闲置物品再次利用-我真是一个大聪明
概述家里闲置物品挺多的,常年躺在角落吃灰,尤其是电子产品,前几天搞定了IPTV,我灵机一动,为何不用闲置物品来组合一个移动便携式的小电视呢?本次利用的闲置物品有:便携显示屏、懒人支架、小米机顶盒、USB网卡、HDMI影音分离器、户外移动电源、DIY蓝牙音箱,滑板。 - 视频 - 正文简单介绍一下,如下图,都标记了序号,和表格序号是对应关系:序号名称参考单价 备注1便携显示屏350一年开不了两次机2懒人支架70刚买回来3小米机顶盒350偶尔拿来投屏4USB网卡65专门为解决小米机顶盒无线信号不好而生的5HDMI影音分离器50为了得到完美音频源,接显示器前提前影音分离,显示器上面其实有个耳机接口,一直怀疑那个接口不完美。 后来比较证实:两者没啥区别。多此一举。 这玩意只适合显示器没音频接口,且播放器没蓝牙功能小概率组合。有蓝牙功能的播放器,自然蓝牙连接音箱了。6户外移动电源2880偶尔户外要用7DIY蓝牙音箱190别人这个音箱好像也是拆卸摩托车的音箱,自己买了电池和功率放大器,音质还行。但很少用,家里最不缺的就是音箱,耳机。8滑板90少年梦,年少没条件学,现在没体能和兴趣学,买回来就玩过两次。结尾男孩子的乐趣大概就是这些无休止的折腾过程吧,目前还有一台闲置笔记本,一直吃灰中,不知道该如何利用,软路由和NAS 家里有主力设备,打造一个PC版本的影音播放器吧,似乎还没有手机投屏便捷一些。想不到更好的主意,还是继续吃灰吧。
追忆时光-music heaven 音乐天堂 杂志-复古磁带播放器
现在听歌,感觉都很杂乱,歌曲也开始实施版权收费制度,忽然很怀念以前用磁带放歌的年代。 music heaven 音乐天堂 杂志大约2002年的时候,高中,好朋友收到一本音乐杂志的礼物,里面夹杂着两盘磁带,我和他住在一起,他都还没来得急听,我已经都快把赞新的杂志快翻脏了! 好兄弟不说那些,相信他也不会归罪与我 这本杂志给我留下了很深的印象,一种有一盘听了没感觉,另一盘被我反复的播放,每首歌都很有意境,其实英文并不好,但调调很上头,难怪音乐不分国界。 后来,大学和工作就很少听到了,歌曲的名字依稀都快忘记了,但音乐的曲子是记在骨子里了,我几乎都记不清楚那本杂志的封面,多年以后,想听,找了半天,觉得这张图片很相似,但并不能确定。记不住杂志的名字和期号,资源自然就不好找,只能根据记忆中的曲子,复原了一下歌曲清单,并下载收藏,整理歌曲的时候,无意中发现了一款复古的磁带播放器,大神级的,很有当年随身听的感觉,简单的修改了一下,这么经典的歌曲,就用它来播放吧!
(手机用户请横屏!)我还很用心的整理个歌词!null01.Sailing Rod Stewart" }I am sailing, I am sailing home again 'cross the sea.I am sailing stormy waters, to be near you, to be free. I am flying, I am flying like a bird 'cross the sky.I am flying passing high clouds, to be near you, to be free.Can you hear me, can you hear me, through the dark night far away?I am dying, forever crying, to be with you; who can say?Can you hear me, can you hear me, through the dark night far away?I am dying, forever, crying to be with you; who can say?We are sailing, we are sailing home again 'cross the sea.We are sailing stormy waters, to be near you, to be free.Oh Lord, to be near you, to be free.02.Kiss From A Rose Seal"}There used to be a graying time all alone on the seaYou became the light on the dark side of meLove remains a drug gets me high, that's how I feelDid you know that when it snows my eyes become enlargedAnd the light that you shine can be seenBaby, I compare you to a kiss from a rose on the greyThe more I get of you, the stranger it feels, yeahNow that your rose is in bloom, a light hits the gloom on the GreyThere is so much a man can tell you, so much he can sayYou remain my power, my pleasure, my pain, babyTo me you're like a growing addiction that I can't denyWon't you tell me is that healthy, babe?But did you know that when it snows, my eyes become enlargedAnd the light that you shine can be seenBaby, I compare you to a kiss from a rose on the greyI've been kissed by a rose on the grey, I've been kissed by a roseThe more I get of you, the stranger it feels, yeahI've been kissed by a rose on the grey (If I should fall...)Now that your rose is in bloom, a light hits the gloom on the GreyThere is so much a man can tell you, so much he can sayYou remain my power, my pleasure, my painTo me you're like a growing addiction that I can't denyWon't you tell me is that healthy, babyBut did you know, that when it snows, my eyes become enlargedAnd the light that you shine can be seenBaby, I compare you to a kiss from a rose on the greyThe more I get of you, the stranger it feels, yeahNow that your rose is in bloom, a light hits the gloom on the GreyNow that your rose is in bloom, a light hits the gloom on the greyYes, I compare you to a kiss from a rose on the greyThe more I get of