毕业设计（论文）电梯自动控制模型设计.doc

课题名称 电梯自动控制模型 课题需要完成的任务：1.根据技术指标进行可行性方案分析及方案论述。2.硬件的框图及电路设计。3.传感器、显示器件、各主要器件、单元电路等的选用方案，性能分析及功能介绍。4.设计硬件电路的电路图。5.软件部分流程图及相关程序设计。6.毕业设计小结。课题计划：2.273.10 查资料，进行初步方案设计。3.113.18 设计最佳方案；设计硬件电路，。3.194.10 编制程序，写毕业论文。4.114.20 修改、完善毕业论文，并做答辩准备。计划答辩时间：4.22电子信息技术系 （部、分院） 2007 年 4 月 18 日英文Diode characteristic and applicationIn all electronic circuit, all must use nearly to the semiconductor diode, it is playing the vital role in many electric circuits, it is born one of earliest semiconductor devices, its application extremely is also widespread.Diode principle of workThe crystal diode is the p-n knot which forms by the p semiconductor and the n semiconductor, forms the space charge level in its contact surface place two side, and constructs from constructs the electric field. When does not have the external voltage, because p-n ties the diffusion current which two side loads currents concentration difference causes and from constructs the drifting electric current which the electric field causes to be equal but is at the electric equilibrium condition.When the outside has the forward voltage bias, the outside electric field and from constructed the electric field to damp mutually disappears the function to cause the current carrier the diffusion current increase to cause to the electric current.When the outside has the reverse voltage bias, the outside electric field and from constructs the electric field further to strengthen, forms in the certainly reverse voltage scope reverse saturation current I0 which has nothing to do with with the reverse bias voltage value.When sur- reverse voltage as high as certain degree, p-n ties in the space charge level the electric-field intensity to achieve the marginal value produces the current carrier to multiply the process, produces the massive electron-hole pairs, has produced the value very big reverse striking current, is called the diode to penetrate the phenomenon.Diode typeThe diode type has very much, according to semiconducting material which uses, may divide into the germanium diode (GETube) and silicon diode (Si tube). According to its different use, may divide into the detector diode, the rectification diode, the zener diode, the switch diode and so on. According to looks after the core structure, also may divide into the contact diode, the surface contact diode and the plane diode. The contact diode is presses with a very thin tinsel in the bright and clean semiconductor chip surface, passes by the pulse electric current, makes to touch a silk end and the chip reliably agglutinates in the same place, forms "the PN knot". Because is a contact, only allows through the small electric current (not to surpass several dozens milliamperes), is suitable in the high frequency undercurrent electric circuit, like radio detection and so on.Surface contact diode "PN knot" area big, allows (several to arrive safely through the big electric current several dozens is peaceful), mainly uses in the alternating current transforming the direct current "the rectification" in the electric circuit.The plane diode is the silicon diode which one kind specially makes, it not only can through the big electric current, moreover the performance stable is reliable, uses in the switch, the pulse and the high-frequency circuit.Diode electric conduction characteristicThe diode most important characteristic is the folk remedy guide electric properties. In the electric circuit, the electric current only can from the diode positive electrode inflow, the cathode flow out. Under explains the diode through the simple experiment to the characteristic and the reverse characteristic.1、characteristic In the electronic circuit, meets the diode positive electrode in the high electric potential end, the cathode meets in the cold end, the diode can lead passes, this connection way, is called to the bias. Must explain, when adds in the diode beginnings and ends forward voltage very hour, the diode still could not lead passes, flows the diode to be extremely weak to the electric current. Only then when the forward voltage achieved some value (this value is called "the threshold voltage", the germanium governs and restrains is0.2VThe silicon governs and restrains is0.6V) Later, the diode will be able honest to lead passes. After leads passes the diode beginnings and ends voltage basically maintains (the germanium to govern and restrain invariablely is0.3VThe silicon governs and restrains is0.7V) Is called the diode "to the pressure drop".2、reverse characteristicIn the electronic circuit, the diode positive electrode meets in the cold end, the cathode meets in the high electric potential end, this time in the diode nearly does not have the electric current to flow, this time the diode is at the closure condition, this connection way, is called the reverse bias. When the diode is in the reverse bias, still could have the weak reverse