A multi-channel electrochemical open circuit potential measurement device

Abstract

The utility model discloses a kind of multi-channel electrochemical open circuit potential measuring devices, including double-pole double-throw 2 winding latching type relay, operational amplifier unit and microcontroller, the operational amplifier unit includes high impedance operational amplifier, the input of the double-pole double-throw 2 winding latching type relay is connected with multiple working electrode, the input of the high impedance operational amplifier is connected with the output of the double-pole double-throw 2 winding latching type relay, the microcontroller is connected with the high impedance operational amplifier.This utility model is on one hand using double-pole double-throw 2 winding latching type relay to realize multi-channel open circuit potential measurement, make electrode and operational amplifier completely disconnected before experiment starts, can effectively reduce power consumption, avoid affecting electrochemical measurement result;On the other hand, application high impedance operational amplifier improves operational amplifier input impedance, and overall structure is simple and small, can be widely applied in electrochemical measurement technical field.

Description

Technical Field

[0001] This utility model relates to the field of electrochemical measurement technology, and in particular to a multi-channel electrochemical open-circuit potential measurement device. Background Technology

[0002] Open-circuit potential measurement is the initial step in electrochemical testing, used to assess the natural electrochemical state of metals or materials in a specific environment. By monitoring the potential at which the redox reaction on the electrode surface reaches dynamic equilibrium, it reflects the interaction between the material and its environment. Existing electrochemical open-circuit potential measurement devices often have low operational amplifier input impedance, which affects measurements of high internal resistance systems. Furthermore, the channel front end experiences absorption current or discharge when the electrode is connected after power-off, thus affecting the electrochemical measurement results. Utility Model Content

[0003] To solve the above-mentioned technical problems, the purpose of this utility model is to provide a multi-channel electrochemical open-circuit potential measurement device with high operational amplifier input impedance and accurate measurement results.

[0004] The technical solution adopted by this utility model is:

[0005] A multi-channel electrochemical open-circuit potential measurement device includes a double-pole double-throw two-winding latched relay, an operational amplifier unit, and a microcontroller. The operational amplifier unit includes a high-impedance operational amplifier. The input terminal of the double-pole double-throw two-winding latched relay is connected to multiple working electrodes. The input terminal of the high-impedance operational amplifier is connected to the output terminal of the double-pole double-throw two-winding latched relay. The microcontroller is connected to the high-impedance operational amplifier.

[0006] Furthermore, the multi-channel electrochemical open-circuit potential measurement device also includes a low-pass filter unit, the input of which is connected to the output of the high-impedance operational amplifier.

[0007] Furthermore, the multi-channel electrochemical open-circuit potential measurement device also includes an analog-to-digital converter, the input of which is connected to the output of the low-pass filter unit, and the analog-to-digital converter is also connected to the microcontroller.

[0008] Furthermore, the microcontroller includes a USB module, which is connected to the analog-to-digital converter.

[0009] Furthermore, there are at least two of the double-pole double-throw two-winding latching relays.

[0010] Furthermore, there are at least four operational amplifier units, and the operational amplifier units are divided into two groups and connected to one of the double-pole double-throw 2-winding locked relays.

[0011] Furthermore, there are at least four low-pass filter units, and the low-pass filter units are divided into two groups and connected to one of the double-pole double-throw 2-winding locked relays.

[0012] Furthermore, the operational amplifier unit includes a voltage follower circuit and a differential circuit. The input terminal of the voltage follower circuit is connected to the output terminal of the double-pole double-throw 2-winding latching relay, and the output terminal of the voltage follower circuit is connected to the input terminal of the differential circuit.

[0013] Furthermore, the voltage follower circuit includes a first high-impedance operational amplifier, and the differential circuit includes a second high-impedance operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor. The non-inverting input terminal of the first high-impedance operational amplifier is connected to the output terminal of the double-pole double-throw 2-winding latching relay. The inverting input terminal of the first high-impedance operational amplifier is connected to the output terminal of the first high-impedance operational amplifier. The output terminal of the first high-impedance operational amplifier is also connected to the inverting input terminal of the second high-impedance operational amplifier through the first resistor and the second resistor. The non-inverting input terminal of the second high-impedance operational amplifier is connected to a reference electrode through the third resistor. The non-inverting input terminal of the second high-impedance operational amplifier is also grounded through the fourth resistor. The inverting input terminal of the second high-impedance operational amplifier is also connected to the output terminal of the second high-impedance operational amplifier through the fifth resistor.

