Constant potential rectifier and feedback control circuit thereof

Abstract

The invention discloses a constant potential rectifier and a feedback control circuit thereof. The constant potential rectifier feedback control circuit comprises an acquisition module used for acquiring a controlled voltage between a third end and a second end of a voltage division module; the closed-loop operation module is connected with the acquisition module, and the closed-loop operation module is also connected with the standard signal source; the closed-loop operation module is used for acquiring a controlled voltage difference between the controlled voltage and the output voltage of the standard signal source; the open-loop operation module is connected with the closed-loop operation module, and the closed-loop operation module is used for amplifying and filtering the controlled voltage difference to generate power voltage; the power amplification module is connected with the open-loop operation module and is used for amplifying the power voltage; the first end of the voltage dividing module is connected with the power amplification module, the second end of the voltage dividing module is grounded, the second end and the third end of the voltage dividing module are both connected with the acquisition module, and the voltage dividing module is used for dividing voltage to provide different potentials. By adopting the scheme, the constant potential rectifier can be prevented from generating oscillation during high-voltage amplification, and the stability of the constant potential rectifier is improved.

Description

Technical Field

[0001] The invention relates to the field of electronic technology, and in particular to a constant potential instrument and a feedback control circuit thereof. Background Art

[0002] Potentiostats are mainly used in many fields such as studying electrochemical reaction mechanisms, measuring metal corrosion rates, evaluating anti-corrosion coating performance, cathodic protection, electroplating, electrolysis, laboratories and scientific research. Potentiostats in the prior art are mostly used in experimental conditions with low cell voltage (less than 20V). For experimental conditions with higher cell voltage, it is necessary to introduce a high-voltage operational amplifier into the feedback loop of the potentiostat to increase the cell voltage of the potentiostat.

[0003] However, when a high-voltage operational amplifier is introduced into the potentiostat, the voltage of the potentiostat during the high-voltage amplification process cannot be stabilized and continues to oscillate. Summary of the invention

[0004] The invention provides a constant potential instrument and a feedback control circuit thereof, so as to avoid oscillation of the constant potential instrument during high voltage amplification and improve the stability of the constant potential instrument.

[0005] According to one aspect of the present invention, a constant potential instrument feedback control circuit is provided, the constant potential instrument feedback control circuit comprising: an acquisition module, a closed-loop operation module, an open-loop operation module, a power amplification module and a voltage division module;

[0006] The acquisition module is used to acquire the controlled voltage between the third end of the voltage divider module and the second end of the voltage divider module;

[0007] The closed-loop operation module is connected to the acquisition module, and the closed-loop operation module is also connected to the standard signal source; the closed-loop operation module is used to obtain the controlled voltage difference between the controlled voltage and the output voltage of the standard signal source;

[0008] The open-loop operation module is connected to the closed-loop operation module, and the closed-loop operation module is used to amplify and filter the controlled voltage difference to generate a power voltage;

[0009] The power amplification module is connected to the open-loop operation module, and the power amplification module is used to amplify the power voltage;

[0010] The first end of the voltage divider module is connected to the power amplification module, the second end of the voltage divider module is grounded, the second end of the voltage divider module and the third end of the voltage divider module are both connected to the acquisition module, and the voltage divider module is used for voltage division to provide different potentials.

[0011] Optionally, the closed-loop operation module includes: a first operational amplifier, a first difference-finding resistor, a second difference-finding resistor, a third difference-finding resistor and a fourth difference-finding resistor;

[0012] The inverting terminal of the first operational amplifier is connected to the first end of the first difference resistor, and the second end of the first difference resistor is connected to the standard signal source; the non-inverting terminal of the first operational amplifier is connected to the first end of the second difference resistor, and the second end of the second difference resistor is connected to the acquisition module; the output end of the first operational amplifier is connected to the open-loop operation module; the third difference resistor is connected between the inverting terminal and the output end of the first operational amplifier; the first end of the fourth difference resistor is connected to the non-inverting terminal of the first operational amplifier, and the second end of the fourth difference resistor is grounded.

