Direct current amplifier

Abstract

An MCU (Microprogrammed Control Unit), a DAC (Digital-to-Analog Converter), a PWM (Pulse-Width Modulation) controller, a power topology and a feedback network are connected to form single equipment, different functions are realized through an interface for realizing signal access of the MCU, and the amplification factor (gain) is no longer determined by an external resistor, but is determined by the maximum equipment range stored in the MCU through software calculation. Therefore, the same hardware platform can be configured into products with different magnification times through software. In addition, an interface of an analog instruction is reconstructed, an externally input 0-5V analog signal is not directly used as a target voltage value, but is used as a proportional reference value, and the MCU executes operation: a target output value = (input voltage / 5V) * range upper limit, so that the DAC is controlled to output corresponding output voltage.

Description

Technical Field

[0001] This invention relates to the field of current amplification technology for electronic devices, and more specifically, to a DC amplifier. Background Technology

[0002] Traditional integrated operational amplifiers have excellent analog signal processing capabilities, can achieve precise voltage amplification, and have excellent linearity and high-frequency response. However, their output power is usually only tens to hundreds of milliwatts, and they can only process signal-level energy. They cannot directly drive loads that require tens, hundreds, or even thousands of watts of power, such as motors, heaters, and high-power LEDs. Therefore, system designers need to add complex power amplification stages, which greatly increases the complexity and design difficulty of the system.

[0003] Conventional programmable switching power supplies can provide DC power of kilowatts or more and can directly drive various heavy loads. However, they are positioned as stable output sources rather than amplifiers. The output value is mostly set through digital interfaces or panel operation. They lack amplification interfaces that can follow changes in external analog input signals in real time and linearly. They cannot meet the needs of scenarios such as analog power load testing and linear power driving, where small signals are proportionally amplified to high power output.

[0004] The stark contrast between traditional integrated operational amplifiers and conventional programmable switching power supplies presents a challenge. On one hand, there are low-power operational amplifiers that can amplify but not drive, while on the other hand, there are high-power switching power supplies that can drive but not amplify. This creates a technological gap in the market for integrated devices that can directly and linearly convert and amplify small-signal voltage / current signals into high-power output. Summary of the Invention

[0005] To simultaneously achieve amplification and driving capabilities, this invention provides a DC amplifier that connects an MCU, DAC, PWM controller, power topology, and feedback network into a single device. Different functions are achieved through the MCU (Microcontroller Unit) interface for signal input. The amplification factor (gain) is no longer determined by an external resistor but by software calculation based on the device's maximum range (Vmax, Imax, Pmax) stored internally in the MCU. This allows the same hardware platform to be configured with products of different amplification factors via software. Furthermore, the analog instruction interface has been restructured. The externally input 0-5V analog signal is no longer directly used as a target voltage value but as a proportional reference value. The MCU performs the calculation: Target output value = (Input voltage / 5V) * Maximum range, and uses this to control the corresponding output voltage of the DAC. Additionally, the reference voltage input of the error amplifier in the switching power supply control chip has been changed from being connected to a fixed source to being connected to the DAC output controlled by the MCU. This means the switching power supply no longer stabilizes at an internally set value but instead outputs a voltage that tracks an externally dynamically changing value.

[0006] The technical solution of this invention is as follows:

[0007] A DC amplifier, including

[0008] The user input module is used to receive analog input signals from the outside, including voltage signals or current signals. The amplitude of the analog input signal represents the set value of the output parameter.

[0009] The microcontroller unit, connected to the user input module, is used to process analog input signals according to the selected output mode and generate corresponding digital control signals;

[0010] The digital-to-analog converter module, connected to the microcontroller unit, is used to convert digital control signals into analog reference voltages;

[0011] The switching power supply controller, connected to the digital-to-analog converter module, is used to receive an analog reference voltage;

[0012] A switching power supply topology circuit, connected to a switching power supply controller, is used to convert the input DC power into a set DC power output under the control of the PWM wave output by the switching power supply controller.

[0013] The negative feedback network is connected between the output terminal of the switching power supply topology circuit and the feedback input terminal of the switching power supply controller. It is used to sample the output voltage of the switching power supply topology circuit, generate a feedback voltage, and transmit it to the switching power supply controller.

[0014] The switching power supply controller compares the feedback voltage with the analog reference voltage and dynamically adjusts the duty cycle of the PWM wave output to the switching power supply topology circuit based on the comparison result, so that the feedback voltage tracks the analog reference voltage, thereby forming a closed-loop control and realizing the linear amplification of the analog input signal into a high-power DC output.

[0015] The aforementioned DC amplifier includes a user input module comprising at least three independent analog input interfaces, which are respectively used to set a constant voltage output mode, a constant current output mode, and a constant power output mode. The microcontroller unit automatically identifies and switches the corresponding output mode according to the interface to which the analog input signal is connected.

[0016] The microcontroller unit is also used for mode management: in constant voltage output mode, the microcontroller unit processes the received voltage input signal according to the preset voltage range V. max The target output voltage is calculated, and the corresponding digital control signal is generated. In constant current output mode, the microcontroller receives the current input signal according to the preset current range I. maxThe target output current is calculated, and the corresponding digital control signal is generated. In constant power mode, the microcontroller receives the power input signal according to the preset current range P. max The target output power is calculated, and the corresponding digital control signal is generated.

[0017] The aforementioned DC amplifier also includes an analog-to-digital converter module, the input terminal of which is connected to the output terminal of the switching power supply topology circuit, and the output terminal of which is connected to the microcontroller unit.

[0018] The microcontroller unit acquires the actual output voltage and current values ​​of the switching power supply topology circuit in real time through the analog-to-digital conversion module. These values ​​are used for output display, overload protection, or as feedback for power calculation in constant power mode.

