A potentiostat and a feedback control circuit thereof

Abstract

This invention discloses a potentiostat and its feedback control circuit. The potentiostat feedback control circuit includes: a data acquisition module for acquiring the controlled voltage between the third and second terminals of a voltage divider module; a closed-loop operation module connected to the data acquisition module, which is also connected to a standard signal source; the closed-loop operation module for obtaining the controlled voltage difference between the controlled voltage and the output voltage of the standard signal source; an open-loop operation module connected to the closed-loop operation module, which amplifies and filters the controlled voltage difference to generate a power voltage; a power amplification module connected to the open-loop operation module, which amplifies the power voltage; and a voltage divider module whose first terminal is connected to the power amplification module, whose second terminal is grounded, and whose second and third terminals are both connected to the data acquisition module, providing different potentials through voltage division. By adopting the above scheme, it is beneficial to avoid oscillation of the potentiostat during high-voltage amplification, thus improving the stability of the potentiostat.

Description

Technical Field

[0001] This invention relates to the field of electronic technology, and in particular to a potentiostat and its feedback control circuit. Background Technology

[0002] Potentiostats are mainly used in various fields such as studying electrochemical reaction mechanisms, measuring metal corrosion rates, evaluating the performance of anti-corrosion coatings, cathodic protection, electroplating, electrolysis, laboratory work, and scientific research. Most existing potentiostats are used under experimental conditions with low cell voltage (less than 20V). For experimental conditions with higher cell voltage, a high-voltage operational amplifier needs to be introduced into the feedback loop of the potentiostat to increase the cell voltage.

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

[0004] This invention provides a potentiostat and its feedback control circuit to avoid oscillation of the potentiostat during high voltage amplification and improve the stability of the potentiostat.

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

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

[0007] The closed-loop calculation module is connected to the acquisition module and is also connected to a standard signal source; the closed-loop calculation 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. The open-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 terminal of the voltage divider module is connected to the power amplifier module, the second terminal of the voltage divider module is grounded, and both the second terminal and the third terminal of the voltage divider module are connected to the acquisition module. The voltage divider module is used to divide voltage to provide different potentials.

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

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

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

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

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

[0016] The first end of the first voltage divider resistor serves as the first end of the voltage divider module, the second end of the first voltage divider resistor serves as the third end of the voltage divider module, the second end of the first voltage divider resistor is connected to the first end of the second voltage divider resistor, the second end of the second voltage divider resistor is grounded, the second end of the second voltage divider resistor serves as the second end of the voltage divider module, and the voltage divider capacitor is connected in parallel with the second voltage divider 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 includes: an addition module and an inversion module;

[0020] The first input terminal of the adder module is connected to the open-loop operation module, the second input terminal of the adder module is connected to the high-frequency perturbation signal source, the output terminal of the adder module is connected to the input terminal of the inverting module, and the output terminal of the inverting module is connected to the power amplifier module.

[0021] The addition module is used to superimpose the high-frequency perturbation signal output by the high-frequency perturbation signal source onto the power voltage; the inversion module is used to reverse the direction of the power voltage with the superimposed high-frequency perturbation signal.

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

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

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

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

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

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

[0028] In this embodiment of the potentiostat feedback control circuit, the voltage divider module is connected to auxiliary electrodes, 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. The power amplification module amplifies the power voltage to control the potentials of the auxiliary electrode, the standard electrode, and the working electrode. This embodiment of the invention achieves feedback control of the potentials of each electrode of the potentiostat through closed-loop and open-loop operation modules, which helps to avoid oscillations in the potentiostat during high-voltage amplification and improves the stability of the potentiostat.

[0029] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of a potentiostat feedback control circuit provided in an embodiment of the present invention;

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

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

[0034] Figure 4 This is a schematic diagram of another potentiostat feedback control circuit provided in an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of another potentiostat feedback control circuit provided in an embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of another potentiostat feedback control circuit provided in an embodiment of the present invention;

[0037] Figure 7 This is a schematic diagram of another potentiostat feedback control circuit provided in an embodiment of the present invention;

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

[0039] Figure 9 This is a schematic diagram of another potentiostat feedback control circuit provided in an embodiment of the present invention. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort 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, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0042] This invention provides a feedback control circuit for a potentiostat. The voltage divider module of this feedback control circuit is connected to an auxiliary electrode, a standard electrode, and a working electrode. An acquisition module acquires the controlled voltage between the standard electrode and the working electrode. A closed-loop calculation module calculates the controlled voltage difference between the controlled voltage and the output voltage of the standard signal source. An open-loop operation module amplifies and filters the controlled voltage difference to generate a power voltage. A power amplification module amplifies the power voltage to control the potentials of the auxiliary electrode, the standard electrode, and the working electrode. This invention achieves feedback control of the potentials of each electrode of the potentiostat through closed-loop and open-loop calculation modules, which helps to avoid oscillations in the potentiostat during high-voltage amplification and improves the stability of the potentiostat. Figure 1 This is a schematic diagram of a potentiostat feedback control circuit provided in an embodiment of the present invention. (Refer to...) Figure 1 The feedback control circuit of the potentiostat includes: a data acquisition module 110, a closed-loop operation module 120, an open-loop operation module 130, a power amplification module 140, and a voltage divider module 150.

