外文翻譯——PWM壓降型

1、 畢業(yè)設(shè)計(論文) 英 文 翻 譯 題 目 基于單片機的數(shù)字PWM控制器設(shè)計與應用硬件學 院 專業(yè)及班級 姓 名 學 號 指 導 教 師 日 期 2012年6月9日 Modeling, Simulation Due to a PWM Buck Type Switching Power and MCUAbstract: Introduce a kind of dormancy of using- restore to the throne in the operation way and improve the anti-interference ability method of the on

2、e-chip computer; Analyses its scope of application, provide and use the circuit concretely; Combine the instance, analyze the characteristic of the hardware and software design under these kind of operation way. Keyword: One-chip computer Restore to the throne /dormancy anti-interference ForewordInt

3、roduction: With the development at full speed of the micro electric technique, the performance of the one-chip computer improves rapidly, demonstrate the outstanding advantage in the operation, logic control, intelligent respect, replaced and enlarged the measuring that the circuit made up, control

4、circuit by digital logical circuit, operation originally to a great extent, use very extensively. But because it have system halted, procedure run critical defect of flying etc, make it limit in a lot of important application of occasion. A lot of technology in anti-interference , for example set up

5、 the software trap, add the hardware to guard the gate in dog's circuit etc, can make this problem have better settlement, but still the existing problem: Guard the gate dog at the movement, mean and appear mistake already and run some time, this is not allowed in some occasions; Procedure appea

6、r circulation mistake very much sometimes, but just guard the gate dog control link include and enter, adopt and guard the gate as to such a mistake dog unable to discern; In measure and control cycle among the long system, one-chip computer spend wait for the peripheral hardware a large amount of t

7、ime, will be interfered too when carry out and wait for the order. To these situations, we have tried the method restored to the throne voluntarily in practice, alternate pulse of adopting etc or restore to the throne waking according to external terms to the one-chip computer up. After being restor

8、ed to the throne each time, the one-chip computer carries out the corresponding procedure, enters dormancy in time after finishing carrying out the task, wait to be restored to the throne neatly. Have solved above-mentioned problems well with this method , and has got better result in the agricultur

9、al voltage transformer comprehensive protector experiment. Now take 51 serial one-chip computers as an example and probe into the concrete principle and implementation method, restored to the throne the signal as the high level.1.A principle and implementation method1.1 Restored to the throne the la

10、w regularly unconditionallyUse timer, special-purpose clock chip or other pulse generator, produce signal of restoring to the throne regularly according to interval that set for. This kind of method is especially suitable for the measuring instrument. In not running actually, sample the analog quant

11、ity of introduction with A/D converter often, then store showing. This course is very fast, but steady for reading, the data per second are only upgraded 1 -2 times, a large amount of time of CPU is used for waiting. Let CPU carry out and enter dormancy directly after the task , restore to the thron

12、e and wake by external world up It carry out the next operation, this is to restore to the throne the law regularly In this way can make anti-interference ability strengthen greatly , have 2 points mainly: . At the dormancy, procedure stop run, can appear PC indicator disorderly procedure that cause

13、s run and fly. Work time in dormancy proportion 1:9, that is to say 1 s have 0.1 time of s used for measuring, sending off showing, there is time dormancy of 0.9s, the probability that the procedure is interfered is 1/10 while running at full speed, whole anti-interference ability raise by 10 times.

14、 Because every 1s is restored to the throne once unconditionally, once present the system halted during a job, can certainly resume when restored to the throne next time. As to only instrument that show, some reading mistake that 1s appear accidentally there is no memory to the next measurement, be

15、could bear , belong to “pass” mistake. This kind is restored to the throne the advantage of dog's circuit for guarding the gate regularly, first, change waiting time into a dormancy state, time to shorten and may be interfered; Second, avoided happening that the dog controls the death circulatio

16、n of the link to include guarding the gate.1.2 The external condition is restored to the throne the lawSome arrival that export or measure is controlled by the outside. For instance, the hot form. of heating, rotate the pulse produced and calculate heat by hot water wheels, there is no hot water to

17、flow, there is no heat to export, CPU only need in fact keep number value, do not need to count. Can imagine hot water wheels rotate when parking warm , CPU idle in will it be will it be one season autumn spring and summer, If let dormancy its , measure have water wheels pulse constantly, anti-inter

18、ference ability can strengthen greatly. So, so long as link up the restoring to the throne of the pulse of the water wheels and CPU, the water wheels rotate a circle each time, CPU is restored to the throne once, hot form. can work normally , this is restored to the throne the law by the external co

19、ndition . Similar application have half electron kilowatt-hour meter , go on one count just when the machinery degree wheels and transfers to a circle, users do not need the electricity, CPU has been knowing the dormancy all the time . The restoring to the throne in the interval not to be regular, b

