Current source

Abstract

The utility model relates to the field of circuit technology, in particular to a current source, which comprises an input module, a processing loop and an output module, and is characterized in that the processing loop comprises an amplitude modulation circuit and a phase modulation circuit; the input module is used for providing variable voltage; the input end of the phase modulation circuit is connected with the output end of the input module, the input end of the amplitude modulation circuit is connected with the output end of the phase modulation circuit, and the output end of the amplitude modulation circuit is connected with the input end of the output module; the phase modulation circuit is connected with a first resistance value regulator, and the first resistance value regulator is used for regulating the output current phase of the phase modulation circuit; and a second resistance value regulator is connected in the amplitude modulation circuit and is used for regulating the amplitude of the output current of the amplitude modulation circuit. According to the invention, the current source can output currents of different specifications so as to meet the power demands of more types of electric appliances, and the adaptability of the current source is improved.

Description

Technical Field

[0001] This application relates to the field of circuit technologies, and particularly to a current source. Background Art

[0002] Constant current sources in modern industrial and scientific research production are developing towards the direction of small size, high precision, good stability, and flexible use. Especially, they have extremely wide applications in transmitter measurement and regulation. A paper named "A Safe and Reliable Adjustable Current Output Method for Power Systems" published in the journal "Instrumentation User" in 2021 discloses an adjustable constant current source. The generation of the adjustable constant current source provides a variable voltage through a DAC, and uses the characteristics of an operational amplifier to convert the voltage signal into a current signal based on the principle of voltage following.

[0003] Figure 1 The output circuit corresponding to "A Safe and Reliable Adjustable Current Output Method for Power Systems" is disclosed. Refer to Figure 1 , R1 and R2 are in a series relationship, and the current values flowing through both are equal. Therefore, as long as their resistance values are also equal, according to the characteristics of the operational amplifier, the potential difference across Ro is equal to V out . Therefore, the output current I L = V out / R o . For a determined Ro, the output current value and V out are in a linear relationship and are independent of the resistance value of the load. Thus, a constant current output of the current signal can be achieved.

[0004] However, the constant current source output circuits disclosed in the prior art can only output direct current of specified specifications and cannot generate alternating current. Summary of the Invention

[0005] In order to enable the current source to output currents of different specifications to meet the power consumption requirements of more types of electrical appliances and improve the adaptability of the current source, this application provides a current source.

[0006] In order to achieve the above object of this application, this application provides a current source.

[0007] A current source provided by this application includes an input module, a processing circuit, and an output module. The processing circuit includes an amplitude modulation circuit and a phase modulation circuit; the input module is used to provide a variable voltage;

[0008] The input end of the phase modulation circuit is connected to the output end of the input module, the input end of the amplitude modulation circuit is connected to the output end of the phase modulation circuit, and the output end of the amplitude modulation circuit is connected to the input end of the output module;

[0009] A first resistance value regulator is connected in the phase modulation circuit, and the first resistance value regulator is used to adjust the phase of the output current of the phase modulation circuit;

[0010] A second resistance value regulator is connected in the amplitude modulation circuit, and the second resistance value regulator is used to adjust the amplitude of the output current of the amplitude modulation circuit.

[0011] Optionally, the phase modulation circuit includes a first operational amplifier, a first resistor, and a second resistor, and the first resistance value regulator includes a first variable resistor and a second variable resistor; the non-inverting terminal of the first operational amplifier is connected to the output terminal of the input module, the non-inverting terminal of the first operational amplifier receives the input signal, and the non-inverting terminal of the first operational amplifier is grounded through the first variable resistor; the inverting terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier through the first resistor to form negative feedback, and the inverting terminal of the first operational amplifier is grounded through the second resistor and the second variable resistor; the negative power input terminal of the first operational amplifier is grounded.

[0012] Optionally, a first capacitor is connected in series between the non-inverting terminal of the first operational amplifier and the output terminal of the input module.

[0013] Optionally, a third resistor is connected in series between the output terminal of the input module and the first capacitor, and the output terminal of the input module is grounded through the third resistor and the second variable resistor.