you, the stranger it feels, yeahNow that your rose is in bloom, a light hits the gloom on the Grey03.the vanishing race air supply"}Sun, I can't slow you downRun, build on sacred groundAll of the leavesd have blown awayGhosts on a distant highwayIn a vanishing raceSleep, if your eyes must closeWeep, over a poisoned roseSoon all the tears will blow awayDust on a distant highwayIn the vanishing raceFly, closer to the sunFight, 'till your world is oneSoon all the stars will burn awayGhosts on a different highwayIn the vanishing raceOh, shall we sleep tonightTake all your dreams and drive awaySmoke on a distant highwayFrom the vanishing raceAll my peopleRespect your Mother EarthThank you for this life and this breathANd all my people's strength04.Music Madonna"}Musicwritten by Madonna and Mirwais Ahmadzai (Spoken:)Hey Mister D.J.Put a record onI wanna dance with my babyDo you like to boogie woogieDo you like my Acid RockHey Mister D.J.Put a record onI wanna dance with my babyAnd when the music startsI never wanna stopIt's gonna drive me crazyMusicChorus:Music makes the people come together[Never gonna stop]Music makes the bourgeoisie and the rebel[Never gonna stop]Don't think of yesterdayAnd I don't look at the clockI like to boogie woogie, uh, uhIt's like riding on the windAnd it never goes awayTouches everything I'm inGot to have it everyday(chorus)Hey Mister D.J.Do you like to boogie woogieDo you like my Acid RockHey Mister D.J.Put a record onI wanna dance with my babyAnd when the music startsI never wanna stopIt's gonna drive me crazyUh, uh, uhDo you like to boogie woogieDo you like my Acid Rock05.Santa Monica Savage Garden"}In Santa Monica in the winter timeThe lazy streets so undemandingI walk into the crowdIn Santa Monica you get your coffee fromThe coolest places on the promenadeWhere people dress just soBeauty so unavoidableeverywhere you turnIt's thereI sit and wonder what am I doing here?But on the telephone line I am anyoneI am anything I want to beI could be a supermodel or Norman MailerAnd you wouldn't know the differenceOr would you?In Santa Monica, all the people gotmodern namesLike Jake or MandyAnd modern bodies tooIn Santa Monica, on the boulevard,You'll have to dodge those in line skatersOr they'll knock you downI never felt so lonely,Never felt so out of placeI never wanted something more than thisBut on the telephone line I am anyoneI am anything I want to beI could be a supermodel or Norman MailerAnd you wouldn't know the differenceOn the telephone line, I am any heightI am any age I want to beI could be a caped crusader, orspace invaderAnd you would know the differenceOr would you?on the telephone line I am anyoneI am anything I want to beI could be a supermodel or Norman MailerAnd you wouldn't know the difference06.you sang to me marc anthony"}I just wanted you to comfort meWhen I called you late last night you seeI was fallin' into loveOh yes, I was crashin' into loveOh of all the words you sang to meAbout life, the truth and bein' free yeaYou sang to me, oh how you sang to meGirl I live off how you make me feelSo I question all this bein' realCuz I'm not afraid to loveFor the first time I'm not afraid of loveOh, this day seems made for you and meAnd you showed me what life needs to beYea you sang to me, oh you sang to meAll the while you were in front of me I never realizedI just can't believe I didn't