[0013] Optionally, the open-loop operation module includes: a second operational amplifier, a first filter amplifying resistor, a second filter amplifying resistor, a third filter amplifying resistor and a filter amplifying capacitor;

[0014] The inverting terminal of the second operational amplifier is connected to the first end of the first filter amplifier resistor, the second end of the first filter amplifier resistor is connected to the closed-loop operation module, the non-inverting terminal of the second operational amplifier is connected to the first end of the second filter amplifier resistor, the second end of the second filter amplifier resistor is grounded, the output end of the second operational amplifier is connected to the power amplifier module, and the third filter amplifier resistor and the filter amplifier capacitor are connected in series between the inverting terminal and the output end of the second operational amplifier.

[0015] Optionally, the voltage dividing module includes: a first voltage dividing resistor, a second voltage dividing resistor and a voltage dividing capacitor;

[0016] The first end of the first voltage-dividing resistor serves as the first end of the voltage-dividing module, the second end of the first voltage-dividing resistor serves as the third end of the voltage-dividing module, the second end of the first voltage-dividing resistor is connected to the first end of the second voltage-dividing resistor, the second end of the second voltage-dividing resistor is grounded, the second end of the second voltage-dividing resistor serves as the second end of the voltage-dividing module, and the voltage-dividing capacitor is connected in parallel with the second voltage-dividing resistor.

[0017] Optionally, the acquisition module includes a differential circuit.

[0018] Optionally, the power amplification module includes a power amplifier.

[0019] Optionally, the potentiostat feedback control circuit further comprises: an addition module and a reverse module;

[0020] The first input end of the adding module is connected to the open-loop operation module, the second input end of the adding module is connected to the high-frequency perturbation signal source, the output end of the adding module is connected to the input end of the reverse module, and the output end of the reverse module is connected to the power amplification module;

[0021] The adding module is used to superimpose the high-frequency perturbation signal output by the high-frequency perturbation signal source on the power voltage; and the reversing module is used to reverse the direction of the power voltage superimposed with the high-frequency perturbation signal.

[0022] Optionally, the adding module includes: a third operational amplifier, a first adding resistor, a second adding resistor and a third adding resistor;

[0023] The inverting end of the third operational amplifier is connected to the first end of the first adding resistor, the second end of the first adding resistor is connected to the high-frequency perturbation signal source, the first end of the second adding resistor is connected to the inverting end of the third operational amplifier, the second end of the second adding resistor is connected to the open-loop operation module, the non-inverting end of the third operational amplifier is grounded, the output end of the third operational amplifier is connected to the reverse module, and the third adding resistor is connected between the inverting end and the output end of the third operational amplifier.

[0024] Optionally, the reverse module includes: a fourth operational amplifier, a first reverse resistor and a second reverse resistor;

[0025] The inverting terminal of the fourth operational amplifier is connected to the first end of the first reverse resistor, the second end of the first reverse resistor is connected to the adding module, the non-inverting terminal of the fourth operational amplifier is grounded, the output terminal of the fourth operational amplifier is connected to the power amplification module, and the second reverse resistor is connected between the inverting terminal and the output terminal of the fourth operational amplifier.

[0026] According to another aspect of the present invention, a potentiostat is provided, the potentiostat comprising an auxiliary electrode, a standard electrode, a working electrode and a potentiostat feedback control circuit as described in any one of the above embodiments;

[0027] The auxiliary electrode is connected to the first end of the voltage divider module of the constant potential instrument feedback control circuit, the working electrode is connected to the second end of the voltage divider module of the constant potential instrument feedback control circuit, and the standard electrode is connected to the third end of the voltage divider module of the constant potential instrument feedback control circuit.

[0028] The voltage divider module of the feedback control circuit of the constant potential instrument of the embodiment of the present invention is connected to the auxiliary electrode, the standard electrode and the working electrode at each end, the acquisition module acquires the controlled voltage between the standard electrode and the working electrode, the closed-loop operation module calculates the controlled voltage difference between the controlled voltage and the output voltage of the standard signal source, the open-loop operation module amplifies and filters the controlled voltage difference to generate a power voltage, and the power amplification module amplifies the power voltage to achieve control of the potential of the auxiliary electrode, the standard electrode and the working electrode. The embodiment of the present invention realizes feedback control of the potential of each electrode of the constant potential instrument through the closed-loop operation module and the open-loop operation module, which is conducive to avoiding oscillation of the constant potential instrument during high-voltage amplification and improving the stability of the constant potential instrument.

