. 3, the weak current signal output circuit in this embodiment includes a current-type voltage transformer U10 (model PT 31D) and an interface JN3, the interface JN3 is externally connected with a three-Phase power supply, and outputs Phase-U, phase-W and Phase-V, and 1 pin and 2 pin of U10 respectively input three-Phase power, wherein the 1 pin is connected with the Phase-U through series resistors R51 (330 k) and R52 (330 k), is connected with the Phase-W through series resistors R55 (330 k) and R56 (330 k), the 2 pin is connected with the Phase-V, the 3 pin is grounded, and the 4 pin outputs a first weak current signal CT.

As shown in fig. 4, the voltage signal output circuit in this embodiment includes an operational amplifier U7A (model LM 2904D), pin 3 of U7A is grounded, pin 2 is connected to CT, pin 1 outputs a first voltage signal and is connected to the comparison circuit, pin 4 is respectively connected to-5 VA and is grounded through a capacitor C30 (0.1U/16V), pin 8 is respectively connected to +5va and is grounded through a capacitor C31 (0.1U/16V), and a capacitor C29 (0.1U/16V) and a resistor R24 (200 k) which are connected in series are connected in parallel between pin 1 and pin 2.

As shown in fig. 4, the comparison circuit in this embodiment includes an operational amplifier U6A (model LM 2903D), the 1 pin of U6A is respectively connected to a multiplexer U9 and +5va (model MC14066 BD) through a resistor R27 (5.1 k), the 2 pin is connected to a triangle wave generation circuit through a resistor R25 (5.1 k), the 3 pin is connected to-5 VA through a resistor R26 (5.1 k), the 4 pin is respectively connected to ground through a capacitor C33 (0.1U/16V), the 8 pin is respectively connected to +5va and ground through a capacitor C32 (0.1U/16V), the 1, 4, 8, 11 pins of the multiplexer U9 are all grounded, the 7 pin is connected to-5 VA, the 14 pin is respectively connected to +5va and ground through a capacitor C34 (0.1U/50V), the 5, 6, 12, 13 pins are connected in parallel and the 1 pin, 2, 3, 9, 10 pin of U6A signal is output to the power circuit.

As shown in fig. 4, the triangular wave generating circuit in this embodiment includes an operational amplifier U6B (model LM 2903D) and U7B (model LM 2904D), pin 6 of U6B is grounded through a resistor R28 (30 k), resistors R29 (3 k) and R30 (10 k) are connected in parallel to pin 7, and +5va is connected through a resistor R29, and a resistor R31 (10 k) is connected in parallel between pin 5 and resistor R30;

the 5 pins of the operational amplifier U7B are grounded through a resistor R34 (51 k), the 6 pins are connected with a resistor R32 (5 k), a capacitor C35 (1 n/16V) is connected between the 6 pins and the 7 pins in parallel, the 7 pins are connected with a resistor R33 (8.2 k) and a resistor R26 in parallel, and the resistor R33 and the resistor R32 are respectively connected with two ends of the resistor R31 in parallel.

The advantage of comparing the first voltage signal with the triangular wave signal in this embodiment: the voltage is an input signal, the triangular wave is a carrier signal, a high level is output between the two intersection points, and the period of the triangular wave is fixed, so that the output is a Pulse Width Modulation (PWM) wave with different periods and certain duty ratios, and the PWM wave energy expresses the input signal well in an equivalent way. PWM is used as a means to facilitate the operation of the circuit

As shown in fig. 4, the power signal output circuit in this embodiment includes an operational amplifier U4A (model LM 2904D), a capacitor C16 (100 p/16V) is connected in parallel between the 1 pin and the 2 pin of U4A, and the 1 pin outputs a power signal to the integrating amplifying circuit, the 2 pin is connected to I-W through a resistor R7 (100 k), the 3 pin is connected to I-W through a resistor R5 (51 k) and to a multiplexer U9, the 4 pin is connected to-5 VA and to ground through a capacitor C15 (0.1U/16V), and the 8 pin is connected to +5va and to ground through a capacitor C14 (0.1U/16V).

Signal CT is the output of the voltage sensor, which measures the actual voltage signal in the circuit, representing the voltage physical quantity; the signal hall+ is the output of the current sensor, which measures the actual current signal in the circuit, representing the current physical quantity. However, they are all presented in the present circuit as voltage signals, and the voltage signals in the circuit are only one expression form, which is equivalent to representing different physical quantities as voltages, so that the operation in the analog circuit is facilitated.