[0019] The aforementioned DC amplifier, the switching power supply controller includes an error amplifier, an analog reference voltage is connected to the non-inverting input of the error amplifier, and a feedback voltage is connected to the inverting input of the error amplifier.

[0020] The output of the error amplifier controls a PWM generator circuit, thus forming the core of the closed-loop control.

[0021] Furthermore, the negative feedback network is a resistor voltage divider network, which divides the high output voltage of the switching power supply topology to obtain a feedback voltage that matches the range of the analog reference voltage.

[0022] The aforementioned DC amplifier, with its switching power supply topology circuit including a switching transistor, a high-frequency transformer, and an output filter, performs high-frequency switching under the control of a PWM wave, chopping the input DC current into high-frequency AC current. After voltage transformation and electrical isolation by the high-frequency transformer, the high-frequency components are filtered out by the output filter, resulting in a smooth and stable output DC current.

[0023] The control method for the aforementioned DC amplifier includes:

[0024] Mode setting steps: Receive the output mode selected by the user. The output mode includes constant voltage mode, constant current mode or constant power mode.

[0025] Signal receiving steps: Receive the analog input signal from the user;

[0026] Signal processing steps: The microcontroller calculates the target output value based on the selected output mode and the amplitude of the analog input signal, and generates the corresponding digital control signal;

[0027] Reference generation steps: Convert the digital control signal into an analog reference voltage using a digital-to-analog converter module;

[0028] Closed-loop control steps: The switching power supply controller compares the feedback voltage from the negative feedback network with the analog reference voltage, and controls the output of the switching power supply topology circuit by adjusting the duty cycle of the PWM wave, so that the feedback voltage continuously approaches the analog reference voltage.

[0029] Power output steps: The amplified DC voltage and current are output by the switching power supply topology circuit to drive the external load.

[0030] Furthermore, the closed-loop control steps include:

[0031] When the load increases and causes the output voltage to drop, the feedback voltage also drops, which leads to an increase in the duty cycle of the PWM wave output by the switching power supply controller, thereby causing the output voltage of the switching power supply topology circuit to rise again.

[0032] When the load decreases and the output voltage increases, the feedback voltage increases accordingly, which reduces the duty cycle of the PWM wave and causes the output voltage to drop, thereby achieving dynamic stability of the output.

[0033] Furthermore, in constant power mode, the signal processing steps include: the microcontroller calculates the target output power value based on the analog input signal, and collects the output voltage and current in real time, calculates the real-time output power, compares the real-time output power with the target output power value, and stabilizes the real-time output power at the target output power value by adjusting the analog reference voltage.

[0034] According to the above-described solution, the beneficial effects of this invention are as follows:

[0035] 1. Achieved high-power amplification of DC signals (voltage, current, power): The core effect is that it can linearly amplify weak DC control signals (0-5V / 0-20mA) into stable DC power (such as 300V / 50A / 15kW) that can directly drive kilowatt-level or even higher power loads, solving the fundamental problem that small signals cannot directly drive large equipment.

[0036] 2. Offers multiple programmable output modes: It features three operating modes: constant voltage, constant current, and constant power. Users can flexibly set the device's operating status by selecting different input interfaces or software commands to meet diverse testing and driving needs.

[0037] 3. Achieves high-precision linear control and output: Based on MCU and high-speed closed-loop feedback control, it maintains a good linear relationship between output and input (fixed amplification factor), with precise control, simple calculation, and easy integration into automation systems.

[0038] 4. Ensures high output stability and dynamic response speed: The combination of PWM control and negative feedback closed loop of switching power supply can quickly respond to load changes (such as load increase or decrease) and automatically adjust to maintain the stability of the set output value, with strong anti-load disturbance capability.

[0039] 5. It has real-time monitoring and display functions: Through the built-in ADC circuit, the MCU can collect and display parameters such as output voltage, current, and power in real time, which makes it convenient for users to monitor the system's working status and improves the availability and safety of the equipment. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the working module structure of the DC amplifier of the present invention.

[0042] Figure 2 This is a schematic diagram of the connection circuit of the microcontroller unit of the DC amplifier of the present invention.

[0043] Figure 3 This is a schematic diagram of the connection circuit of the switching power supply controller for the DC amplifier of the present invention.

[0044] Figure 4 This is a schematic diagram of the connection circuit of the switching power supply topology of the DC amplifier of the present invention.

[0045] Figure 5 This is a schematic diagram of the connection circuit for the auxiliary power supply circuit of the DC amplifier of the present invention.

[0046] Figure 6 This is a schematic diagram of the connection circuit for the error amplification and current sampling circuit of the DC amplifier of the present invention.

[0047] Figure 7 This is a schematic diagram of the connection circuit for the user input signal processing circuit of the DC amplifier of the present invention. Figure 1 .

[0048] Figure 8 This is a schematic diagram of the connection circuit for the user input signal processing circuit of the DC amplifier of the present invention. Figure 2 .

[0049] Figure 9 This is a schematic diagram of the connection circuit for the user input signal processing circuit of the DC amplifier of the present invention. Figure 3 . Detailed Implementation

[0050] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0051] A DC amplifier, such as Figure 1 As shown, including

[0052] The user input module is used to receive analog input signals from the outside, including voltage signals or current signals. The amplitude of the analog input signal represents the set value of the output parameter.

