CN202978723U - Numerical-control stabilized power supply circuit - Google Patents

Abstract

The utility model discloses a numerical-control stabilized power supply circuit. A full-wave rectification and filter circuit and a power supply circuit are connected with a 220V alternating-current power supply; the full-wave rectification and filter circuit, a direct current-direct current conversion circuit, a full-bridge inverter circuit and an LC filter circuit are sequentially connected, and an output terminal of the LC filter circuit outputs an alternating voltage of 0-180V; an output terminal of a filter is connected with a single-chip microcomputer sequentially through a current transformer, a filter and rectification circuit and an analog-to-digital converter; the power supply circuit is connected with the single-chip microcomputer and supplies power to the single-chip microcomputer; and a PWM output terminal and an SPWM output terminal of the single-chip microcomputer are connected with the direct current-direct current conversion circuit and the full bridge inverter circuit respectively. The numerical-control stabilized power supply circuit provided by the utility model is advantaged by improving the output precision and efficiency of the power supply and facilitating the operation of the users.

Description

Numerical control stabilized power supply circuit

technical field

The utility model relates to a circuit, in particular to a digitally controlled voltage stabilized power supply circuit. the

Background technique

With the rapid advancement of society, the number of electrical equipment is increasing day by day. However, the aging and development lag of power transmission and distribution facilities, as well as poor design and insufficient power supply cause the voltage of end users to be too low, while the voltage of end users is often too high. Unstable voltage will cause fatal injury or malfunction to the equipment, affect production, cause delay in delivery, unstable quality and other losses. At the same time, it accelerates the aging of the equipment, affects the service life and even burns the accessories, so that the owner faces the trouble of repairing or updating the equipment in a short period of time, which wastes resources; in serious cases, safety accidents may even occur, causing immeasurable losses. In real life and experiments, various power supplies are often used, and the voltage requirements are diverse. How to design a power supply circuit with stable voltage, high output voltage precision and wide adjustment range has become a hot spot in the application of electronic technology. the

A stabilized power supply is an electronic device that can provide a stable AC or DC power supply to a load. In the market, there are various regulated power supply products, including adjustable and fixed. However, there are some common problems, such as low conversion efficiency, high power consumption, low output accuracy, too small adjustable range, unable to meet the requirements of a specific voltage, insufficient output stability, excessive ripple current, and adjustable resistors are generally used It is difficult to adjust and operate, and it is easy to wear and age. the

Utility model content

The utility model aims at avoiding the disadvantages of the above-mentioned prior art, and provides a digitally controlled voltage stabilizing power supply circuit to improve the output precision and efficiency of the power supply and to facilitate the user's operation. the

The utility model adopts the following technical solutions for solving technical problems. the

Numerical control stabilized power supply circuit, its structural characteristics are, including full-wave rectification filter circuit, DC-DC conversion circuit, full-bridge inverter circuit, LC filter circuit, current transformer, filter rectifier circuit, analog-to-digital converter, single-chip microcomputer, power supply circuit and input and output equipment; the full-wave rectification and filter circuit and the power supply circuit are connected to the 220V AC power supply; the full-wave rectification and filter circuit, the DC-DC conversion circuit, the full-bridge inverter circuit and the LC filter circuit are connected in sequence , and the output terminal of the LC filter circuit outputs 0-180V AC voltage; the output terminal of the LC filter circuit is also connected to the single chip microcomputer through a current transformer, a filter rectifier circuit and an analog-to-digital converter; The power supply circuit is connected with the single-chip microcomputer and provides power for the single-chip microcomputer, the PWM output terminal of the single-chip microcomputer is connected with the DC-DC conversion circuit, and the SPWM output terminal of the single-chip microcomputer is connected with the full-bridge inverter circuit connected; the single-chip microcomputer is also connected with the input and output devices. the

The numerical control stabilized power supply circuit of the utility model also has the following technical characteristics. the

The input and output devices include a keyboard and a display. the

The display is an LCD display. the

Compared with the prior art, the beneficial effects of the utility model are reflected in:

The numerically controlled voltage stabilized power supply circuit of the utility model uses a single-chip microcomputer to realize the output voltage setting, stepwise adjustment of the output voltage, and digital control of the output voltage of the stabilized voltage power supply. Bridge inverter (DC/AC), LC filter rectification, A/D conversion and single-chip control unit. The regulated power supply part adopts a symmetrical full-bridge power converter based on PWM control and SPWM control. The numerical control part adopts the A/D output to carry on the digital reference terminal of the error comparator of FGA25N120 to realize the setting, step adjustment and display of the output voltage and other functions. The system design block diagram is given in this paper, each part of the circuit is analyzed, and the necessary experimental waveforms are given, and the design method is proved to be feasible by testing. the