As shown in fig. 4, the integrating amplifying circuit in this embodiment includes an operational amplifier U5A (model LM 2904D), U5B, U a (model LM 2904D) and U8B, pin 1 of U5A is connected to pin 6 of U5B through a resistor R13 (20 k), a capacitor C21 (0.01U/16V) is connected in parallel between pin 2 and pin 1, pin 3 is grounded through a capacitor C18 (1U/50V) and connected to pin 1 of U4A through resistors R9 (51 k) and R10 (51 k) in series, pin 4 is connected to-5 VA and connected to ground through a capacitor C20 (0.1U/16V), and pin 8 is connected to +5va and grounded through a capacitor C19 (0.1U/16V), respectively;

the 5 pins of the operational amplifier U5B are grounded through a resistor R12 (10 k), a capacitor C22 (0.1U/16V) and a resistor R14 (20 k) which are mutually connected in parallel are connected between the 6 pins and the 7 pins in parallel, and the 7 pins are respectively connected with the 6 pins of the U8B through a resistor R16 (1 k) and the 2 pins of the U8A through a resistor R20 (5.1 k);

the 5 pins of the operational amplifier U8B are grounded through a resistor R15 (10 k), capacitors C23 (0.1U/16V) are connected in parallel at two ends of the resistor R15, a capacitor C24 (0.01U/16V) and a resistor R17 (1.5 k) which are connected in parallel with each other are connected in parallel between the 6 pins and the 7 pins of the U8B, the 7 pins output an analog quantity ZJ_OP through a resistor R18 (1 k), and the negative electrode of the R18 is grounded through a diode D6 (model 1N 4148);

the 3 pins of the operational amplifier U8A are grounded through a resistor R19 (5.1 k), capacitors C25 (0.1U/16V) are connected in parallel at two ends of the resistor R19, a capacitor C28 (0.01U/16V) and a resistor R21 (15 k) which are connected in parallel with each other are connected in parallel between the 2 pins and the 1 pins of the U8B, the 1 pin outputs an analog quantity ZJ_CL through a resistor R22 (1 k), the negative electrode of the R22 is grounded through a diode D7 (model 1N 4148), the 4 pins of the U8A are respectively connected with-5 VA and grounded through a capacitor C27 (0.1U/16V), and the 8 pins are respectively connected with +5VA and grounded through a capacitor C26 (0.1U/16V).

As shown in fig. 5-8, the detection circuit in this embodiment further includes a power supply circuit, where the power supply circuit converts an input power supply voltage into a power supply voltage to supply power to each circuit; the power supply circuit comprises an interface JN1, a rectifier bridge U3 (model DB 107S), a first voltage stabilizer U2 (model 78L05 ACZ) and a second voltage stabilizer U1 (model 79L05 ACZ), wherein the interface JN1 is externally connected with a power supply voltage and a load, pins 1-3 of the JNI are respectively input into AV_1, AV_2 and DV_B1+, and pin 4 are grounded, and

pins

5 and 6 respectively output analog quantities ZJ_OP and ZJ_CL;

the 1 pin of the rectifier bridge U3 is connected with AV_1, the 2 pin is connected with AV_2, the 4 pin outputs DV_B1-, the 3 pin is grounded, and a capacitor C3 (1U/50V) is connected between the 4 pin and the 3 pin in parallel;

the 1 pin of the first voltage stabilizer U2 is respectively connected with DV_B1+ and grounded through a capacitor C11 (47U/25V), grounded through a capacitor C10 (0.1U/50V), grounded through a 2 pin, and respectively outputs +5VA and grounded through a capacitor C9 (0.1U/16V), grounded through a capacitor C12 (47U/25V) and grounded through a diode D2 (model is SMAJ 6.0);

the pin 2 of the second voltage stabilizer U1 is respectively connected with DV_B1-and grounded through a capacitor C5 (47U/25V), grounded through a capacitor C7 (0.1U/50V), grounded through a pin 3, and respectively outputs-5 VA and grounded through a capacitor C8 (0.1U/16V), grounded through a capacitor C6 (47U/25V) and grounded through a diode D1 (model is SMAJ 6.0).