[0053] The microcontroller unit, connected to the user input module, is used to process analog input signals according to the selected output mode and generate corresponding digital control signals;

[0054] The digital-to-analog converter module, connected to the microcontroller unit, is used to convert digital control signals into analog reference voltages;

[0055] The switching power supply controller, connected to the digital-to-analog converter module, is used to receive an analog reference voltage;

[0056] A switching power supply topology circuit, connected to a switching power supply controller, is used to convert the input DC power into a set DC power output under the control of the PWM wave output by the switching power supply controller.

[0057] The negative feedback network is connected between the output terminal of the switching power supply topology circuit and the feedback input terminal of the switching power supply controller. It is used to sample the output voltage of the switching power supply topology circuit, generate a feedback voltage, and transmit it to the switching power supply controller.

[0058] The switching power supply controller compares the feedback voltage with the analog reference voltage and dynamically adjusts the duty cycle of the PWM wave output to the switching power supply topology circuit based on the comparison result, so that the feedback voltage tracks the analog reference voltage, thereby forming a closed-loop control and realizing the linear amplification of the analog input signal into a high-power DC output.

[0059] The connection circuit of the microcontroller unit is as follows: Figure 2 As shown.

[0060] A circuit for a DC amplifier, such as Figure 3 As shown, it includes the first chip.

[0061] The first pin of the first chip is connected to the other end of the 25th capacitor, the other end of the 35th resistor, and the other end of the 38th resistor, respectively. One end of the 25th capacitor is connected to the ground wire, the 7th pin of the first chip, the 9th pin of the first chip, and the 10th pin of the first chip, respectively. One end of the 35th resistor is connected to the other end of the 23rd capacitor, the other end of the 33rd resistor, and the ground wire, respectively. One end of the 38th resistor is connected to the output circuit.

[0062] The second pin of the first chip is connected to the other end of the eighteenth capacitor, the other end of the twentieth capacitor, one end of the twenty-third capacitor, one end of the thirty-third resistor, and the other end of the second rheostat PR2. One end of the eighteenth capacitor is connected to the third pin of the first chip, the other end of the twenty-eighth resistor, and the other end of the twenty-ninth resistor. One end of the twentieth capacitor is connected to one end of the twenty-ninth resistor. The other end of the twenty-ninth resistor is connected to the other end of the twenty-eighth resistor, one end of the eighteenth capacitor, and the third pin of the first chip. The other end of the twenty-third capacitor is connected to one end of the thirty-fifth resistor, the other end of the thirty-third resistor, and the ground wire. The other end of the thirty-third resistor is connected to the other end of the twenty-third capacitor, the end of the thirty-fifth resistor, and the ground wire. One end of the second potentiometer is connected to the other end of the thirty-first resistor. One end of the thirty-first resistor is connected to the reference circuit and one end of the twenty-seventh resistor. The other end of the twenty-seventh resistor is connected to one end of the rheostat CCA1. The other end of the rheostat CCA1 is connected to the other end of the twenty-sixth resistor, one end of the seventeenth capacitor, and the fifteenth pin of the first chip. One end of the twenty-sixth resistor is connected to the current source IS.

[0063] The third pin of the first chip is connected to one end of the eighteenth capacitor, the other end of the twenty-eighth resistor, and the other end of the twenty-ninth resistor. The other end of the eighteenth capacitor is connected to the other end of the twentieth capacitor, one end of the twenty-third capacitor, one end of the thirty-third resistor, the other end of the second potentiometer, and the second pin of the first chip. One end of the twenty-eighth resistor is connected to the other end of the seventeenth capacitor, and one end of the twenty-ninth resistor is connected to one end of the twentieth capacitor.

[0064] The fourth pin of the first chip is connected to one end of the thirty-ninth resistor, one end of the twenty-seventh capacitor, the other end of the thirty-sixth resistor, the cathode of the thirteenth diode, and the cathode of the nineteenth diode. The other end of the thirty-ninth resistor is connected to the reference circuit, the other end of the twenty-seventh capacitor, and one end of the fortieth resistor. One end of the thirty-sixth resistor is connected to the other end of the thirty-second resistor, the other end of the twenty-first capacitor, the other end of the first oscillation timing capacitor, the other end of the first oscillation timing resistor, the other end of the fourteenth capacitor, and the ground wire. The anode of the thirteenth diode is connected to the other end of the fortieth resistor, one end of the twenty-ninth capacitor, and the drain of the sixth power transistor. The other end of the twenty-ninth capacitor is grounded. The gate of the sixth power transistor is connected to one end of the forty-fifth resistor and the other end of the forty-eighth resistor. One end of the forty-eighth resistor is connected to the output circuit. The source of the sixth power transistor is connected to the other end of the forty-fifth resistor and the ground wire.

[0065] The fifth pin of the first chip is connected to one end of the first oscillation timing capacitor. The other end of the first oscillation timing capacitor is connected to the other end of the fourteenth capacitor, the other end of the first oscillation timing resistor, the ground wire, the other end of the thirty-second resistor, the other end of the twenty-first capacitor, and one end of the thirty-sixth resistor.

[0066] The sixth pin of the first chip is connected to one end of the first oscillation timing resistor. The other end of the first oscillation timing resistor is connected to the other end of the fourteenth capacitor, the ground wire, the other end of the thirty-second resistor, the other end of the twenty-first capacitor, one end of the thirty-sixth resistor, and the other end of the first oscillation timing capacitor.

[0067] The seventh pin of the first chip is connected to one end of the twenty-fifth capacitor, the ninth pin of the first chip, the tenth pin of the first chip, and the ground wire, respectively. The other end of the twenty-fifth capacitor is connected to the first pin of the first chip, the other end of the thirty-eighth resistor, and the other end of the thirty-fifth resistor, respectively.

[0068] The eighth pin of the first chip is connected to the first external contact C1;

[0069] The ninth pin of the first chip is connected to the ground wire, the tenth pin of the first chip, the seventh pin of the first chip, and one end of the twenty-fifth capacitor, respectively.