see it in your eyesI didn't see it, I can't believe itOh but I feel itWhen you sing to meHow I long to hear you sing beneath the clear blue skiesAnd I promise you this time I'll see it in your eyesI didn't see it, I can't believe itOh but I feel itWhen u sing to meJust to think you live inside of meI had no idea how this could beNow I'm crazy for your loveCan't believe I'm crazy for your loveThe words you said you sang to meAnd you showed me where I wanna beYea you sang to me, oh you sang to me07.Don't Cry For Me Argentina Madonna"}It won't be easy, you'll think it strangeWhen I try to explain how I feelThat I still need your love after all that I've doneYou won't believe meAll you will see is a girl you once knewAlthough she's dressed up to the ninesAt sixes and sevens with youI had to let it happen, I had to changeCouldn't stay all my life down that hillLooking out of the window, staying out of the sunSo I chose freedomRunning around trying everything newBut nothing impressed me at allI never expected it toDon't cry for me ArgentinaThe truth is I never left youAll through my wild daysMy mad existenceI kept my promiseDon't keep your distanceAnd as for fortune, and as for fameI never invited them inThough it seemed to the world they were all I desiredThey are illusionsThey're not the solutions they promised to beThe answer was here all the timeI love you and hope you love meDon't cry for me Argentina......Don't cry for me ArgentinaThe truth is I never left youAll through my wild daysMy mad existenceI kept my promiseDon't keep your distanceHave I said too much? There's nothing more I can thinkof to say to youBut all you have to do is look at me to know that everyword is true08.Babe Take That"}BabeTake ThatI come to your doorto see you againBut where you once stoodwas an old man insteadI ask where you'd beHe said she's moved on you seeAll I have is a numberYou'd better ask her not meSo I picked up the phone and dialled your numberNot sure to put it down or speak Then a voice I once knew answered in a sweet voiceShe said 'hello' then pausedbefore I began to speakBabe , I'm here againI tell you I'm here againWhere have you beenBabe , I 'm back againI tell you I'm back againWhere have you beenYou held your voice wellThere were tears I could tellBut where were you nowwas you gonna tell me in timeJust give me a townand I'll be straight downI got so much to tell you about where I have beenAs I walk down your roadCan't wait to be near you I can't keep this feeling in insideAs I stand at your door You answer in a sweet voiceYou say 'hello' then paused before I began to speakAs I looked awayI saw a face behind you A little boy stood at your door and as I looke againI saw his face with shiningHe had my eyesHe had my smile Babe , I'm back againI tell you I'm back againI 'm here for youBabe , please take me back take me backBack home againBabe , please hold my closehold me closeLike you used to doBabe......09.Shape Of My Heart Sting"}He deals the cards as a meditation And those he plays never suspect He doesn't play for the money he wins He don't play for respect He deals the cards to find the answer The sacred geometry of chance The hidden law of a probable outcome The numbers lead a dance I know that the spades are the swords of a soldier I know that the clubs are weapons of war I know that diamonds mean money for this art But that's not