Simple micro-current control circuit and device

Abstract

The utility model provides a simple micro-current control circuit and device, and relates to the technical field of micro-current control, only one operational amplifier device and one precision resistor are adopted, and when a first voltage signal accessed to an inverted input end of an operational amplifier and a second voltage signal accessed to a normal input end of the operational amplifier are determined, the precision resistor is switched on; the load current can be determined, and the current cannot be changed due to the change of the load, so that the purpose of micro-current constant current is achieved; moreover, the voltage difference between a first voltage signal accessed to the inverting input end of the operational amplifier and a second voltage signal accessed to the normal input end of the operational amplifier can be adjusted according to the needs, thereby achieving the control of the size and direction of the load current, and achieving the effects of low cost and diversified use modes.

Description

Technical Field

[0001] This application relates to the field of micro-current control technology, and particularly to a simple micro-current control circuit and device. Background Art

[0002] Micro-current control circuits play an important role in many fields that require high precision and small current control, which helps to improve the performance and accuracy of equipment. For example, in the biomedical field, micro-currents can be precisely controlled to stimulate nerves for the treatment of nervous system diseases or for neuroscience research; in the semiconductor manufacturing field, the injected ion current can be precisely controlled to achieve specific electrical properties; in the field of industrial automation, it can be used in the design of precision measuring instruments.

[0003] Existing simple micro-current control circuits are composed of a reference voltage chip, a zener diode or an operational amplifier circuit in combination with a triode or a MOS transistor. More complex micro-current control circuits involve more devices, require more peripheral circuit devices, and are expensive. Moreover, existing micro-current control circuits can only output unidirectional current and lack the ability to switch the current direction. Summary of the Utility Model

[0004] To overcome the deficiencies in the prior art, this application provides a simple micro-current control circuit and device with a simple structure and adjustable current output direction and magnitude.

[0005] A simple micro-current control circuit provided by this application includes an operational amplifier and a first resistor R1. The inverting input terminal of the operational amplifier is connected to a first voltage signal through the first resistor R1. The non-inverting input terminal of the operational amplifier is connected to a second voltage signal. The output terminal of the operational amplifier is connected between the inverting input terminal of the operational amplifier and the first resistor R1 through a load, and is used to control the magnitude and direction of the current passing through the load by adjusting the voltage difference between the first voltage signal and the second voltage signal.

[0006] In a possible implementation, the magnitude of the current passing through the load is:

[0007] I RL =(U SIG1 -U SIG2 ) / R1

[0008] where U SIG1 represents the voltage value of the first voltage signal, U SIG2 represents the voltage value of the second voltage signal, and R1 represents the resistance value of the first resistor R1.

[0009] In a possible implementation, when the voltage value of the first voltage signal is greater than the voltage value of the second voltage signal, the direction of the current passing through the load is from the inverting input terminal of the operational amplifier to the output terminal of the operational amplifier.

[0010] In a possible implementation, when the voltage value of the first voltage signal is less than the voltage value of the second voltage signal, the direction of the current passing through the load is from the output terminal of the operational amplifier to the inverting input terminal of the operational amplifier.

[0011] In a possible implementation, the first voltage signal and the second voltage signal are DC voltages or AC voltages.

[0012] In a possible implementation, the model of the operational amplifier is LMC6041IM.

[0013] In a possible implementation, the positive power input pin and the negative power input pin of the operational amplifier are respectively connected to the corresponding operating voltages.

[0014] In a possible implementation, the first resistor R1 is a precision resistor.

[0015] A simple microcurrent control device provided by the present application employs the simple microcurrent control circuit described in any one of the above.

[0016] Compared with the prior art, the beneficial effects of the present application are as follows:

[0017] The simple microcurrent control circuit and device provided in this embodiment only employ one operational amplifier device. When the first voltage signal connected to the inverting input terminal of the operational amplifier and the second voltage signal connected to the non-inverting input terminal of the operational amplifier are determined, the load current can be determined and will not change due to the change of the load, thus achieving the purpose of microcurrent constant current; and the voltage difference between the first voltage signal connected to the inverting input terminal of the operational amplifier and the second voltage signal connected to the non-inverting input terminal of the operational amplifier can be adjusted as needed to control the magnitude and direction of the load current. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1The circuit diagram of the simple micro-current control circuit according to an embodiment of the present application is shown;

[0020] Figure 2 The schematic circuit diagram of the magnitude and direction of the load current when the first voltage signal and the second voltage signal in an embodiment of the present application are determined is shown;

[0021] Figure 3 The schematic circuit diagram of the magnitude and direction of the load current when the first voltage signal and the second voltage signal in another embodiment of the present application are determined is shown. Detailed implementation manners

[0022] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the 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 drawings are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application.