[0070] The tenth pin of the first chip is connected to the ground wire, the ninth pin of the first chip, the seventh pin of the first chip, and one end of the twenty-fifth capacitor, respectively.

[0071] The eleventh pin of the first chip is connected to the second external terminal C2;

[0072] The twelfth pin of the first chip is connected to DC power and one end of the fourteenth capacitor. The other end of the fourteenth capacitor is connected to the other end of the first oscillation timing resistor, the other end of the first oscillation timing capacitor, the other end of the thirty-second resistor, the other end of the twenty-first capacitor, and one end of the thirty-sixth resistor.

[0073] The thirteenth pin of the first chip is connected to the reference circuit, the other end of the sixteenth capacitor, and the fourteenth pin of the first chip, respectively, and one end of the sixteenth capacitor is grounded.

[0074] The fourteenth pin of the first chip is connected to the reference circuit, the other end of the sixteenth capacitor, and the thirteenth pin of the first chip, respectively.

[0075] The fifteenth pin of the first chip is connected to the other end of the twenty-sixth resistor, the other end of the variable resistor CCA1, the sliding end of the variable resistor CCA1, and one end of the seventeenth capacitor. One end of the twenty-sixth resistor is connected to the current source IS, and the other end of the seventeenth capacitor is connected to one end of the twenty-eighth resistor.

[0076] The sixteenth pin of the first chip is connected to one end of the thirty-second resistor and one end of the twenty-first capacitor. The other end of the thirty-second resistor is connected to the other end of the fourteenth capacitor, the other end of the first oscillation timing resistor, ground, the other end of the first oscillation timing capacitor, the other end of the twenty-first capacitor, and one end of the thirty-sixth resistor. The other end of the twenty-first capacitor is connected to the other end of the fourteenth capacitor, the other end of the first oscillation timing resistor, ground, the other end of the first oscillation timing capacitor, the other end of the thirty-second resistor, and one end of the thirty-sixth resistor.

[0077] The power switch topology module also includes a short-circuit protection circuit, which is connected to the fourth pin of the first chip, one end of the thirty-ninth resistor, one end of the twenty-seventh capacitor, the other end of the thirty-sixth resistor, and the cathode of the thirteenth diode.

[0078] The cathode of the nineteenth diode in the short-circuit protection circuit is connected to the fourth pin of the first chip, one end of the thirty-ninth resistor, one end of the twenty-seventh capacitor, the other end of the thirty-sixth resistor, and the cathode of the thirteenth diode, respectively. The anode of the nineteenth diode in the short-circuit protection circuit is connected to the drain of the seventh power transistor.

[0079] The drain of the seventh power transistor in the short-circuit protection circuit is connected to the anode of the nineteenth diode. The gate of the seventh power transistor is connected to the other end of the fifty-fifth resistor, the cathode of the fourth photodiode, and one end of the third switch. The source of the seventh power transistor is connected to the other end of the fifty-sixth resistor. One end of the fifty-fifth resistor is connected to the reference circuit, one end of the fifty-sixth resistor, and one end of the fifty-seventh resistor. The anode of the fourth photodiode is connected to the other end of the fifty-seventh resistor. The other end of the third switch is grounded.

[0080] like Figure 4 As shown,

[0081] The first pin of the first transformer is connected to the cathode of the fourth diode and the collector of the first MOSFET, respectively. The anode of the fourth diode is connected to the emitter of the first MOSFET, the cathode of the seventh diode, the emitter of the fourth MOSFET, one end of the ninth capacitor, and the anode of the fifth diode, respectively.

[0082] The base of the first MOSFET is connected to the other end of the seventh resistor, the other end of the eighth resistor, and the second external terminal C2. One end of the seventh resistor is connected to DC power, and one end of the eighth resistor is grounded.

[0083] The emitter of the first MOSFET is connected to the anode of the fourth diode, the cathode of the seventh diode, the emitter of the fourth MOSFET, one end of the ninth capacitor, and the anode of the fifth diode. The cathode of the fifth diode is connected to the anode of the sixth diode. The cathode of the sixth diode is grounded. The other end of the ninth capacitor is grounded. The anode of the seventh diode is connected to the third pin of the first transformer. The cathode of the fourth diode is connected to the collector of the first MOSFET and the first pin of the first transformer.

[0084] The collector of the first MOSFET is connected to the cathode of the fourth diode and the first pin of the first transformer, respectively.

[0085] The emitter of the fourth MOSFET is connected to the anode of the fourth diode, the cathode of the seventh diode, the emitter of the first MOSFET, one end of the ninth capacitor, and the anode of the fifth diode.

[0086] The collector of the fourth MOSFET is connected to the anode of the seventh diode and the third pin of the first transformer, respectively.

[0087] The base of the fourth MOSFET is connected to one end of the sixteenth resistor, one end of the seventeenth resistor, and the second external terminal C2. The other end of the sixteenth resistor is connected to DC power, and the other end of the seventeenth resistor is grounded.

[0088] The second pin of the first transformer is connected to the other end of the fourth resistor, and one end of the fourth resistor is connected to direct current.

[0089] The third pin of the first transformer is connected to the anode of the seventh diode and the collector of the fourth MOSFET, respectively.