20、ut confirmed according to the external condition of this method. In some occasions, the time of the dormancy will be very long, very effective to improving anti-interference ability.2 .The hardware realizes the main point2.1 Restored to the throne regularly unconditionallyGenerally have 2 kinds of m

21、ethods. Use the timer or the special-purpose clock chip to be restored to the throne. Fig1, in order to use the timing circuit that 555 circuit makes up; Can use the clock chips of X1126 ,etc too , wake CPU up with the alarm signal after setting up warning time. This kind of method is suitable when

22、the long interval is made, can also follow the result of this operation ，determine to wake time up in alarm next time temporarily, very flexible and convenient. The signal of using the system to be inherent is as reducing the pulse regularly. Use 50Hz worker power make reducing after having a faceli

23、ft frequently, already omit the timer, gathered the corresponding signal for the phase place which measured the electric current signal at the same time, as Fig. 2 shows.2.2 External conditions are restored to the throne Send external condition pulse to and is restored to the throne the end son afte

24、r having a facelift. To that above-mentioned water wheels or the ammeter spend a pulse produced, can use Schmitt's trigger to have a facelift; For writing down the instrument of the biggest or minimum，can use the window comparator. In order to realize the electrification that is regulated，can us

25、e the electronic electric potential device, establish upper and lower limits with the order of the one-chip computer.2.3 Reduce cycle and restored to the throne the high electricity at ordinary timesIn Fig3, restored to the throne the signal during high level Tr, the one-chip computer is in the stat

26、e of restoring to the throne, the procedure does not run, anti-interference ability is the strongest; After the high level, the one-chip computer begins to hold the conduct procedure. That is to say, are restored to the throne and suitable for the time that the procedure carries out during the low l

27、evel Td of the signal, this time should be greater than the execution cycle of the procedure each time. It is restore to the throne cycle and restore to the throne high level of signal take empty than very much important to choose rationally. As to simple to show instrument, restore to the throne cy

28、cle determine data break cycle, low electricity is it measure, hank over all time shown to greater than to want at ordinary times; Otherwise, cant present forever the mistake of the intact executive program. Monolithic integrated circuit in Ts and Tr period all can effectively the ant jamming, but i

29、s best the unnecessary time arrangement in Tr. When the program time is long, when as far as possible the request reduces Tr, may join the differentiating circuit, like chart 1 center C30, R26, D9. 2.4 Treatment of output end sons(1) Restore to the throne straight pulseDuring all I/O mouth of one-ch

30、ip computer turn into the high level when restoring to the throne. That is to say output for low pin normally, will according to restore to the throne cycle appear the width for the straight pulse of Tr. This straight pulse will influence the normal output, 2 methods are dealt with:   Connect i

31、n parallel electric capacity suppress , capacity confirm according to Tr time that restore to the throne on the son in end. Reducing Tr can be reduced and connected the electric capacity in parallel. It is invalid to design the peripheral circuit into the high level. (2) Fault-tolerantChoose the cap

32、acity that the output end connects the electric capacity in parallel fault-tolerantly and properly, can realize fault-tolerant control. Reduced cycle in a certain, because interfered exporting the wrong level. Because the keeping function of electric capacity, can't still enable exporting the ch

33、ange to the valid level within this cycle; Next cycle , the mistake is corrected. So, so long as does not make mistakes in 2 cycles in succession, it is very fault-tolerant to export Certainly, this kind of method will make the normal output change lag behind for one cycle, just really reflect the o

34、utput end son.2.5 has the electricity to measure and restore to the throne manuallySome system is it make some initialize and operate to want at electricity for the first time. Restored to the throne and already become the beginning condition of normal running each time while adopting the way of res

35、toring to the throne to run , it is unable to distinguish and have the electricity for the first time. In some pin connects the electric capacity of one1PF to the ground, measure this pin after being restored to the throne, if low level to have electricity for the first time. Give system set up one

36、restore to the throne button, that is to say a common one manual to restore to the throne, this button is not joined and being restored to the throne in the end, is connected in parallel in the electric capacity both ends to the ground of above-mentioned pins.3. The software realizes the main point3

37、.1 is it resume with zero clearing RAM to outputRestore to the throne the last all pin turn high level into , is it should take place unnecessary change for low pin to make regularly, so, should resume the state. of all pins immediately after being restored to the throne. There are 2 kinds of method

38、s : Analyze and judge immediately after being restored to the throne this time, provide the state of the pin according to the need; In being RAM it is the last state that come down, these RAM when restored. To the throne regularly can the zero clearing one; But electricity or manual to restore to th

