1、 毕业论文英文翻译资料 题 目： 直流开关稳压电源的保护技术 院 （系）： 电子电器工程系 专 业： 电气工程及其自动化 学生姓名： 班 级： 学 号： 指导教师： 2012 年 12 月 10 日 桂林电子科技大学毕业设计英文资料翻译 1 DC Switching Power Supply Protection Technology Abstract: The DC switching power supply protection system, protection system design principles and machine protection measures, an
2、analysis of switching power supply in the range of protected characteristics and its design methodology, introduced a number of practical protection circuit. Keywords: switching power supply protection circuit system design A、 Introduction DC switching regulator used in the price of more expensive h
3、igh-power switching devices, the control circuit is also more complex, In addition, the load switching regulators are generally used a large number of highly integrated electronic systems installed devices. Transistors and integrated device tolerance electricity, less heat shocks. Switching Regulato
4、rs therefore should take into account the protection of voltage regulators and load their own safety. Many different types of circuit protection, polarity protection, introduced here, the program protection, over-current protection, over-voltage protection, under-voltage protection and over-temperat
5、ure protection circuit. Usually chosen to be some combination of protection, constitutes a complete protection system. B、 Polarity protection DC switching regulator input is generally not regulated DC power supply. Operating errors or accidents as a result of the situation will take its wrong polari
6、ty； switching power supply will be damaged. Polarity protection purposes, is to make the switching regulator only when the correct polarity is not connected to DC power supply regulator to work at. Connecting a single device can achieve power polarity protection. Since the diode D to flow through sw
7、itching regulator input total current, this circuit applied in a low-power switching regulator more suitable. Power in the larger occasion, while the polarity protection circuit as a procedure to protect a link, save the power required for polarity protection diodes, power consumption will be reduce
8、d. In order to easy to operate, make it easier to identify the correct polarity or not, collect the next light. C、 Procedures to protect Switching power supply circuit is rather complicated, basically can be divided into low-power and high-power part of the control part of the switch. Switch is a hi
9、gh-power transistors, for the protection of the transistor switch is turned on or off power safety, we must first modulator, amplifier and other low-power control circuit. To this end, the boot to ensure the correct procedures. Switching Regulators generally take the input of a small inductor, the 桂
10、林电子科技大学毕业设计英文资料翻译 2 input filter capacitor. Moment in the boot, filter capacitor will flow a lot of surge current, the surge current can be several times more than the normal input current. Such a large surge current may contact the general power switch or relay contact melting, and the input fuse.
11、In addition, the capacitor surge current will damage to shorten the life span of premature damage. To this end, the boot should be access to a current limiting resistor, through the current limiting resistor to capacitor charging. In order not to make the current limiting resistor excessive power co
12、nsumption, thus affecting the normal switching regulator, and the transient process in the boot after a short period then automatically relays it to DC power supply directly to the switching regulator power supply. This circuit switching regulator called a soft start circuit. Switching regulator con
13、trol circuit of the logic components required or op-amp auxiliary power supply. To this end, the auxiliary power supply must be in the switch circuit. This control circuit can be used to ensure the boot. Normal boot process is: to identify the polarity of input power, voltage protection procedures b
14、oot auxiliary power supply circuit and through current limiting resistor R of the switching regulator input capacitor C charge modulation switching regulator circuit, short -circuit current limiting resistor stability switching regulator. In the switching regulator, the machines just because the out
15、put capacitance, and charge to the rated output voltage value of the need for a certain period of time. During this time, sampling the output amplifier with low input voltage sampling, closed-loop regulation characteristics of the system will force the switching of the transistor conduction time len
16、gthened, so that switching transistor during this period will tend to continuous conduction, and easily damaged. To this end, the requirements of this paragraph in the boot time, the switch to switch the output modulation circuit transistor base drive signal of the pulse width modulation, can guaran
17、tee the switching transistor by the cut-off switches are becoming more and more normal state, therefore the protection of the setting up of a boot to tie in with the soft start. D、 Over-current protection When the load short-circuit, overload control circuit failure or unforeseen circumstances, such
18、 as would cause the flow of switching voltage regulator transistor current is too large, so that increased power tubes, fever, if there is no over-current protection device, high power switching transistor may be damaged. Therefore, the switching regulator in the over-current protection is commonly used. The most economical way is to use simple fuse. As a result of the heat capacity of small transistors, general fuse protection in general can not play a role in the rapid fuse common fuse. This method has the advantage of the protection of vulnerable,