[0090] The fourth pin of the first transformer is connected to the anode of the eighth diode and the other end of the eighth capacitor. The cathode of the eighth diode is connected to the other end of the twelfth resistor and the other end of the fourteenth resistor. One end of the eighth capacitor is connected to one end of the twelfth resistor, the other end of the thirteenth resistor, the one end of the fourteenth resistor, the other end of the fifteenth resistor, and one end of the nineteenth resistor. One end of the thirteenth resistor and one end of the fifteenth resistor are both connected to the gate of the third power transistor. The other end of the nineteenth resistor is connected to the sixth pin of the first transformer, the ground wire, the anode of the ninth diode, the source of the third power transistor, and the anode of the ninth diode.

[0091] The fifth pin of the first transformer is connected to the second pin of the second transformer and the other end of the eleventh resistor.

[0092] The sixth pin of the first transformer is connected to the other end of the nineteenth resistor, the ground wire, the source of the third power transistor, and the anode of the ninth diode. One end of the nineteenth resistor is connected to the other end of the thirteenth resistor, one end of the twelfth resistor, one end of the fourteenth resistor, one end of the fifteenth resistor, and one end of the eighth capacitor. The gate of the third power transistor is connected to one end of the thirteenth resistor and one end of the fifteenth resistor. The drain of the third power transistor is connected to the anode of the third diode, the cathode of the ninth diode, the source of the second power transistor, the other end of the tenth resistor, and the seventh pin of the first transformer.

[0093] The seventh pin of the first transformer is connected to the other end of the tenth resistor, the source of the second power transistor, the anode of the third diode, the cathode of the ninth diode, and the drain of the third power transistor. One end of the tenth resistor is connected to the other end of the sixth resistor, the other end of the second resistor, one end of the third resistor, one end of the fifth resistor, and one end of the first capacitor. The gate of the second power transistor is connected to one end of the second resistor and one end of the sixth resistor. The cathode of the third diode is connected to the drain of the second power transistor, the first resistor, and a fixed voltage (+300V). The anode of the ninth diode is connected to the source of the third power transistor, ground, one end of the nineteenth resistor, and the sixth pin of the first transformer. The source of the third power transistor is connected to the first resistor, a fixed positive current (300V), and the cathode of the third diode.

[0094] The eighth pin of the first transformer is connected to the anode of the second diode and the other end of the first capacitor. The cathode of the second diode is connected to the other end of the third resistor and the other end of the fifth resistor. One end of the first capacitor is connected to the other end of the second resistor, one end of the third resistor, one end of the fifth resistor, one end of the sixth resistor, and one end of the tenth resistor.

[0095] The first pin of the second transformer is connected to the other end of the sixth capacitor and one end of the third capacitor. One end of the sixth capacitor is connected to the other end of the second capacitor, one end of the seventh capacitor, one end of the ninth resistor, and one end of the eighteenth resistor. The other end of the third capacitor is connected to one end of the eleventh resistor.

[0096] The second pin of the second transformer is connected to the other end of the eleventh resistor and the fifth pin of the first transformer, respectively.

[0097] The third pin of the second transformer is connected to the second anode of the eleventh diode and one end of the twelfth capacitor, respectively. The cathode of the eleventh diode is connected to the other end of the twenty-second inductor, the other end of the twelfth capacitor is connected to one end of the twenty-fourth resistor, and the other end of the twenty-fourth resistor is connected to the other end of the twenty-third resistor.

[0098] The fourth pin of the second transformer is connected to one end of the tenth capacitor and the first anode of the eleventh diode, respectively. The other end of the tenth capacitor is connected to one end of the twenty-third resistor, the other end of the twenty-third resistor is connected to the other end of the twenty-fourth resistor, and the cathode of the eleventh diode is connected to the other end of the twenty-second inductor.

[0099] The fifth and sixth pins of the second transformer are both connected to the other end of the twentieth resistor and the current source IS, and one end of the twentieth resistor is grounded.

[0100] The seventh pin of the second transformer is connected to the second anode of the tenth diode and one end of the thirteenth capacitor, respectively. The cathode of the tenth diode is connected to the other end of the twenty-first inductor, the twenty-second resistor, and the twenty-first resistor, respectively. The other end of the thirteenth capacitor is connected to one end of the twenty-first resistor.

[0101] The eighth pin of the second transformer is connected to one end of the eleventh capacitor and the first anode of the tenth diode. The other end of the eleventh capacitor is connected to one end of the twenty-second resistor. The other end of the twenty-second resistor is connected to the twenty-first inductor, the cathode of the tenth diode, and the other end of the twenty-first resistor. The cathode of the tenth diode is connected to the other end of the twenty-first inductor, the other end of the twenty-second resistor, and the other end of the twenty-first resistor.

[0102] The first pin of the second adjustable potentiometer is connected to the output circuit, the thirtieth resistor, one end of the nineteenth capacitor, and one end of the twenty-second inductor. The other end of the thirtieth resistor is connected to the ground wire, the other end of the nineteenth capacitor, and one end of the twenty-third inductor. The other end of the twenty-third inductor is grounded. The other ends of the thirtieth resistor, the other end of the nineteenth capacitor, and one end of the twenty-third inductor are all grounded. The other end of the twenty-second inductor is connected to the cathode of the eleventh diode.

[0103] The second pin and the third pin of the second adjustable potentiometer are both grounded.

[0104] The fourth pin of the second adjustable potentiometer is connected to a fixed voltage (5V), the other end of the twenty-fifth resistor, the other end of the fifteenth capacitor, and one end of the twenty-first inductor. One end of the twenty-fifth resistor is grounded, one end of the fifteenth capacitor is grounded, and the other end of the twenty-first inductor is connected to the other end of the twenty-second resistor, the cathode of the tenth diode, and the other end of the twenty-first resistor.

[0105] The first pin of the first adjustable potentiometer is connected to one end of the first fuse. The other end of the first fuse is connected to one end of the fourth capacitor, the first DC circuit, and the first pin of the first common-mode inductor. The other end of the fourth capacitor is connected to the second pin of the first adjustable potentiometer, the second DC circuit, and the third pin of the first common-mode inductor.