The numerically controlled voltage stabilized power supply circuit of the utility model adopts a symmetrical half-bridge power converter based on FGA25N120, and adopts an 8-bit single-chip microcomputer AT89S52 as the numerical control core, and through external A/D conversion and single-chip microcomputer output modulation PWM, the output accuracy of the power supply is improved and Efficiency, and user-friendly operation, realizes the digital control stabilized power supply based on the single-chip microcomputer. the

Description of drawings

Fig. 1 is the structural block diagram of the digital control stabilized power supply circuit of the present utility model. the

FIG. 2 is a circuit diagram of the power supply circuit in FIG. 1 . the

FIG. 3 is a circuit diagram of the DC-DC conversion circuit in FIG. 1 . the

FIG. 4 is a circuit diagram of the full-bridge inverter circuit in FIG. 1 . the

FIG. 5 is a circuit diagram of the analog-to-digital converter in FIG. 1 . the

Fig. 6 is a circuit diagram of the microcontroller, keyboard and display in Fig. 1. the

The utility model will be further described below through specific embodiments in conjunction with the accompanying drawings. the

Detailed ways

Refer to Figure 1, the digitally controlled stabilized power supply circuit, including full-wave rectification filter circuit, DC-DC conversion circuit, full-bridge inverter circuit, LC filter circuit, current transformer, filter rectifier circuit, analog-to-digital converter, single-chip microcomputer, power supply circuit and input and output equipment; the full-wave rectification and filter circuit and the power supply circuit are connected to the 220V AC power supply; the full-wave rectification and filter circuit, the DC-DC conversion circuit, the full-bridge inverter circuit and the LC filter circuit are connected in sequence, And output 0～180V AC voltage by the output end of described LC filter circuit; The output end of described LC filter circuit is also connected with described single-chip microcomputer through current transformer, filter rectifier circuit and analog-to-digital converter successively; The circuit is connected with the single-chip microcomputer and provides power for the single-chip microcomputer, the PWM output terminal of the single-chip microcomputer is connected with the DC-DC conversion circuit, and the SPWM output terminal of the single-chip microcomputer is connected with the full-bridge inverter circuit ; The single-chip microcomputer is also connected with the input and output devices. the

The input and output devices include a keyboard and a display. the

The display is an LCD display. the

The numerically controlled voltage stabilized power supply circuit of the utility model adopts the AT89S52 single-chip microcomputer to realize the digital control of the symmetrical half-bridge power converter based on PWM control, realizes the setting of the DC output voltage from 0V to 180V and the continuous adjustment of the step value of 0.5V, the maximum The output current is 200mA, and functions such as displaying the output voltage and output current are realized at the same time. the

The input 220V voltage is converted into a DC 220V voltage through full-wave rectification and filtering, and then converted into an adjustable AC voltage of 0-180V through DC-DC conversion and full-bridge inverter. After LC filtering, high-order harmonics are filtered out. After output. And in order to measure the size of the output voltage, the output voltage is converted by current transformer, filter and rectifier, and TLC1549A/D, and then input into the single chip microcomputer for measurement and comparison. The 220V voltage supplies power to the single chip microcomputer through the self-made power supply circuit (5V and 15V), and serves as a starting circuit for DC-DC conversion and full-bridge inverter. The output voltage and output current are displayed through the keyboard and 12864 display. the

The circuit shown in Figure 2 is the power supply circuit. Because the system circuit needs +15V and +5V DC power supply, we must design the auxiliary power supply. The auxiliary power output uses three-terminal regulators 7815, 7915, and 7805 to achieve +15V and +5V DC voltages. the

The circuit shown in FIG. 3 is the DC-DC conversion circuit. This circuit uses a fully-controlled device V, which is an IGBT (insulated gate bipolar transistor) in the figure, and a freewheeling diode VD is set to provide a channel for the inductive current in the load when V is turned off; it is mainly used for electronic circuits. The power supply can also drive a DC motor or a battery load, etc. In the latter two cases, there will be a counter electromotive force in the load, as shown by Em in Figure 3. The DC-DC conversion circuit is connected with the PWM output end of the single-chip microcomputer, and is controlled by the single-chip microcomputer. Pulse Width Modulation (PWM): Keep the switching period T constant and adjust the switch on time. the