[0029] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 is a schematic diagram of a constant potential instrument feedback control circuit provided by an embodiment of the present invention;

[0032] Figure 2 is a schematic diagram of voltage variation of a standard electrode provided by an embodiment of the present invention;

[0033] Figure 3 is a schematic diagram of voltage changes of another standard electrode provided by an embodiment of the present invention;

[0034] Figure 4 is a schematic diagram of another constant potential instrument feedback control circuit provided by an embodiment of the present invention;

[0035] Figure 5 is a schematic diagram of another constant potential instrument feedback control circuit provided by an embodiment of the present invention;

[0036] Figure 6 is a schematic diagram of another constant potential instrument feedback control circuit provided by an embodiment of the present invention;

[0037] Figure 7 is a schematic diagram of another constant potential instrument feedback control circuit provided by an embodiment of the present invention;

[0038] Figure 8is a schematic diagram of voltage changes of another standard electrode provided by an embodiment of the present invention;

[0039] Fig. 9 It is a schematic diagram of another constant potential instrument feedback control circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0041] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0042] The embodiment of the present invention provides a constant potential instrument feedback control circuit. Each end of the voltage divider module of the constant potential instrument feedback control circuit is connected to an auxiliary electrode, a standard electrode and a working electrode, the acquisition module acquires the controlled voltage between the standard electrode and the working electrode, the closed-loop operation module calculates the controlled voltage difference between the controlled voltage and the output voltage of the standard signal source, the open-loop operation module amplifies and filters the controlled voltage difference to generate a power voltage, and the power amplifier module amplifies the power voltage to achieve control of the potential of the auxiliary electrode, the standard electrode and the working electrode. The embodiment of the present invention realizes feedback control of the potential of each electrode of the constant potential instrument through a closed-loop operation module and an open-loop operation module, which is conducive to avoiding oscillation of the constant potential instrument during high-voltage amplification and improving the stability of the constant potential instrument. Figure 1 Schematic diagram of a constant potential instrument feedback control circuit provided by an embodiment of the present invention. Figure 1 The constant potential instrument feedback control circuit includes: an acquisition module 110, a closed-loop operation module 120, an open-loop operation module 130, a power amplification module 140 and a voltage division module 150.

[0043] The acquisition module 110 is used to acquire the controlled voltage between the third end of the voltage divider module 150 and the second end of the voltage divider module 150; the closed-loop operation module 120 is connected to the acquisition module, and the closed-loop operation module 120 is also connected to the standard signal source 200; the closed-loop operation module 120 is used to obtain the controlled voltage difference between the controlled voltage and the output voltage of the standard signal source 200; the open-loop operation module 130 is connected to the closed-loop operation module 120, and the closed-loop operation module 130 is used to amplify and filter the controlled voltage difference to generate a power voltage; the power amplifier module 140 is connected to the open-loop operation module 130, and the power amplifier module 140 is used to amplify the power voltage; the first end of the voltage divider module 150 is connected to the power amplifier module 140, the second end of the voltage divider module 150 is grounded, the second end of the voltage divider module 150 and the third end of the voltage divider module 150 are both connected to the acquisition module 110, and the voltage divider module 150 is used to divide the voltage to provide different potentials.

[0044] Specifically, each end of the voltage divider module 150 is connected to the auxiliary electrode CE, the standard electrode RE and the working electrode WE. The first end of the voltage divider module 150 is connected to the auxiliary electrode CE, the second end of the voltage divider module 150 is connected to the working electrode WE, and the third end of the voltage divider module 150 is connected to the standard electrode RE. The output voltage of the standard signal source 200 is the target voltage between the second end and the third end of the voltage divider module 150, that is, the target potential difference between the standard electrode RE and the working electrode WE.

