电子信息工程专业毕业设计论文外文翻译基于单片机的开关电源设计

1、合 肥 学 院 电 子 系electronic dept, hefei university论 文 翻 译 专 业： 08电子系电子信息工程专业 班 级： 电子信息（1）班 姓 名： 学 号： 指导教师： 论文题目: 基于单片机的开关电源设计 【摘 要】本论文是有关基于单片机的开关电源设计的论述，开关电源在日常生活中应用非常广泛，比如电视机、电脑、冰箱以及其它常用的电子产品都需要开关电源，如今是数字化时代，用单片机实现电子产品十分方便，所以在这次设计中使用了单片机实现。在这次设计文档中，详细阐述了开关电源与线性电源的比较，方案论证，总体结构设计，并附以相关电路图表示，最后生成了相关的pcb电路

2、图。【关键词】线性，半导体，开关，储能，转换，滤波【abstract】 this paper is discourse based on single chip switching power supply design, switching power supplies in their daily lives in a very wide range, such as televisions, computers, refrigerators and other commonly used electronic products require switching power supply

3、, now is the digital age, withsingle-chip electronic products is very convenient, so the mcu used in this design. in the design documents, elaborated a comparison of the switching power supply and linear power demonstration program, the overall structural design, accompanied by the relevant circuit

4、diagram, and finally generate the pcb schematic.【key words】 linear, semiconductors, switches, energy storage, conversion, filteringthe design based on single chip switching power supply 1、uses the switching power supply products are widely used in industrial automation and control, military equipmen

5、t, scientific equipment, led lighting, industrial equipment, communications equipment,electrical equipment,instrumentation, medical equipment, semiconductor cooling and heating, air purifiers, electronic refrigerator, lcd monitor, led lighting, communications equipment, audio-visual products, securi

6、ty, computer chassis, digital products and equipment and other fields.2、introduction with the rapid development of power electronics technology, power electronics equipment and people's work, the relationship of life become increasingly close, and electronic equipment without reliable power, int

7、o the 1980s, computer power and the full realization of the switching power supply, the first to complete the computer power new generation to enter the switching power supply in the 1990s have entered into a variety of electronic, electrical devices, program-controlled switchboards, communications,

8、 electronic testing equipment power control equipment, power supply, etc. have been widely used in switching power supply, but also to promote the rapid development of the switching power supply technology . switching power supply is the use of modern power electronics technology to control the rati

9、o of the switching transistor to turn on and off to maintain a stable output voltage power supply, switching power supply is generally controlled by pulse width modulation (pwm) ics and switching devices (mosfet, bjt) composition. switching power supply and linear power compared to both the cost and

10、 growth with the increase of output power, but the two different growth rates. a power point, linear power supply costs, but higher than the switching power supply. with the development of power electronics technology and innovation, making the switching power supply technology to continue to innova

11、te, the turning points of this cost is increasingly move to the low output power side, the switching power supply provides a broad space for development. the direction of its development is the high-frequency switching power supply, high frequency switching power supply miniaturization, and switchin

12、g power supply into a wider range of application areas, especially in high-tech fields, and promote the miniaturization of high-tech products, light of. in addition, the development and application of the switching power supply in terms of energy conservation, resource conservation and environmental

13、 protection are of great significance.3、classification modern switching power supply, there are two: one is the dc switching power supply; the other is the ac switching power supply. introduces only dc switching power supply and its function is poor power quality of the original eco-power (coarse) -

14、 such as mains power or battery power, converted to meet the equipment requirements of high-quality dc voltage (varitronix) . the core of the dc switching power supply dc / dc converter. dc switching power supply classification is dependent on the classification of dc / dc converter. in other words,

15、 the classification of the classification of the dc switching power supply and dc/dc converter is the classification of essentially the same, the dc / dc converter is basically a classification of the dc switching power supply. dc /dc converter between the input and output electrical isolation can b

16、e divided into two categories: one is isolated called isolated dc/dc converter; the other is not isolated as non-isolated dc / dc converter. isolated dc / dc converter can also be classified by the number of active power devices. the single tube of dc / dc converter forward (forward), flyback (flyba

17、ck) two. the double-barreled double-barreled dc/ dc converter forward (doubletransistor forward converter), twin-tube flyback (double transistr flyback converter), push-pull (push the pull converter) and half-bridge (half-bridge converter) four. four dc / dc converter is the full-bridge dc / dc conv

18、erter (full-bridge converter).non-isolated dc / dc converter, according to the number of active power devices can be divided into single-tube, double pipe, and four three categories. single tube to a total of six of the dc / dc converter, step-down (buck) dc / dc converter, step-up (boost) dc / dc c