The circuit shown in FIG. 4 is the full-bridge inverter circuit, which is a 0-180V sine wave inverter output circuit using full-bridge inverter. The inverter bridge circuit is composed of four MOS tubes including VM1 ~ VM4. Using bipolar modulation, the SPWM pulse wave sent by the single-chip microcomputer ST89S52 is added to the input terminal of the isolated drive optocoupler TIL117 after passing through the hardware delay interlock isolation circuit. The optocoupler power supply is provided by a self-made power supply. The output pulse of the optocoupler provides drive current for the gates of VM1 and VM3 and the gates of VM2 and VM4. In order to prevent the short circuit caused by the straight-through of the bridge arm composed of VM1 and VM3 or VM2 and VM4, there is a dead time of about 2us between the complementary driving pulses, and the minimum safe working dead time is set by software programming and hardware interlock respectively. zone time. The fast recovery diodes VD1~VD6 connected in antiparallel with the main switching tube provide a path for the output to feed back energy to the DC loop. The single-chip microcomputer ST89S52 outputs the SPWM driving pulse of the inverter bridge. The I/O port of the microcontroller is connected to the gate of the field effect tube through the optocoupler, and the isolation and rapidity of the optocoupler are used to control the gate of the field effect tube to realize strong current control and weak current. the

The circuit shown in FIG. 5 is a circuit diagram of the analog-to-digital converter. In this part, the TLC1549 10-bit AD converter is used to collect real-time data, convert the analog signal into a digital signal, display it through the single-chip microcomputer and control the external output circuit. TLC1549 is a 10-bit switched capacitor, successive approximation AD converter. The chip has 2 data input terminals, a tri-state output port (CS), 1 I/O CLOCK port and a digital output port (DATA OUT), which can realize a three-bus control port to the serial port of the master controller data transmission. It has automatic sample and hold internally, can calibrate the conversion range according to the proportional range, and has the function of anti-noise interference, and the maximum total error of the switched capacitor is 4.8mV at full scale during design, so it can be widely used in analog and digital conversion circuits. Connect a 2mA current transformer to the corresponding matching resistor at both ends of the output circuit, and then convert it to 0-5V DC through filtering and rectification, so that AD can better collect. the

The circuit shown in Figure 6 is a single-chip microcomputer control circuit. The control circuit is composed of three parts: MCU AT89S52, LCD12864 display and buttons. Using liquid crystal display module ms12864r (LCD). Serial port control, the control is complicated, but it can display Chinese characters and simple graphics, etc., with powerful functions, it is easy to realize the required functions. the

The digitally controlled voltage stabilized power supply circuit of the utility model controls the on-off of the thyristor by outputting PWM pulses from the single-chip microcomputer, and then controls the DC/DC conversion circuit and the full-bridge inverter circuit, so as to realize the output from 220V AC to 0~180V controllable AC, During the test, the output AC voltage range of the circuit is 0~180V, the output PWM and SPWM waveforms of the microcontroller are normal, and the DC/DC module and inverter module can also work normally with self-made regulated power supply for external input. the

Claims (3)

1. Numerical control stabilized power supply circuit, characterized in that it includes a full-wave rectification filter circuit, a DC-DC conversion circuit, a full-bridge inverter circuit, an LC filter circuit, a current transformer, a filter rectifier circuit, an analog-to-digital converter, a single-chip microcomputer, power supply circuit and input and output equipment; the full-wave rectification and filter circuit and the power supply circuit are connected to the 220V AC power supply; the full-wave rectification and filter circuit, DC-DC conversion circuit, full-bridge inverter circuit and LC filter circuit are connected in sequence connected, and the output terminal of the LC filter circuit outputs 0-180V AC voltage; the output terminal of the LC filter circuit is also connected to the single-chip microcomputer through a current transformer, a filter rectifier circuit and an analog-to-digital converter; Described power supply circuit is connected with described single-chip microcomputer and provides power for described single-chip microcomputer, and the PWM output end of described single-chip microcomputer is connected with described DC-DC conversion circuit, and the SPWM output end of described single-chip microcomputer is connected with described full-bridge inverter circuit connected; the single-chip microcomputer is also connected with the input and output devices. 2. The digitally controlled voltage stabilized power supply circuit according to claim 1, wherein said input and output devices include a keyboard and a display. 3. The digitally controlled voltage stabilized power supply circuit according to claim 2, wherein the display is an LCD display. the

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