[0014] Optionally, the amplitude modulation circuit includes a second operational amplifier, a third operational amplifier, a fourth resistor, a fifth resistor, and a sixth resistor, and the second resistance value regulator includes a third variable resistor,

[0015] the non-inverting terminal of the second operational amplifier is grounded, the inverting terminal of the second operational amplifier is connected to the output terminal of the first operational amplifier, the inverting terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier through the third variable resistor to form negative feedback, and a seventh resistor is connected in series between the inverting terminal of the second operational amplifier and the output terminal of the phase modulation circuit; the output terminal of the second operational amplifier is connected to the input terminal of the output module, the fourth resistor is connected in series between the output terminal of the second operational amplifier and the input terminal of the output module, and one end of the third variable resistor far from the inverting terminal of the second operational amplifier is connected between the fourth resistor and the output module;

[0016] the inverting terminal of the third operational amplifier is connected to the output terminal of the third operational amplifier to form negative feedback, the non-inverting terminal of the third operational amplifier receives the input signal, the non-inverting terminal of the third operational amplifier is connected to the output terminal of the second operational amplifier through the fifth resistor to form negative feedback, the output terminal of the third operational amplifier is connected to the output terminal of the second operational amplifier through the sixth resistor, and the output terminal of the third operational amplifier is connected between the fourth resistor and the output module;

[0017] The negative power input terminal of the second operational amplifier and the negative power input terminal of the third operational amplifier are both grounded.

[0018] Optionally, a second capacitor is connected in series between the inverting terminal and the output terminal of the second operational amplifier.

[0019] Optionally, a third capacitor is connected in series between the inverting terminal and the output terminal of the third operational amplifier.

[0020] Optionally, the current source includes more than two processing circuits.

[0021] Optionally, the first resistance value regulator and / or the second resistance value regulator is a variable resistor.

[0022] Optionally, the first resistance value regulator and / or the second resistance value regulator is a programmable digital potentiometer.

[0023] In summary, the present application includes the following beneficial technical effects:

[0024] The processing circuit includes an amplitude modulation circuit and a phase modulation circuit. A first resistance value regulator is provided in the phase modulation circuit, and a second resistance value regulator is provided in the amplitude modulation circuit. The user can determine whether to adjust the amplitude and / or phase of the output current according to actual needs. When there is an adjustment requirement, the user can adjust the amplitude (or phase) of the output current by adjusting the resistance value of the resistance value regulator located in the amplitude modulation circuit (or phase modulation circuit), so that the current source can meet the power consumption requirements of more types of electrical appliances and improve the adaptability of the current source;

[0025] The current source includes at least one processing circuit. When multiple processing circuits are provided, the current source has multiple lines capable of outputting current, so that the current source can supply power to multiple electrical devices simultaneously. The user can separately adjust the amplitude and phase of the current output by multiple processing circuits, so that the current source can simultaneously meet the usage requirements of electrical appliances with different specifications and improve the adaptability of the current source. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a circuit diagram of an existing current source described in the background art;

[0027] Figure 2 It is a module schematic diagram of a current source provided by an embodiment of the present application;

[0028] Figure 3 It is a circuit diagram of a current source provided by an embodiment of the present application;

[0029] Figure 4 It is a circuit structure diagram of a digital potentiometer provided by an embodiment of the present application;

[0030] Figure 5 The schematic diagram of a +5V power supply circuit for powering an operational amplifier provided by an embodiment of the present application;

[0031] Figure 6 For Figure 3 The initial output waveform diagram of the currents output from two processing loops of the current source shown;

[0032] Figure 7 For Figure 3 The phase - modulation output waveform diagram of the two - path currents of the current source shown when the resistance value of the first variable resistor is different;

[0033] Figure 8 For Figure 3 The amplitude - modulation output waveform diagram of the two - path currents of the current source shown when the resistance value of the third variable resistor is different;

[0034] Figure 9 For Figure 3 The amplitude - modulation output waveform diagram of the two - path currents of the current source shown when the resistance value of the second variable resistor is different.

