Direct-current stabilized power supply circuit

Abstract

The embodiment of the utility model provides a direct-current stabilized power supply circuit, which comprises a single chip microcomputer, a keyboard input module, a D / A converter, an amplifier, a driver and a digital display module, the input end of the single-chip microcomputer is electrically connected with the keyboard input module, the output end of the single-chip microcomputer is electrically connected with the input end of the D / A converter and the input end of the driver, the output end of the driver is electrically connected with the input end of the digital display module, the input end of the D / A converter is electrically connected with reference voltage, and the output end of the D / A converter is electrically connected with the input end of the amplifier. The amplifier outputs a target voltage. The DC stabilized power supply circuit adopts the single-chip microcomputer to control output, displays an output voltage value in real time through the digital display module, can accurately output a target voltage, has high control precision and reliability, is easy to manufacture, convenient to operate and high in voltage stability, and has a better application prospect compared with a pure digital circuit in the prior art. The DC stabilized power supply circuit can meet higher and higher requirements of people.

Description

Technical Field

[0001] This utility model relates to the field of power supply technology, and more specifically, to a DC regulated power supply circuit. Background Technology

[0002] As people's living standards continue to improve, digital control has become a popular pursuit, and the convenience it brings is undeniable. Numerical control DC regulated power supplies are a prime example, with DC regulated power supplies evolving towards digitalization and using digital circuits for automatic control. However, most existing DC regulated power supplies are purely digital circuit designs, which can no longer meet the increasingly higher demands people have for DC regulated power supplies. Utility Model Content

[0003] This application provides a DC regulated power supply circuit that is controlled by a single-chip microcomputer. Compared with the pure digital circuit design in the prior art, it has the advantages of convenient operation, high control accuracy, high voltage stability and easy manufacturing.

[0004] According to an embodiment of this application, a DC regulated power supply circuit is provided, including: a microcontroller, a keyboard input module, a D / A converter, an amplifier, a driver, and a digital display module; the input terminal of the microcontroller is electrically connected to the keyboard input module, the output terminal of the microcontroller is electrically connected to the input terminal of the D / A converter and the input terminal of the driver, and the output terminal of the driver is electrically connected to the input terminal of the digital display module; the input terminal of the D / A converter is electrically connected to a reference voltage, the output terminal of the D / A converter is electrically connected to the input terminal of the amplifier, and the amplifier outputs a target voltage.

[0005] In some embodiments of this application, the microcontroller includes chip U1, the D / A converter includes chip U2, the P00, P01, P02, P03, P04, P05, P06, and P07 pins of chip U1 are electrically connected to the lsbDI0, DI1, DI2, DI3, DI4, DI5, DI6, and msbDI7 pins of chip U2, the ILE pin of chip U2 is electrically connected to the power supply VCC, the CS, Xfer, WR1, and WR2 pins of chip U2 are all grounded, and the Vref pin of chip U2 is electrically connected to the reference voltage. Chip U2 is electrically connected to the input terminal of the amplifier.

[0006] In some embodiments of this application, chip U1 is a microcontroller of model 80C51, and chip U2 is a digital-to-analog converter chip of model DAC0832.

[0007] In some embodiments of this application, the amplifier includes an operational amplifier AR1, a resistor R6, a voltage inverter AR2, and a variable resistor R7. The Iout1 pin of the chip U2 is electrically connected to the inverting input terminal of the operational amplifier AR1, and the Iout2 pin of the chip U2 is grounded to the non-inverting input terminal of the operational amplifier AR1. The output terminal of the operational amplifier AR1 is electrically connected to one end of the resistor R6 and the Rfb pin of the chip U2, respectively. The inverting input terminal of the voltage inverter AR2 is electrically connected to the other end of the resistor R6 and one end of the variable resistor R7, respectively. The non-inverting input terminal of the voltage inverter AR2 is grounded, and the output terminal of the voltage inverter AR2 outputs the target voltage of the DC regulated power supply circuit.