[0014] Furthermore, the low-pass filter unit includes a sixth resistor and a first capacitor. One end of the sixth resistor is connected to the output terminal of the high-impedance operational amplifier, and the other end of the sixth resistor is grounded through the capacitor.

[0015] The beneficial effects of this invention are as follows: It includes a double-pole double-throw 2-winding latched relay, an operational amplifier unit, and a microcontroller. The operational amplifier unit includes a high-impedance operational amplifier. The input terminal of the double-pole double-throw 2-winding latched relay is connected to multiple working electrodes. The input terminal of the high-impedance operational amplifier is connected to the output terminal of the double-pole double-throw 2-winding latched relay. The microcontroller is connected to the high-impedance operational amplifier. On the one hand, this invention uses a double-pole double-throw 2-winding latched relay to achieve multi-channel open-circuit potential measurement. By completely disconnecting the electrodes from the operational amplifier before the experiment begins, power consumption can be effectively reduced, avoiding interference with electrochemical measurement results. On the other hand, the application of a high-impedance operational amplifier with an input impedance ≥10TΩ improves the operational amplifier's input impedance, and the overall structure is simple and compact. Attached Figure Description

[0016] Figure 1 This is a structural block diagram of a multi-channel electrochemical open-circuit potential measuring device provided in one embodiment of the present invention;

[0017] Figure 2 A structural block diagram of a multi-channel electrochemical open-circuit potential measuring device provided in another embodiment of this utility model;

[0018] Figure 3 A structural block diagram of a multi-channel electrochemical open-circuit potential measuring device provided in another embodiment of this utility model;

[0019] Figure 4 The circuit diagram of a double-pole double-throw two-winding latching relay provided in one embodiment of the present invention;

[0020] Figure 5 A circuit diagram of an operational amplifier unit provided in one embodiment of this utility model;

[0021] Figure 6 The circuit diagram of a low-pass filter unit provided in one embodiment of this utility model is shown. Detailed Implementation

[0022] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0023] Open-circuit potential measurement is the initial step in electrochemical testing, used to assess the natural electrochemical state of metals or materials in a specific environment. It reflects the interaction between the material and its environment by monitoring the potential at which the redox reaction on the electrode surface reaches dynamic equilibrium. Measurement principle: After immersing the electrode in the solution, the stability of the system is determined by the change in potential difference between the reference electrode (such as a saturated calomel electrode) and the working electrode. When the potential stabilizes over time, the recorded potential is the open-circuit potential. Existing electrochemical open-circuit potential measurement devices often have low operational amplifier input impedance, which affects measurements of high internal resistance systems. Furthermore, the channel front end absorbs current or discharges when the electrode is connected after power-off, thus affecting the electrochemical measurement results.

[0024] In view of this, this utility model proposes a multi-channel electrochemical open-circuit potential measurement device, including a double-pole double-throw two-winding latched relay, an operational amplifier unit, and a microcontroller. The operational amplifier unit includes a high-impedance operational amplifier. The input terminal of the double-pole double-throw two-winding latched relay is connected to multiple working electrodes, and the input terminal of the high-impedance operational amplifier is connected to the output terminal of the double-pole double-throw two-winding latched relay. The microcontroller is connected to the high-impedance operational amplifier. This utility model, on the one hand, uses a double-pole double-throw two-winding latched relay to achieve multi-channel open-circuit potential measurement, completely disconnecting the electrodes from the operational amplifier before the experiment begins, effectively reducing power consumption and avoiding interference with electrochemical measurement results; on the other hand, the application of a high-impedance operational amplifier with an input impedance ≥10TΩ improves the operational amplifier's input impedance, and the overall structure is simple and compact.

[0025] Reference Figure 1 , Figure 1 This is a structural block diagram of a multi-channel electrochemical open-circuit potential measuring device provided in one embodiment of the present invention. The multi-channel electrochemical open-circuit potential measuring device includes a double-pole double-throw 2-winding latched relay, an operational amplifier unit, and a microcontroller. The operational amplifier unit includes a high-impedance operational amplifier. The input terminal of the double-pole double-throw 2-winding latched relay is connected to multiple working electrodes. The input terminal of the high-impedance operational amplifier is connected to the output terminal of the double-pole double-throw 2-winding latched relay. The microcontroller is connected to the high-impedance operational amplifier.