[0045] The acquisition module 110 acquires the voltage between the second end and the third end of the voltage divider module 150, and the voltage acquired by the acquisition module 110 is the controlled voltage. Exemplarily, the acquisition module 110 may be a differential circuit. The closed-loop operation module 120 acquires the controlled voltage and the output voltage of the standard signal source 200, and calculates the voltage difference between the controlled voltage and the output voltage of the standard signal source 200, i.e., the controlled voltage difference. For example, the closed-loop operation module 120 may be a closed-loop operation circuit. The closed-loop operation module 120 can resist external interference and parameter changes through a feedback mechanism, which is beneficial to avoid the influence of parameter changes on the calculation results, improve the gain stability of the constant potential instrument feedback control circuit, and thus avoid oscillation of the constant potential instrument feedback control circuit. The open-loop operation module 130 acquires the controlled voltage difference, and amplifies and filters the controlled voltage difference to generate a power voltage. Since the voltage output by the closed-loop operation module 120 is small, the power amplifier module 140 cannot amplify the small voltage. Therefore, the open-loop operation module 130 is set to amplify the controlled voltage difference output by the closed-loop operation module 120 to meet the needs of the power amplifier module 140. For example, the open-loop operation module 130 is an open-loop operation circuit. The power amplifier module 140 obtains the power voltage and amplifies the power voltage to change the voltage applied to the voltage divider module 150, thereby changing the potential of each end of the voltage divider module 150. Exemplarily, the power amplifier module 140 can be a power amplifier. Figure 2 Schematic diagram of voltage change of a standard electrode provided by an embodiment of the present invention. Figure 2 , the voltage of the standard electrode RE of the constant potential instrument feedback control circuit provided in this embodiment gradually stabilizes from oscillation.

[0046] It should be noted that the output voltage of the standard signal source 200 may also be superimposed with a low-frequency perturbation signal, so that each electrode of the constant potential instrument has a corresponding low-frequency perturbation signal to meet the use requirements of the constant potential instrument. Figure 3 Schematic diagram of voltage variation of another standard electrode provided by an embodiment of the present invention. Figure 3 When the output voltage of the standard signal source 200 of the constant potential instrument feedback control circuit provided in this embodiment is superimposed with a low-frequency perturbation signal, the voltage of the standard electrode RE is stable, and the voltage of the standard electrode RE is also superimposed with the low-frequency perturbation signal, thereby meeting the use requirements of the low-frequency perturbation of the constant potential instrument.

[0047] The voltage divider module 150 of the feedback control circuit of the constant potential instrument in the embodiment of the present invention is connected to the auxiliary electrode CE, the standard electrode RE and the working electrode WE at each end, the acquisition module 110 acquires the controlled voltage between the standard electrode RE and the working electrode WE, the closed-loop operation module 120 calculates the controlled voltage difference between the controlled voltage and the output voltage of the standard signal source 200, the open-loop operation module 130 amplifies and filters the controlled voltage difference to generate a power voltage, and the power amplifier module 140 amplifies the power voltage to achieve control of the potential of the auxiliary electrode CE, the standard electrode RE and the working electrode WE. The embodiment of the present invention realizes feedback control of the potential of each electrode of the constant potential instrument through the closed-loop operation module 120 and the open-loop operation module 130, which is conducive to avoiding oscillation of the constant potential instrument during high-voltage amplification and improving the stability of the constant potential instrument.

[0048] Figure 4 Schematic diagram of another constant potential instrument feedback control circuit provided by an embodiment of the present invention. Based on the above embodiment, optionally, refer to Figure 4 The closed-loop operation module includes: a first operational amplifier OP1, a first difference-finding resistor R1, a second difference-finding resistor R2, a third difference-finding resistor R3 and a fourth difference-finding resistor R4.

[0049] The inverting terminal of the first operational amplifier OP1 is connected to the first end of the first difference resistor R1, and the second end of the first difference resistor R1 is connected to the standard signal source 200; the non-inverting terminal of the first operational amplifier OP1 is connected to the first end of the second difference resistor R2, and the second end of the second difference resistor R2 is connected to the acquisition module 110; the output end of the first operational amplifier OP1 is connected to the open-loop operation module 130; the third difference resistor R3 is connected between the inverting terminal and the output end of the first operational amplifier OP1; the first end of the fourth difference resistor R4 is connected to the non-inverting terminal of the first operational amplifier OP1, and the second end of the fourth difference resistor R4 is grounded.

[0050] Figure 5 Schematic diagram of another constant potential instrument feedback control circuit provided by an embodiment of the present invention. Based on the above embodiments, optionally, refer to Figure 5 The open-loop operation module 130 includes: a second operational amplifier OP2, a first filter amplifier resistor R5, a second filter amplifier resistor R6, a third filter amplifier resistor R7 and a filter amplifier capacitor C1.

