Bidirectional signal detection circuit

Abstract

The utility model relates to the technical field of signal detection, in particular to a bidirectional signal detection circuit, which comprises a signal processing unit and a signal processing unit, comprising a bias assembly used for carrying out voltage division on a to-be-detected point corresponding to a to-be-detected circuit, a signal conversion assembly connected with the bias assembly and used for converting a current signal of the to-be-detected point into a voltage signal, and a signal amplification assembly used for amplifying the voltage signal to output a to-be-detected amplified voltage signal; the signal detection unit is used for detecting the voltage and the current of the point position to be detected; the power supply unit comprises a power supply, a power supply follower and a following capacitor; the power supply follower is connected with the power supply and isolates the power supply from a load to output constant voltage; and the following capacitor is connected with the power supply follower in parallel and is matched with the power supply follower to maintain the constant voltage by suppressing noise generated by the power supply follower. According to the utility model, detection of bidirectional signals is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to signal detection technical field especially relates to a kind of bidirectional signal detection circuit. BACKGROUND

[0002] In the prior art, the power supply for operational amplifier in the circuit for signal detection adopts positive and negative power supply (Power+, Power-), and after the signal is processed by operational amplifier, a signal conditioning circuit needs to be added to convert the negative signal into a positive signal, so that the MCU in the rear stage can sample it; the circuit is relatively complex, and requires positive and negative power supply; if the signal to be processed needs to be sampled, another signal conditioning circuit is also needed to convert the negative signal into a positive signal, because the MCU can generally only sample signals higher than the ground level.

[0003] Chinese patent publication No. CN221686493U discloses a kind of anti-interference current signal detection amplification circuit, including first operational amplifier, second operational amplifier, compensation circuit, small diode group and magnetic bead, the positive input end of two operational amplifiers is connected, the reverse input end of two operational amplifiers is connected compensation circuit respectively, magnetic bead is connected to small diode group and compensation circuit, the positive input end of second operational amplifier is configured to be connected signal input end of rear end current signal detection circuit by resistance.Such, by setting magnetic bead, inhibit high-frequency noise and spike interference on signal line and power line, the current signal of power panel is amplified by two operational amplifiers and the signal clipping of small diode group, eliminate positive and negative peak values of signal, realize the effect of preventing high-frequency noise and spike interference on the current signal of power panel;Make the positive input end of two operational amplifiers be connected and the reverse input end of two be connected compensation circuit respectively, voltage division compensation, realize the amplification effect of the current signal of power panel.Obviously, the anti-interference current signal detection amplification circuit has the problem that due to the complexity of the circuit, positive and negative power supply is required, if the signal to be processed needs to be sampled, another signal conditioning circuit is also needed to convert the negative signal into a positive signal, and the MCU can generally only sample signals higher than the ground level, so it cannot realize the bidirectional detection of the signal by single power supply. UTILITY MODEL CONTENTS

[0004] Therefore, the utility model aims to provide a kind of bidirectional signal detection circuit and system to overcome the problem that due to the complexity of the circuit in the prior art, positive and negative power supply is required, if the signal to be processed needs to be sampled, another signal conditioning circuit is also needed to convert the negative signal into a positive signal, and the MCU can generally only sample signals higher than the ground level, so it cannot realize the bidirectional detection of the signal by single power supply.

[0005] To achieve the above-mentioned purpose, the utility model provides a kind of bidirectional signal detection circuit, comprising:

[0006] The signal processing unit comprises a biasing component for dividing voltage of the to-be-detected point corresponding to the to-be-detected circuit, a signal converting component connected to the biasing component for converting current signal of the to-be-detected point into voltage signal, and a signal amplifying component for amplifying the voltage signal to output a to-be-detected amplified voltage signal.

[0007] The signal detecting unit is connected to the signal processing unit for detecting voltage and current of the to-be-detected point.