The working principle of the circuit is as follows:

the input end (pins 1 and 2) of the current type voltage transformer U10 is connected with three-phase electricity through JN3, the current of a primary coil (a coil between pins 1 and 2) is limited to mA-level current through a current limiting resistor, a series-connected current limiting resistor converts a voltage signal into a weak current signal, and a secondary coil (a coil between pins 3 and 4) outputs mA-level current signal (CT) through induction; the current signal is converted and amplified into a first voltage signal through an I/V conversion circuit of the transport amplifier U7A to participate in subsequent operation; in the comparison circuit, the operational amplifier U6B, U B generates a typical triangular wave signal in a combined way, and the typical triangular wave signal is compared with a first voltage signal output by the operational amplifier U7A, two paths of signals are input into the same-direction end and the opposite-direction end of the 3 pin and the 2 pin of the operational amplifier U6A, and the comparison result is output to the multiplexer U9; on the other hand, the second weak current signal hall+ output from the current transformer (on the connection interface JN2, output from JN 2) is converted into a second voltage signal through the sampling resistor; in the circuit, a stepping sampling resistor is adopted, and 12 sampling resistors with different resistance values are specially selected for sampling selection according to actual measurement of load moment of different types of actuators and the proportional relation of moment sizes among different loads; the 12 different levels of resistance values respectively correspond to an actuator load, and each different resistance is selected through a dial switch JN4 and a dial switch JN 5; in engineering practice, the load of each user is not consistent, and different resistance grades can be selected according to the load types of specific users; when the load moment is large, the load induced current is large, and a sampling resistor with a small resistance value is selected; when the load moment is small, the load induced current is small, and a sampling resistor with a large resistance value is selected. The purpose of selecting the sampling resistor is to control the final moment output voltage in a linear region, prevent the moment output voltage from being too small and from being poor in resolution, and have low moment detection precision; and when the moment output voltage is too large, the operational amplifier is saturated in output, and the moment detection value is distorted. Only by reasonably taking the value of the sampling resistor, the moment output voltage of all load types is controlled to be in a linear region, so that the aim of accurate detection can be achieved.

Then, the weak current signal HALL+ output by the current transformer is sampled by a 12-level stepping sampling resistor, and then a second voltage signal is output by proportional amplification of the operational amplifier U4B; the output voltage signal of U9 and the output signal of U4B are multiplied by U4A, and then signals related to power are output; the power signal forms a three-stage proportional-integral amplifying circuit through U5A, U B and U8A, the power signal is further conditioned to a proper value range to output analog quantity, and the output analog quantity represents a moment value ZJ_CL of the motor in the anticlockwise direction; the power signal passes through U5A, U5B and U8B to form a three-stage proportional-integral amplifying circuit, the power signal is further conditioned to a proper value range to output analog quantity, and the output analog quantity represents a moment value ZJ_OP of the motor in the clockwise direction.

In the specific application of the actuator, the detection circuit can be used as a detection circuit of the maximum protection value of the motor load moment. But also in other devices as a measurement application of load power. Engineering practice proves that the circuit has good linearity and accuracy, and is convenient for operators to use and high in efficiency.

The above examples are merely illustrative of the preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model, and various modifications and improvements made by those skilled in the art to the technical solution of the present utility model should fall within the scope of protection defined by the claims of the present utility model without departing from the spirit of the present utility model.

Claims

1. The stepped current analog moment detection circuit is characterized by comprising a weak current signal output circuit, a voltage signal output circuit, a comparison circuit, a stepped weak current signal acquisition circuit, a power signal output circuit and an integral amplification circuit, wherein the weak current signal output circuit converts input three-phase electricity into a first weak current signal, the stepped weak current signal acquisition circuit acquires a second weak current signal in a stepped manner, converts the second weak current signal into a second voltage signal and amplifies the second voltage signal to output the second voltage signal to the power signal output circuit, the voltage signal output circuit converts the first weak current signal into a first voltage signal and amplifies the first voltage signal to output the first voltage signal to the comparison circuit, and the comparison circuit compares the first voltage signal with an applied standard voltage and outputs a result; the power signal output circuit multiplies the signal output by the comparison circuit and the second voltage signal to output a power signal, and the integration amplifying circuit amplifies the power signal and outputs analog quantities respectively.

2. The stepping current analog quantity moment detection circuit according to claim 1, wherein the stepping weak current signal acquisition circuit comprises an interface JN2, an operational amplifier U4B, a dial switch JN4 and JN5, the interface JN2 is externally connected with a current transformer, the 2 pin is grounded, the 1 pin outputs a weak current signal hall+ and is grounded through a diode D3, the 1 pin is respectively input into the dial switch JN4, JN5 and 6 pins of the input U4B through a resistor R3, the 2,4, 6, 8, 10, 12 pins of the JN4, the 2,4, 6, 8, 10, 12 pins of the JN5 are all connected in parallel and are connected with each other through a resistor R101, the 3 pin is grounded through a resistor R102, the 5 pin is grounded through a resistor R103, the 7 pin is grounded through a resistor R104, the 9 pin is grounded through a resistor R106, the 11 pin is grounded through a resistor R5, the 1 pin is grounded through a resistor R3, the resistor R108, the 2 pin is grounded through a resistor R7, the 7 pin is grounded through a resistor R7, the resistor R11, and the resistor 11 pin is grounded through a resistor 11, the resistor 11, and the resistor 11 is connected in parallel to each other, and the 2,4, the 1 pins of the resistor 12 pin, the resistor 11, and the pin 12 pin, and the resistor 11 are grounded through the resistor 11 are connected in parallel.