[0106] The second pin of the first adjustable potentiometer is connected to the other end of the fourth capacitor, the second DC circuit, and the third pin of the first common-mode inductor. The second pin of the first common-mode inductor is connected to one end of the fifth capacitor and the third pin of the first bridge rectifier. The fourth pin of the first common-mode inductor is connected to the other end of the fifth capacitor and the second pin of the first bridge rectifier.

[0107] The first pin of the first bridge rectifier is connected to one end of the ninth resistor, one end of the second capacitor, and one end of the first resistor, respectively. The second pin of the first bridge rectifier is connected to the other end of the fifth capacitor and the fourth pin of the first common-mode inductor, respectively. The third pin of the first bridge rectifier is connected to one end of the fifth capacitor and the second pin of the first common-mode inductor, respectively. The fourth pin of the first bridge rectifier is connected to the ground wire, the other end of the eighteenth resistor, and the other end of the seventh capacitor, respectively. The other end of the ninth resistor, one end of the eighteenth resistor, one end of the seventh capacitor, and the other end of the second capacitor are all connected to one end of the sixth capacitor.

[0108] like Figure 5 As shown,

[0109] The first pin of the second chip is connected to the anode of the fifteenth diode and the second pin of the third transformer, respectively. The cathode of the fifteenth diode is connected to the other end of the thirty-fourth resistor and the other end of the twenty-fourth capacitor, respectively. One end of the thirty-fourth resistor, the first pin of the twenty-fourth capacitor, the first pin of the third transformer, one end of the twenty-second capacitor, and the first pin of the second bridge rectifier are all connected to one end of the thirty-seventh resistor.

[0110] The second pin of the second chip is connected to the other end of the 32nd capacitor, the anode of the first Zener diode DZ1, the other end of the 30th capacitor, the ground wire, and the fourth pin of the third transformer. One end of the 32nd capacitor is connected to the first pin of the optocoupler U4 and the fourth pin of the second chip. The cathode of the first Zener diode DZ1 and one end of the 30th capacitor are both connected to the third pin of the second chip and one end of the 42nd resistor.

[0111] The third pin of the second chip is connected to the cathode of the first Zener diode DZ1, one end of the thirtieth capacitor, and one end of the forty-second resistor. The other end of the forty-second resistor is connected to the cathode of the sixteenth diode, and the anode of the sixteenth diode is connected to the third pin of the third transformer.

[0112] The fourth pin of the second chip is connected to one end of the thirty-second capacitor and the first pin of the optocoupler U4. The other end of the thirty-second capacitor is connected to the second pin of the second chip, the anode of the first Zener diode DZ1, the other end of the thirtieth capacitor, the ground wire, and the fourth pin of the third transformer. The second pin of the optocoupler U4 is connected to one end of the forty-seventh resistor. The third pin of the optocoupler U4 is grounded. The fourth pin of the optocoupler U4 is connected to the cathode of the fifth Zener diode U5, the other end of the fiftieth resistor, and one end of the fifty-first resistor. The anode of the fifth Zener diode is grounded. One end of the fiftieth resistor is connected to the positive power supply voltage VCC, the other end of the forty-seventh resistor, and one end of the fixed terminal of the first variable resistor RP1. The other end of the fifty-first resistor is connected to one end of the thirty-fourth capacitor. The other end of the thirty-fourth capacitor is connected to the fifth Zener diode U5 and the sliding terminal of the first variable resistor RP1. The other end of the fixed terminal of the first variable resistor RP1 is grounded.

[0113] The sixth pin of the second chip is connected to the other end of the thirty-seventh resistor. One end of the thirty-seventh resistor is connected to the first pin of the second bridge rectifier, one end of the twenty-second capacitor, one end of the thirty-fourth resistor, the large end of the twenty-fourth capacitor, and the first pin of the third transformer. The second pin of the second bridge rectifier is connected to the second AC interface. The third pin of the second bridge rectifier is connected to the first AC interface. The fourth pin of the second bridge rectifier is grounded. The other end of the twenty-second capacitor is grounded. The other ends of the thirty-fourth resistor and the twenty-fourth capacitor are both connected to the cathode of the fifteenth diode. The anode of the fifteenth diode is connected to the first pin of the second chip and the second pin of the third transformer, respectively.

[0114] The first pin of the third transformer is connected to one end of the twenty-fourth capacitor, one end of the thirty-fourth resistor, one end of the twenty-second capacitor, the first pin of the second bridge rectifier, and one end of the thirty-seventh resistor.

[0115] The second pin of the third transformer is connected to the anode of the fifteenth diode and the first pin of the second chip, respectively. The cathode of the fifteenth diode is connected to the other end of the thirty-fourth resistor and the other end of the twenty-fourth capacitor, respectively.

[0116] The third pin of the third transformer is connected to the anode of the sixteenth diode, the cathode of the sixteenth diode is connected to the other end of the forty-second resistor, and one end of the forty-second resistor is connected to one end of the thirtieth capacitor, the cathode of the first Zener diode DZ1, and the third pin of the second chip.

[0117] The fourth pin of the third transformer is connected to the ground wire, the other end of the thirtieth capacitor, the anode of the first Zener diode DZ1, the second pin of the second chip, and the other end of the thirty-second capacitor.

[0118] The fifth pin of the third transformer is connected to the other end of the twenty-sixth capacitor and the ground wire, respectively. One end of the twenty-sixth capacitor is connected to the cathode of the fourteenth diode, the positive power supply voltage VCC, and one end of the forty-first resistor.