the shape of my heart He may play the jack of diamonds He may lay the queen of spades He may conceal a king in his hand While the memory of it fades I know that the spades are the swords of a soldier I know that the clubs are weapons of war I know that diamonds mean money for this art But that's not the shape of my heart That's not the shape......the shape of my heartAnd if I told you that I loved you You'd maybe think there's something wrong I'm not a man of too many faces The mask I wear is one Well, those who speak know nothin' And find out to their cost Like those who curse their luck in too many places And those who fear are lost I know that the spades are the swords of a soldier I know that the clubs are weapons of war I know that diamonds mean money for this art But that's not the shape of my heart That's not the shape of my heart That's not the shape......the shape of my heart10.bitch Meredith Brooks"}I hate the world todayYou're so good to me, I know but I can't changeTried to tell you but you looked at me like maybe I'm an angel underneathInnocent and SweetYesterday I criedYou must have been relieved to see the softer sideI can understand how you'd be so confusedI don't envy you I'm a little bit of everything, all rolled into oneBrooks Meredith(Chorus)I'm a bitch, I'm a lover, I'm a child, I'm a mother,I'm a sinner, I'm a saintI do not feel ashamedI'm your hell, I'm your dream,I'm nothin in between,You know you wouldn't want it any other way.So take me as I amThis may mean you'll have to be a stronger manRest assured that when I start to make you nervous And I'm goin to extremes Tomorrow I will change and today won't mean a thingJust when you thinkYou got me figured outThe season's already changingI think it's cool,You do what you doAnd don't try to save me(Chorus 2x)I'm a bitch, I'm a teaseI'm a goddess on my kneesWhen you're hurt, when you sufferI'm your angel undercoverI've been numb, I'm revivedCan't say I'm not aliveYou know I wouldn't want it any other way.....11.Sunny Came Home Shawn Colvin"}Sunny came home to her favorite roomSunny sat down in the kitchenShe opened a book and a box of toolsSunny came home with a missionShe says days go by I'm hypnotizedI'm walking on a wireI close my eyes and fly out of my mindInto the fireSunny came home with a list of namesShe didn't believe in transcendenceIt's time for a few small repairs she saidSunny came home with a vengeanceShe says days go by I don't know whyI'm walking on a wireI close my eyes and fly out of my mindInto the fireGet the kids and bring a sweaterDry is good and wind is betterCount the years, you always knew itStrike a match, go on and do itDays go by I'm hypnotizedI'm walking on a wireI close my eyes and fly out of my mindInto the fireLight the sky and hold on tightThe world is burning downShe's out there on her own and she's alrightSunny came homeSunny came home...12.That's Why You Go Away Michael Learns"}Baby won't you tell me why there is sadness in your eyesI don't wanna say goodbye to youLove is one big illusion I should try to forgetbut there is something left in my headYou're the one who set it up now you're the one to make it stopI'm the one who's feeling lost right nowNow you want me to forget every little thing you saidbut there is something left in my headI won't forget the way you're kissingThe feeling's so strong were lasting for so