[0008] The power supply unit is connected to the signal processing unit and the signal detecting unit respectively for supplying power to the signal processing unit, the signal detecting unit and the to-be-detected circuit respectively, and comprises a power supply, a power supply follower connected to the power supply for outputting constant voltage by isolating the power supply from the load, and a follow-up capacitor connected in parallel to the power supply follower for suppressing noise generated by the power supply follower to maintain the constant voltage with the power supply follower.

[0009] Further, the biasing component comprises:

[0010] A filter resistor connected to the power supply follower for providing a passing path of biasing current and limiting variation amplitude of the biasing current.

[0011] A first filter capacitor connected in parallel to the filter resistor for absorbing fluctuating voltage.

[0012] Further, the biasing component further comprises:

[0013] A second filter capacitor connected to the first filter capacitor for absorbing noise on ground wire.

[0014] A first analog grounding point connected to the second filter capacitor for isolating direct current component generated by the biasing component and removing high-frequency noise generated by the biasing component.

[0015] Further, the signal converting component comprises:

[0016] A signal sampling resistor for collecting terminal voltage of the to-be-detected point.

[0017] A first input resistor connected to the signal sampling resistor and arranged between a first output end of the to-be-detected point and the signal sampling resistor.

[0018] A second input resistor connected to the signal sampling resistor and arranged between the to-be-detected point and a second output end of the to-be-detected point.

[0019] The first input resistor and the second input resistor cooperate to adjust the voltage of the circuit to be detected to within the signal detection range.

[0020] Further, the signal amplification component comprises:

[0021] An operational amplifier connected to the first input resistor and the second input resistor respectively to differentially amplify the voltage signal between the points to be detected.

[0022] A feedback resistor arranged between the negative input terminal and the output terminal of the operational amplifier to determine the gain of the operational amplifier.

[0023] Further, the filter resistor and the feedback resistor have equal resistance values.

[0024] Further, the power supply unit comprises:

[0025] A power supply;

[0026] A power supply follower connected to the power supply to output a constant voltage by isolating the power supply from the load.

[0027] A follow-up capacitor connected in parallel to the power supply follower to cooperate with the power supply follower to maintain the constant voltage by suppressing the noise generated by the power supply follower.

[0028] Further, the signal detection unit comprises:

[0029] A voltage dividing protection resistor arranged at the output terminal of the operational amplifier to divide the output voltage of the operational amplifier.

[0030] A noise suppression component connected to the voltage dividing protection resistor to suppress the noise generated by the current fluctuation on the ground wire.

[0031] Further, the signal detection unit further comprises:

[0032] An AD converter connected to the voltage dividing protection resistor and the noise suppression component respectively to convert the analog signal to a digital signal.

[0033] A display component connected to the AD converter to display the digital signal.

[0034] Further, the noise suppression component comprises:

[0035] A noise suppression capacitor connected to the voltage dividing protection resistor to filter out the high-frequency noise or unwanted high-frequency components on the ground wire.

[0036] A second analog ground point in series with the noise rejection capacitor to isolate a digital ground point from an analog ground point.

[0037] Compared with the prior art, the utility model has the beneficial effects that the utility model discloses a signal detection unit, a signal processing unit and a power supply unit are arranged, specific biasing components and a signal processing circuit are arranged, the signal processed by the operational amplifier is always a positive signal, and the signal can be directly input into an MCU for sampling processing, the detection circuit structure of the prior art is complex, positive and negative power supplies are needed, and if the signal to be processed needs to be sampled, an additional signal conditioning circuit is needed to convert the negative signal into a positive signal, and therefore, the detection of the bidirectional signal is realized.

[0038] Further, the utility model discloses a first filter capacitor, a second filter capacitor and a first analog ground point are arranged, the noise of the biasing voltage of the biasing components is filtered out, the output of the operational amplifier is kept as a positive signal when the input signal is -I, the bidirectional signal detection is further realized, the signal noise is filtered out, and the precision of the biasing voltage is improved.