[0008] In some embodiments of this application, the keyboard input module includes a + button S1, a - button S2, a square wave button S3, a sawtooth wave button S4, resistors R1, R2, R3, and R4. One end of the + button S1 is electrically connected to one end of the resistor R1 and the P10 / T pin of the chip U1. One end of the - button S2 is electrically connected to one end of the resistor R2 and the P11 / T pin of the chip U2. One end of the square wave button S3 is electrically connected to one end of the resistor R3 and the P12 pin of the chip U2. One end of the sawtooth wave button S4 is electrically connected to one end of the resistor R4 and the P13 pin of the chip U2. The other ends of resistors R1, R2, R3, and R4 are all electrically connected to the power supply VCC. The other ends of the + button S1, - button S2, square wave button S3, and sawtooth wave button S4 are all grounded.

[0009] In some embodiments of this application, the microcontroller further includes a microcontroller reset input circuit, which includes a reset button S5, a capacitor C3, and a resistor R5. One end of the reset button S5 and the positive terminal of the capacitor C3 are electrically connected to the power supply VCC. The other end of the reset button S5, the negative terminal of the capacitor C3, and one end of the resistor R5 are electrically connected to the RESET pin of the chip U1, and the other end of the resistor R5 is grounded.

[0010] In some embodiments of this application, the microcontroller further includes an external crystal oscillator circuit, which includes a crystal Y, a capacitor C4, and a capacitor C5. One end of the crystal Y and one end of the capacitor C4 are electrically connected to an external crystal oscillator input XT2, and the other end of the crystal Y and one end of the capacitor C5 are electrically connected to an external crystal oscillator input XT1. The other ends of the capacitor C4 and the other ends of the capacitor C5 are grounded.

[0011] In some embodiments of this application, the driver includes chip U3, chip U4, resistors R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, and R23. Pins A and B of chip U3 are electrically connected to pin P14 of chip U1. Pin CLK of chip U3 is electrically connected to pin P15 of chip U1. Pin Q0 of chip U3 is electrically connected to one end of resistor R8. Pin Q1 of chip U3 is electrically connected to one end of resistor R9. Pin Q2 of chip U3 is electrically connected to one end of resistor R10. Pin Q3 of chip U3 is electrically connected to one end of resistor R11. Pin Q4 of chip U3 is electrically connected to one end of resistor R12. Pin Q5 of chip U3 is electrically connected to resistor R13. One end of 13 is electrically connected; pin Q6 of chip U3 is electrically connected to one end of resistor R14; pin Q7 of chip U3 is electrically connected to one end of resistor R15, pin A of chip U4, and pin B of chip U4; pin CLK of chip U4 is electrically connected to pin P15 of chip U1; pin Q0 of chip U4 is electrically connected to one end of resistor R16; pin Q1 of chip U4 is electrically connected to one end of resistor R17; pin Q2 of chip U4 is electrically connected to one end of resistor R18; pin Q3 of chip U4 is electrically connected to one end of resistor R19; pin Q4 of chip U4 is electrically connected to one end of resistor R20; pin Q5 of chip U4 is electrically connected to one end of resistor R21; pin Q6 of chip U4 is electrically connected to one end of resistor R22; pin Q7 of chip U4 is electrically connected to one end of resistor R23; and pin Q4... Pins, the chip U3 All pins are electrically connected to the power supply VCC.

[0012] In some embodiments of this application, the digital display module includes a digital tube display unit BIT1 and a digital tube display unit BIT2. Pin a of digital tube display unit BIT1 is electrically connected to the other end of resistor R8; pin b of digital tube display unit BIT1 is electrically connected to the other end of resistor R9; pin c of digital tube display unit BIT1 is electrically connected to the other end of resistor R10; pin d of digital tube display unit BIT1 is electrically connected to the other end of resistor R11; pin e of digital tube display unit BIT1 is electrically connected to the other end of resistor R12; pin f of digital tube display unit BIT1 is electrically connected to the other end of resistor R13; pin g of digital tube display unit BIT1 is electrically connected to the other end of resistor R14; and pin dp of digital tube display unit BIT1 is electrically connected to the other end of resistor R15. Pin a of display unit BIT2 is electrically connected to the other end of resistor R16. Pin b of digital tube display unit BIT2 is electrically connected to the other end of resistor R17. Pin c of digital tube display unit BIT2 is electrically connected to the other end of resistor R18. Pin d of digital tube display unit BIT2 is electrically connected to the other end of resistor R19. Pin e of digital tube display unit BIT2 is electrically connected to the other end of resistor R20. Pin f of digital tube display unit BIT2 is electrically connected to the other end of resistor R21. Pin g of digital tube display unit BIT2 is electrically connected to the other end of resistor R22. Pin dp of digital tube display unit BIT2 is electrically connected to the other end of resistor R23. The VCC pins of digital tube display unit BIT1 and digital tube display unit BIT2 are both electrically connected to the power supply VCC.