19、onverters, dc / dc converter, boost buck (buck boost) device of cuk the dc / dc converter, the zeta dc / dc converter and sepic, the dc / dc converter. dc / dc converters, the buck and boost type dc / dc converter is the basic buck-boost of cuk, zeta, sepic, type dc / dc converter is derived from a

20、single tube in this six. the twin-tube cascaded double-barreled boost (buck-boost) dc / dc converter dc / dc converter. four dc / dc converter is used, the full-bridge dc / dc converter (full-bridge converter). isolated dc / dc converter input and output electrical isolation is usually transformer t

21、o achieve the function of the transformer has a transformer, so conducive to the expansion of the converter output range of applications, but also easy to achieve different voltage output , or a variety of the same voltage output.power switch voltage and current rating, the converter's output po

22、wer is usually proportional to the number of switch. the more the number of switch, the greater the output power of the dc / dc converter, four type than the two output power is twice as large, single-tube output power of only four 1/4. a combination of non-isolated converters and isolated converter

23、s can be a single converter does not have their own characteristics. energy transmission points, one-way transmission and two-way transmission of two dc / dc converter. dc / dc converter with bi-directional transmission function, either side of the transmission power from the power of lateral load p

24、ower from the load-lateral side of the transmission power. dc / dc converter can be divided into self-excited and separately controlled. with the positive feedback signal converter to switch to self-sustaining periodic switching converter, called self-excited converter, such as the the luo yeer (roy

25、er,) converter is a typical push-pull self-oscillating converter. controlled dc / dc converter switching device control signal is generated by specialized external control circuit.4、the switching power supply.people in the field of switching power supply technology side of the development of power e

26、lectronic devices, while the development of the switching inverter technology, the two promote each other to promote the switching power supply annual growth rate of more than two digits toward the light, small, thin, low-noise, high reliability, the direction of development of anti-jamming. switchi

27、ng power supply can be divided into ac / dc and dc / dc two categories, ac / ac dc / ac, such as inverters, dc / dc converter is now modular design technology and production processes at home and abroad have already matured and standardization, and has been recognized by the user, but ac / dc modula

28、r, its own characteristics make the modular process, encounter more complex technology and manufacturing process. hereinafter to illustrate the structure and characteristics of the two types of switching power supply. self-excited: no external signal source can be self-oscillation, completely self-e

29、xcited to see it as feedback oscillation circuit of a transformer. separate excitation: entirely dependent on external sustain oscillations, excited used widely in practical applications. according to the excitation signal structure classification; can be divided into pulse-width-modulated and pulse

30、 amplitude modulated two pulse width modulated control the width of the signal is frequency, pulse amplitude modulation control signal amplitude between the same effect are the oscillation frequency to maintain within a certain range to achieve the effect of voltage stability. the winding of the tra

31、nsformer can generally be divided into three types, one group is involved in the oscillation of the primary winding, a group of sustained oscillations in the feedback winding, there is a group of load winding. such as shanghai is used in household appliances art technological production of switching

32、 power supply, 220v ac bridge rectifier, changing to about 300v dc filter added to the collector of the switch into the transformer for high frequency oscillation, the feedback winding feedback to the base to maintain the circuit oscillating load winding induction signal, the dc voltage by the recti

33、fier, filter, regulator to provide power to the load. load winding to provide power at the same time, take up the ability to voltage stability, the principle is the voltage output circuit connected to a voltage sampling device to monitor the output voltage changes, and timely feedback to the oscilla

34、tor circuit to adjust the oscillation frequency, so as to achieve stable voltage purposes, in order to avoid the interference of the circuit, the feedback voltage back to the oscillator circuit with optocoupler isolation.5、technology developmentsthe high-frequency switching power supply is the direc

35、tion of its development, high-frequency switching power supply miniaturization, and switching power supply into the broader field of application, especially in high-tech fields, and promote the development and advancement of the switching power supply, an annual more than two-digit growth rate towar

36、d the light, small, thin, low noise, high reliability, the direction of the anti-jamming. switching power supply can be divided into ac / dc and dc / dc two categories, the dc / dc converter is now modular design technology and production processes at home and abroad have already matured and standar

37、dized, and has been recognized by the user, but modular ac / dc, because of its own characteristics makes the modular process, encounter more complex technology and manufacturing process. in addition, the development and application of the switching power supply in terms of energy conservation, reso

38、urce conservation and environmental protection are of great significance.the switching power supply applications in power electronic devices as diodes, igbt and mosfet. scr switching power supply input rectifier circuit and soft start circuit, a small amount of applications, the gtr drive difficult,