longBut I'm not the man your heart is missingThat's why you go away I knowYou were never satisfied no matter how I triedNow you wanna say goodbye to meLove is one big illusion I should try to forgetbut there is something left in my headI won't forget the way you're kissingThe feeling's so strong were lasting for so longBut I'm not the man your heart is missingThat's why you go away I know yes I knowSitting here all alone in the middle of nowhereDon't know which way to goThere ain't so much to say now between usThere ain't so much for youI won't forget the way you're kissingThe feeling's so strong were lasting for so longBut I'm not the man your heart is missingThat's why you go away I know13.looking for the summer chris rea"}Look deep inside the april faceA change is clearly taking placeLooking for the summerChris ReaThe eyes take on a certain gazeAnd leave behind the springtime daysGo looking for the summerThis ain't no game of kiss and tellThe implications how you know so wellGo looking for the summerTo play the passion out that haunts you soLooking for the summerRemember love how it was the sameWe scratched and hurt each others growing painsWe were looking for the summerAnd still i stand this very dayWith a burning wish to fly awayI'm still looking, looking for the summer14.jesus to a child michael george "}Kindness in your eyesI guess you heard me cryYou smiled at meLike Jesus to a childI'm blessed, I knowHeaven sent and heaven stoleYou smiled at meLike Jesus to a childAnd what have I learnedFrom all this pain?I thought I'd never feel the sameAbout anyoneOr anything againBut now I knowWhen you find loveWhen you know that it existsThen the lover that you missWill come to youOn those cold, cold nightsMichael GeorgeWhen you've been lovedWhen you know it holds such blissThen the lover that you kissedWill comfort youWhen there's no hope in sightSadness in your eyesNo one guessed, or no one triedYou smiled at meLike Jesus to a childLoveless and coldWith your last breath you saved my soulYou smiled at meLike Jesus to a childAnd what have I learnedFrom all theseI've waited for you all those yearsAnd just when it beganHe took your love awayBut I still sayWhen you find loveThen the lover that you missWill come to youOn those cold, cold nightsWhen you've been lovedWhen you know it holds such blissThen the lover that you kissedWill comfort youWhen there's no hope in sightSo the words you could not sayI'll sing them for youAnd the love we would have madeI'll make it for twoFor every single memoryHas become a part of meYou will always beMy loveWell, I've been lovedSo I know just what love isAnd the lover that I kissedIs always by my sideOh the lover I still missWas Jesus to a child{/collapse}
电液伺服阀特性参数、定义、技术术语,如何测试操作。
概述: 一个电液伺服作动器(舵机)的测试项目,涉及到电液伺服阀的特性参数定义,比如:压力增益 、零位、零偏和零漂、分辨率、内漏、控制流量、空载流量曲线、名义流量曲线、流量增益、名义流量增益、线性度、对称度、滞环、遮盖、瞬态响应、频率响应。 这一堆堆的概念看的我云里雾里,书面定义的解释往往都比较“冷淡”,但很严禁和准确,仔细想想也能理解,它喜欢用一些逻辑思维和专业术语来描述。但作为我,看完了概念,头脑一阵晕,不知道在讲什么? : [/A:汗] 还好,不懂不可怕,但不能妥协,想尽办法搞定它,咱可以进入学习模式... 电液伺服阀特性,你半天不能理解也算正常,因为这些概念覆盖了:电气、液压、数学等学科,基础还需要很不错,才真正理解学习。正文 本文,我会根据我的理解,重新进行整理描述,也算时我的笔记了,以下内容不仅仅是视频内容,还进行了一些扩展内容。压力增益 Pressure Gain压力增益定义: 当控制流量为零时,负载压降对输入电流的变化率。解释: 将伺服阀的AB口,用压力传感器堵死,给伺服阀输入一个完整的正负信号,让阀芯走完全程,会得出横坐标为输入电流I,纵坐标为AB口压力变化P的曲线:然后,我们取±40%额定压力区域内的负载压力和输入电流关系曲线的平均斜率,就是压力增益。零位、零偏和零漂 Null,Null Bias,Null Shift零位定义: 负载压降为零时,是控制流量为零的输入出级相对几何位移。