[0013] In some embodiments of this application, the DC regulated power supply circuit further includes an overcurrent protection module, which is electrically connected to the microcontroller and the amplifier respectively, and is used to send a shutdown signal to the microcontroller after a preset time delay when the current flowing through the amplifier exceeds a first current threshold.

[0014] The beneficial effects of the embodiments of this application are as follows:

[0015] This DC regulated power supply circuit uses a microcontroller to control the output and displays the output voltage value in real time through a digital display module. It can accurately output the target voltage, has high control precision, high reliability, is easy to manufacture, convenient to operate, and has high voltage stability. Compared with the pure digital circuits in the existing technology, this DC regulated power supply circuit can meet people's increasingly higher requirements. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the composition of a DC regulated power supply circuit provided in an embodiment of this application;

[0018] Figure 2 A schematic diagram of the circuit principle of a keyboard input module in a DC regulated power supply circuit provided in this application embodiment;

[0019] Figure 3 A schematic diagram of the microcontroller reset input circuit in a DC regulated power supply circuit provided in this application embodiment;

[0020] Figure 4 A schematic diagram of the circuit principle of a microcontroller, D / A converter and amplifier in a DC regulated power supply circuit provided for an embodiment of this application;

[0021] Figure 5 A schematic diagram of the circuit principle of the external crystal oscillator circuit for a single-chip microcomputer in a DC regulated power supply circuit provided in this application embodiment;

[0022] Figure 6 This is a schematic diagram of the circuit principle of the driver and digital display module in a DC regulated power supply circuit provided in an embodiment of this application. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0024] It should be noted that the terms "comprising" and "having," and any variations thereof, in the embodiments and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, it may include a series of structures, without being limited to the structures listed, but may optionally include structures not listed, or may optionally include other components inherent to these structures.

[0025] This application discloses a DC regulated power supply circuit, which uses a microcontroller to control the increase or decrease of the output voltage, and the output voltage is digitally displayed. It is mainly used for equipment requiring high power accuracy, or for scientific research experiments. Detailed descriptions follow.

[0026] Figure 1 A DC regulated power supply circuit according to an embodiment of this application is shown. For example... Figure 1 As shown, the DC regulated power supply circuit includes a microcontroller, a keyboard input module, a D / A converter, an amplifier, a driver, and a digital display module. Specifically, the input terminal of the microcontroller is electrically connected to the keyboard input module, and the output terminal of the microcontroller is electrically connected to the input terminals of the D / A converter and the driver, respectively. The output terminal of the driver is electrically connected to the input terminal of the digital display module. The input terminal of the D / A converter is electrically connected to a reference voltage, and the output terminal of the D / A converter is electrically connected to the input terminal of the amplifier, which outputs the target voltage. This DC regulated power supply circuit controls the microcontroller to generate waveforms through the input from the keyboard input module. The D / A converter converts these waveforms into analog voltages, which are then amplified by the amplifier before being output. During this process, the microcontroller is also electrically connected to the digital display module through the driver to display the real-time voltage value.

