Broadband signal detection circuit

By designing a broadband signal detection circuit including multiple signal processing circuits, the phase delay problem of sampled signals relative to input signals in wide frequency AC power supply in the prior art is solved, and high-precision AC voltage sampling and real-time functional control are realized sex.

CN119395350APending Publication Date: 2025-02-07SICHUAN GANHUA POWER TECH CO LTD
View PDF 0 Cites 0 Cited by

Patent Information

Application Number
CN202411588187.1
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2024-11-08
Publication Date
2025-02-07

AI Technical Summary

Technical Problem

The existing AC voltage detection circuit has phase delay of the sampled signal relative to the input signal in a wide frequency AC power supply, resulting in the problem of reducing sampling accuracy and real-time functional control.

Method used

A broadband signal detection circuit is designed, including a broadband signal voltage divider circuit, a peak detection circuit, a signal peak holding circuit, a sampling signal power amplifier circuit, a valley detection circuit, a periodic refresh circuit, a peak point detection circuit and a sampling signal error The refresh circuit eliminates the delay of the sampling signal relative to the input voltage by periodically detecting the change of the wide frequency AC input voltage.

Benefits of technology

Achieve high-precision AC voltage sampling, eliminates sampling errors caused by Y capacitors and temperature changes, avoids the use of high-voltage filter capacitors, improves the reliability of the circuit, and realizes AC input surge voltage suppression and surge current Precise control of suppression and voltage over-undervoltage protection.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN119395350A_ABST
    Figure CN119395350A_ABST
Patent Text Reader

Abstract

The invention provides a broadband signal detection circuit. The broadband signal detection circuit comprises a broadband signal voltage division circuit, a broadband signal peak detection circuit, a signal peak holding circuit and a sampling signal power amplification circuit which are connected in sequence, the broadband signal valley point detection circuit, the detection signal cycle-by-cycle refresh circuit, the broadband signal over-peak point detection circuit and the sampling signal error refresh circuit are connected in sequence; the input end of the broadband signal voltage division circuit is connected with a broadband alternating current power supply, and the output end of the broadband signal voltage division circuit is also connected to the input end of the broadband signal valley point detection circuit; the output end of the broadband signal peak detection circuit is connected with the output end of the detection signal cycle-by-cycle refresh circuit; the output end of the sampling signal error refresh circuit is connected with the input end of the sampling signal power amplification circuit; the output end of the sampling signal power amplification circuit is an AC voltage sampling signal output end. The detection circuit is high in voltage sampling precision and high in response speed.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] The present invention mainly relates to the technical field of signal detection, and in particular to a broadband signal detection circuit. Background Art

[0002] Broadband signals are ubiquitous in various energy supply and function control applications. The detection accuracy and speed of their signal amplitude directly affect the accuracy and timeliness of product function control, especially in AC power supply applications. AC voltage sampling is an indispensable circuit in power supply voltage detection and control.

[0003] There are many ways to detect AC voltage in existing circuits. One is to first use diode rectification, capacitor filtering, and then use resistor voltage division to obtain the required AC voltage sampling signal; the other is to first use resistor voltage division, then use diode rectification, capacitor filtering to obtain the required AC voltage sampling signal. Figure 1 As shown, it adopts deformed differential sampling to obtain the required AC voltage sampling signal.

[0004] Figure 1 The circuit adopts a deformed differential AC voltage sampling circuit, which solves the influence of line Y capacitance on AC voltage sampling accuracy and the influence of working temperature change on AC voltage sampling accuracy, and avoids the defects of high-voltage filter capacitors in the sampling circuit. However, there is a contradiction between the voltage ripple coefficient of the sampling output and the real-time performance of the sampling signal, that is, to reduce the voltage ripple coefficient of the sampling output, the sampling signal energy storage filter time constant must be increased, and increasing the sampling signal energy storage filter time constant will cause a phase delay of the sampling signal relative to the input signal, which ultimately affects the signal sampling accuracy and the real-time performance of the function control, resulting in problems such as the discreteness of the AC input voltage over-voltage and under-voltage protection points and the control delay of the AC surge voltage and current suppression circuit.