[0051] The inverting end of the second operational amplifier OP2 is connected to the first end of the first filter amplifier resistor R5, the second end of the first filter amplifier resistor R5 is connected to the closed-loop operation module 120, the non-inverting end of the second operational amplifier OP2 is connected to the first end of the second filter amplifier resistor R6, the second end of the second filter amplifier resistor R6 is grounded, the output end of the second operational amplifier OP2 is connected to the power amplifier module 140, and the third filter amplifier resistor R7 and the filter amplifier capacitor C1 are connected in series between the inverting end and the output end of the second operational amplifier OP2.

[0052] Specifically, combined Figure 4 and Figure 5 When the controlled voltage is greater than the output voltage of the standard signal source 200, the controlled voltage difference output by the operation circuit formed by the first operational amplifier OP1 is a positive value greater than 0. After being amplified by the operation circuit formed by the second operational amplifier OP2, it becomes a negative value. Among them, the gain of the operation circuit formed by the second operational amplifier OP2 is negative. That is, the input value of the power amplifier module 140 becomes smaller, and the output voltage of the power amplifier module 140 also decreases accordingly, so that the potential difference between the third end of the voltage divider module 150 and the second end of the voltage divider module 150 is reduced, that is, the controlled voltage between the standard electrode RE and the working electrode WE is reduced.

[0053] When the controlled voltage is less than the output voltage of the standard signal source 200, the controlled voltage difference output by the operation circuit formed by the first operational amplifier OP1 is a negative value less than 0. After being amplified by the operation circuit formed by the second operational amplifier OP2, it becomes a positive value. Among them, the gain of the operation circuit formed by the second operational amplifier OP2 is negative. That is, the input value of the power amplifier module 140 increases, and the output voltage of the power amplifier module 140 also increases accordingly, thereby increasing the potential difference between the third end of the voltage divider module 150 and the second end of the voltage divider module 150, that is, the controlled voltage between the standard electrode RE and the working electrode WE increases.

[0054] Figure 6 Schematic diagram of another constant potential instrument feedback control circuit provided by an embodiment of the present invention. Based on the above embodiments, optionally, refer to Figure 6 The voltage dividing module 150 includes: a first voltage dividing resistor R8, a second voltage dividing resistor R9 and a voltage dividing capacitor C2.

[0055] The first end of the first voltage-dividing resistor R8 serves as the first end of the voltage-dividing module 150, the second end of the first voltage-dividing resistor R8 serves as the third end of the voltage-dividing module 150, the second end of the first voltage-dividing resistor R8 is connected to the first end of the second voltage-dividing resistor R9, the second end of the second voltage-dividing resistor R9 is grounded, the second end of the second voltage-dividing resistor R9 serves as the second end of the voltage-dividing module 150, and the voltage-dividing capacitor C2 is connected in parallel with the second voltage-dividing resistor R9.

[0056] The auxiliary electrode CE is connected to the first end of the first voltage-dividing resistor R8 , the standard electrode RE is connected to the second end of the first voltage-dividing resistor R8 , and the working electrode WE is connected to the second end of the second voltage-dividing resistor R9 .

[0057] Figure 7 Schematic diagram of another constant potential instrument feedback control circuit provided by an embodiment of the present invention. Based on the above embodiments, optionally, refer to Figure 7 The constant potential instrument feedback control circuit also includes: an adding module 160 and a reversing module 170 .

[0058] A first input end of the adding module 160 is connected to the open-loop operation module 130, a second input end of the adding module 160 is connected to the high-frequency perturbation signal source 300, an output end of the adding module 160 is connected to an input end of the reversing module 170, and an output end of the reversing module 170 is connected to the power amplification module 140; the adding module 160 is used to superimpose the high-frequency perturbation signal output by the high-frequency perturbation signal source 300 on the power voltage; the reversing module 170 is used to reverse the direction of the power voltage superimposed with the high-frequency perturbation signal.