[0026] Specifically, this embodiment of the invention uses a double-pole double-throw 2-winding latching relay of model G6SK-2F 3DC to isolate the device. Before the experiment begins, the electrodes are kept completely disconnected from the operational amplifier, avoiding the problem that the front end of the channel absorbs current or discharges when the electrodes are connected after power failure, which would affect the electrochemical measurement results. Compared with normally closed relays, the use of 2-winding latching relays helps to reduce current consumption.

[0027] The high input impedance operational amplifier in the operational amplifier unit is used to increase the input impedance and reduce the current absorbed by the op-amp, especially when measuring systems with high impedance. Simultaneously, the differential circuit in the operational amplifier unit converts the bipolar signal into a unipolar positive voltage signal for acquisition by an analog-to-digital converter.

[0028] The microcontroller is used to send the acquired signals to the host computer for display and storage. The controller model STM32F103C8T6 can be used.

[0029] Reference Figure 2 , Figure 2The diagram shows the structure of a multi-channel electrochemical open-circuit potential measuring device according to another embodiment of the present invention. As an optional implementation, the multi-channel electrochemical open-circuit potential measuring device further includes a low-pass filter unit, the input of which is connected to the output of a high-impedance operational amplifier.

[0030] Specifically, the low-pass filter unit is used to filter out interference signals, making the signal smooth and stable.

[0031] Reference Figure 2 As an optional implementation, the multi-channel electrochemical open-circuit potential measurement device also includes an analog-to-digital converter, the input of which is connected to the output of a low-pass filter unit, and the analog-to-digital converter is also connected to a microcontroller.

[0032] Specifically, the analog-to-digital converter is used to convert analog signals into digital signals for communication transmission, and an analog-to-digital converter of model ADS1256 can be used.

[0033] Reference Figure 2 As an optional implementation, the microcontroller includes a USB module that connects to an analog-to-digital converter.

[0034] Specifically, the USB module serves as a communication interface, used to enable signal transmission between the microcontroller and the host computer.

[0035] Based on the aforementioned double-pole double-throw 2-winding latching relay, operational amplifier unit, low-pass filter unit, analog-to-digital converter, USB module, and microcontroller, the working process of the multi-channel electrochemical open-circuit potential measurement device of this utility model embodiment is as follows: when the electrodes are connected, the double-pole double-throw 2-winding latching relay remains closed at the start of the experiment. The signal passes through a voltage follower circuit and a differential circuit composed of a high input impedance operational amplifier, is processed by the low-pass filter unit, is acquired by the analog-to-digital converter, and is finally sent by the microcontroller to the host computer via USB for display and storage.

[0036] Reference Figure 3 , Figure 3 In another embodiment of this utility model, a structural block diagram of a multi-channel electrochemical open-circuit potential measuring device is provided. As an optional implementation, at least two double-pole double-throw two-winding latching relays are used.

[0037] In some alternative embodiments, such as Figure 4The diagram shows the circuit schematic of a double-pole double-throw 2-winding latching relay. This invention uses two double-pole double-throw 2-winding latching relays, connected to four working electrodes (electrode 1, electrode 2, electrode 3, and electrode 4), with the reference electrode connected to the reference electrode interface. It can support 4-channel synchronous measurement to improve the efficiency of open-circuit potential measurement.

[0038] As an optional implementation, there are at least four operational amplifier units, and the operational amplifier units are divided into pairs and connected to a double-pole double-throw 2-winding latching relay.

[0039] As a further optional implementation, the operational amplifier unit includes a voltage follower circuit and a differential circuit. The input terminal of the voltage follower circuit is connected to the output terminal of a double-pole double-throw 2-winding latching relay, and the output terminal of the voltage follower circuit is connected to the input terminal of the differential circuit.

[0040] Specifically, each operational amplifier unit corresponds to a working electrode. The input signal is first buffered by a voltage follower circuit to provide high input impedance and low output impedance, thereby ensuring the stability of the signal source. Then, the positive and negative voltages (i.e., differential signals) are converted into positive voltage signals (i.e., single-ended output signals) by a differential circuit.