electrical current to flow the diode, was called leaks the electric current. When the diode beginnings and ends reverse voltage increases to some value, the reverse electricity inoperables for lack of a quorum increases suddenly, the diode will lose the folk remedy to the electric conduction characteristic, this kind of condition will be called the diode penetrating.Diode main parameterUses for to express the diode performance quality and the applicable scope technical specification, is called the diode the parameter. The different type diode has the different characteristic parameter. Speaking of the beginner, must understand following several main parameters:1、volume correction to operating currentMost Taisho which is refers to when diode long-term continuous working allows to pass to the magnitude of current. Because electric current through pipe time can cause the tube core to give off heat, the temperature rise, the temperature surpasses the tolerance range (the silicon tube is140About, the germanium tube is90When about), can cause the tube core heat but to damage. Therefore, in the diode use do not have to surpass the diode volume correction to the work magnitude of current. For example, commonly used IN4,0014,007The germanium diode volume correction to the operating current is 1A。2、highest reverse working voltageAdds when the diode beginnings and ends reverse voltage as high as a definite value, can penetrate the pipe, loses the unilateral conduction ability. In order to guarantee the use security, has stipulated the highest reverse working voltage value. For example, the IN4001 diode reverse pressure resistance is 50V, the IN4007 reverse pressure resistance is 1000V.3、reverse electrical currentThe reverse electrical current is refers to the diode in the stipulation temperature and under the highest reverse voltage function, has flowed the diode reverse electrical current. Reverse electrical current smaller, the pipe single direction electric conductivity is better. The worth noting is the reverse electrical current and the temperature has close relationship, probably the temperature every time elevates 10, the reverse electrical current increases a time. For example 2AP1 germanium diode, in 25 o'clock reverse electrical currents if is 250UATemperature increment to 35, the reverse electrical current will rise to 500UA, infer from this, when 75, its reverse electrical current has reached 8MANot only has lost the folk remedy to the electric conduction characteristic, but also can cause the pipe heat but to damage. Also like, the 2CP10 silicon diode, 25 o'clock reverse electrical currents are only 5UATemperature increment to 75 o'clock, reverse electrical current also only 160UA. Therefore the silicon diode has the good stability compared to the germanium diode under the high temperature.Detecting diode qualityThe beginner may use the avonmeter detecting diode performance under the extra-curricular condition the quality. Before the test allocates move set clock for the avonmeter change-over switch the ohm files the RX1K files position (attention not to have first to use the RX1 files, in order to avoid electric current oversized burns out diode), will be then red, the black two tables pen short-circuits, carries on the ohm to adjust the zero.1、characteristic test(In table positive electrode) builds the avonmeter black table pen touches the diode the positive electrode, the red table pen (in table cathode) builds touches the diode the cathode. If the table needle does not suspend to 0 values but is stops in dial among, the by now resistance number was the diode forward resistance, the general forward resistance smaller was better. If the forward resistance is 0 values, explained the tube core short-circuits the damage, if the forward resistance approaches the infinity value, explained the tube core shuts. Short-circuits the pipe which and shuts all not to be able to use.2、reverse characteristic testBuilds Wan Qiebiao red table pen touches the diode the positive electrode, the black table pen builds touches the diode the cathode, if the table needlework or approaches the infinity value in the infinity value, the pipe is qualified.Diode application1、rectification diodeUsing the diode unilateral conductivity, may the alternating current which changes in turn the direction transform the sole direction the pulsating direct current.2、on-off elementThe diode the resistance is very small under the forward voltage function, is at leads passes the condition, is equal switch which puts through in; Under the reverse voltage function, the resistance is very big, is at the closure condition, is similar to switch which separates. Using the diode switch characteristic, may compose each logic circuit.3、restricts the partAfter the diode guide passes, it is being invariable (the silicon tube to the pressure drop basic maintenance is0.7VThe germanium tube