[0027] In some embodiments, such as Figure 4 As shown, the microcontroller includes chip U1, and the D / A converter includes chip U2. In the specific implementation, chip U1 is a model 80C51 microcontroller. Pins 1-8 of chip U1 are all P1 I / O ports, namely pins P10 / T, P11 / T, P12, P13, P14, P15, P16, and P17. Pin 9 of chip U1 is the reset channel, i.e., the RESET pin. Pin 10 of chip U1 is the serial input channel, i.e., the RXD pin. Pin 11 of chip U1 is the serial output channel, i.e., the TXD pin. Pin 12 of chip U1 is external interrupt 0, i.e., the INT0 pin. Pin 13 of chip U1 is external interrupt 1, i.e., the INT1 pin. Pin 14 of chip U1 is external clock 0, i.e., the T0 pin. Pin 15 of chip U1 is external clock 1, i.e., the T1 pin. Pin 16 of chip U1 is the external write channel, i.e., ... Pin 17 of chip U1 is the external read channel, i.e. Pins 18 and 19 of chip U1 are external clock input pins, i.e., X2 and X1 pins respectively. Pins 21–28 of chip U1 are P2 I / O ports, i.e., P20, P21, P22, P23, P24, P25, P26, and P27 pins respectively. Pin 29 of chip U1 is the external program memory read / select channel, i.e., PSEN pin. Pin 30 of chip U1 is the address latch. Pin 31 of chip U1 is the program memory address enable input, i.e. Pins 32–39 of chip U1 are all P0 I / O ports, namely P00, P01, P02, P03, P04, P05, P06, and P027. In the specific implementation, chip U2 is a DAC0832 digital-to-analog converter chip. Pin 1 of chip U2 is the chip select signal (CS pin), pin 17 is the data transfer signal (Xfer pin), pin 2 is the write strobe signal for the input register (WR1 pin), pin 18 is the write strobe signal for the DAC register (WR2 pin), pin 19 is the data enable latch signal (ILE pin), and pins 4–7 of chip U2 are all data input channels, i.e., DI... Pins 3, DI2, DI1, and lsbDI0, and pins 13–16 of chip U2 are all data input channels, namely msbDI7, DI6, DI5, and DI4. Pins 11 and 12 of chip U2 are current output pins, namely Iout1 and Iout2. Pin 8 of chip U2 is the reference voltage input port, namely Vref. Pin 9 of chip U2 is the feedback signal input pin, namely Rfb. The feedback resistor is located inside chip U2. In more detail, the P00, P01, P02, P03, P04, P05, P06, and P07 pins of chip U1 are electrically connected to the lsbDI0, DI1, DI2, DI3, DI4, DI5, DI6, and msbDI7 pins of chip U2. The ILE pin of chip U2 is electrically connected to the power supply VCC. The CS, Xfer, WR1, and WR2 pins of chip U2 are all grounded, and the Vref pin of chip U2 is electrically connected to the reference voltage. Chip U2 is electrically connected to the input terminal of the amplifier.

[0028] Furthermore, such as Figure 4As shown, the amplifier includes operational amplifier AR1, resistor R6, voltage inverter AR2, and variable resistor R7. Operational amplifier AR1 converts the current values ​​output from the Iout1 and Iout2 pins of chip U2 into voltage values. Voltage inverter AR2 converts negative voltage into positive voltage. Variable resistor R7 is a variable resistor, and resistor R6 can be selected as 10Ω. Resistor R6 and variable resistor R7 are used to amplify the gain. Specifically, the Iout1 pin of chip U2 is electrically connected to the inverting input of operational amplifier AR1, and the Iout2 pin of chip U2 and the non-inverting input of operational amplifier AR1 are both grounded. The output of operational amplifier AR1 is electrically connected to one end of resistor R6 and the Rfb pin of chip U2. The inverting input of voltage inverter AR2 is electrically connected to the other end of resistor R6 and one end of variable resistor R7. The non-inverting input of voltage inverter AR2 is grounded. The output of voltage inverter AR2 outputs the target voltage of the DC regulated power supply circuit.

[0029] In other embodiments, such as Figure 2 As shown, the keyboard input module includes a + button S1, a - button S2, a square wave button S3, a sawtooth wave button S4, resistors R1, R2, R3, and R4. Resistors R1, R2, R3, and R4 are pull-up resistors for the microcontroller pin inputs, used to protect the internal circuitry and clamp the uncertain level of the microcontroller's port interface to a high level. Additionally, the + button S1 can be used to execute a voltage increase subroutine when pressed, the - button S2 can be used to execute a voltage decrease subroutine when pressed, the square wave button S3 can be used to execute a square wave subroutine when pressed, and the sawtooth wave button S4 can be used to execute a sawtooth wave subroutine when pressed. One end of the + button S1 is electrically connected to one end of resistor R1 and the P10 / T pin of chip U1. One end of the - button S2 is electrically connected to one end of resistor R2 and the P11 / T pin of chip U2. One end of the square wave button S3 is electrically connected to one end of resistor R3 and the P12 pin of chip U2. One end of the sawtooth wave button S4 is electrically connected to one end of resistor R4 and the P13 pin of chip U2. The other ends of resistors R1, R2, R3, and R4 are all electrically connected to the power supply VCC. The other ends of the + button S1, - button S2, square wave button S3, and sawtooth wave button S4 are all grounded.