[0039] Further, the utility model discloses a power supply, a power supply follower and a following capacitor are arranged, the output value of the differential amplification circuit is kept as a positive value, the direction of the signal can be determined according to the output of the operational amplifier, and the conversion and detection of the bidirectional signal are realized. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 It is a whole circuit schematic view of the bidirectional signal detection circuit of the utility model embodiment.

[0041] Figure 2 It is a specific structure connection block diagram of the bidirectional signal detection circuit of the utility model embodiment. DETAILED DESCRIPTION

[0042] In order to make the purpose and the advantage of the utility model more clear and obvious, the utility model is further described below in combination with the embodiment, and it should be understood that the specific embodiment described here is only used for explaining the utility model, and is not used for limiting the utility model.

[0043] The preferred embodiments of the utility model are described below with reference to the drawings. Those skilled in the art should understand that these embodiments are only used for explaining the technical principles of the utility model, and are not used for limiting the protection scope of the utility model.

[0044] Please refer to Figure 1 , Figure 2 As shown in the figure, they are the utility model embodiment Figure 1The utility model discloses a whole circuit schematic diagram and specific structure connection block diagram of bidirectional signal detection circuit, and the utility model discloses a kind of bidirectional signal detection circuit, comprising

[0045] Signal processing unit, including the biasing component for the voltage division of the to-be-detected point corresponding to the to-be-detected circuit and the signal conversion component connected with the biasing component for converting the current signal of the to-be-detected point into voltage signal and the signal amplification component for amplifying the voltage signal to output the to-be-detected amplified voltage signal;

[0046] Signal detection unit, connected with the signal processing unit, for detecting the voltage and current of the to-be-detected point;

[0047] Power supply unit, connected with the signal processing unit and the signal detection unit respectively, for supplying power to the signal processing unit, the signal detection unit and the to-be-detected circuit respectively, comprising power supply, power supply follower connected with the power supply for outputting constant voltage by isolating power supply and load, and follow-up capacitor connected with the power supply follower in parallel for suppressing the noise generated by the power supply follower to maintain the constant voltage with the power supply follower.

[0048] Specifically, the to-be-detected point includes a first point and a second point, and the first point and the second point are respectively Figure 1 two input terminals of the operational amplifier.

[0049] Specifically, the positive input terminal of the power supply follower is connected to the VREF_ZERO terminal.

[0050] Specifically, the gain of the circuit is G=R56 / R54.

[0051] Specifically, the bias voltage of the operational amplifier input required by the circuit when VREF_ZERO is provided, and the bias voltage is preferably set to 1 / 2Power+, when the signal I / -I is zero, the output voltage of the pin 1 of the operational amplifier is VREF_ZERO; when the input signal I is input, the output of the differential circuit is VREF_ZERO+I*R55*G, and when the input signal is -I, the output of the differential circuit is VREF_ZERO-I*R55*G, the output control value of the differential amplification circuit is between 0 and Power+, the current input and output maintain a linear relationship, and subsequent sampling can confirm the direction of the signal by determining whether the output of the operational amplifier is greater than VREF_ZERO or less than VREF_ZERO, and the input signal can also be restored through the function expression Vout=VREF_ZERO±I*R55*G.

[0052] In the implementation, the utility model discloses a signal detection unit, signal processing unit and power supply unit are set up, through setting specific bias component and signal processing circuit, make the signal after the operation of handling is always positive signal, to be directly inputed to the sampling processing in the MCU, the detection circuit structure complex of prior art, need positive and negative power supply, if need to sample the signal of being handled, then need additional signal conditioning circuit to convert the negative signal into the positive signal problem, therefore, realize the detection of bidirectional signal.

[0053] Specifically, the bias component comprises:

[0054] Filtering resistance connected with the power follower, to provide a passageway for bias current, and limit the variation amplitude of the bias current;

[0055] First filtering capacitor connected with the filtering resistance in parallel, to absorb fluctuating voltage.