[0119] The sixth pin of the third transformer is connected to the anode of the fourteenth diode. The cathode of the fourteenth diode is connected to one end of the twenty-sixth capacitor, the positive power supply voltage VCC, and one end of the forty-first resistor. The other end of the forty-first resistor is connected to the anode of the first photodiode. The cathode of the first photodiode is grounded.

[0120] like Figure 6 As shown,

[0121] The reference circuit is connected to one end of the forty-sixth resistor, the other end of the forty-sixth resistor is connected to the anode of the third photodiode, and the cathode of the third photodiode is grounded.

[0122] The inverting input of the first operational amplifier is connected to one end of the thirty-first capacitor, the other end of the thirty-third capacitor, one end of the fifty-second resistor, and one end of the forty-third resistor. The other end of the thirty-first capacitor is connected to the non-inverting input of the first operational amplifier, the negative power supply terminal of the first operational amplifier, and the ground wire. One end of the thirty-third capacitor is connected to the inverting input of the second operational amplifier, the other end of the forty-ninth resistor, the other end of the forty-fourth resistor, and the output terminal of the first operational amplifier. The other end of the fifty-second resistor is connected to the non-inverting input of the second operational amplifier, one end of the fifty-fourth resistor, and the reference circuit. The other end of the forty-third resistor is connected to the power supply IS.

[0123] The non-inverting input of the first operational amplifier is connected to the other end of the thirty-first capacitor, the negative power supply terminal of the first operational amplifier, and the ground wire, respectively.

[0124] The negative power supply terminal of the first operational amplifier is connected to the non-inverting input terminal of the first operational amplifier, the other end of the thirty-first capacitor, and the ground wire.

[0125] The positive power supply terminal of the first operational amplifier is connected to the other end of the first heat sink, the positive power supply voltage VCC, and one end of the twenty-eighth capacitor. One end of the first heat sink is connected to the drain of the fifth power transistor, and the other end of the twenty-eighth capacitor is grounded.

[0126] The output of the first operational amplifier is connected to the other end of the forty-fourth resistor, the other end of the forty-ninth resistor, the inverting input of the first operational amplifier, and one end of the thirty-third capacitor.

[0127] The inverting input of the second operational amplifier is connected to one end of the thirty-third capacitor, the other end of the forty-ninth resistor, the other end of the forty-fourth resistor, and the output of the first operational amplifier. The other end of the thirty-third capacitor is connected to one end of the fifty-second resistor, the inverting input of the first operational amplifier, one end of the thirty-first capacitor, and one end of the forty-third resistor. One end of the forty-ninth resistor is connected to the third pin of the second photodiode.

[0128] The non-inverting input of the second operational amplifier is connected to one end of the 54th resistor, the other end of the 52nd resistor, and the reference circuit. The other end of the 54th resistor is connected to the anode of the 17th diode and the anode of the 18th diode. The cathode of the 18th diode is connected to the voltage feedback circuit. The cathode of the 17th diode is connected to one end of the 53rd resistor and the output of the second operational amplifier.

[0129] The output of the second operational amplifier is connected to the other end of the fifty-third resistor and the cathode of the seventeenth diode, respectively. One end of the fifty-third resistor is connected to the first pin of the second photodiode.

[0130] The second pin of the second photodiode is connected to the source and ground of the fifth power transistor, respectively.

[0131] The gate of the fifth power transistor is connected to one end of the forty-fourth resistor, and the other end of the forty-fourth resistor is connected to the other end of the forty-ninth resistor, the inverting input of the second operational amplifier, one end of the thirty-third capacitor, and the output of the first operational amplifier.

[0132] like Figure 7 As shown,

[0133] The APGI setting voltage is connected to the other end of the eleventh fuse. One end of the eleventh fuse is connected to the other end of the eighty-first resistor, one end of the twenty-fifth capacitor, and one end of the thirty-ninth resistor. The other end of the thirty-ninth resistor is grounded, and the other end of the twenty-fifth capacitor is grounded. The eighty-first resistor is connected to the other end of the thirteenth capacitor, the other end of the seventy-sixth capacitor, the other end of the eightieth resistor, and one end of the fourth bidirectional breakdown diode TV4. The other end of the fourth bidirectional breakdown diode TV4 is grounded, one end of the thirteenth capacitor is grounded, one end of the seventy-sixth capacitor is grounded, and one end of the eightieth resistor is connected to the non-inverting input of the third operational amplifier.

[0134] The negative power supply terminal of the third operational amplifier is connected to a -5V voltage, and the positive power supply terminal of the third operational amplifier is connected to a +15V voltage.

[0135] The inverting input of the third operational amplifier is connected to the other end of the twelfth resistor and the other end of the seventy-fourth capacitor. One end of the twelfth resistor and one end of the seventy-fourth capacitor are connected to the output of the third operational amplifier and the other end of the seventy-eighth resistor, respectively. One end of the seventy-eighth resistor is connected to one end of the eighty-second resistor and the non-inverting input of the fourth operational amplifier, respectively. The other end of the eighty-second resistor is grounded.

[0136] The inverting input of the fourth operational amplifier is connected to one end of the seventeenth resistor, the other end of the seventy-fifth capacitor, and the other end of the fourteenth resistor. The other end of the seventeenth resistor is grounded. One end of the seventy-fifth capacitor is connected to the other end of the seventy-fifth resistor and the output of the fourth operational amplifier. One end of the fourteenth resistor is connected to one end of the seventy-fifth resistor, the third pin of the third bidirectional trigger diode, and the other end of the nineteenth resistor.

[0137] The first pin of the third bidirectional trigger diode is grounded, and the second pin of the third bidirectional trigger diode is connected to a +3.3V voltage.