3. The stepped current analog quantity moment detection circuit according to claim 2, wherein the weak current signal output circuit comprises a current type voltage transformer U10 and an interface JN3, the interface JN3 is externally connected with a three-Phase power supply and outputs Phase-U, phase-W and Phase-V, pins 1 and 2 of the U10 are respectively input with three-Phase power, the pin 1 is connected with the Phase-U through series resistors R51 and R52, the pin 2 is connected with the Phase-W through series resistors R55 and R56, the pin 3 is grounded, and the pin 4 is output with the first weak current signal CT.

4. The stepped current analog quantity moment detection circuit according to claim 3, wherein the voltage signal output circuit comprises an operational amplifier U7A, 3 pins of the operational amplifier U7A are grounded, 2 pins are connected with CT,1 pin outputs a first voltage signal and is connected with the comparison circuit, 4 pins are respectively connected with-5 VA and grounded through a capacitor C30, 8 pins are respectively connected with +5va and grounded through a capacitor C31, and a capacitor C29 and a resistor R24 which are connected in series with each other are connected in parallel between 1 pin and 2 pin.

5. The stepped current analog quantity moment detection circuit according to claim 4, wherein the comparison circuit comprises an operational amplifier U6A, pin 1 of the U6A is respectively connected with a multiplexer U9 and +5va through a resistor R27, pin 2 is connected with a triangle wave generation circuit through a resistor R25, pin 3 is respectively connected with-5 VA and grounded through a capacitor C33, pin 8 is respectively connected with +5va and grounded through a capacitor C32, pins 1, 4, 8 and 11 of the multiplexer U9 are all grounded, pin 7 is connected with +5va and grounded through a capacitor C34, pins 5, 6, 12 and 13 are connected in parallel and connected with pin 1 of the U6A, and pins 2, 3, 9 and 10 are connected with signals to the power signal output circuit.

6. The stepping current analog quantity moment detection circuit according to claim 5, wherein the triangular wave generation circuit comprises operational amplifiers U6B and U7B, pin 6 of U6B is grounded through a resistor R28, resistors R29 and R30 are connected in parallel on pin 7, and a resistor R31 is connected between pin 5 and resistor R30 in parallel through a resistor R29;

7. The stepped current analog quantity torque detection circuit according to claim 6, wherein the power signal output circuit comprises an operational amplifier U4A, a capacitor C16 is connected in parallel between pins 1 and 2 of U4A, and pin 1 outputs a power signal to the integrating amplifying circuit, pin 2 is connected with I-W through a resistor R7, pin 3 is connected with I-W through a resistor R5 and a multiplexer U9, pin 4 is connected with-5 VA and is grounded through a capacitor C15, and pin 8 is connected with +5va and is grounded through a capacitor C14.

8. The stepped current analog quantity moment detection circuit according to claim 7, wherein the integrating amplifying circuit comprises operational amplifiers U5A, U5B, U a and U8B, pin 1 of U5A is connected to pin 6 of U5B through resistor R13, parallel capacitor C21 is connected between pin 2 and pin 1, pin 3 is connected to ground through capacitor C18 and pin 1 of U4A through resistors R9 and R10 connected in series, pin 4 is connected to-5 VA and to ground through capacitor C20, and pin 8 is connected to +5va and to ground through capacitor C19, respectively;

9. The stepped-current analog quantity torque detection circuit according to claim 8, wherein the detection circuit further comprises a power supply circuit that converts an input power supply voltage into a power supply voltage to power each circuit; the power supply circuit comprises an interface JN1, a rectifier bridge U3, a first voltage stabilizer U2 and a second voltage stabilizer U1, wherein the interface JN1 is externally connected with power supply voltage and load, pins 1-3 of the JNI are respectively input into AV_1, AV_2 and DV_B1+, pins 4 are grounded, and pins 5 and 6 respectively output analog quantities ZJ_OP and ZJ_CL;