[0041] Reference Figure 5 , Figure 5 The circuit diagram of the operational amplifier unit provided in one embodiment of this utility model is shown below. As a further optional implementation, the voltage follower circuit includes a first high-impedance operational amplifier, and the differential circuit includes a second high-impedance operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor. The non-inverting input terminal of the first high-impedance operational amplifier is connected to the output terminal of a double-pole double-throw 2-winding latching relay. The inverting input terminal of the first high-impedance operational amplifier is connected to the output terminal of the first high-impedance operational amplifier. The output terminal of the first high-impedance operational amplifier is also connected to the inverting input terminal of the second high-impedance operational amplifier through the first resistor and the second resistor. The non-inverting input terminal of the second high-impedance operational amplifier is connected to a reference electrode through the third resistor. The non-inverting input terminal of the second high-impedance operational amplifier is also grounded through the fourth resistor. The inverting input terminal of the second high-impedance operational amplifier is also connected to the output terminal of the second high-impedance operational amplifier through the fifth resistor.

[0042] Specifically, such as Figure 5 As shown, each voltage follower circuit consists of a high-impedance operational amplifier (...). Figure 5The high-impedance operational amplifiers U4A, U5A, U6A, and U7A are configured as unity-gain buffers (i.e., voltage followers). The input signal is directly connected to the non-inverting input (+) of the first high-impedance operational amplifier, and the inverting input (-) of the first high-impedance operational amplifier is connected to the output, forming a negative feedback loop to ensure that the output voltage of the first high-impedance operational amplifier follows the input voltage. The power supply pins of the first high-impedance operational amplifier are connected to the positive power supply (+P_9V) and the negative power supply (P_-9V).

[0043] The output of the voltage follower circuit passes through the first resistor ( Figure 5 The resistors R41, R42, R43, and R44) and the second resistor ( Figure 5 Resistors R8, R16, R20, and R25 are connected to the second high-impedance operational amplifier (...). Figure 5 The inverting input (-) of the high-impedance operational amplifiers U4B, U5B, U6B, and U7B is connected to the reference electrode via a third resistor. Figure 5 Resistors R9, R17, R21, and R26 are connected to the non-inverting input (+) of the second high-impedance operational amplifier. The non-inverting input (+) of the second high-impedance operational amplifier is also connected to the fourth resistor ( Figure 5 The pull-down resistors R11, R18, R23, and R27 in the middle are grounded, and the output of the second high-impedance operational amplifier is connected to the fifth resistor ( Figure 5 The resistors R7, R12, R19 and R24 in the circuit are connected to its inverting input terminal (-) to form a negative feedback loop, and its output terminal is also connected to the subsequent circuit.

[0044] As an optional implementation, there are at least four low-pass filter units, and the low-pass filter units are divided into pairs and connected to a double-pole double-throw 2-winding latching relay.

[0045] Reference Figure 6 , Figure 6 The circuit diagram of a low-pass filter unit provided in one embodiment of the present invention is shown below. As an optional implementation, the low-pass filter unit includes a sixth resistor and a first capacitor. One end of the sixth resistor is connected to the output terminal of a high-impedance operational amplifier, and the other end of the sixth resistor is grounded through the capacitor.

[0046] Specifically, the sixth resistor ( Figure 6 One end of resistors R32, R33, R34, and R35 is connected to the output of the second high-impedance operational amplifier, and the other end is connected through the first capacitor ( Figure 6 The capacitors C10, C11, C12, and C15 in the middle are grounded to form a simple RC low-pass filter, thereby effectively filtering out interference in the output signal of the second high-impedance operational amplifier.

[0047] The above description of the structure and operation of the multi-channel electrochemical open-circuit potential measuring device of this utility model demonstrates that, compared with existing electrochemical open-circuit potential measuring devices, this utility model has the following advantages:

[0048] I. A double-pole double-throw 2-winding latching relay is used to realize multi-channel open-circuit potential measurement. Before the experiment starts, the electrodes are completely disconnected from the operational amplifier, which can effectively reduce power consumption and avoid affecting the electrochemical measurement results.