解释: 就是伺服阀没有通电,没有通液(四个油口全部堵死),自然状态下,阀芯的初始位置,就是零位。零偏定义: 在规定试验条件下,调好伺服阀的零点,经过一段时间后,由于阀的结构尺寸,组件应力,电性能等可能使它发生微小变化,即输入电流为零时,输出流量不为零,零点发生了变化。为使输出流量为零,必须预置某一电流,即零偏电流。解释: 正常情况下,当伺服阀没有输入信号时,伺服阀AB口不应该有流量输出(注意,非泄露的流量),但事实上,当伺服阀存在零偏现象后,伺服阀AB口,总会有流量输出。这就是零偏,为了消除零偏,就需要施加一定的电信号,使得伺服阀AB口没有流量输出,这个施加的电流信号,就是零偏电流。(AB方向取平均值)如何测试操作:A.活塞处于全缩位,观察活塞运动情况,给舵机施加逐渐增加负信号,当活塞开始伸缩,减小电流,活塞停止,记录该电流值;(比如: 0.14mA,参考数据)B.活塞处于全伸位,观察活塞运动情况,给舵机施加逐渐增加正信号,当活塞开始缩回,减小电流,活塞停止,记录该电流值;(比如:+0.16mA,参考数据)C.将上面A、B步骤的记录值相加,取平均值,就是该舵机的零偏电流值:比如:零漂定义 因压力、温度等工作条件的变化而引气的零偏的变化,以额定电流的百分比表示。解释: 受到工作环境(供油压力、回油压力、系统温度)的影响,导致了伺服阀存在了零偏现象,这个就是零漂。判定伺服阀零漂合格的要求: 一般规定,供油压力变化为供油压力的±20%,零漂值应小于额定电流的2%; 回油压力从0~0.7MPa变化时,零漂值应小于额定电流的2%; 温度变化范围从 30~+135℃时,零漂值应小于额定电流的4%;调零 超出以上值时,就需要调零的动作,两种方式,一种是电气调零,另一种是机械调零,电气调零很容易理解,这里就不提了,机械调零,见下图,伺服阀专门会有一个调零螺钉,注意,不要超过一圈,如果超过一圈都还没满足要求,那就要另找原因了。 机械调零其实也很容易理解,就是调整喷嘴挡板的初始偏移角度来进行补偿。 分辨率(门限/阈值) Threshold分辨率(门限/阈值)定义: 是伺服阀的输出产生变化所需的最小输入电流之增量,以额定电流的百分比表示。解释: 就是使活塞杆可以移动的最小电流值(伸缩取平均值)和额定电流值的百分比。如何测试操作: 伸出活塞位置在3.8 5.1mm(避免活塞在极限位置), A.逐渐调节电流,当活塞杆外伸时,记录其电流值和极性,比如 0.01mA(参考数据) B.逐渐调节电流,当活塞杆回缩时,记录其电流值和极性,比如+0.03mA(参考数据) C.将上面A、B步骤的记录值相减,取平均值,就是该舵机的门限电流值:比如:内漏 Internal Leakage内漏定义: 伺服阀控制流量为零时,从进油口到回油口的内部流量,它随进油口压力和输出电流的变化而变化。解释: 伺服阀AB口堵死,P口供压,输入信号为零,查看回油口的流量情况。如何测试: 对于舵机来说,要分别在三个位置观察泄露情况。 驱动舵机活塞在中位,保持1分钟,泄露量不应大于984cc/min(参考数据) 驱动舵机活塞在全伸位,保持1分钟,泄露量不应大于984cc/min(参考数据) 驱动舵机活塞在全缩位,保持1分钟,泄露量不应大于984cc/min(参考数据)控制流量、空载流量曲线、名义流量曲线 CONTROL FLOW,FLOW CURVE,NORMAL FLOW CURVE控制流量定义: 从伺服阀的控制油口A或B流出的流量。负载压降为零时的控制流量为空载流量,负载压降部位零时的控制流量称为负载流量。空载流量曲线定义 空载控制流量随输入电流在正负额定电流之间做出的一个完整循环的连续曲线。名义流量曲线 空载流量曲线中点的轨迹解释补充: 事实上,他并不是一条直线,而是如下图,存在1.无效区2.正常流量区域3.饱和区域,需要说明的是上图,由于空载流量线性度比较好,会很容易误导名义流量曲线是直线,当然,如果空载流量线性度确实很完美,那名义流量曲线就会是接近直线。为啥要反复强调这个问题,是不想让你和名义流量增益曲线搞混,继续往下看。流量增益、名义流量增益 FLOW GAIN,NORMAL FLOW GAIN流量增益定义: 流量曲线的斜率。解释: 单位输入伺服阀电流的变化量,施加到伺服阀后,伺服阀所对应的输出流量的变化量,它是在负载压力为零的情况下测得的。伺服阀的流量增益,直接影响着伺服系统中的开环放大系数。 几何图像表示为空载流量曲线的各点的切线,下图中的黄色切线。名义流量增益定义: 从名义流量曲线的零流量向两极性方向各作一条与名义流量曲线偏差最小的直线,为名义流量增益线解释: 图中黄色和蓝色的的直线,注意:并不是一条直线。线性度 LINEARITY线性度定义: 名义流量曲线的直线性,用名义流量曲线与名义流量增益的最大偏差来衡量,并以额定电流的百分比表示。解释: 见下图几何表达,△i除以额定电流的百分比就是线性度。对称度 SYMMETRY对称度定义: 两个极性的名义流量增益一直的程度,用二者之差对较大者的百分比表示。解释: 见下图几何表达,SYMMETRY的计算方法,其中S为名义流量增益线的斜率。滞环 Hysteresis滞环的定义: 在正负额定电流之间,以小于测试设备动态特性起作用的速度循环,对于产生相同输出的往与返的输入电流之差的最大值以其与额定电流的百分比表示。解释: 几何图像表达,会更直观一些。遮盖 LAP遮盖的定义: 滑阀位于零位时,固定节流棱边与可动节流棱边轴向位置的相对关系。解释: 几何图像表达,下图描述了阀芯和阀体之间的配合关系以及影响流量变化趋势的情况。注意区分清楚,正遮盖,零遮盖和负遮盖。瞬态响应(阶跃响应) Transient response阶跃响应的定义: 阶跃信号输入时,输出的跟踪特性。解释: 当我们给伺服阀输入一个阶跃信号后,快速记录伺服阀的输出流量对阶跃输入信号的跟踪过程,以时间域的曲线标识出来,这就是伺服阀的瞬态响应。主要研究的是伺服阀的快速性。主要指标:最大超调量:上升时间: 首次从零到达稳态的时间,如果没有超调的系统而言,从稳态的10%上升到稳态的90%所需要的时间。峰值时间:过渡过程时间振荡次数: 响应曲线穿越稳态值次数的一半计算,下图的振荡次数为1频率响应 FREQUENCY RESPONSE频率响应的定义: 当横幅正弦输入信号在规定的频率范围内变化时,控制流量对输入电流的复数比。 解释: 首先我们需要复习一下三角函数: 频率特性包括了幅频特性和相频特性,其中,幅频特性用幅频比表示幅频比 AMPLITUDE RATIO幅频比定义: 通常用输出流量幅值Ai与同一输入电流幅值下指定基准低频时(5或者10Hz)的输出流量幅值A0之比随输入电流频率变化的曲线表示。表示:dB = 20 log10(Ai/A0). 通常以幅值瞬间到 3dB时的频率为幅频宽,为啥是 3dB? 因为 3dB所对应的幅值比为0.707,也就是说,此时的幅值已经衰减到了70%,在弱的话,输出信号的就太弱了,算是个判定标准。 说明,以上的是《液压伺服与比例控制》书中的解释,但视频教程给的是输出流量和输入信号幅值的比值。我查阅了英文资料: 初步认为书中的描述更准确一些,还需要进一步确认落实。相频特性 PHASE LAG相频特性的定义: 相频特性是输出流量与输入电流的相位差随输入电流频率变化的曲线,以度标识 下图的φ就是相频特性落后的几何表达,相频为啥要定义90°? 这表示输出信号比输入信号落后了90°,这是一个及格线,要是再慢,就不合格了。伯德图 BODE DIAGRAM 伯德图可以清晰的表示清楚幅频和相频曲线,上部分是幅频特性曲线,下部分为相频特性曲线,其中0.5表示输入信号为额定输入电流信号的0.5%时的幅频相频特性曲线。50表示表示输入信号为额定输入电流信号的50%时的幅频相频特性曲线。幅频和相频意义 - 隐藏 - 参考文档:SAE ARP490F 2008 Electrohydraulic Servovalves 《液压伺服与比例控制》 宋锦文 陈建文C.LiVEE | 电液伺服阀特性参数解读 王鑫
2023年11月29日
Wednesday.