[0005] Figure 2 Simulation Figure 1 The deformed differential AC voltage sampling circuit is affected by the transient input voltage. It is not difficult to find that in order to reduce the AC ripple of the AC voltage sampling signal, the RC filter time constant at the output end of the sampling signal must be increased. Increasing the filter parameter time constant will naturally affect the speed of AC voltage sampling, especially in the wide frequency AC voltage detection circuit. The same filter time constant will lead to a serious lag problem between the voltage sampling signal and the input AC voltage. Figure 2The input voltage V(IN+, IN-) is a normal 115V (phase voltage) in the first 10 cycles. In the 11th cycle, the input voltage V(IN+, IN-) suddenly changes to 165V (phase voltage). In the 31st cycle, the input voltage V(IN+, IN-) suddenly changes to a normal 115V (phase voltage). The data shows that the rise of the input voltage V(IN+, IN-) has basically no lag effect on the sampling voltage V(vin_sen), while the decrease of the input voltage V(IN+, IN-) has a serious lag effect on the sampling voltage V(vin_sen). The sampling voltage V(vin_sen) lags behind the input voltage by about 24 cycles and 59.75ms. Figure 1 In the operation of frequency transient and wide frequency AC power input, the surge voltage suppression function, surge current suppression function, input voltage overvoltage protection function and input voltage undervoltage protection function of the conventional deformed differential AC voltage detection circuit shown will fail to varying degrees.

[0006] It can be seen that the existing AC voltage detection circuits have technical problems such as the insertion of Y capacitors and temperature changes affecting the sampling accuracy error due to their respective circuit characteristics, and serious phase lag between the AC voltage sampling signal and the input AC voltage during wide-frequency AC power supply operation, which ultimately causes varying degrees of failure of the input voltage over- and under-voltage protection function and the surge voltage and current suppression function. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a broadband signal detection circuit with high sampling accuracy and fast response speed.

[0008] In order to solve the above technical problems, the present invention provides a broadband signal detection circuit, comprising: a broadband signal voltage divider circuit, a broadband signal peak detection circuit, a signal peak holding circuit, and a sampling signal power amplifier circuit connected in sequence; a broadband signal valley point detection circuit, a detection signal cycle-by-cycle refresh circuit, a broadband signal peak point detection circuit, and a sampling signal error refresh circuit connected in sequence; and the input end of the broadband signal voltage divider circuit is connected to a broadband AC power supply, and the output end of the broadband signal voltage divider circuit is also connected to the input end of the broadband signal valley point detection circuit; the output end of the broadband signal peak detection circuit is connected to the output end of the detection signal cycle-by-cycle refresh circuit; the output end of the sampling signal error refresh circuit is connected to the input end of the sampling signal power amplifier circuit; the output end of the sampling signal power amplifier circuit is an AC voltage sampling signal output end.

[0009] Furthermore, it includes: a series branch consisting of a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R10, a resistor R9, a resistor R8, a resistor R7 and a resistor R6, one end of the resistor R1 is connected to the broadband signal input terminal L-IN, the resistor R5 and the resistor R10 are grounded, one end of the resistor R6 is connected to the broadband signal input terminal N-IN, and the resistor R4 and the resistor R5 are connected to a broadband signal peak detection circuit.

[0010] Furthermore, it includes: a capacitor C1 and a capacitor C2, the capacitor C1 is connected in parallel with the resistor R5, and the capacitor C2 is connected in parallel with the resistor R10.

[0011] Further, it includes: an operational amplifier U1-A and an operational amplifier U1-B, a series branch consisting of a resistor R11, a resistor R17 and a resistor R18, one end of the resistor R11 is connected to the in-phase input end of the transport amplifier U1-A, and the end of the resistor R11 connected to the resistor R17 is connected between the resistor R4 and the resistor R5; one end of the resistor R18 is connected to the cathode of the diode D1, and the anode of the diode D1 is connected to the output end of the transport amplifier U1-A; and it also includes a resistor R16, a resistor R17 and a series branch consisting of a resistor R18, a resistor R19 and a resistor R20. 5. A series branch of resistors R13, R14 and R19, wherein the inverting input terminal of the transport amplifier U1-A is connected between the resistors R14 and R13, the non-inverting input terminal of the operational amplifier U1-B is connected between the resistors R15 and R16, the reverse input terminal of the operational amplifier U1-B is connected between the resistors R17 and R18, the output terminal of the operational amplifier U1-B is connected to the anode of the diode D2, and the cathode of the diode D2 is connected to the cathode of the diode D1.