[0056] Specifically, the bias component further comprises:

[0057] Second filtering capacitor connected with the first filtering capacitor, to absorb noise on the ground wire;

[0058] First analog ground connected with the second filtering capacitor, to isolate the direct current component generated by the bias component, and remove the high-frequency noise generated by the bias component.

[0059] Specifically, the filtering resistance is R51, the first filtering capacitor is C31, and the second filtering capacitor is C30.

[0060] In the implementation, the utility model discloses a first filtering capacitor, second filtering capacitor and first analog ground are set up, through filtering the noise of the bias voltage of bias component, and realize the output of operational amplifier is positive signal when input signal is -I, further realize bidirectional signal detection, and filter the signal noise, improve the precision of bias voltage.

[0061] Specifically, the signal conversion component comprises:

[0062] Signal sampling resistance, to collect the terminal voltage of the detection point;

[0063] First input resistance connected with the signal sampling resistance, which is arranged between the first output end of the detection point and the signal sampling resistance;

[0064] Second input resistance connected with the signal sampling resistance, which is arranged between the detection point and the second output end of the detection point;

[0065] The first input resistor and the second input resistor cooperate to adjust the voltage of the circuit to be detected to within a signal detection range.

[0066] Specifically, the signal sampling resistor is R55, the first input resistor is R52, and the second input resistor is R54.

[0067] Specifically, the signal amplification component includes:

[0068] An operational amplifier is connected to the first input resistor and the second input resistor, respectively, to differentially amplify the voltage signal between the points to be detected.

[0069] A feedback resistor is arranged between the negative input terminal and the output terminal of the operational amplifier to determine the gain of the operational amplifier.

[0070] Specifically, the feedback resistor is R56.

[0071] Specifically, the filter resistor and the feedback resistor have equal resistance values.

[0072] Specifically, the power supply unit includes:

[0073] A power supply;

[0074] A power supply follower is connected to the power supply and outputs a constant voltage by isolating the power supply from the load.

[0075] A follow-up capacitor is connected in parallel to the power supply follower and cooperates with the power supply follower to maintain the constant voltage by suppressing the noise generated by the power supply follower.

[0076] Specifically, the follow-up capacitor is C32.

[0077] In implementation, the output value of the differential amplification circuit is maintained at a positive value by arranging the power supply, the power supply follower, and the follow-up capacitor, so that the direction of the signal can be determined according to the output of the operational amplifier, and the conversion and detection of the bidirectional signal are realized.

[0078] Specifically, the signal detection unit includes:

[0079] A voltage division protection resistor is arranged at the output terminal of the operational amplifier to divide the output voltage of the operational amplifier.

[0080] A noise suppression component is connected to the voltage division protection resistor to suppress the noise generated by the current fluctuation on the ground wire.

[0081] Specifically, the voltage division protection resistor is R53.

[0082] Specifically, the signal detection unit further comprises:

[0083] an AD converter connected with the voltage division protection resistor and the noise suppression component respectively, for converting the analog signal into a digital signal;

[0084] a display component connected with the AD converter, for displaying the digital signal.

[0085] Specifically, the AD converter and the display component constitute an MCU.

[0086] Those skilled in the art can understand that the type of the AD converter is not limited herein, as long as the function of converting the analog signal into the digital signal is met.

[0087] Specifically, the preferred embodiment of the display component is a liquid crystal display screen, and those skilled in the art can make adaptive replacement to the type of the display component according to the actual situation.

[0088] Specifically, the noise suppression component comprises:

[0089] a noise suppression capacitor connected with the voltage division protection resistor, for filtering the high-frequency noise or the unwanted high-frequency component on the ground wire;

[0090] a second analog ground point connected with the noise suppression capacitor in series, for isolating the digital ground point and the analog ground point.

[0091] Specifically, the noise suppression capacitor is C33.

[0092] So far, the technical scheme of the utility model has been described in combination with the preferred embodiments shown in the drawings, but those skilled in the art can easily understand that the protection scope of the utility model is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without deviating from the principles of the utility model, and the technical schemes after the changes or replacements will all fall within the protection scope of the utility model.