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

[0044] Specifically, the voltage divider module 150 is connected to an auxiliary electrode CE, a standard electrode RE, and a working electrode WE at each terminal. The first terminal of the voltage divider module 150 is connected to the auxiliary electrode CE, the second terminal is connected to the working electrode WE, and the third terminal is connected to the standard electrode RE. The output voltage of the standard signal source 200 is the target voltage between the second and third terminals 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 and third terminals of the voltage divider module 150. The voltage acquired by the acquisition module 110 is the controlled voltage. For example, the acquisition module 110 can be a differential circuit. The closed-loop calculation 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 calculation module 120 can be a closed-loop calculation circuit. The closed-loop calculation module 120, through a feedback mechanism, can resist external interference and parameter changes, which helps to avoid the influence of parameter changes on the calculation results, improves the gain stability of the potentiostat feedback control circuit, and thus avoids oscillations in the potentiostat feedback control circuit. The open-loop calculation module 130 acquires the controlled voltage difference, amplifies and filters the controlled voltage difference to generate a power voltage. Because the voltage output by the closed-loop operation module 120 is relatively small, the power amplifier module 140 cannot amplify it. Therefore, an open-loop operation module 130 is configured to amplify the controlled voltage difference output by the closed-loop operation module 120 to meet the requirements 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 acquires this power voltage and amplifies it to change the voltage applied to the voltage divider module 150, thereby changing the potential at each terminal of the voltage divider module 150. Exemplarily, the power amplifier module 140 can be a power amplifier. Figure 2 This is a schematic diagram illustrating the voltage change of a standard electrode according to an embodiment of the present invention. (Refer to...) Figure 2 In this embodiment, the voltage of the standard electrode RE in the potentiostat feedback control circuit gradually stabilizes from oscillation.

[0046] It should be noted that the output voltage of the standard signal source 200 can also be superimposed with a low-frequency perturbation signal, so that each electrode of the potentiostat has a corresponding low-frequency perturbation signal to meet the usage requirements of the potentiostat. Figure 3 This is a schematic diagram illustrating the voltage change of another standard electrode provided in an embodiment of the present invention. (Refer to...) Figure 3 The potentiostat feedback control circuit provided in this embodiment ensures that the voltage of the standard electrode RE is stable when the output voltage of the standard signal source 200 is superimposed with a low-frequency perturbation signal, and the voltage of the standard electrode RE is also superimposed with a low-frequency perturbation signal, thus meeting the low-frequency perturbation requirements of the potentiostat.

[0047] In this embodiment of the potentiostat feedback control circuit, the voltage divider module 150 is connected to an auxiliary electrode CE, a standard electrode RE, and a working electrode WE. The acquisition module 110 acquires the controlled voltage between the standard electrode RE and the working electrode WE. The closed-loop calculation 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. The power amplification module 140 amplifies the power voltage to control the potentials of the auxiliary electrode CE, the standard electrode RE, and the working electrode WE. This embodiment of the invention achieves feedback control of the potentials of each electrode of the potentiostat through the closed-loop calculation module 120 and the open-loop calculation module 130, which helps to avoid oscillations in the potentiostat during high-voltage amplification and improves the stability of the potentiostat.

[0048] Figure 4 This is a schematic diagram of another potentiostat feedback control circuit provided in an embodiment of the present invention. Optionally, based on the above embodiments, refer to... Figure 4 The closed-loop operation module includes: a first operational amplifier OP1, a first differential resistor R1, a second differential resistor R2, a third differential resistor R3, and a fourth differential resistor R4.

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

[0050] Figure 5 This is a schematic diagram of another potentiostat feedback control circuit provided in an embodiment of the present invention. Optionally, based on the above embodiments, 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 input of the second operational amplifier OP2 is connected to the first end of the first filter amplification resistor R5. The second end of the first filter amplification resistor R5 is connected to the closed-loop operational module 120. The non-inverting input of the second operational amplifier OP2 is connected to the first end of the second filter amplification resistor R6. The second end of the second filter amplification resistor R6 is grounded. The output terminal of the second operational amplifier OP2 is connected to the power amplification module 140. The third filter amplification resistor R7 and the filter amplification capacitor C1 are connected in series between the inverting input and the output terminal of the second operational amplifier OP2.