[0012] Furthermore, it includes: an operational amplifier U2-A, wherein the non-inverting input terminal of the operational amplifier U2-A is connected to one end of the resistor R19, the inverting input terminal of the operational amplifier U2-A is grounded, and the output terminal of the operational amplifier U2-A is connected to the positive electrode of the diode D3.

[0013] Furthermore, it includes: an operational amplifier U2-B, the non-inverting input terminal of the operational amplifier U2-B is connected to the cathode of the diode D3, the inverting input terminal of the operational amplifier U2-B is connected to the sampling signal error refresh circuit, and the output terminal of the operational amplifier U2-A is the AC voltage sampling signal output terminal.

[0014] Further, it includes: an operational amplifier U3-A and an operational amplifier U3-B, a series branch consisting of a resistor R20, a resistor R24, a resistor R25, a resistor R23, a resistor R21 and a resistor R22; the inverting input terminal of the operational amplifier U3-A is connected to one end of the resistor R20, and the non-inverting input terminal of the operational amplifier U3-A is connected to between the resistor R21 and the resistor R23; the inverting input terminal of the operational amplifier U3-B is connected to one end of the resistor R22, the non-inverting input terminal of the operational amplifier U3-B is connected between the resistor R24 ​​and the resistor R25, and the output terminal of the operational amplifier U3-B is connected to the output terminal of the operational amplifier U3-A and to one end of the resistor R26.

[0015] Further, it includes: a transistor Q1-A, the base of which is connected to the output end of the operational amplifier U3-B through a resistor R27; the emitter of the transistor Q1-A is grounded, and the collector of the transistor Q1-A is connected to the broadband signal peak point detection circuit.

[0016] Furthermore, it includes: an operational amplifier U4-A, a parallel branch composed of a resistor R29 and a diode D4, one end of the parallel branch is connected to the collector of the transistor Q1-A, and the other end is connected to the in-phase input terminal of the operational amplifier U4-A, and the inverting input terminal of the operational amplifier U4-A is connected between the series branch composed of the resistor R30 and the resistor R31.

[0017] Further, it includes: an operational amplifier U4-B, a series branch consisting of resistors R32, R33 and R34, and a series branch consisting of resistors R35, R36, R38 and R39, one end of the resistor R34 is grounded, one end of the resistor R32 is connected to the collector of the transistor Q1-A through the resistor R28, the inverting input of the operational amplifier U4-B is connected between the resistor R32 and the resistor R36, the non-inverting input of the operational amplifier U4-B is connected between the resistor R35 and the resistor R36, the output of the operational amplifier U4-B is connected between the resistor R37 and the resistor R38, and is also connected to the base of the transistor Q1-B, the emitter of the transistor Q1-B is grounded, and the collector of the transistor Q1-B is connected to the non-inverting input of the operational amplifier U2-B.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1) It eliminates the sampling error caused by the insertion of the Y capacitor in the circuit, eliminates the influence of temperature on the sampling accuracy of the AC voltage, avoids the use of high-voltage rectifier devices and high-voltage filter capacitors, and improves the circuit reliability; 2) By detecting the change of the wide-frequency AC input voltage cycle by cycle, the delay of the sampling signal relative to the input voltage change is eliminated, and precise control of the functions such as AC input surge voltage suppression, AC input surge current suppression, and AC input voltage over- and under-voltage protection is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated into and constitute a part of the present invention. The accompanying drawings illustrate embodiments of the present invention and together with the specification serve to explain the principles of the present invention. In the accompanying drawings:

[0020] Figure 1 The present invention is a circuit schematic diagram of an existing AC voltage detection circuit;

[0021] Figure 2 yes Figure 1 Input voltage transient simulation diagram of the circuit shown;

[0022] Figure 3 is a circuit block diagram of a broadband signal detection circuit according to an embodiment of the present invention;

[0023] Figure 4 is a circuit schematic diagram of a broadband signal detection circuit according to an embodiment of the present invention;

[0024] Figure 5 It is a simulation diagram of input voltage transient of a broadband signal detection circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present invention. For ordinary technicians in this field, the present invention can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0026] It should be understood that when a component is referred to as being "on another component," "connected to another component," "coupled to another component," or "contacting another component," it may be directly on, connected to, coupled to, or contacting the other component, or there may be intervening components. In contrast, when a component is referred to as being "directly on another component," "directly connected to," "directly coupled to," or "directly contacting" another component, there are no intervening components. Similarly, when a first component is referred to as being "electrically in contact with" or "electrically coupled to" a second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even without direct contact between conductive components.