[0049] 2. Applying a high-impedance operational amplifier to make the input impedance ≥10TΩ can improve the input impedance of the operational amplifier;

[0050] Third, it adopts two double-pole double-throw 2-winding latching relays, which are connected to four working electrodes, and can support 4-channel synchronous measurement to improve the efficiency of open circuit potential measurement. The overall structure is simple and compact.

[0051] It should be noted that the improvement of this utility model lies in the various components of the multi-channel electrochemical open-circuit potential measuring device and the connection relationship between the various components. Any signal acquisition, signal transmission or signal conversion mentioned in the specification is based on the existing data processing level. This utility model does not make any improvement in the data processing method. This utility model only involves structural improvements and does not involve method improvements, let alone any software improvements.

[0052] In this utility model, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0053] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0054] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A multi-channel electrochemical open-circuit potential measuring device, characterized in that: The device includes a double-pole double-throw 2-winding latched relay, an operational amplifier unit, and a microcontroller. The operational amplifier unit includes a high-impedance operational amplifier. The input terminal of the double-pole double-throw 2-winding latched relay is connected to multiple working electrodes. The input terminal of the high-impedance operational amplifier is connected to the output terminal of the double-pole double-throw 2-winding latched relay. The microcontroller is connected to the high-impedance operational amplifier.

2. The multi-channel electrochemical open-circuit potential measuring device according to claim 1, characterized in that: The multi-channel electrochemical open-circuit potential measurement device also includes a low-pass filter unit, the input of which is connected to the output of the high-impedance operational amplifier.

3. The multi-channel electrochemical open-circuit potential measuring device according to claim 2, characterized in that: The multi-channel electrochemical open-circuit potential measurement device also includes an analog-to-digital converter, the input of which is connected to the output of the low-pass filter unit, and the analog-to-digital converter is also connected to the microcontroller.

4. The multi-channel electrochemical open-circuit potential measuring device according to claim 3, characterized in that: The microcontroller includes a USB module, which is connected to the analog-to-digital converter.

5. The multi-channel electrochemical open-circuit potential measuring device according to claim 1, characterized in that: The number of double-pole double-throw two-winding latching relays is at least two.

6. The multi-channel electrochemical open-circuit potential measuring device according to claim 1, characterized in that: The operational amplifier unit comprises at least four units, and the operational amplifier units are divided into two groups and connected to one of the double-pole double-throw 2-winding locked relays.

7. The multi-channel electrochemical open-circuit potential measuring device according to claim 2, characterized in that: The low-pass filter unit comprises at least four units, and the low-pass filter units are divided into two groups and connected to one of the double-pole double-throw 2-winding locked relays.

8. The multi-channel electrochemical open-circuit potential measuring device according to claim 1, characterized in that: The operational amplifier unit includes a voltage follower circuit and a differential circuit. The input terminal of the voltage follower circuit is connected to the output terminal of the double-pole double-throw 2-winding latching relay, and the output terminal of the voltage follower circuit is connected to the input terminal of the differential circuit.

9. The multi-channel electrochemical open-circuit potential measuring device according to claim 8, characterized in that: The voltage follower circuit includes a first high-impedance operational amplifier, and the differential circuit includes a second high-impedance operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor. The non-inverting input terminal of the first high-impedance operational amplifier is connected to the output terminal of the double-pole double-throw 2-winding latching relay. The inverting input terminal of the first high-impedance operational amplifier is connected to the output terminal of the first high-impedance operational amplifier. The output terminal of the first high-impedance operational amplifier is also connected to the inverting input terminal of the second high-impedance operational amplifier through the first resistor and the second resistor. The non-inverting input terminal of the second high-impedance operational amplifier is connected to a reference electrode through the third resistor. The non-inverting input terminal of the second high-impedance operational amplifier is also grounded through the fourth resistor. The inverting input terminal of the second high-impedance operational amplifier is also connected to the output terminal of the second high-impedance operational amplifier through the fifth resistor.

10. The multi-channel electrochemical open-circuit potential measuring device according to claim 2, characterized in that: The low-pass filter unit includes a sixth resistor and a first capacitor. One end of the sixth resistor is connected to the output terminal of the high-impedance operational amplifier, and the other end of the sixth resistor is grounded through the capacitor.

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