[0030] In other embodiments, such as Figure 3As shown, the microcontroller also includes a microcontroller reset input circuit, which includes a reset button S5, a capacitor C3, and a resistor R5. The capacitor C3 is a polarized capacitor. Specifically, one end of the reset button S5 and the positive terminal of the capacitor C3 are electrically connected to the power supply VCC. The other end of the reset button S5, the negative terminal of the capacitor C3, and one end of the resistor R5 are electrically connected to the RESET pin of the chip U1, and the other end of the resistor R5 is grounded. In a specific embodiment, the capacitor C3 can be a 10uF / 16V electrolytic capacitor, i.e., a 10uF capacitor with a voltage rating of 16V.

[0031] In other embodiments, such as Figure 5 As shown, the microcontroller also includes an external crystal oscillator circuit, which includes a crystal Y, capacitor C4, and capacitor C5. Capacitors C4 and C5 are used to eliminate the inductance during crystal oscillation. Specifically, one end of crystal Y and one end of capacitor C4 are electrically connected to the external crystal oscillator input XT2, and the other end of crystal Y and one end of capacitor C5 are electrically connected to the external crystal oscillator input XT1. The other ends of capacitors C4 and C5 are both grounded. In a specific embodiment, crystal Y can be a 11.0592MHz crystal oscillator.

[0032] In other embodiments, such as Figure 6 As shown, the driver includes chip U3, chip U4, resistors R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, and R23. In a specific embodiment, both chip U3 and chip U4 can be selected as 74HC164 shift registers. Pins 1 and 2 of chips U3 and U4 are the inputs of the shift register, i.e., pins A and B. Pin 8 of chips U3 and U4 is the clock pulse for the shift register, i.e., the CLK pin. Pin 9 of chips U3 and U4 is the center reset input (active low). The pins, pins 3–pin 6 and pins 10–pin 13 of chips U3 and U4 are all outputs of the shift register, namely pins Q0, Q1, Q2, Q3, Q4, Q5, Q6, and Q7. In detail, pins A and B of chip U3 are electrically connected to pin P14 of chip U1, meaning DP is the input of shift register 74HC164. Pin CLK of chip U3 is electrically connected to pin P15 of chip U1, meaning SH is the clock pulse of shift register 74HC164. Pin Q0 of chip U3 is electrically connected to one end of resistor R8. Pin Q1 of chip U3 is electrically connected to one end of resistor R9. Pin Q2 of chip U3 is electrically connected to one end of resistor R10. Pin Q3 of chip U3 is electrically connected to one end of resistor R11. Pin Q4 of chip U3 is electrically connected to one end of resistor R12. Pin Q5 of chip U3 is electrically connected to one end of resistor R13. Pin Q6 of chip U3 is electrically connected to one end of resistor R14. Pin Q7 of chip U3 is... Do not connect the following to one end of resistor R15, pin A of chip U4, or pin B of chip U4. Connect the CLK pin of chip U4 to pin P15 of chip U1, i.e., SH is the clock pulse for the shift register 74HC164. Connect the Q0 pin of chip U4 to one end of resistor R16. Connect the Q1 pin of chip U4 to one end of resistor R17. Connect the Q2 pin of chip U4 to one end of resistor R18. Connect the Q3 pin of chip U4 to one end of resistor R19. Connect the Q4 pin of chip U4 to one end of resistor R20. Connect the Q5 pin of chip U4 to one end of resistor R21. Connect the Q6 pin of chip U4 to one end of resistor R22. Connect the Q7 pin of chip U4 to one end of resistor R23. Pins, chip U3 All pins are electrically connected to the power supply VCC.