[0027] refer to Figure 3 and Figure 4 As shown, the broadband signal detection circuit of this embodiment includes a broadband signal voltage divider circuit 110, a broadband signal peak detection circuit 120, a signal peak holding circuit 130, a sampling signal power amplifier circuit 140, a broadband signal valley point detection circuit 150, a detection signal cycle-by-cycle refresh circuit 160, a broadband signal peak point detection circuit 170, and a sampling signal error refresh circuit 180.

[0028] Among them, the input end of the broadband signal voltage divider circuit 110 is connected to the AC power supply, the output end of the broadband signal voltage divider circuit 110 is connected to the input end of the broadband signal peak detection circuit 120, the output end of the broadband signal peak detection circuit 120 is connected to the input end of the signal peak holding circuit 130, the output end of the signal peak holding circuit 130 is connected to the input end of the sampling signal power amplifier circuit 140, and the output end of the sampling signal power amplifier circuit 140 outputs a smooth AC voltage sampling signal. The output end of the broadband signal voltage divider circuit 110 is also connected to the input end of the broadband signal valley point detection circuit 150, the output end of the broadband signal valley point detection circuit 150 is connected to the input end of the detection signal cycle-by-cycle refresh circuit 160, the output end of the detection signal cycle-by-cycle refresh circuit 160 is respectively connected to the input end of the signal peak holding circuit 130 and the input end of the broadband signal peak point detection circuit 170, the output end of the broadband signal peak point detection circuit 170 is connected to the input end of the sampling signal error refresh circuit 180, the output end of the sampling signal error refresh circuit 180 is connected to the input end of the sampling signal power amplifier circuit 140, and the output end of the sampling signal power amplifier circuit 140 outputs a smooth AC voltage sampling signal.

[0029] The broadband signal voltage divider circuit 110 may be composed of a resistor network or a resistor and capacitor network, and divides the AC power supply into a required signal voltage amplitude through the resistor network and transmits it to the broadband signal peak detection circuit 120 at the subsequent stage.

[0030] For example, the broadband signal voltage divider circuit 110 includes a series branch consisting of a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R10, a resistor R9, a resistor R8, a resistor R7 and a resistor R6, one end of the resistor R1 is connected to the broadband signal input terminal L-IN, the resistor R5 and the resistor R10 are grounded, one end of the resistor R6 is connected to the broadband signal input terminal N-IN, and the resistor R4 and the resistor R5 are connected to the broadband signal peak detection circuit.

[0031] More optimally, the broadband signal voltage divider circuit 110 further includes a capacitor C1 and a capacitor C2 . The capacitor C1 is connected in parallel with the resistor R5 , and the capacitor C2 is connected in parallel with the resistor R10 .

[0032] The broadband signal peak detection circuit 120 can be composed of an operational amplifier, a resistor, a capacitor, and a semiconductor device with a unidirectional conduction characteristic. The signal voltage obtained by the resistor network of the broadband signal voltage divider circuit 110 is rectified and impedance transformed by resistors, capacitors, an operational amplifier, and a semiconductor device with a unidirectional conduction characteristic to obtain a low-impedance AC positive and negative half-wave unipolar signal pulsating voltage, which is transmitted to the subsequent signal peak holding circuit 130.

[0033] For example, the broadband signal peak detection circuit 120 includes an operational amplifier U1-A and an operational amplifier U1-B, and a series branch consisting of a resistor R11, a resistor R17 and a resistor R18, one end of the resistor R11 is connected to the in-phase input terminal of the transport amplifier U1-A, and the end of the resistor R11 connected to the resistor R17 is connected between the resistor R4 and the resistor R5; one end of the resistor R18 is connected to the cathode of the diode D1, and the anode of the diode D1 is connected to the output terminal of the transport amplifier U1-A.

[0034] The broadband signal peak detection circuit 120 also includes a series branch consisting of a resistor R16, a resistor R15, a resistor R13, a resistor R14 and a resistor R19 in sequence, the inverting input terminal of the transport amplifier U1-A is connected between the resistor R14 and the resistor R13, the non-inverting input terminal of the operational amplifier U1-B is connected between the resistor R15 and the resistor R16, the reverse input terminal of the operational amplifier U1-B is connected between the resistor R17 and the resistor R18, the output terminal of the operational amplifier U1-B is connected to the positive electrode of the diode D2, and the negative electrode of the diode D2 is connected to the negative electrode of the diode D1.