39、e throne when pushing in conformity with zero clearing, is it embody to want when the software is worked outing at the beginning. If calculate time allows, try one's best to take method 1. Restore to the throne cycle probability made mistakes to calculate very little, according to 2 for the 2nd

40、time in succession. 4 output end son that narrate connect treatment method of electric capacity in parallel, can reach kind anti-interference result very.3.2 realizes crossing over and is restored to the throne alternate time sequenceregularly to controlWork in way of restoring to the throne now, st

41、art anew and carry out the same procedure repeatedly each time. Can be divided into 2 kinds of situations: As to simple to show instrument, carry on measurement ，send off showing after being restored to the throne each time, have causality between restoring to the throne twice . need is it switch ov

42、er to the dormancy to waiting original only. Should pay attention to, measurement, give total time used to show is it is it restore to the throne low electricity at ordinary times to smaller than to want, otherwise can't present forever the mistake of the intact executive program. For having app

43、lication that time sequence controlled , after being restored to the throne each time , should check first that see the sign left last cycle , in order to determine what is done this cycle . That is to say every is it restore to the throne operation of cycle to stride , by is it transmit to indicate

44、 all, these indicate while leaving in inside RAM , the zero clearing only when have the electricity for the first time. For example, the protecting synthetically device of above-mentioned voltage transformer , is restored to the throne regularly according to the interval of 20ms. It reaches the norm

45、al working state through, certain movement order after having the electricity, such as Fig. 4; Write a part of the procedure of the software according to this movement, such as Fig. 5.In 4 Fig, act as person who protect the beginning at the electricity, is it transmit power 0 to try at first. 5s, po

46、ints out and transmits power soon; Transmit power formally after waiting for 30s. It is start-up time in 1s after transmitting power, does not measure the electric current. Start after finishing, if all going well, the location is put" normal sign ", person who protect restore to the thron

47、e cycle enter normal running in the next one. Try 0 that transmits power. 5s is it is it realize to count once restoring to the throne to delay time, restore to the throne time 20ms each time. At having electricity for the first time, make all zero clearing to inside RAM, make it is it time Ts to tr

48、ansmit power not to try =Dormancy after 25. After restoring to the throne, is it have electric pin to have electricity for the first time already, is it is it is it is it time the measuring of Ts to transmit power to try to get to go on to measure next time. If Ts * 0, is it in is it prolong period

49、to transmit power, is it enter dormancy after the 1 to reduce Ts to prove. Act as Ts-1 = 0, the course which waited for 30s that should enter and lose electrical power. Just when Ts decreases progressively to 0, make it is it indicate to wait for not to lose electrical power Td =1500. When the proce

50、dure is restored to the throne beginning again, measure to Ts =0 but Td * 0, is it is it is it transmit power to try to cross already to indicate, at is it wait for the course of 30s to lose electrical power now. In this way, the whole process is transmitted each other by such these parameters as Tr

51、, Td , Ts etc, go on step by step.Result:Conclusion Anti-interference is an important problem in an electronic design, especially Important in the one-chip computer. This is because the one-chip computer has procedures to run particularity that flies, the consequence that it is interfered may be the

52、 system halted, may send out various kinds of mistakes or illegal movements before the system halted too, make the whole system produce the mortality mistake. So, only guarantee it is not enough yet for one-chip computer not to crash, study how to reduce the risk interfered, it can befault-toierant

53、how is it after and make mistakes. This text is it act as some exploration from two these to try hard, hope these elementary opinions can play some function of casting a brick to attract jade, helpful to everybody; Hope too every colleague explore together, improve our design level together.I.FAST s

54、emiconductors make it possible to have high speed and high frequency switching in power electronics . High speed switching causes weight and volume reduction of equipment, but some unwanted effects such as radio frequency interference appeared . Compliance with electromagnetic compatibility (EMC) re

55、gulations is necessary for producers to present their products to the markets. It is important to take EMC aspects already in design phase . Modeling and simulation is the most effective tool to analyze EMC consideration before developing the products. A lot of the previous studies concerned the low

56、 frequency analysis of power electronics components . Different types of power electronics converters are capable to be considered as source of EMI. They could propagate the EMI in both radiated and conducted forms. Line Impedance Stabilization Network (LISN) is required for measurement and calculat

57、ion of conducted interference level . Interference spectrum at the output of LISN is introduced as the EMC evaluation criterion . National or international regulations are the references for the evaluation of equipment in point of view of EMC . II. SOURCE, PATH AND VICTIM OF EMI Undesired voltage or

58、 current is called interference and their cause is called interference source. In this paper a high-speed switching power supply is the source of interference. Interference propagated by radiation in area around of an interference source or by conduction through common cabling or wiring connections. In this study conducted emis