[0035] Reference numerals: 1, input module; 21, amplitude - modulation circuit; 211, first operational amplifier; 212, first resistor; 213, second resistor; 214, third resistor; 215, first capacitor; 22, phase - modulation circuit; 221, second operational amplifier; 222, third operational amplifier; 223, fourth resistor; 224, fifth resistor; 225, sixth resistor; 226, second capacitor; 227, third capacitor; 228, seventh resistor; 3, output module; 4, first resistor value regulator; 41, first variable resistor; 42, second variable resistor; 51, third variable resistor.

[0036] The realization, functional features and advantages of the object of the present application will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0037] The following details the embodiments of the present application. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application.

[0038] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is 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 therefore should not be construed as a limitation to the present application.

[0039] In the description of the present application, unless otherwise specified and defined, it should be noted that the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the communication inside two elements. It can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0040] Refer to Figure 2 As shown, it is a schematic diagram of a module of a current source provided by an embodiment of the present application. In this embodiment, a current source includes an input module 1, a processing circuit, and an output module 3. The input module 1 is used to provide a variable voltage. In this embodiment, the input module 1 can be a current-output DAC or a voltage-output DAC. DAC is a digital-to-analog converter. The main function of the DAC is to convert a digital signal into a continuous analog current or voltage signal. The current or voltage signal output by the DAC is processed by the processing circuit and then output from the output module 3 to obtain an output current.

[0041] The number of processing circuits can be one or more than two. In the preferred embodiment of this embodiment, the number of processing circuits is more than two. When there are multiple processing circuits, the current source has multiple lines capable of outputting current, so that the current source can supply power to multiple electrical devices simultaneously. It should be noted that when the number of processing circuits is multiple, the multiple processing circuits can be connected to the same input module 1, or the multiple processing circuits can be divided into several groups, and the processing circuits in each group are connected to an input module 1. It is also possible to configure an input module 1 for each processing circuit to supply power, and this embodiment does not make any restrictions. In this embodiment, the number of processing circuits is two, and the input ends of the two processing circuits are both connected to the output end of the same input module 1, and the output ends of the two processing circuits are respectively connected to an output module 3.

[0042] Refer to Figure 3, the processing circuit includes a phase modulation circuit 21 and an amplitude modulation circuit 22. The input end of the phase modulation circuit 21 is connected to the output end of the input module 1, the input end of the amplitude modulation circuit 22 is connected to the output end of the phase modulation circuit 21, and the output end of the amplitude modulation circuit 22 is connected to the input end of the output module 3; a first resistance value regulator 4 is connected in the amplitude modulation circuit, and the first resistance value regulator 4 can adjust the amplitude of the output current of the amplitude modulation circuit 22; a second resistance value regulator is connected in the phase modulation circuit 21, and the second resistance value regulator is used to adjust the phase of the output current of the phase modulation circuit 21. In actual use, the user can adjust the resistance value of the first resistance value regulator 4 to adjust the phase of the output current, and adjust the resistance value of the second resistance value regulator to adjust the amplitude of the output current, so that the current source can meet the power consumption requirements of more types of electrical appliances and improve the adaptability of the current source.

[0043] Referring to Figure 3 , the phase modulation circuit 21 includes a first operational amplifier 211, a first resistor 212 and a second resistor 213. In the preferred embodiment of this embodiment, the phase modulation partial circuit is mainly built based on a low-noise and high-gain operational amplifier of model OP07; the first resistance value regulator 4 includes a first variable resistor 41 and a second variable resistor 42; the non-inverting terminal of the first operational amplifier 211 is connected to the output end of the input module 1, the non-inverting terminal of the first operational amplifier 211 receives the input signal, and the non-inverting terminal of the first operational amplifier 211 is grounded through the first variable resistor 41; the inverting terminal of the first operational amplifier 211 is connected to the output end of the first operational amplifier 211 through the first resistor 212 to form negative feedback, and the inverting terminal of the first operational amplifier 211 is grounded through the second resistor 213 and the second variable resistor 42; in this embodiment, the operational amplifier is powered by dual power supplies.