[0035] The signal peak holding circuit 130 can be composed of an operational amplifier, a capacitor, and a semiconductor device with a unidirectional conduction characteristic. The broadband signal peak detection circuit 120 obtains a low-impedance AC positive and negative half-wave unipolar signal pulsating voltage through rectification and impedance transformation of resistors and capacitors, an operational amplifier, and a semiconductor device with a unidirectional conduction characteristic, performs sampling signal energy storage filtering, and transmits it to the sampling signal power amplifier circuit 140.

[0036] For example, the signal peak holding circuit 130 includes an operational amplifier U2-A, the non-inverting input terminal of the operational amplifier U2-A is connected to one end of the resistor R19, the inverting input terminal of the operational amplifier U2-A is grounded, and the output terminal of the operational amplifier U2-A is connected to the anode of the diode D3.

[0037] The sampling signal power amplifier circuit 140 may be composed of an operational amplifier or other semiconductor devices with current amplification characteristics, and the sampling signal after energy storage filtering of the signal peak holding circuit 130 is power amplified to obtain a smooth DC signal with good linearity corresponding to the AC voltage amplitude.

[0038] For example, the sampling signal power amplifier circuit 140 includes an operational amplifier U2-B, the non-inverting input terminal of the operational amplifier U2-B is connected to the cathode of the diode D3, the inverting input terminal of the operational amplifier U2-B is connected to the sampling signal error refresh circuit, and the output terminal of the operational amplifier U2-A is the AC voltage sampling signal output terminal.

[0039] The broadband signal valley point detection circuit 150 may be composed of a comparator or an operational amplifier and a resistor and capacitor. The signal voltage obtained by dividing the AC power supply through a resistor network is subjected to differential comparison to obtain a cycle-by-cycle AC zero-crossing pulse signal, which is then transmitted to the detection signal cycle-by-cycle refresh circuit 160.

[0040] For example, the broadband signal valley point detection circuit includes an operational amplifier U3-A and an operational amplifier U3-B, and a series branch consisting of a resistor R20, a resistor R24, a resistor R25, a resistor R23, a resistor R21 and a resistor R22; the inverting input terminal of the operational amplifier U3-A is connected to one end of the resistor R20, and the non-inverting input terminal of the operational amplifier U3-A is connected between the resistor R21 and the resistor R23; the inverting input terminal of the operational amplifier U3-B is connected to one end of the resistor R22, and the non-inverting input terminal of the operational amplifier U3-B is connected between the resistor R24 ​​and the resistor R25, and the output terminal of the operational amplifier U3-B is connected to the output terminal of the operational amplifier U3-A and to one end of the resistor R26.

[0041] The detection signal cycle-by-cycle refresh circuit 160 can be composed of a transistor or an operational amplifier or a comparator and a resistor, and converts the cycle-by-cycle AC zero-crossing pulse signal generated by the voltage valley point detection circuit 150 into a cycle-by-cycle AC zero-crossing discharge signal, and transmits it to the input end of the signal peak holding circuit 130, so as to realize the cycle-by-cycle refresh of the AC voltage sampling signal and eliminate the delay problem of the sampling signal voltage. At the same time, the voltage sampling signal refreshed cycle by cycle is also transmitted to the broadband signal peak point detection circuit 170.

[0042] For example, the detection signal cycle-by-cycle refresh circuit 160 includes a transistor Q1-A, the base of which is connected to the output end of the operational amplifier U3-B through a resistor R27; the emitter of the transistor Q1-A is grounded, and the collector of the transistor Q1-A is connected to a broadband signal peak point detection circuit.

[0043] The broadband signal peak point detection circuit 170 can be composed of a transistor or an operational amplifier or a comparator and a resistor and capacitor. The voltage sampling signal refreshed cycle by cycle by the detection signal cycle-by-cycle refresh circuit 160 is subjected to hysteresis comparison to obtain an AC voltage peak point square wave pulse signal which is transmitted to the sampling signal error refresh circuit 180 as a timing control signal for refreshing the sampling signal cycle by cycle error.