[0033] Furthermore, such as Figure 6As shown, the digital display module includes digital tube display unit BIT1 and digital tube display unit BIT2. Pin a of digital tube display unit BIT1 is electrically connected to the other end of resistor R8; pin b of digital tube display unit BIT1 is electrically connected to the other end of resistor R9; pin c of digital tube display unit BIT1 is electrically connected to the other end of resistor R10; pin d of digital tube display unit BIT1 is electrically connected to the other end of resistor R11; pin e of digital tube display unit BIT1 is electrically connected to the other end of resistor R12; pin f of digital tube display unit BIT1 is electrically connected to the other end of resistor R13; pin g of digital tube display unit BIT1 is electrically connected to the other end of resistor R14; and pin dp of digital tube display unit BIT1 is electrically connected to the other end of resistor R15. Pin a of BIT2 is electrically connected to the other end of resistor R16. Pin b of digital tube display unit BIT2 is electrically connected to the other end of resistor R17. Pin c of digital tube display unit BIT2 is electrically connected to the other end of resistor R18. Pin d of digital tube display unit BIT2 is electrically connected to the other end of resistor R19. Pin e of digital tube display unit BIT2 is electrically connected to the other end of resistor R20. Pin f of digital tube display unit BIT2 is electrically connected to the other end of resistor R21. Pin g of digital tube display unit BIT2 is electrically connected to the other end of resistor R22. Pin dp of digital tube display unit BIT2 is electrically connected to the other end of resistor R23. The VCC pins of digital tube display units BIT1 and BIT2 are both electrically connected to the power supply VCC.

[0034] In the specific implementation process, existing programs (i.e., software writing) can also be burned into the microcontroller to realize functions such as step increase / decrease of voltage, automatic scanning of the keyboard, control of the digital display module, automatic refresh of the digital display module, and zero-crossing protection of the circuit.

[0035] In addition, such as Figure 1 As shown, the DC regulated power supply circuit in this embodiment further includes an overcurrent protection module, which is electrically connected to the microcontroller and the amplifier respectively. The overcurrent protection module is used to send a shutdown signal to the microcontroller after a preset delay when the current flowing through the amplifier exceeds a first current threshold. It should be noted and understood that the overcurrent protection module can be located within the microcontroller; that is, the overcurrent protection function can be achieved by burning a corresponding existing program into the microcontroller. Of course, the overcurrent protection module can also be a separate component, as long as it can achieve the overcurrent protection function; this application does not impose any restrictions on this.

[0036] The above describes the various modules of the DC regulated power supply circuit provided in this embodiment and their interconnections. The following section will discuss further details. Figure 1 – Figure 6 The working principle of the DC regulated power supply circuit is described in detail.

[0037] In this embodiment, the digital-to-analog converter chip of the D / A converter in the DC regulated power supply circuit is a DAC0832, which is a monolithic current-output 8-bit digital-to-analog converter manufactured using CMOS technology. The DAC0832 has three operating modes: unbuffered, single-buffered, and double-buffered. In this DC regulated power supply circuit, the P0 IO port of chip U1 is directly connected to the data ports (pins 4–7 and 13–16) of the DAC0832 (i.e., chip U2). The WR1, CS, WR2, and Xfer pins are grounded, and ILE = 1, indicating that the D / A converter is in a pass-through state. When the microcontroller's data port outputs a digital signal, this signal is immediately transmitted to the DAC input register and then directly to the DAC data register. After a short setup time, the corresponding analog voltage is obtained.

[0038] The implementation of stepping 0.1V is described below.

[0039] Because the output voltage range is 10V, and the reference voltage Vref ranges from -10V to +10V, the reference voltage can be 5.12V. Therefore, the resolution of the output voltage at pin 8 of the DAC0832 is:

[0040]

[0041] That is, for every 1 increment at the input data terminal of the D / A converter, the voltage increases by 0.02V. The voltage output terminal of the D / A converter is connected to the input terminal of operational amplifier AR1, which has a gain of 5. This allows us to obtain the voltage resolution of the output voltage.

[0042] 0.02V × 5 = 0.1V

[0043] Therefore, when adjusting the voltage, the voltage is increased or decreased in increments of 0.1V.

[0044] The microcontroller's software can be written using existing modular programming methods. The system software consists of a main control program, a digital display subroutine, and a keyboard service subroutine. Automatic keyboard scanning, automatic display refresh, and zero-crossing protection functions can also be added. During system initialization, the digital tube displays a voltage of 0.0V. The software then scans the four buttons for presses. Pressing the + button (S1) executes the voltage increase subroutine; pressing the - button (S2) executes the voltage decrease subroutine; pressing the square wave button (S3) executes the square wave subroutine; and pressing the sawtooth wave button (S4) executes the sawtooth wave subroutine.