[0044] Referring to Figure 3 , a third resistor 214 is connected in series between the output end of the input module 1 and the first capacitor 215, and the output end of the input module 1 is grounded through the third resistor 214 and the second variable resistor 42. The third resistor 214 can protect the phase modulation circuit 21 to prevent the input end of the voltage / current from being directly grounded.

[0045] Referring to Figure 3 , a first capacitor 215 is connected in series between the non-inverting terminal of the first operational amplifier 211 and the output end of the input module 1. The first capacitor 215 can respond to the transient change of the input signal. Through the long-term change of the input signal, the first capacitor 215 can play an integral role, enabling the system to respond to the control deviation. When the input rectangular pulse signal sent by the input module 1 undergoes a jump, the voltage received by the first operational amplifier 211 is kept unchanged, the offset voltage of the amplifier circuit is eliminated, and the circuit is protected.

[0046] The amplitude modulation circuit 22 is mainly built based on the high-voltage and high-current operational amplifier with the model number OPA549. The operational amplifier with the model number OPA549 can indirectly sense the load without the need to series a power resistor at the output current terminal. This allows directly adjusting the current amplitude using the resistor value regulator 4 (rheostat or digital potentiometer), or digitally controlling the operational amplifier with the model number OPA549 using a voltage or current output DAC. This embodiment has no restrictions. In this embodiment, OPA549 requires a ±5V constant voltage power supply, and the maximum operating current is not less than 10A. The circuit schematic diagram of the positive 5V power supply circuit is as Figure 4 shown. The design principle of the negative 5V power supply is the same as that of the positive 5V. As long as the function of providing a constant voltage power supply for the operational amplifier with the model number OPA549 can be achieved, for the sake of simplicity of the specification, it will not be elaborated here.

[0047] Referring to Figure 3 , the amplitude modulation circuit 22 includes a second operational amplifier 221, a third operational amplifier 222, a fourth resistor 223, a fifth resistor 224, and a sixth resistor 225. The second resistor value regulator includes a third variable resistor 51.

[0048] The non-inverting terminal of the second operational amplifier 221 is grounded. The inverting terminal of the second operational amplifier 221 is connected to the output terminal of the first operational amplifier 211. The inverting terminal of the second operational amplifier 221 is connected to the output terminal of the second operational amplifier 221 through the third variable resistor 51 to form negative feedback. A seventh resistor 228 is connected in series between the inverting terminal of the second operational amplifier 221 and the output terminal of the phase modulation circuit 21. The output terminal of the second operational amplifier 221 is connected to the input terminal of the output module 3. The fourth resistor 223 is connected in series between the output terminal of the second operational amplifier 221 and the input terminal of the output module 3. One end of the third variable resistor 51 far from the inverting terminal of the second operational amplifier 221 is connected between the fourth resistor 223 and the output module 3.

[0049] The inverting terminal of the third operational amplifier 222 is connected to the output terminal of the third operational amplifier 222 to form negative feedback. The non-inverting terminal of the third operational amplifier 222 receives the input signal. The non-inverting terminal of the third operational amplifier 222 is connected to the output terminal of the second operational amplifier 221 through the fifth resistor 224 to form negative feedback. The output terminal of the third operational amplifier 222 is connected to the output terminal of the second operational amplifier 221 through the sixth resistor 225. The output terminal of the third operational amplifier 222 is connected between the fourth resistor 223 and the output module 3.

[0050] Referring to Figure 3, a second capacitor 226 is connected in series between the inverting terminal and the output terminal of the second operational amplifier 221, and a third capacitor 227 is connected in series between the inverting terminal and the output terminal of the third operational amplifier 222; both the second capacitor 226 and the third capacitor 227 can play a filtering role, reducing the AC pulsating ripple and ensuring the stability and reliability of the circuit.