39、 low switching frequency, gradually replace the igbt and mosfet. direction of development of the switching power supply is a high-frequency, high reliability, low power, low noise, jamming and modular. small, thin, and the key technology is the high frequency switching power supply light, so foreign

40、 major switching power supply manufacturers have committed to synchronize the development of new intelligent components, in particular, is to improve the secondary rectifier loss, and the power of iron oxygen (mn? zn) materials to increase scientific and technological innovation in order to improve

41、the magnetic properties of high frequency and large magnetic flux density (bs), and capacitor miniaturization is a key technology. smt technology allows the switching power supply has made considerable progress, the arrangement of the components in the circuit board on both sides, to ensure that the

42、 light of the switching power supply, a small, thin. high-frequency switching power supply is bound to the traditional pwm switching technology innovation, realization of zvs, zcs soft-switching technology has become the mainstream technology of the switching power supply, and a substantial increase

43、 in the efficiency of the switching power supply. indicators for high reliability, switching power supply manufacturers in the united states by reducing the operating current, reducing the junction temperature and other measures to reduce the stress of the device, greatly improve the reliability of

44、products. modularity is the overall trend of switching power supply, distributed power systems can be composed of modular power supply, can be designed to n +1 redundant power system, and the parallel capacity expansion. for this shortcoming of the switching power supply running noise, separate the

45、pursuit of high frequency noise will also increase, while the use of part of the resonant converter circuit technology to achieve high frequency, in theory, but also reduce noise, but some the practical application of the resonant converter technology, there are still technical problems, it is still

46、 a lot of work in this field, so that the technology to be practical. power electronics technology innovation, switching power supply industry has broad prospects for development. to accelerate the pace of development of the switching power supply industry in china, it must take the road of technolo

47、gical innovation, out of joint production and research development path with chinese characteristics and contribute to the rapid development of china's national economy.developments and trends of the switching power supply 1955 u.s. royer (gh.roger) invented the self-oscillating push-pull transi

48、stor single-transformer dc-dc converter is the beginning of the high-frequency conversion control circuit 1957 check race jen, sen, invented a self-oscillating push-pull dual transformers, 1964, u.s. scientists canceled frequency transformer in series the idea of switching power supply, the power su

49、pply to the size and weight of the decline in a fundamental way. 1969 increased due to the pressure of the high-power silicon transistor, diode reverse recovery time shortened and other components to improve, and finally made a 25-khz switching power supply. at present, the switching power supply to

50、 the small, lightweight and high efficiency characteristics are widely used in a variety of computer-oriented terminal equipment, communications equipment, etc. almost all electronic equipment is indispensable for a rapid development of today's electronic information industry power mode. bipolar

51、 transistor made of 100khz, 500khz power mos-fet made, though already the practical switching power supply is currently available on the market, but its frequency to be further improved. to improve the switching frequency, it is necessary to reduce the switching losses, and to reduce the switching l

52、osses, the need for high-speed switch components. however, the switching speed will be affected by the distribution of the charge stored in the inductance and capacitance, or diode circuit to produce a surge or noise. this will not only affect the surrounding electronic equipment, but also greatly r

53、educe the reliability of the power supply itself. which, in order to prevent the switching kai - closed the voltage surge, rc or lc buffers can be used, and the current surge can be caused by the diode stored charge of amorphous and other core made of magnetic buffer . however, the high frequency mo

54、re than 1mhz, the resonant circuit to make the switch on the voltage or current through the switch was a sine wave, which can reduce switching losses, but also to control the occurrence of surges. this switch is called the resonant switch. of this switching power supply is active, you can, in theory

55、, because in this way do not need to greatly improve the switching speed of the switching losses reduced to zero, and the noise is expected to become one of the high-frequency switching power supply the main ways. at present, many countries in the world are committed to several trillion hz converter

56、 utility.6、the principle of introduction the switching power supply of the process is quite easy to understand, linear power supplies, power transistors operating in the linear mode and linear power, the pwm switching power supply to the power transistor turns on and off state, in both states, on th

57、e power transistor v - security product is very small (conduction, low voltage, large current; shutdown, voltage, current) voltammetric product / power device is power semiconductor devices on the loss. compared with the linear power supply, the pwm switching power supply more efficient process is a

58、chieved by "chopping", that is cut into the amplitude of the input dc voltage equal to the input voltage amplitude of the pulse voltage. the pulse duty cycle is adjusted by the switching power supply controller. once the input voltage is cut into the ac square wave, its amplitude through the transformer to raise or lower. number of groups of output voltage can be increased by increasing the number of primary and secondary windings of the transformer. after the last ac waveform after the rectifier filter the dc output voltage. the main purpose of the