is0.3V) . Using this characteristic, the achievement restricts the part in the electric circuit, may limit the signal scope in the certain scope.4、continues flows the diodeContinues in in the switching power supply inductance and the relay equisignal load flows the function.5、detector diodeIn radio detecting action.6、changes accommodates the diodeUse in television high frequency tuner.The triode sentences the fracture definitelyThe triode casts and the base pin distinction is electronic technology beginner's basic skills, in order to help the reader rapidly to grasp measured sentences the method, the author summarizes four mnemonics: "Three inversions, looks for the base extremely; The PN knot, decides casts; Along the arrow, deflects in a big way; Measured does not permit, to move the mouth." Under lets us carry on the explanation by the sentence.一、 three inversions, looks for the base extremelyAs everybody knows that, the triode includes the semiconductor device which two PN ties. Ties the connection way according to two PN to be different, may divide into NPN and the PNP two kind of different electric conduction types triode, chart 1 is their electric circuit mark and the equivalent circuit.Tests the triode to have to use amp the ohm to keep off, and the choice R×100 or R×1k keeps off the position. Chart 2 drew the equivalent circuit which the amp ohm kept off. By the chart obviously, is in the table which the red table pen connects the battery cathode, the black table pen then is connecting in the table the battery positive electrode.Supposes us not to know was measured the triode is NPN PNP, also cannot distinguish clearly various base pins is any electrode. Which base pin the test first step is judges is the base extremely. By now, we no matter what took two electrodes (for example these two electrodes were 1, 2), inverted with the amp two tables pens surveys it, the back-resistance, the observation table needle deflection angle; Then, again takes 1, 32 electrodes and 2, 32 electrodes, inverts separately surveys them, the back-resistance, the observation table needle deflection angle. In these three inversions survey, inevitably some two measurement result close: Namely in the inversion survey the table needle time deflects in a big way, time deflects slightly; Is left over time is inevitably inverts around the survey the needle deflection angle all very small, this had not measured that base pin is the base which we must seek (the senate map-read 1, chart 2 is not extremely difficult to understand its truth).二、 the PN knot, decides castsAfter discovers the triode the base extremely, we may act according to the base the direction which PN ties with other two electrodes between to determine the pipe extremely the electric conduction type (chart 1). The avonmeter black table pen contact base extremely, the red table pen contacts in other two electrodes no matter what an electrode, if the table needle deflection angle is very big, then explained was measured the triode is the NPN tube; If the table needle deflection angle is very small, then was measured the tube is PNP.三、is suitable the arrow, deflects in a big wayHas discovered base extremely b, moreover two electrodes which are collecting electrode c, which is emitter electrode e?By now we might use to measure penetration electric current ICEO method determination collecting electrode c and emitter electrode e.(1) regarding the NPN triode, penetration electric current metering circuit like chart 3 shows. According to this principle, with the amp black, the red table pen inverts between the survey two-pole, back-resistance Rce and Rec, although in two surveys avonmeter needle deflection angle all very small, but carefully observes, the general meeting has a time of deflection angle to be slightly big, this time the electric current flows to certainly is: Black table pen -> c -> b extremely -> the e extremely -> red table pen, the electric current flows to extremely happen to is consistent with the triode mark in arrow direction ("along arrow"), therefore this time black table pen meets certainly is collecting electrode c, the red table pen meets certainly is emitter electrode e.(2) regarding the PNP triode, the truth also is similar to NPN, its electric current flows to certainly is: Black table pen -> e -> b extremely -> the c extremely -> red table pen, its electric current flows to extremely is also consistent with the triode mark in arrow direction, therefore this time black table pen meets certainly is emitter electrode e, the red table pen meets certainly is collecting electrode c (the senate map-read 1, chart 3 may know).四、could not measure, moves the mouthIf in "is suitable the arrow, deflects in a big way" in survey process around, if when inverts two surveys needle deflection too small with difficulty differentiates, wants "to move the mouth". The concrete method is: In "was suitable