[0044] For example, the broadband signal peak point detection circuit 170 includes an operational amplifier U4-A, a parallel branch consisting of a resistor R29 and a diode D4, one end of the parallel branch is connected to the collector of the transistor Q1-A, and the other end is connected to the non-inverting input terminal of the operational amplifier U4-A, and the reverse phase input terminal of the operational amplifier U4-A is connected between the series branches consisting of resistors R30 and R31.

[0045] The signal error refresh circuit 180 can be composed of a comparator or an operational amplifier, a transistor, and a resistor and capacitor. Under the action of the timing control signal of the cycle-by-cycle error refresh generated by the broadband signal peak point detection circuit 170, it detects the error between the sampled output signal and the actual AC voltage signal, and outputs the error constant current discharge signal in time at the moment when the AC signal crosses the peak point, and transmits it to the signal peak holding circuit 130, so that the energy storage capacitor of the holding circuit is discharged at a constant current, so as to achieve the purpose of refreshing the AC voltage detection signal cycle by cycle.

[0046] For example, the signal error refresh circuit 180 includes an operational amplifier U4-B, a series branch consisting of resistors R32, R33 and R34, a series branch consisting of resistors R35, R36, R38 and R39, one end of resistor R34 is grounded, one end of resistor R32 is connected to the collector of transistor Q1-A through resistor R28, the inverting input of the operational amplifier U4-B is connected between resistor R32 and resistor R36, the non-inverting input of the operational amplifier U4-B is connected between resistor R35 and resistor R36, the output of the operational amplifier U4-B is connected between resistor R37 and resistor R38, and is also connected to the base of transistor Q1-B, the emitter of transistor Q1-B is grounded, and the collector of transistor Q1-B is connected to the non-inverting input of the operational amplifier U2-B.

[0047] Figure 5 is a simulation diagram of input voltage transient of a broadband signal detection circuit according to an embodiment of the present invention, referring to Figure 5 It can be seen that the broadband signal detection circuit of this embodiment has the following advantages: 1) It eliminates the sampling error caused by the insertion of the Y capacitor in the line, eliminates the influence of temperature on the sampling accuracy of the AC voltage, avoids the use of high-voltage rectifier devices and high-voltage filter capacitors, and improves the circuit reliability; 2) By detecting the changes in the wide-frequency AC input voltage cycle by cycle, the delay of the sampling signal relative to the input voltage change is eliminated, and precise control of functions such as AC input surge voltage suppression, AC input surge current suppression, and AC input voltage over- and under-voltage protection is achieved.

[0048] For those skilled in the art, the above invention disclosure is only for example and does not constitute a limitation of the present invention. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and corrections to the present invention. Such modifications, improvements and corrections are suggested in the present invention, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of the present invention.

[0049] Although the present invention has been described with reference to the current specific embodiments, those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and various equivalent changes or substitutions may be made without departing from the spirit of the present invention. Therefore, any changes or modifications to the above embodiments within the spirit of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A broadband signal detection circuit, characterized in that: include: A broadband signal voltage divider circuit, a broadband signal peak detection circuit, a signal peak holding circuit, and a sampling signal power amplifier circuit are connected in sequence; a broadband signal valley point detection circuit, a detection signal cycle-by-cycle refresh circuit, a broadband signal peak point detection circuit, and a sampling signal error refresh circuit are connected in sequence, and The input end of the broadband signal voltage divider circuit is connected to a broadband AC power supply, and the output end of the broadband signal voltage divider circuit is also connected to the input end of the broadband signal valley point detection circuit; the output end of the broadband signal peak detection circuit is connected to the output end of the detection signal cycle-by-cycle refresh circuit; the output end of the sampling signal error refresh circuit is connected to the input end of the sampling signal power amplifier circuit; the output end of the sampling signal power amplifier circuit is an AC voltage sampling signal output end.

2. The broadband signal detection circuit according to claim 1, characterized in that: include: A series branch is formed by resistors R1, R2, R3, R4, R5, R10, R9, R8, R7 and R6, one end of the resistor R1 is connected to the broadband signal input terminal L-IN, the resistor R5 and the resistor R10 are grounded, one end of the resistor R6 is connected to the broadband signal input terminal N-IN, and the resistor R4 and the resistor R5 are connected to the broadband signal peak detection circuit.