[0059] Specifically, according to actual use requirements, a high-frequency perturbation signal can also be introduced into the constant potential instrument feedback control circuit. The acquisition module 110 collects the voltage between the second end and the third end of the voltage divider module 150, and the voltage collected by the acquisition module 110 is the controlled voltage. Exemplarily, the acquisition module 110 can be a differential circuit. The closed-loop operation module 120 obtains the controlled voltage and the output voltage of the standard signal source 200, and calculates the voltage difference between the controlled voltage and the output voltage of the standard signal source 200, that is, the controlled voltage difference. For example, the closed-loop operation module 120 can be a closed-loop operation circuit. The closed-loop operation module 120 can resist external interference and parameter changes through a feedback mechanism, which is conducive to avoiding the influence of parameter changes on the calculation results, improving the gain stability of the constant potential instrument feedback control circuit, and thus avoiding oscillation of the constant potential instrument feedback control circuit. The open-loop operation module 130 obtains the controlled voltage difference, and amplifies and filters the controlled voltage difference to generate a power voltage. Since the voltage output by the closed-loop operation module 120 is small, the power amplifier module 140 cannot amplify the small voltage. Therefore, the open-loop operation module 130 is set to amplify the controlled voltage difference output by the closed-loop operation module 120 to meet the needs of the power amplifier module 140. The addition module 160 obtains the power voltage and the high-frequency perturbation signal output by the high-frequency perturbation signal source 300, and superimposes the high-frequency perturbation signal on the power voltage. The direction of the power voltage superimposed with the high-frequency perturbation signal output by the addition module 160 is opposite to the reverse direction of the power voltage output by the closed-loop operation module 130. The reverse module 170 obtains the power voltage superimposed with the high-frequency perturbation signal, and reverses the direction of the power voltage superimposed with the high-frequency perturbation signal, so that the direction of the power voltage superimposed with the high-frequency perturbation signal is the same as the reverse direction of the controlled voltage collected by the collection module 110. The power amplifier module 140 obtains the power voltage and amplifies the power voltage to change the voltage applied to the voltage divider module 150, thereby changing the potential of each end of the voltage divider module 150. Figure 8 Schematic diagram of voltage change of another standard electrode provided by an embodiment of the present invention. Figure 8 When the high-frequency perturbation signal source 300 outputs a high-frequency perturbation signal, the voltage of the standard electrode RE is stable, and the voltage of the standard electrode RE is also superimposed with the high-frequency perturbation signal, thereby meeting the use requirements of the high-frequency perturbation of the potentiostat.

[0060] Fig. 9 Schematic diagram of another constant potential instrument feedback control circuit provided by an embodiment of the present invention. Based on the above embodiments, optionally, refer to Fig. 9 The adding module 160 includes: a third operational amplifier OP3, a first adding resistor R10, a second adding resistor R11 and a third adding resistor R12.

[0061] The inverting end of the third operational amplifier OP3 is connected to the first end of the first adding resistor R10, the second end of the first adding resistor R10 is connected to the high-frequency perturbation signal source 300, the first end of the second adding resistor R11 is connected to the inverting end of the third operational amplifier OP3, the second end of the second adding resistor R11 is connected to the open-loop operation module 130, the non-inverting end of the third operational amplifier OP3 is grounded, the output end of the third operational amplifier OP3 is connected to the inverting module 170, and the third adding resistor R12 is connected between the inverting end and the output end of the third operational amplifier OP3.

[0062] Based on the above embodiments, optionally, continue to refer to Fig. 9 The reverse module 170 includes: a fourth operational amplifier OP4, a first reverse resistor R13 and a second reverse resistor R14.

[0063] The inverting end of the fourth operational amplifier OP4 is connected to the first end of the first reverse resistor R13, the second end of the first reverse resistor R13 is connected to the adding module 160, the non-inverting end of the fourth operational amplifier OP4 is grounded, the output end of the fourth operational amplifier OP4 is connected to the power amplification module 140, and the second reverse resistor R14 is connected between the inverting end and the output end of the fourth operational amplifier OP4.

[0064] Exemplarily, the output voltage of the standard signal source 200 may also be superimposed with a low-frequency perturbation signal according to actual use requirements. The working process of the closed-loop operation module 120 and the open-loop operation module 130 when the output voltage of the standard signal source 200 is superimposed with a low-frequency perturbation signal is the same as the working process when the output voltage of the standard signal source 200 is not superimposed with a low-frequency perturbation signal, and will not be repeated again. When the output voltage of the standard signal source 200 is superimposed with a low-frequency perturbation signal, the high-frequency perturbation signal source 300 stops outputting the high-frequency perturbation signal, that is, the high-frequency perturbation signal and the low-frequency perturbation signal are not generated at the same time.