[0023] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0024] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality of" means two or more unless otherwise specifically defined.

[0025] In the present application, unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0026] In this application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is less than that of the second feature.

[0027] In view of the technical problems proposed by the background art, this application provides a simple micro-current control circuit and device, which has a simple structure and the output direction and magnitude of the current are adjustable.

[0028] See the attached Figure 1 In an embodiment of this application, a simple micro-current control circuit includes an operational amplifier U1 and a first resistor R1. The operational amplifier U1 uses the model LMC6041IM and includes eight pins. Its pins 1, 5, and 8 are all NC pins, that is, empty pins; its pin 4 is the negative power supply input pin, and a working voltage of -15V is connected; its pin 7 is the positive power supply input pin, and a working voltage of +15V is connected; its pin 2 is the inverting input terminal, and is connected to a first voltage signal SIG1 through the first resistor R1; its pin 3 is the non-inverting input terminal, which is used to connect a second voltage signal SIG2; its pin 6 is the output terminal, which is used to connect a load and is connected to the inverting input terminal of the operational amplifier U1; the first resistor R1 uses a precision resistor.

[0029] In this micro-current control circuit, the feedback circuit of the operational amplifier U1 is used as the output terminal of the micro-current. The voltage of the non-inverting input terminal of the operational amplifier U1 is the voltage value of the second voltage signal SIG2, which is represented by U SIG2 ; According to the virtual short of the operational device, the voltage of the inverting input terminal of the operational amplifier U1 is equal to the voltage of the non-inverting input terminal of the operational amplifier U1, and the voltage value is also U SIG2 ; The current I R1 passing through R1 can be calculated as I R1 = (U SIG1 - U SIG2 ) / R1, where U SIG1 represents the voltage value of the second voltage signal SIG1. From the virtual open of the operational device, it can be known that the load current I RL = I R1 = (U SIG1 - U SIG2 ) / R1. Among them, virtual short and virtual open should be technical features well-known to those skilled in the art and will not be elaborated here.

[0030] When the voltage value U of the first voltage signal SIG1 connected to the inverting input terminal of the operational amplifier U1 SIG1 and the voltage value U of the second voltage signal SIG2 connected to the non-inverting input terminal of the operational amplifier U1 SIG2 are determined, and the resistance value R1 of the first resistor R1 is determined, the load current can be determined and will not change due to the change of the load, thus achieving the purpose of micro-current constant current; and through the above load current I RL According to the calculation formula, it is also possible to adjust the voltage value U of the first voltage signal SIG1 connected to the inverting input terminal of the operational amplifier U1 as needed SIG1 and the voltage value U of the second voltage signal SIG2 connected to the non-inverting input terminal of the operational amplifier U1 SIG2 The voltage difference between them realizes the control of the magnitude and direction of the load current I RL .

[0031] For example, referring to the accompanying description Figure 2 , in an embodiment, the voltage value U of the first voltage signal SIG1 connected to the inverting input terminal of the operational amplifier U1 is adjusted SIG1 to DC3V, the voltage value U of the second voltage signal SIG2 connected to the non-inverting input terminal of the operational amplifier U1 is SIG2 DC2V, the resistance value R1 of the first resistor R1 is 100Ω, the load RL is connected between the inverting input terminal and the output terminal of the operational amplifier U1, and the resistance value of the load RL is 1000Ω, then by calculating I RL1 =(U SIG1 -U SIG2 ) / R1 = +10mA, and the direction of the load current I RL1 is from the inverting input terminal of the operational amplifier U1 to the output terminal of the operational amplifier U1

[0032] Referring to the accompanying description Figure 3 , in another embodiment, the voltage value U of the first voltage signal SIG1 connected to the inverting input terminal of the operational amplifier U1 is adjusted SIG1 to DC1V, the voltage value U of the second voltage signal SIG2 connected to the non-inverting input terminal of the operational amplifier U1 is SIG2 DC2V, the resistance value R1 of the first resistor R1 is 100Ω, the load RL is connected between the inverting input terminal and the output terminal of the operational amplifier U1, and the resistance value of the load RL is 1000Ω, then by calculating I RL1 =(U SIG1 -U SIG2 ) / R1 = -10mA, and the load current I RL1The direction points from the output terminal of the operational amplifier U1 to the inverting input terminal of the operational amplifier U1.

[0033] Then when the voltage value U of the first voltage signal SIG1 is greater than the voltage value U of the second voltage signal SIG2 , the direction of the load current points from the inverting input terminal of the operational amplifier U1 to the output terminal of the operational amplifier U1; when the voltage value U of the first voltage signal SIG1 is less than the voltage value U of the second voltage signal SIG2 , the direction of the load current points from the output terminal of the operational amplifier U1 to the inverting input terminal of the operational amplifier U1.