Claims

1. A bidirectional signal detection circuit, characterized in that, include: The signal processing unit includes a bias component for dividing the voltage at the point to be detected corresponding to the circuit to be detected, a signal conversion component connected to the bias component for converting the current signal at the point to be detected into a voltage signal, and a signal amplification component for amplifying the voltage signal to output an amplified voltage signal to be detected. A signal detection unit, which is connected to the signal processing unit, is used to detect the voltage and current of the point to be detected; A power supply unit, which is connected to the signal processing unit and the signal detection unit respectively, is used to supply power to the signal processing unit, the signal detection unit and the circuit under test respectively. It includes a power supply, a power follower connected to the power supply to isolate the power supply from the load and output a constant voltage, and a follower capacitor connected in parallel with the power follower to suppress the noise generated by the power follower and cooperate with the power follower to maintain the constant voltage.

2. The bidirectional signal detection circuit according to claim 1, characterized in that, The bias component includes: A filter resistor, connected to the power follower, is used to provide a path for the bias current and limit the variation of the bias current. The first filter capacitor, which is connected in parallel with the filter resistor, is used to absorb voltage fluctuations.

3. The bidirectional signal detection circuit according to claim 2, characterized in that, The bias component further includes: The second filter capacitor is connected to the first filter capacitor and is used to absorb noise on the ground wire. The first analog ground point is connected to the second filter capacitor to isolate the DC component generated by the bias component and to remove the high-frequency noise generated by the bias component.

4. The bidirectional signal detection circuit according to claim 3, characterized in that, The signal conversion component includes: A signal sampling resistor is used to acquire the terminal voltage of the point to be detected. A first input resistor is connected to the signal sampling resistor and is positioned between the first output terminal of the point to be detected and the signal sampling resistor. The second input resistor is connected to the signal sampling resistor and is disposed between the point to be detected and the second output terminal of the point to be detected. The first input resistor and the second input resistor work together to adjust the voltage of the circuit under test to within the signal detection range; the resistance values ​​of the first input resistor and the second input resistor are equal.

5. The bidirectional signal detection circuit according to claim 4, characterized in that, The signal amplification component includes: An operational amplifier, which is connected to the first input resistor and the second input resistor respectively, is used to differentially amplify the voltage signal between the points to be detected; A feedback resistor is placed between the negative input terminal and the output terminal of the operational amplifier to determine the gain of the operational amplifier.

6. The bidirectional signal detection circuit according to claim 5, characterized in that, The resistance value of the filter resistor is equal to that of the feedback resistor.

7. The bidirectional signal detection circuit according to claim 6, characterized in that, The power supply unit includes: power supply; A power follower, which is connected to the power supply, outputs a constant voltage by isolating the power supply from the load; A follower capacitor, connected in parallel with the power follower, helps maintain the constant voltage by suppressing noise generated by the power follower.

8. The bidirectional signal detection circuit according to claim 7, characterized in that, The signal detection unit includes: A voltage divider protection resistor is installed at the output terminal of the operational amplifier to divide the output voltage of the operational amplifier. A noise suppression component, connected to the voltage divider protection resistor, is used to suppress noise generated by current fluctuations on the ground wire.

9. The bidirectional signal detection circuit according to claim 8, characterized in that, The signal detection unit further includes: The AD converter is connected to the voltage divider protection resistor and the noise suppression component respectively, and is used to convert analog signals into digital signals; A display component, which is connected to the AD converter, is used to display the digital signal.

10. The bidirectional signal detection circuit according to claim 9, characterized in that, The noise suppression component includes: A noise suppression capacitor, which is connected to the voltage divider protection resistor, is used to filter out high-frequency noise or unwanted high-frequency components on the ground wire. The second analog grounding point is connected in series with the noise suppression capacitor to isolate the digital grounding point from the analog grounding point.

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