[0051] By adjusting the resistance value of the first variable resistor 41, the output current phase can be adjusted. In the phase adjustment circuit, the first variable resistor 41 and the first capacitor 215 form a phase compensation circuit, and the output phase can be adjusted by adjusting the first variable resistor 41.

[0052] Figure 3 The current source shown includes two processing loops, and the Figure 3 The processing loop composed of the upper half of the phase adjustment circuit 21 and the amplitude modulation circuit 22 is denoted as the first processing loop, and the output current after being processed by the first processing loop is I1; the processing loop composed of the lower half of the Figure 3 phase adjustment circuit 21 and the amplitude modulation circuit 22 is denoted as the second processing loop, and the output current after being processed by the second processing loop is I2; in this embodiment, the output phase of the output current I1 can be adjusted by adjusting the first variable resistor R4 in the first processing loop, and the output phase of the output current I2 can be adjusted by adjusting the first variable resistor R 15 in the second processing loop. The calculation formula for the tangent value of the output current phase angle is

[0053]

[0054] where, ω in the formula represents the angular frequency, and ω is usually in radians per second (rad / s). In an AC circuit, ω is related to the frequency and initial phase of the sinusoidal current and is used to describe the law of current change; R represents the resistance value of the first variable resistor 41 connected to the circuit. In this embodiment, R represents the value of R4 or R 15 value; C represents the value of the first capacitor 215;

[0055] In addition, the second variable resistor 42 is a voltage dividing resistor. By adjusting the second variable resistor 42, the magnitude of the input voltage can be changed, thereby adjusting the amplitude of the output current; in this embodiment, the input voltage U of the first operational amplifier 211 in the first processing loop is U = Uac * R2 / (R1 + R2), where Uac is the total voltage output by the input module, R1 represents the resistance value of the third resistor 214, and R2 represents the resistance value of the second variable resistor 42.

[0056] By adjusting the resistance value of the third variable resistor 51, the amplitude of the output current can be adjusted. In the amplitude modulation circuit 22, the third variable resistor 51 is a feedback resistor. By adjusting the resistance value of the third variable resistor 51 (such asFigure 3 R9 or R in 20 ) to change the feedback coefficient, thereby adjusting the gain of the operational amplifier; in this embodiment, the gain expression of the operational amplifier in the first processing loop amplitude modulation circuit 22 is G = 1 + R9 / R6; the gain expression of the operational amplifier in the second processing loop amplitude modulation circuit 22 is G = 1 + R 20 / R 17 ; R6 and / or R 17 is the seventh resistor 228, R9 and R 20 is the third variable resistor 51, R9 and / or R 20 takes the value of the resistance of the third variable resistor 51 connected to the circuit.

[0057] In some examples of this embodiment, the first resistor value regulator 4 and / or the second resistor value regulator is a variable resistor, such as a slide rheostat or a resistance box, etc.;

[0058] In another example of this embodiment, the first resistor value regulator 4 and / or the second resistor value regulator is a digital potentiometer. In the preferred implementation manner of this embodiment, the resistor value regulator 4 is a programmable digital potentiometer. Compared with the traditional rotary rheostat, the digital potentiometer can change the resistance value without physical contact, so it has higher precision and repeatability; in addition, the user can control and configure the programmable digital potentiometer by programming (such as setting parameters such as voltage, current range, gain, and filtering), improving the convenience and accuracy of the current source during use and adjustment.

[0059] In this embodiment, the programmable digital potentiometer is built based on the integrated chip AD5293. As Figure 5 shown, it can be equivalent to the circuit shown in Figure 5 (b). The expression of the digitally programmed output resistance between the W terminal and the B terminal is

[0060]

[0061] In the formula, D is the decimal equivalent of the binary code loaded in the 10-bit RDAC register. D is a parameter inside the integrated chip and can be adjusted through a program; R AB is the resistance between the A terminal and the B terminal. Similarly, the expression of the digitally programmed output resistance between the W terminal and the A terminal is

[0062]

[0063] In this case, the selected models of the resistor value regulator 4 are as follows. For the first variable resistor 41 and the second variable resistor 42, resistors with a model of 20 kΩ can be selected (total resistance value is 20 kΩ); for the third variable resistor 51, a resistor with a model of 100 kΩ is selected (total resistance value is 100 kΩ).