[0052] Specifically, in combination 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 operational circuit composed of the first operational amplifier OP1 is a positive value greater than 0. After amplification by the operational circuit composed of the second operational amplifier OP2, it becomes a negative value. The gain of the operational circuit composed of the second operational amplifier OP2 is negative. That is, the input value of the power amplifier module 140 decreases, and the output voltage of the power amplifier module 140 also decreases accordingly, thereby reducing the potential difference between the third terminal and the second terminal of the voltage divider module 150, i.e., reducing the controlled voltage between the standard electrode RE and the working electrode WE.

[0053] When the controlled voltage is less than the output voltage of the standard signal source 200, the controlled voltage difference output by the operational circuit composed of the first operational amplifier OP1 is a negative value less than 0. After amplification by the operational circuit composed of the second operational amplifier OP2, it becomes a positive value. The gain of the operational circuit composed of the second operational amplifier OP2 is negative. That is, as the input value of the power amplifier module 140 increases, the output voltage of the power amplifier module 140 also increases, thereby increasing the potential difference between the third terminal and the second terminal of the voltage divider module 150, i.e., increasing the controlled voltage between the standard electrode RE and the working electrode WE.

[0054] Figure 6 This is a schematic diagram of another potentiostat feedback control circuit provided in an embodiment of the present invention. Optionally, based on the above embodiments, refer to... Figure 6 The voltage divider module 150 includes: a first voltage divider resistor R8, a second voltage divider resistor R9, and a voltage divider capacitor C2.

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

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

[0057] Figure 7 This is a schematic diagram of another potentiostat feedback control circuit provided in an embodiment of the present invention. Optionally, based on the above embodiments, refer to... Figure 7 The potentiostat feedback control circuit also includes an adder module 160 and an inverter module 170.

[0058] The first input terminal of the adder module 160 is connected to the open-loop operation module 130, the second input terminal of the adder module 160 is connected to the high-frequency perturbation signal source 300, the output terminal of the adder module 160 is connected to the input terminal of the inverter module 170, and the output terminal of the inverter module 170 is connected to the power amplifier module 140. The adder module 160 is used to superimpose the high-frequency perturbation signal output by the high-frequency perturbation signal source 300 onto the power voltage. The inverter module 170 is used to reverse the direction of the power voltage superimposed with the high-frequency perturbation signal.

[0059] Specifically, high-frequency perturbation signals can be introduced into the potentiostat feedback control circuit according to actual usage requirements. The acquisition module 110 acquires the voltage between the second and third terminals of the voltage divider module 150; the voltage acquired by the acquisition module 110 is the controlled voltage. For example, the acquisition module 110 can be a differential circuit. The closed-loop calculation 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 calculation module 120 can be a closed-loop calculation circuit. The closed-loop calculation module 120, through its feedback mechanism, can resist external interference and parameter changes, which helps to avoid the influence of parameter changes on the calculation results, improves the gain stability of the potentiostat feedback control circuit, and thus avoids oscillations in the potentiostat feedback control circuit. The open-loop calculation module 130 acquires the controlled voltage difference and amplifies and filters it to generate a power voltage. Since the voltage output by the closed-loop operation module 120 is relatively small, the power amplifier module 140 cannot amplify it. Therefore, the open-loop operation module 130 amplifies the controlled voltage difference output by the closed-loop operation module 120 to meet the requirements of the power amplifier module 140. The adder module 160 acquires 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 onto the power voltage. The direction of the power voltage output by the adder module 160 with the superimposed high-frequency perturbation signal is opposite to the direction of the power voltage output by the closed-loop operation module 130. The inverting module 170 acquires the power voltage with the superimposed high-frequency perturbation signal and reverses its direction so that the direction of the power voltage with the superimposed high-frequency perturbation signal is the same as the direction of the controlled voltage acquired by the acquisition module 110. The power amplifier module 140 acquires this power voltage and amplifies it to change the voltage applied to the voltage divider module 150, thereby changing the potential at each terminal of the voltage divider module 150. Figure 8 This is a schematic diagram illustrating the voltage change of another standard electrode provided in an embodiment of the present invention. (Refer to...) Figure 8 The potentiostat feedback control circuit provided in this embodiment ensures that the voltage of the standard electrode RE is stable when the high-frequency perturbation signal source 300 outputs a high-frequency perturbation signal, and the voltage of the standard electrode RE is also superimposed with the high-frequency perturbation signal, thus meeting the high-frequency perturbation requirements of the potentiostat.

[0060] Figure 9 This is a schematic diagram of another potentiostat feedback control circuit provided in an embodiment of the present invention. Optionally, based on the above embodiments, refer to... Figure 9 The adder module 160 includes: a third operational amplifier OP3, a first adder resistor R10, a second adder resistor R11, and a third adder resistor R12.