[0065] When the output voltage of the standard signal source 200 is superimposed with the low-frequency perturbation signal, the operation circuit formed by the third operational amplifier OP3 reverses the power voltage. The operation circuit formed by the fourth operational amplifier OP4 reverses the reverse direction of the power voltage output by the operation circuit formed by the third operational amplifier OP3, so that the direction of the power voltage is the same as the reverse direction of the controlled voltage collected by the collection module 110.

[0066] The filter bandwidth of the constant potentiostat feedback control circuit is related to the filter bandwidth of the open-loop operation module 130. By changing the sizes of the first filter amplifier resistor R5, the third filter amplifier resistor R7 and the filter amplifier capacitor C1 in the open-loop operation module 130, the filter bandwidth of the constant potentiostat feedback control circuit can be changed.

[0067] In practical applications, it can be determined whether the perturbation signal introduced by the constant potential instrument feedback control circuit is a high-frequency perturbation signal or a low-frequency perturbation signal according to the filter bandwidth of the constant potential instrument feedback control circuit. For example, the filter bandwidth of the constant potential instrument feedback control circuit is 1kHz. When the filter bandwidth of the constant potential instrument feedback control circuit is greater than 1kHz, it is considered that the perturbation signal introduced by the constant potential instrument feedback control circuit is a high-frequency perturbation signal. At this time, the perturbation signal is introduced into the constant potential instrument feedback control circuit by the high-frequency perturbation signal source 300; when the filter bandwidth of the constant potential instrument feedback control circuit is less than 1kHz, it is considered that the perturbation signal introduced by the constant potential instrument feedback control circuit is a low-frequency perturbation signal. At this time, the perturbation signal is introduced into the constant potential instrument feedback control circuit by the standard signal source 200, and the low-frequency perturbation signal is superimposed on the output voltage of the standard signal source 200.

[0068] The embodiment of the present invention further provides a constant potential instrument, which includes an auxiliary electrode, a standard electrode, a working electrode, and a constant potential instrument feedback control circuit provided by any of the above embodiments.

[0069] The auxiliary electrode is connected to the first end of the voltage divider module of the constant potential instrument feedback control circuit, the working electrode is connected to the second end of the voltage divider module of the constant potential instrument feedback control circuit, and the standard electrode is connected to the third end of the voltage divider module of the constant potential instrument feedback control circuit.

[0070] Among them, the constant potentiostat provided in this embodiment has the beneficial effects of the constant potentiostat feedback control circuit provided in any of the above embodiments, which will not be described in detail here.

[0071] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0072] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A constant potential instrument feedback control circuit, characterized in that: include: Acquisition module, closed-loop operation module, open-loop operation module, power amplification module and voltage division module; The acquisition module is used to acquire the controlled voltage between the third end of the voltage divider module and the second end of the voltage divider module; The closed-loop operation module is connected to the acquisition module, and the closed-loop operation module is also connected to the standard signal source; the closed-loop operation module is used to obtain the controlled voltage difference between the controlled voltage and the output voltage of the standard signal source; The open-loop operation module is connected to the closed-loop operation module, and the closed-loop operation module is used to amplify and filter the controlled voltage difference to generate a power voltage; The power amplification module is connected to the open-loop operation module, and the power amplification module is used to amplify the power voltage; The first end of the voltage divider module is connected to the power amplification module, the second end of the voltage divider module is grounded, the second end of the voltage divider module and the third end of the voltage divider module are both connected to the acquisition module, and the voltage divider module is used for voltage division to provide different potentials.

2. The potentiostat feedback control circuit according to claim 1, characterized in that: The closed-loop operation module includes: a first operational amplifier, a first difference resistor, a second difference resistor, a third difference resistor and a fourth difference resistor; The inverting terminal of the first operational amplifier is connected to the first end of the first difference resistor, and the second end of the first difference resistor is connected to the standard signal source; the non-inverting terminal of the first operational amplifier is connected to the first end of the second difference resistor, and the second end of the second difference resistor is connected to the acquisition module; the output end of the first operational amplifier is connected to the open-loop operation module; the third difference resistor is connected between the inverting terminal and the output end of the first operational amplifier; the first end of the fourth difference resistor is connected to the non-inverting terminal of the first operational amplifier, and the second end of the fourth difference resistor is grounded.

