【正文】 emperature of the shell or the internal device temperature exceeds the allowed value, the heat conduction thirstier on, so that LED warning light. If the opt coupler with, would enable the whole circuit alarm action to protect the switching regulator. It can also be used as a power transistor as the overtemperature protection, crystal switch the base current by ntype gate control thirstier TT201 thermal bypass, cutoff switch to cut off the collector current to prevent overheating. H、 The future development of relay protection Protection technology to future trends is puterized, work, intelligent, protection and control, measurement and data munications integration development. 1) Computerized Along with the rapid development of puter hardware, microputer protection and development in hardware. Former north electricity institute of puter line protection hardware has experienced three development stages: from eight single CPU structure of the microputer relay protection, less than 5 years time to develop more CPU structure, and to develop the large don39。s input overvoltage protection, including overvoltage protection and output overvoltage protection. Switching regulator is not used in DC power supply voltage regulator and rectifier, such as battery voltage, if too high, so switching regulator is not working properly, or even damage to internal devices, therefore, it is necessary to use the input overvoltage protection circuit. Using transistors and relays protection circuit. In the circuit, when the input DC power supply voltage higher than the voltage regulator diode breakdown voltage value, the breakdown voltage regulator tube, a current flowing through resistor R, so that V turnon transistor, relay, normally closed contact off open, cut off the input. Voltage regulator voltage regulator which controls the value of Vs. = EarwaxUBE. The polarity of input power with the input protection circuit can be bined with overvoltage protection, polarity protection constitute a differential circuit and over voltage protection. Output overvoltage protection switching power supply is essential. In particular, for the 5V output of the switching regulator, it is a lot of load on a high level of integration of the logic device. If at work, switching regulator sudden damage to the switch transistor, the output potential may be increased immediately to the importation of nonregulated DC power supply voltage value, causing great loss instantaneous. Commonly used method is shortcircuit protection thirsted. The simplest overvoltage protection circuit. When the output voltage is too high, the regulator tube breakdown triggered thirstier turnon, the output shortcircuit, resulting in overcurrent through the fuse or circuit protective device to cut off the input to protect the load. This circuit is equivalent to the response time of the opening time 桂林電子科技大學(xué)畢業(yè)設(shè)計(jì)英文資料 翻譯 3 of thirstier is about 5 ~ 10μs. The disadvantage is that its action is fixed voltage, temperature coefficient, and action points of instability. In addition, there is a voltage regulator control parameters of the discrete, model overvoltage startup the same but has different values, difficult to debug. Esc a sudden increase in output voltage, transistors V1, V2 conduction, the thruster conduction. Reference voltage Vs. by type. F、 Undervoltage protection Output voltage below the value to reflect the input DC power supply, switching regulator output load internal or unusual occurrence. Input DC power supply voltage drops below the specified value would result in switching regulator output voltage drops, the input current increases, not only endanger the switching transistor, but also endanger the input power. Therefore, in order to set up due to voltage protection. Due to simple voltage protection. When no voltage regulator input normal, ZD breakdown voltage regulator tube, transistors V conduction, the relay action, contact pullin, powerswitching regulator. When the input below the minimum allowable voltage value, the regulator tube ZD barrier, V cutoff, contact Kaihop, switching regulator can not work. Internal switching regulator, as the control switch transistor circuit disorders or failure will decrease the output voltage。 畢業(yè)論文英文翻譯資料 題 目： 直流開關(guān)穩(wěn)壓電源的保護(hù)技術(shù) 院 （系）： 電子電器工程系 專 業(yè)： 電氣工程及其自動(dòng)化 學(xué)生姓名： 班 級(jí)： 學(xué) 號(hào)： 指導(dǎo)教師： 2020 年 12 月 10 日 桂林電子科技大學(xué)畢業(yè)設(shè)計(jì)英文資料 翻譯 0 DC Switching Power Supply Protection Technology Abstract: The DC switching power supply protection system, protection system design principles and machine protection measures, an 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 highpower switching devices, the control circuit is also more plex, In addition, the load switching regulators are generally used a large number of highly integrated electronic systems installed devices. Tra