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

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

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

[0064] For example, depending on actual usage requirements, the output voltage of the standard signal source 200 can also be superimposed with a low-frequency perturbation signal. The operation 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 when the output voltage of the standard signal source 200 is not superimposed with a low-frequency perturbation signal, and will not be described 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 will not be generated simultaneously.

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

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

[0067] In practical applications, the type of perturbation signal introduced by the potentiostat feedback control circuit can be determined as either a high-frequency or low-frequency perturbation signal based on the filtering bandwidth of the potentiostat feedback control circuit. For example, consider a potentiostat feedback control circuit with a filtering bandwidth of 1kHz. When the filtering bandwidth is greater than 1kHz, the perturbation signal is considered a high-frequency perturbation signal, and in this case, the perturbation signal is introduced into the potentiostat feedback control circuit by the high-frequency perturbation signal source 300. When the filtering bandwidth is less than 1kHz, the perturbation signal is considered a low-frequency perturbation signal, and in this case, the perturbation signal is introduced into the potentiostat feedback control circuit by the standard signal source 200, with the low-frequency perturbation signal superimposed on the output voltage of the standard signal source 200.

[0068] This invention also provides a potentiostat. The potentiostat includes an auxiliary electrode, a standard electrode, a working electrode, and the potentiostat feedback control circuit provided in any of the above embodiments.

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

[0070] The potentiostat provided in this embodiment has the beneficial effects of the potentiostat feedback control circuit provided in any of the above embodiments, which will not be elaborated here.

[0071] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and no limitation is imposed herein.

[0072] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A feedback control circuit for a potentiostat, characterized in that, include: Acquisition module, closed-loop operation module, open-loop operation module, power amplifier module, and voltage divider module; The acquisition module is used to acquire the controlled voltage between the third terminal of the voltage divider module and the second terminal of the voltage divider module; The closed-loop calculation module is connected to the acquisition module and is also connected to a standard signal source; the closed-loop calculation 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. The open-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 terminal of the voltage divider module is connected to the power amplifier module, the second terminal of the voltage divider module is grounded, and both the second terminal and the third terminal of the voltage divider module are connected to the acquisition module. The voltage divider module is used to divide voltage 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 differential resistor, a second differential resistor, a third differential resistor, and a fourth differential resistor; The inverting input of the first operational amplifier is connected to the first terminal of the first differential resistor, and the second terminal of the first differential resistor is connected to the standard signal source; the non-inverting input of the first operational amplifier is connected to the first terminal of the second differential resistor, and the second terminal of the second differential resistor is connected to the acquisition module; the output terminal of the first operational amplifier is connected to the open-loop operational module; the third differential resistor is connected between the inverting input and the output terminal of the first operational amplifier; the first terminal of the fourth differential resistor is connected to the non-inverting input of the first operational amplifier, and the second terminal of the fourth differential resistor is grounded.

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

4. The potentiostat feedback control circuit according to claim 1, characterized in that, The voltage divider module includes: a first voltage divider resistor, a second voltage divider resistor, and a voltage divider capacitor; The first end of the first voltage divider resistor serves as the first end of the voltage divider module, the second end of the first voltage divider resistor serves as the third end of the voltage divider module, the second end of the first voltage divider resistor is connected to the first end of the second voltage divider resistor, the second end of the second voltage divider resistor is grounded, the second end of the second voltage divider resistor serves as the second end of the voltage divider module, and the voltage divider capacitor is connected in parallel with the second voltage divider 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 1-6, characterized in that, The potentiostat feedback control circuit also includes: an addition module and an inversion module; The first input terminal of the adder module is connected to the open-loop operation module, the second input terminal of the adder module is connected to the high-frequency perturbation signal source, the output terminal of the adder module is connected to the input terminal of the inverting module, and the output terminal of the inverting module is connected to the power amplifier module. The addition module is used to superimpose the high-frequency perturbation signal output by the high-frequency perturbation signal source onto the power voltage; the inversion module is used to reverse the direction of the power voltage with the superimposed high-frequency perturbation signal.

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

9. The potentiostat feedback control circuit according to claim 7, characterized in that, The inverting module includes: a fourth operational amplifier, a first inverting resistor, and a second inverting resistor; The inverting input of the fourth operational amplifier is connected to the first terminal of the first reverse resistor, the second terminal of the first reverse resistor is connected to the adder module, the non-inverting input of the fourth operational amplifier is grounded, the output terminal of the fourth operational amplifier is connected to the power amplifier module, and the second reverse resistor is connected between the inverting input 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 described in any one of claims 1-9; The auxiliary electrode is connected to the first terminal of the voltage divider module of the potentiostat feedback control circuit, the working electrode is connected to the second terminal of the voltage divider module of the potentiostat feedback control circuit, and the standard electrode is connected to the third terminal of the voltage divider module of the potentiostat feedback control circuit.

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