科技论文Frequency conversion control system microcontroller peripheral circuit design系 别 尚德光伏学院 专 业 应用电子技术 班 级 0903 学生姓名 学 号 指导教师 2011年 4 月1无锡科技职业学院科技论文 Frequency conversion control system microcontroller peripheral circuit design_Frequency conversion control system microcontroller peripheral circuit design【 abstract 】 single-chip microcomputer with appropriate peripheral devices and applications, consists of the application system become the minimum system. The article to the frequency conversion control system of the single chip microcomputer buffer circuit design is discussed.【 key words 】 frequency conversion control; Single chip microcomputer; Buffer circuitThis design USES the choice PHILIPS semiconductors company with manual reset function MAX708 products. MAX708 can also monitor the second power signal, as the processor provide voltage drop into warning function, using this function, the system can be in power supply fall to reset before performing some safety operation, save parameters, send warning signals or switching back-up battery, etc. In addition, the system also expanded the programmable peripheral PSD303 chip. Because the system I/O mouth quantity and real ?The product MAX708 that designs to adopt to choose PHILIPS that the semi-conductor companies take to move to reset function.The MAX708 can also keep watch on the second power signal and provide the electric voltage the early-warning function for dropping into for processor and make use of this function, system can when the power drop into to carry out some safety operations before resetting, keep parameter, send out alert signal or cut over spare battery etc.On top of that, the system expanded programmable outer circle chip PSD303.Because the I of system|the O amount still have a very big margin with actual amount needed, past the system expanded two slices of 8255 Ases again, the one was used for connecting a keyboard and shown electric circuit, the one is used for contact to send letter number, and urgent parking signal.etc.A, keyboard with show electric circuitDesign at this in, establish an operation electric circuit of 9 keys to replace physically the operation button on the scene.6 LEDs show that electric circuit is used for to show to turn soon, electric current, and adjust to try of related items showing.Moreover, for the sake of easy to the spot work it established 5 s then 4 of matrix type keyboard, used for when the system software waits to appear a mistake, but again the inconvenience directly carry on modifying to the procedure of adjust to try of use.Two, become repeatedly system designThe modern becomes repeatedly in the technique and mainly has 2 kinds to become repeatedly technique:Hand over-keep-hand over to become repeatedly a technique and hand over-hand over to become repeatedly a technique.Hand over-keep-hand over to become repeatedly technique for hand over-keep-hand over to become repeatedly and adjust soon system to provide to become repeatedly the power.Hand over-keep-hand over to become repeatedly constitute electric circuit have already commutated electric circuit and negative change electric circuit two parts, commutate electric circuit work repeatedly the alternate current commutate into direct current and go against to change electric circuit again direct current negative change into adjustable frequency alternate current.According to becoming repeatedly the property of the power can is divided into electric voltage type and electric current type to become repeatedly.This design is used and handed over-hand over and become repeatedly electric circuit is an impassability and lead in the center direct current link, but become the becoming of alternate current of different frequency to the alternate current of the charged barbed wire net fixed frequency direct transformation repeatedly electric circuit.This kind of becomes repeatedly the electric circuit be extensively applied to the big power alternate current motive adjusts to soon spread system and physically use of mainly is three mutually output to hand over-hand over to become repeatedly electric circuit.The characteristics of this kind of electric circuit:(1)Because is a direct transformation, have no in the center link, so compare general of the inverter efficiency have to be high;(2)It is direct to output electric voltage with its exchanges from communicate that some parts that input electric voltage wave wrap net constitute, as a result its exportation frequency the ratio input the frequency of AC power low, the exportation wave form is also good;(3)Because being limited by charged barbed wire net frequency, usually outputting the frequency of electric voltage is lower, or so for 1/3 of charged barbed wire net