[0045] In summary, this application discloses a DC regulated power supply circuit that uses a microcontroller to control the output and displays the output voltage value in real time through a digital display module. It can accurately output the target voltage, has high control precision, high reliability, is easy to manufacture, convenient to operate, and has high voltage stability. Compared with the pure digital circuits in the prior art, this DC regulated power supply circuit can meet people's increasingly higher requirements.

[0046] It will be understood by those skilled in the art that the accompanying drawings are merely schematic diagrams of one embodiment, and the components shown in the drawings are not necessarily essential for implementing this invention. It should also be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0047] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, in the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0048] Finally, it should be noted that the above-described embodiments are merely specific implementations of this utility model, used to illustrate the technical solution of this utility model, and not to limit it. The protection scope of this utility model is not limited thereto. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this utility model. These modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope described in the claims.

Claims

1. A DC regulated power supply circuit, characterized in that, include: Microcontroller, keyboard input module, D / A converter, amplifier, driver and digital display module; The input terminal of the microcontroller is electrically connected to the keyboard input module. The output terminal of the microcontroller is electrically connected to the input terminal of the D / A converter and the input terminal of the driver, respectively. The output terminal of the driver is electrically connected to the input terminal of the digital display module. The input terminal of the D / A converter is electrically connected to the reference voltage. The output terminal of the D / A converter is electrically connected to the input terminal of the amplifier. The amplifier outputs the target voltage.

2. The DC regulated power supply circuit according to claim 1, characterized in that, The microcontroller includes chip U1, and the D / A converter includes chip U2. The P00, P01, P02, P03, P04, P05, P06, and P07 pins of chip U1 are electrically connected to the lsbDI0, DI1, DI2, DI3, DI4, DI5, DI6, and msbDI7 pins of chip U2. The ILE pin of chip U2 is electrically connected to the power supply VCC. The CS, Xfer, WR1, and WR2 pins of chip U2 are all grounded, and the Vref pin of chip U2 is electrically connected to the reference voltage. Chip U2 is electrically connected to the input terminal of the amplifier.

3. The DC regulated power supply circuit according to claim 2, characterized in that, The chip U1 is a microcontroller of model 80C51, and the chip U2 is a digital-to-analog converter chip of model DAC0832.

4. The DC regulated power supply circuit according to claim 2, characterized in that, The amplifier includes an operational amplifier AR1, a resistor R6, a voltage inverter AR2, and a variable resistor R7. The Iout1 pin of the chip U2 is electrically connected to the inverting input of the operational amplifier AR1, and the Iout2 pin of the chip U2 is grounded to the non-inverting input of the operational amplifier AR1. The output of the operational amplifier AR1 is electrically connected to one end of the resistor R6 and the Rfb pin of the chip U2. The inverting input of the voltage inverter AR2 is electrically connected to the other end of the resistor R6 and one end of the variable resistor R7. The non-inverting input of the voltage inverter AR2 is grounded, and the output of the voltage inverter AR2 outputs the target voltage of the DC regulated power supply circuit.

5. The DC regulated power supply circuit according to claim 2, characterized in that, The keyboard input module includes a + button S1, a - button S2, a square wave button S3, a sawtooth wave button S4, resistors R1, R2, R3, and R4. One end of the + button S1 is electrically connected to one end of resistor R1 and the P10 / T pin of chip U1. One end of the - button S2 is electrically connected to one end of resistor R2 and the P11 / T pin of chip U2. One end of the square wave button S3 is electrically connected to one end of resistor R3 and the P12 pin of chip U2. One end of the sawtooth wave button S4 is electrically connected to one end of resistor R4 and the P13 pin of chip U2. The other ends of resistors R1, R2, R3, and R4 are all electrically connected to the power supply VCC. The other ends of the + button S1, - button S2, square wave button S3, and sawtooth wave button S4 are all grounded.

6. The DC regulated power supply circuit according to claim 2, characterized in that, The microcontroller also includes a microcontroller reset input circuit, which includes a reset button S5, a capacitor C3, and a resistor R5. One end of the reset button S5 and the positive terminal of the capacitor C3 are electrically connected to the power supply VCC. The other end of the reset button S5, the negative terminal of the capacitor C3, and one end of the resistor R5 are electrically connected to the RESET pin of the chip U1, and the other end of the resistor R5 is grounded.