焦点

李知恩-IU 131118-Ji Eun Lee IU's
最近好像被李知恩圈粉了,一种天然的美,看起来很纯净,特意搜了以下她的资料,以下信息来自百度:李知恩(IU)1993年5月16日出生于韩国首尔特别市,韩国流行乐女歌手、影视演员、节目主持人。更多外文名: 아이유(艺名) / 이지은(本名) / Ji Eun Lee - 视频 -
机械液压设计知识,项目经验分享-导航页-做点有意义的事情
概述:感悟、计划的事情想说两句 - 视频 - 基础知识分享之基础知识一:机械相关常用软件主要内容相关连接Office家族 Word、Excel、Visio、PDF点击查看详情常用的工程材料主要内容相关连接金属:碳钢、不锈钢、铝合金橡胶:丁晴橡胶、氟橡胶、硅橡胶、氟硅橡胶、乙丙橡胶 工程塑料:聚四氟乙烯、亚克力点击查看详情常用五金、标件主要内容相关连接螺纹:认识螺纹、螺纹区别 R、ZG、PC、M、NPT、G、UNF 法兰、标件、抱箍、卡箍点击查看详情设计软件Solidworks设计主要内容相关连接零件设计、工程图、装配图点击查看详情焊接件设计、钣金设计、管道/电缆设计Routing、插件介绍:花键、齿轮、网站/软件资源点击查看详情分析主要内容相关连接有限元Simulation点击查看详情流体仿真Flow Simulation点击查看详情CAD/CAXA主要内容相关连接CAD/CAXA:基础用法、图框、图库、装配清单点击查看详情基础知识分享之基础知识二:液体相关管接头主要内容相关连接焊接A型管接头、74°扩口管接头、卡套管接头、37°球头管接头点击查看详情密封圈主要内容相关连接O型密封圈、骨架油封点击查看详情管道主要内容相关连接钢管、软管、橡胶钢丝软管、金属波纹管点击查看详情识图主要内容相关连接液压符号、系统原理图点击查看详情液压阀种类和用法方向主要内容相关连接单向阀/止回阀、换向阀点击查看详情流量主要内容相关连接节流阀、调速阀点击查看详情压力主要内容相关连接溢流/泄压阀、减压阀、平衡阀点击查看详情比例阀伺服阀主要内容相关连接液压阀介绍之比例阀Proportional valves,伺服阀Servo valve点击查看详情大口径阀门主要内容相关连接大口径阀门:球阀、蝶阀、闸阀、调节阀、减压阀点击查看详情液压泵主要内容相关连接齿轮泵、叶片泵、柱塞泵、离心泵、手摇泵、气动增压泵点击查看详情液压附件主要内容相关连接蓄能器、过滤器、换热器、加热器、油冷机点击查看详情执行元件油缸/作动器、液压马达集成油路设计集成块流体介质主要内容相关连接液压介质,航空油液特性资料点击查看详情航空SKYDROL液压油(蓝油/紫油) 系统设计技术建议点击查看详情基础知识分享之基础知识三:仪表相关压力测量传感器、压力表流量测量涡轮流量计、齿轮流量计、科式质量流量计、孔板流量计、浮子流量计温度测量PT100、温度变送器液位测量直视液位、浮球液位计、磁翻板液位计角度测量角度编码器、直线行程测量LVDT磁致伸缩位移传感器、光栅尺、拉线位移传感器力测量拉压力传感器、称重传感器基础知识分享之基础知识四:气动系统低压(小于等于0.8MPa)接头,气管、气动阀门、减压阀、换向阀、增压器、真空系统、空压机 气源高压(大于0.8MPa)调压阀、高压气泵项目简述通用液压系统液压泵站设计液压阀/伺服阀测试系统液压泵/马达测试系统液压缸/作动器加载测试系统航空测试相关CMMCOMPONENT MAINTENANC MAUNALFUELFuel Nozzle主要内容相关连接Fuel Nozzle/Fuel Manifold Adapter 燃油喷嘴 知识经验分享点击查看详情Fuel PumpFCUFuel Control Units主要内容相关连接Fuel Control Assembly 燃调 知识经验分享点击查看详情APUAuxiliary Power UnitAir SystemATSAir Turbine Starters主要内容相关连接air turbine engine starter ATS 空气启动机 