[0034] In addition, in other embodiments, the first voltage signal SIG1 connected to the inverting input terminal of the operational amplifier U1 and the second voltage signal SIG2 connected to the non-inverting input terminal of the operational amplifier U1 can be voltage values that change periodically in magnitude in addition to being fixed voltage values, so that the direction and magnitude of the load current change accordingly. That is, when any of the voltage values of the first voltage signal SIG1 connected to the inverting input terminal of the operational amplifier U1 and the second voltage signal SIG2 connected to the non-inverting input terminal of the operational amplifier U1 is not fixed, the calculated magnitude and direction of the load current are also not fixed to meet the micro-current control requirements in special scenarios.

[0035] For example, the first voltage signal SIG1 connected to the inverting input terminal of the operational amplifier U1 is a square wave signal with a periodically changing magnitude, and the voltage value changes according to a cycle of 0V, 3V, 0V, 3V. The voltage value U of the second voltage signal SIG2 connected to the non-inverting input terminal of the operational amplifier U1 SIG2 is DC2V, the resistance value R1 of the first resistor R1 is 100Ω, the load RL is connected between the inverting input terminal and the output terminal of the operational amplifier U1, and the resistance value of the load RL is 1000Ω. Then by calculating I RL1 =(U SIG1 -U SIG2 ) / R1, the load current I RL1 is an alternating current that changes periodically with magnitudes of -10mA, +10mA, -10mA, +10mA. That is, the direction of the load current I RL1 points from the inverting input terminal of the operational amplifier U1 to the output terminal of the operational amplifier U1, or from the output terminal of the operational amplifier U1 to the inverting input terminal of the operational amplifier U1 according to the frequency of the first voltage signal SIG1.

[0036] The simple micro-current control circuit provided by the present application only uses an operational amplifier device and a precision resistor. When the first voltage signal connected to the inverting input terminal of the operational amplifier and the second voltage signal connected to the non-inverting input terminal of the operational amplifier are determined, the load current can be determined, and the current will not change due to the change of the load, so as to achieve the purpose of constant micro-current; and according to needs, the voltage difference between the first voltage signal connected to the inverting input terminal of the operational amplifier and the second voltage signal connected to the non-inverting input terminal of the operational amplifier can be adjusted to control the magnitude and direction of the load current, so as to achieve the effects of low price and diversified usage methods.

[0037] The present utility model also provides a simple micro-current control device, which adopts the above simple micro-current control circuit, and has a simple structure and adjustable current output direction and magnitude. Since the principle of solving problems by the control device in the embodiments of the present application is similar to that of the above control circuit in the embodiments of the present application, the implementation of the control device can refer to the implementation of the control circuit, and the repeated parts will not be described again.

[0038] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0039] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A simple micro-current control circuit, characterized in that: It includes an operational amplifier and a first resistor R1, the inverting input terminal of the operational amplifier is connected to a first voltage signal via the first resistor R1, the non-inverting input terminal of the operational amplifier is connected to a second voltage signal, the output terminal of the operational amplifier is connected between the inverting input terminal of the operational amplifier and the first resistor R1 via a load, and is used to control the magnitude and direction of the current passing through the load by adjusting the voltage difference between the first voltage signal and the second voltage signal; wherein, when the voltage value of the first voltage signal is greater than the voltage value of the second voltage signal, the direction of the current passing through the load is from the inverting input terminal of the operational amplifier to the output terminal of the operational amplifier; when the voltage value of the first voltage signal is less than the voltage value of the second voltage signal, the direction of the current passing through the load is from the output terminal of the operational amplifier to the inverting input terminal of the operational amplifier.

2. The simple micro-current control circuit according to claim 1, characterized in that: The magnitude of the current passing through the load is: AND RL =(U SIG1 -IN SIG2 ) / R1 Among them, U SIG1 represents the voltage value of the first voltage signal, U SIG2 represents the voltage value of the second voltage signal, and R1 represents the resistance value of the first resistor R1.

3. The simple micro-current control circuit according to claim 2, characterized in that: The first voltage signal and the second voltage signal are direct current voltage or alternating current voltage.

4. The simple micro-current control circuit according to claim 1, characterized in that: The model of the operational amplifier is LMC6041IM.

5. The simple micro-current control circuit according to claim 4, characterized in that: The positive power input pin and the negative power input pin of the operational amplifier are respectively connected to corresponding operating voltages.

6. The simple micro-current control circuit according to claim 1, characterized in that: The first resistor R1 is a precision resistor.

7. A simple micro-current control device, characterized in that: The invention comprises the simple micro-current control circuit as described in any one of claims 1 to 6.

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