[0064] Taking the following Figure 3 two processing circuits as an example, the amplitude modulation and phase modulation effects of the current source of the present application are verified. The first processing circuit is the experimental group, and the second processing circuit is the control group.

[0065] Based on Figure 3 the circuit shown and the relevant parameters in the schematic diagram, a system simulation model is built under the PLECS platform. Figure 6 The following shows the output waveforms of the two currents when R2 = R13 = 4.82 kΩ and R4 = R15 = 10 kΩ, and the third variable resistors R9 and R20 are adjusted to 15 kΩ each. At this time, the two currents are in the same phase, the current peak value is about 14.15 A, and the effective value is about 10 A.

[0066] Verification of the phase modulation function:

[0067] First, keep the second variable resistor 42 fixed. If the first variable resistor R 15 in the second processing circuit remains unchanged, adjust the first variable resistor R4 in the first processing circuit. Set the first variable resistor R4 to 30 kΩ, 60 kΩ, 90 kΩ, and 120 kΩ respectively to obtain the simulation output waveforms of the two currents, as shown in Figure 7 . It can be seen that during the process of gradually increasing the first variable resistor R4, the phase angle by which the output current I1 of the first processing circuit lags behind the output current I2 of the second processing circuit gradually increases, but the amplitudes of the currents in the two processing circuits always remain unchanged. Similarly, if the first variable resistor R4 remains unchanged and the first variable resistor R 15 is increased, it can be obtained that the phase angle by which the output current I1 (i.e., I1 in the attached drawing) of the first processing circuit leads the output current I2 (i.e., I2 in the attached drawing) of the second processing circuit gradually increases, and the amplitudes of the two currents also remain unchanged.

[0068] Verification of the amplitude modulation function:

[0069] If the first variable resistor R4 and the first variable resistor R 15 are adjusted to 15 kΩ each, R2 = R13 = 4.82 kΩ is fixed, and the values of the third variable resistors R9 and R 20 are set to 1 kΩ, 4 kΩ, 7 kΩ, and 10 kΩ respectively for simulation, the current waveforms as shown in Figure 8 are obtained. It can be seen that when the third variable resistors R9 and R 20When it increases, the output current gradually increases, but the phase relationship remains unchanged, achieving the effect of amplitude modulation. If you want to adjust the amplitude of the output current I1 of the first processing circuit alone, you only need to adjust the third variable resistor R9 alone. If you want to adjust the amplitude of the output current I2 of the second processing circuit alone, you only need to adjust the third variable resistor R 20 That's all.

[0070] If the first variable resistor R4 and the first variable resistor R 15 are adjusted to both be 15 kΩ, and R9 = R20 = 10 kΩ remains fixed, and the second variable resistor R2 and the second variable resistor R 13 are respectively set to 1 kΩ, 2 kΩ, 3 kΩ, 4 kΩ simultaneously for simulation, and the Figure 9 shown output current waveforms are obtained. It can be seen that by adjusting the values of the second variable resistor R2 and the first variable resistor R 13 , the effect of amplitude modulation can also be achieved, but the change in the amplitude of the output current is more affected by the second variable resistor R2 and / or the first variable resistor R 13 . Therefore, when adjusting the amplitude of the output current, the second variable resistor 42 can be used as a coarse adjustment resistor, and the third variable resistor 51 can be used as a fine adjustment resistor.

[0071] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", "one implementation manner", "one preferred implementation manner" or "some examples", etc., mean 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 expressions 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 a suitable manner in any one or more embodiments or examples.