[0138] One end of the nineteenth resistor is connected to the other end of the thirty-first resistor, one end of the thirty-second resistor, one end of the nineteenth capacitor, and the MI setting voltage level. The other end of the thirty-second resistor is grounded, the other end of the nineteenth capacitor is grounded, and one end of the thirty-first resistor is connected to the 2.5V setting voltage level.

[0139] The above circuit structure has three components, which serve as three analog input interfaces. These three interfaces control the device output in constant voltage, constant current, and constant power modes, respectively. Figure 7 , Figure 8 , Figure 9 As shown.

[0140] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A DC amplifier, characterized in that, include The user input module is used to receive analog input signals from the outside, including voltage signals or current signals. The amplitude of the analog input signal represents the set value of the output parameter. The microcontroller unit, connected to the user input module, is used to process analog input signals according to the selected output mode and generate corresponding digital control signals; The digital-to-analog converter module, connected to the microcontroller unit, is used to convert digital control signals into analog reference voltages; The switching power supply controller, connected to the digital-to-analog converter module, is used to receive an analog reference voltage; A switching power supply topology circuit, connected to a switching power supply controller, is used to convert the input DC power into a set DC power output under the control of the PWM wave output by the switching power supply controller. The negative feedback network is connected between the output terminal of the switching power supply topology circuit and the feedback input terminal of the switching power supply controller. It is used to sample the output voltage of the switching power supply topology circuit, generate a feedback voltage, and transmit it to the switching power supply controller. The switching power supply controller compares the feedback voltage with the analog reference voltage and dynamically adjusts the duty cycle of the PWM wave output to the switching power supply topology circuit based on the comparison result, so that the feedback voltage tracks the analog reference voltage, thereby forming a closed-loop control and realizing the linear amplification of the analog input signal into a high-power DC output.

2. A DC amplifier according to claim 1, characterized in that, The user input module includes at least three independent analog input interfaces, which are used to set the constant voltage output mode, constant current output mode and constant power output mode respectively. The microcontroller unit automatically identifies and switches the corresponding output mode according to the interface to which the analog input signal is connected. The microcontroller unit is also used for mode management: in constant voltage output mode, the microcontroller unit processes the received voltage input signal according to the preset voltage range V. max The target output voltage is calculated, and the corresponding digital control signal is generated. In constant current output mode, the microcontroller receives the current input signal according to the preset current range I. max The target output current is calculated, and the corresponding digital control signal is generated. In constant power mode, the microcontroller receives the power input signal according to the preset current range P. max The target output power is calculated, and the corresponding digital control signal is generated.

3. A DC amplifier according to claim 1, characterized in that, It also includes an analog-to-digital converter module, whose input is connected to the output of the switching power supply topology circuit and whose output is connected to the microcontroller unit; The microcontroller unit acquires the actual output voltage and current values ​​of the switching power supply topology circuit in real time through the analog-to-digital conversion module. These values ​​are used for output display, overload protection, or as feedback for power calculation in constant power mode.

4. A DC amplifier according to claim 1, characterized in that, The switching power supply controller includes an error amplifier. An analog reference voltage is connected to the non-inverting input of the error amplifier, and a feedback voltage is connected to the inverting input of the error amplifier. The output of the error amplifier controls a PWM generator circuit, thus forming the core of the closed-loop control.

5. A DC amplifier according to claim 4, characterized in that, The negative feedback network is a resistor voltage divider network, which divides the high output voltage of the switching power supply topology to obtain a feedback voltage that matches the range of the analog reference voltage.

6. A DC amplifier according to claim 1, characterized in that, The switching power supply topology circuit includes a switching transistor, a high-frequency transformer, and an output filter. Under the control of the PWM wave, the switching transistor performs high-frequency switching action, chopping the input DC current into high-frequency AC current. After voltage transformation and electrical isolation by the high-frequency transformer, the high-frequency components are filtered out by the output filter, resulting in a smooth and stable DC current output.

7. A DC amplifier according to claim 1, characterized in that, The control methods for DC amplifiers include: Mode setting steps: Receive the output mode selected by the user. The output mode includes constant voltage mode, constant current mode or constant power mode. Signal receiving steps: Receive the analog input signal from the user; Signal processing steps: The microcontroller calculates the target output value based on the selected output mode and the amplitude of the analog input signal, and generates the corresponding digital control signal; Reference generation steps: Convert the digital control signal into an analog reference voltage using a digital-to-analog converter module; Closed-loop control steps: The switching power supply controller compares the feedback voltage from the negative feedback network with the analog reference voltage, and controls the output of the switching power supply topology circuit by adjusting the duty cycle of the PWM wave, so that the feedback voltage continuously approaches the analog reference voltage. Power output steps: The amplified DC voltage and current are output by the switching power supply topology circuit to drive the external load.

8. A DC amplifier according to claim 7, characterized in that, The closed-loop control steps include: When the load increases and causes the output voltage to drop, the feedback voltage also drops, which leads to an increase in the duty cycle of the PWM wave output by the switching power supply controller, thereby causing the output voltage of the switching power supply topology circuit to rise again. When the load decreases and the output voltage increases, the feedback voltage increases accordingly, which reduces the duty cycle of the PWM wave and causes the output voltage to drop, thereby achieving dynamic stability of the output.

9. A DC amplifier according to claim 1, characterized in that, In constant power mode, the signal processing steps include: the microcontroller calculates the target output power value based on the analog input signal, and collects the output voltage and current in real time. The real-time output power is obtained by calculation, the real-time output power is compared with the target output power value, and the real-time output power is stabilized at the target output power value by adjusting the analog reference voltage.

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