3. The broadband signal detection circuit as claimed in claim 2, characterized in that: include: Capacitor C1 and capacitor C2, the capacitor C1 is connected in parallel with the resistor R5, and the capacitor C2 is connected in parallel with the resistor R10.

4. The broadband signal detection circuit according to claim 1, wherein: include: An operational amplifier U1-A and an operational amplifier U1-B, a series branch consisting of a resistor R11, a resistor R17 and a resistor R18, one end of the resistor R11 is connected to the non-inverting input end of the transport amplifier U1-A, and the end of the resistor R11 connected to the resistor R17 is connected between the resistor R4 and the resistor R5; one end of the resistor R18 is connected to the cathode of the diode D1, and the anode of the diode D1 is connected to the output end of the transport amplifier U1-A; It also includes a series branch consisting of a resistor R16, a resistor R15, a resistor R13, a resistor R14 and a resistor R19 in sequence, the inverting input terminal of the transport amplifier U1-A is connected between the resistor R14 and the resistor R13, the non-inverting input terminal of the operational amplifier U1-B is connected between the resistor R15 and the resistor R16, the reverse input terminal of the operational amplifier U1-B is connected between the resistor R17 and the resistor R18, the output terminal of the operational amplifier U1-B is connected to the positive electrode of the diode D2, and the negative electrode of the diode D2 is connected to the negative electrode of the diode D1.

5. The broadband signal detection circuit as claimed in claim 1, characterized in that: include: Operational amplifier U2-A, the non-inverting input terminal of the operational amplifier U2-A is connected to one end of the resistor R19, the inverting input terminal of the operational amplifier U2-A is grounded, and the output terminal of the operational amplifier U2-A is connected to the positive electrode of the diode D3.

6. The broadband signal detection circuit as claimed in claim 1, characterized in that: include: Operational amplifier U2-B, the non-inverting input terminal of the operational amplifier U2-B is connected to the cathode of the diode D3, the inverting input terminal of the operational amplifier U2-B is connected to the sampling signal error refresh circuit, and the output terminal of the operational amplifier U2-A is the AC voltage sampling signal output terminal.

7. The broadband signal detection circuit as claimed in claim 1, characterized in that: include: The operational amplifier U3-A and the operational amplifier U3-B are a series branch consisting of a resistor R20, a resistor R24, a resistor R25, a resistor R23, a resistor R21 and a resistor R22; the inverting input terminal of the operational amplifier U3-A is connected to one end of the resistor R20, and the non-inverting input terminal of the operational amplifier U3-A is connected between the resistor R21 and the resistor R23; the inverting input terminal of the operational amplifier U3-B is connected to one end of the resistor R22, and the non-inverting input terminal of the operational amplifier U3-B is connected between the resistor R24 ​​and the resistor R25, and the output terminal of the operational amplifier U3-B is connected to the output terminal of the operational amplifier U3-A and to one end of the resistor R26.

8. The broadband signal detection circuit as claimed in claim 1, characterized in that: include: Transistor Q1-A, the base of the transistor Q1-A is connected to the output end of the operational amplifier U3-B through a resistor R27; the emitter of the transistor Q1-A is grounded, and the collector of the transistor Q1-A is connected to the broadband signal peak point detection circuit.

9. The broadband signal detection circuit according to claim 1, wherein: include: An operational amplifier U4-A, a parallel branch consisting of a resistor R29 and a diode D4, one end of the parallel branch is connected to the collector of the transistor Q1-A, and the other end is connected to the in-phase input terminal of the operational amplifier U4-A, and the inverting input terminal of the operational amplifier U4-A is connected between the series branch consisting of the resistor R30 and the resistor R31.

10. The broadband signal detection circuit according to claim 1, wherein: include: An operational amplifier U4-B, a series branch consisting of resistors R32, R33 and R34, and a series branch consisting of resistors R35, R36, R38 and R39, one end of the resistor R34 is grounded, one end of the resistor R32 is connected to the collector of the transistor Q1-A through the resistor R28, the inverting input of the operational amplifier U4-B is connected between the resistor R32 and the resistor R36, the non-inverting input of the operational amplifier U4-B is connected between the resistor R35 and the resistor R36, the output of the operational amplifier U4-B is connected between the resistor R37 and the resistor R38, and is also connected to the base of the transistor Q1-B, the emitter of the transistor Q1-B is grounded, and the collector of the transistor Q1-B is connected to the non-inverting input of the operational amplifier U2-B.