[0072] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. A current source, characterized in that, It includes an input module (1), a processing circuit, and an output module (3). The processing circuit includes an amplitude modulation circuit (22) and a phase modulation circuit (21); the input module (1) is used to provide a variable voltage. The input end of the phase modulation circuit (21) is connected to the output end of the input module (1), the input end of the amplitude modulation circuit (22) is connected to the output end of the phase modulation circuit (21), and the output end of the amplitude modulation circuit (22) is connected to the input end of the output module (3). A first resistance value regulator (4) is connected in the phase modulation circuit (21), and the first resistance value regulator (4) is used to adjust the phase of the output current of the phase modulation circuit (21). A second resistance value regulator is connected in the amplitude modulation circuit (22), and the second resistance value regulator is used to adjust the amplitude of the output current of the amplitude modulation circuit (22).

2. The current source according to claim 1, wherein The phase modulation circuit (21) includes a first operational amplifier (211), a first resistor (212), and a second resistor (213). The first resistance value regulator (4) includes a first variable resistor (41) and a second variable resistor (42). The non-inverting terminal of the first operational amplifier (211) is connected to the output end of the input module (1). The non-inverting terminal of the first operational amplifier (211) receives an input signal, and the non-inverting terminal of the first operational amplifier (211) is grounded through the first variable resistor (41). The inverting terminal of the first operational amplifier (211) is connected to the output end of the first operational amplifier (211) through the first resistor (212) to form negative feedback. The inverting terminal of the first operational amplifier (211) is grounded through the second resistor (213) and the second variable resistor (42).

3. The current source according to claim 2, wherein, A first capacitor (215) is connected in series between the non-inverting terminal of the first operational amplifier (211) and the output end of the input module (1).

4. A current source as claimed in claim 3, wherein, A third resistor (214) is connected in series between the output end of the input module (1) and the first capacitor (215). The output end of the input module (1) is grounded through the third resistor (214) and the second variable resistor (42).

5. A current source according to any one of claims 1 to 4, characterized in that The amplitude modulation circuit (22) includes a second operational amplifier (221), a third operational amplifier (222), a fourth resistor (223), a fifth resistor (224), and a sixth resistor (225). The second resistance value regulator includes a third variable resistor (51). The non-inverting terminal of the second operational amplifier (221) is grounded. The inverting terminal of the second operational amplifier (221) is connected to the output end of the first operational amplifier (211). The inverting terminal of the second operational amplifier (221) is connected to the output end of the second operational amplifier (221) through the third variable resistor (51) to form negative feedback. A seventh resistor (228) is connected in series between the inverting terminal of the second operational amplifier (221) and the output end of the phase modulation circuit (21). The output end of the second operational amplifier (221) is connected to the input end of the output module (3). The fourth resistor (223) is connected in series between the output end of the second operational amplifier (221) and the input end of the output module (3). One end of the third variable resistor (51) far from the inverting terminal of the second operational amplifier (221) is connected between the fourth resistor (223) and the output module (3). The inverting terminal of the third operational amplifier (222) is connected to the output terminal of the third operational amplifier (222) to form negative feedback; the non-inverting terminal of the third operational amplifier (222) receives an input signal, and the non-inverting terminal of the third operational amplifier (222) is connected to the output terminal of the second operational amplifier (221) through a fifth resistor (224) to form negative feedback. The output terminal of the third operational amplifier (222) is connected to the output terminal of the second operational amplifier (221) through a sixth resistor (225), and the output terminal of the third operational amplifier (222) is connected between the fourth resistor (223) and the output module (3).

6. A current source according to claim 5, wherein, A second capacitor (226) is connected in series between the inverting terminal and the output terminal of the second operational amplifier (221).

7. An current source according to claim 5, characterized in that, A third capacitor (227) is connected in series between the inverting terminal and the output terminal of the third operational amplifier (222).

8. A current source according to any one of claims 1, 2, 3, 4, 6 or 7, characterized in that, The current source includes more than two processing circuits.

9. A current source according to any one of claims 1, 2, 3, 4, 6 or 7, characterized in that, The first resistance value regulator (4) and / or the second resistance value regulator is a variable resistor.

10. A current source according to any one of claims 1, 2, 3, 4, 6 or 7, characterized in that, The first resistance value regulator (4) and / or the second resistance value regulator is a programmable digital potentiometer.

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