7. The DC regulated power supply circuit according to claim 2, characterized in that, The microcontroller also includes an external crystal oscillator circuit, which includes a crystal Y, a capacitor C4, and a capacitor C5. One end of the crystal Y and one end of the capacitor C4 are electrically connected to an external crystal oscillator input XT2, and the other end of the crystal Y and one end of the capacitor C5 are electrically connected to an external crystal oscillator input XT1. The other ends of the capacitor C4 and the other ends of the capacitor C5 are grounded.

8. The DC regulated power supply circuit according to claim 2, characterized in that, The driver includes chip U3, chip U4, resistors R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, and R23. Pins A and B of chip U3 are electrically connected to pin P14 of chip U1. Pin CLK of chip U3 is electrically connected to pin P15 of chip U1. Pin Q0 of chip U3 is electrically connected to one end of resistor R8. Pin Q1 of chip U3 is electrically connected to one end of resistor R9. Pin Q2 of chip U3 is electrically connected to one end of resistor R10. Pin Q3 of chip U3 is electrically connected to one end of resistor R11. Pin Q4 of chip U3 is electrically connected to one end of resistor R12. Pin Q5 of chip U3 is electrically connected to one end of resistor R13. The connections are as follows: pin Q6 of chip U3 is electrically connected to one end of resistor R14; pin Q7 of chip U3 is electrically connected to one end of resistor R15, pin A of chip U4, and pin B of chip U4; pin CLK of chip U4 is electrically connected to pin P15 of chip U1; pin Q0 of chip U4 is electrically connected to one end of resistor R16; pin Q1 of chip U4 is electrically connected to one end of resistor R17; pin Q2 of chip U4 is electrically connected to one end of resistor R18; pin Q3 of chip U4 is electrically connected to one end of resistor R19; pin Q4 of chip U4 is electrically connected to one end of resistor R20; pin Q5 of chip U4 is electrically connected to one end of resistor R21; pin Q6 of chip U4 is electrically connected to one end of resistor R22; pin Q7 of chip U4 is electrically connected to one end of resistor R23; and pin Q6 of chip U4 is electrically connected to one end of resistor R22. Pins, the chip U3 All pins are electrically connected to the power supply VCC.

9. The DC regulated power supply circuit according to claim 8, characterized in that, The digital display module includes a digital tube display unit BIT1 and a digital tube display unit BIT2. Pin a of digital tube display unit BIT1 is electrically connected to the other end of resistor R8; pin b of digital tube display unit BIT1 is electrically connected to the other end of resistor R9; pin c of digital tube display unit BIT1 is electrically connected to the other end of resistor R10; pin d of digital tube display unit BIT1 is electrically connected to the other end of resistor R11; pin e of digital tube display unit BIT1 is electrically connected to the other end of resistor R12; pin f of digital tube display unit BIT1 is electrically connected to the other end of resistor R13; pin g of digital tube display unit BIT1 is electrically connected to the other end of resistor R14; pin dp of digital tube display unit BIT1 is electrically connected to the other end of resistor R15. The a pin of T2 is electrically connected to the other end of resistor R16. The b pin of digital tube display unit BIT2 is electrically connected to the other end of resistor R17. The c pin of digital tube display unit BIT2 is electrically connected to the other end of resistor R18. The d pin of digital tube display unit BIT2 is electrically connected to the other end of resistor R19. The e pin of digital tube display unit BIT2 is electrically connected to the other end of resistor R20. The f pin of digital tube display unit BIT2 is electrically connected to the other end of resistor R21. The g pin of digital tube display unit BIT2 is electrically connected to the other end of resistor R22. The dp pin of digital tube display unit BIT2 is electrically connected to the other end of resistor R23. The VCC pins of digital tube display unit BIT1 and digital tube display unit BIT2 are both electrically connected to the power supply VCC.

10. The DC regulated power supply circuit according to claim 1, characterized in that, The DC regulated power supply circuit further includes an overcurrent protection module, which is electrically connected to the microcontroller and the amplifier respectively, and is used to send a shutdown signal to the microcontroller after a preset time delay when the current flowing through the amplifier exceeds a first current threshold.

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