3. The potentiostat feedback control circuit according to claim 1, characterized in that: The open-loop operation module includes: a second operational amplifier, a first filter amplifying resistor, a second filter amplifying resistor, a third filter amplifying resistor and a filter amplifying capacitor; The inverting terminal of the second operational amplifier is connected to the first end of the first filter amplifier resistor, the second end of the first filter amplifier resistor is connected to the closed-loop operation module, the non-inverting terminal of the second operational amplifier is connected to the first end of the second filter amplifier resistor, the second end of the second filter amplifier resistor is grounded, the output end of the second operational amplifier is connected to the power amplifier module, and the third filter amplifier resistor and the filter amplifier capacitor are connected in series between the inverting terminal and the output end of the second operational amplifier.

4. The potentiostat feedback control circuit according to claim 1, characterized in that: The voltage dividing module comprises: a first voltage dividing resistor, a second voltage dividing resistor and a voltage dividing capacitor; The first end of the first voltage-dividing resistor serves as the first end of the voltage-dividing module, the second end of the first voltage-dividing resistor serves as the third end of the voltage-dividing module, the second end of the first voltage-dividing resistor is connected to the first end of the second voltage-dividing resistor, the second end of the second voltage-dividing resistor is grounded, the second end of the second voltage-dividing resistor serves as the second end of the voltage-dividing module, and the voltage-dividing capacitor is connected in parallel with the second voltage-dividing resistor.

5. The potentiostat feedback control circuit according to claim 1, characterized in that: The acquisition module includes a differential circuit.

6. The potentiostat feedback control circuit according to claim 1, characterized in that: The power amplification module includes a power amplifier.

7. The potentiostat feedback control circuit according to any one of claims 1 to 6, characterized in that: The potentiostat feedback control circuit also includes: an addition module and a reverse module; The first input end of the adding module is connected to the open-loop operation module, the second input end of the adding module is connected to the high-frequency perturbation signal source, the output end of the adding module is connected to the input end of the reverse module, and the output end of the reverse module is connected to the power amplification module; The adding module is used to superimpose the high-frequency perturbation signal output by the high-frequency perturbation signal source on the power voltage; and the reversing module is used to reverse the direction of the power voltage superimposed with the high-frequency perturbation signal.

8. The potentiostat feedback control circuit according to claim 7, characterized in that: The adding module includes: a third operational amplifier, a first adding resistor, a second adding resistor and a third adding resistor; The inverting end of the third operational amplifier is connected to the first end of the first adding resistor, the second end of the first adding resistor is connected to the high-frequency perturbation signal source, the first end of the second adding resistor is connected to the inverting end of the third operational amplifier, the second end of the second adding resistor is connected to the open-loop operation module, the non-inverting end of the third operational amplifier is grounded, the output end of the third operational amplifier is connected to the reverse module, and the third adding resistor is connected between the inverting end and the output end of the third operational amplifier.

9. The potentiostat feedback control circuit according to claim 7, characterized in that: The reverse module includes: a fourth operational amplifier, a first reverse resistor and a second reverse resistor; The inverting terminal of the fourth operational amplifier is connected to the first end of the first reverse resistor, the second end of the first reverse resistor is connected to the adding module, the non-inverting terminal of the fourth operational amplifier is grounded, the output terminal of the fourth operational amplifier is connected to the power amplification module, and the second reverse resistor is connected between the inverting terminal and the output terminal of the fourth operational amplifier.

10. A potentiostat, characterized in that: include: An auxiliary electrode, a standard electrode, a working electrode and a potentiostat feedback control circuit as claimed in any one of claims 1 to 9; The auxiliary electrode is connected to the first end of the voltage divider module of the constant potential instrument feedback control circuit, the working electrode is connected to the second end of the voltage divider module of the constant potential instrument feedback control circuit, and the standard electrode is connected to the third end of the voltage divider module of the constant potential instrument feedback control circuit.

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