知识经验分享点击查看详情ACMAir Cycle Machine主要内容相关连接Air Cycle Machine ACM空气循环机 知识经验分享点击查看详情HYDRAULIC GROUND POWER UNITS主要内容相关连接Ground hydraulic unit/ hydraulic car 飞机地面液压车点击查看详情Lube oil system主要内容相关连接Lube & Scavenge Pump滑油泵 知识经验分享点击查看详情LD 4Fire Resistant Phosphate Ester Hydraulic Fluid For Aircraft主要内容相关连接NAS1611 O RING, 航空磷酸酯液压油O型密封圈,航空紫油,蓝油点击查看详情航空SKYDROL液压油(蓝油/紫油) 系统设计技术建议点击查看详情调节阀主要内容相关连接谈一谈工业调节阀(调节概述及基础知识)(一)点击查看详情谈一谈工业调节阀(调节阀计算书和选型)(二)点击查看详情
流体有限元分析仿真 Flow simulation ,solidworks
概述 前面我们刚讲了 有限元分析仿真 simulation ,solidworks,ansys ,这期我们一起学习Solidworks Flow simulation,下面是我做的涡流管的分析动画,如果你对涡流管很感兴趣,可以看看 神奇的涡流管,进一步分析ACM: air cycle machine 的制冷原理 作用 通过Solidworks Flow simulation,可以对流体(可流动的介质,比如:气体、液体)进行特性分析,比如在整个系统中的压力、压损、流量、温度...可以很直观的看到流体工作过程中的流动状态动画。教程首先请打开模型,如下图: 抱歉,我的软件显示有点异常,还请允许我偷个懒,调用以下以前购买的一个教程,操作都一样,不影响学习方法。 :##(doge) 1.打开要分析的模型。 2.新建项目,向导,设置单位,选择公制国际单位,根据习惯修改常用的参数单位。3.分析类型选择内部流畅,物理特性选择影响你分析的项。不影响就不选。4.添加流体的介质,空气?水?油液? 5.定义模型的材质或特性6.选择绝热或粗糙度影响,不影响就默认,下一步7.参数确认,注意模型初始温度和流体温度8.为模型添加封盖,分析必须在一个封闭的空间,并且请记得检查流体,是否正常。如果报错,请尝试取消排除不具备流动的腔体来消除错误,直到没有报错,并可以显示出流体的腔体,才能进行下一步分析。后面的教程需要你回复查阅哦,站长需要你的互动,精神支持! - 隐藏 -
液压介质,航空油液特性资料
这张照片是不是很美,多年来,一直搞航空,总会和这些油液打交道,特意做了油液样本的收藏,觉得很有意义。 航空油液的特性是搞液压必须研究的东西,尤其是油液的黏度,可润滑性,密度,腐蚀性,都需要关注。 所以,特意整理了本帖,来汇总分享,顺便说一声,在整理油液资料的时候,还有意外的发现,一个国外的网站,竟然油液的资料收录的比较全面,不知道正常国内能不能打开。 需要特别说明一下,搜索资料的时候,需要找到老外的对应标准,国内油液的称呼或叫法在国外网站是搜索不到的。比如我们说的航空煤油RP 3 对应老外的就是fuel ,mil c 7024 美军mil标准。航空油液特性资料。航空煤油,RP 3,航空红油,YH 15,航空紫油,航空蓝油,LD 4,BMS3 11,航空滑油,MIL PRF 23699航空冷却液 60## - 隐藏 -
这辈子必须要完成的37件事-xc修改版
有些有意义的事情,需要自己给自己订计划,强制执行。 人生苦短,时间一晃而过,蓦然回首,我们这些年白活了吗? 哪些是有意义的事情,各人看法不一,以下是我改编版的37件有意义的事情,有的看似疯狂,其实那才是人生的闪光点。正在逐步完成中! 最后想说,不要年纪轻轻就活出了七老八十的样子,马上行动起来,我认为这样的计划,你也需要一份。
减肥笔记
概述2021年10月份,我开始减肥。减肥四字真言:少吃,多动。我们理性的分析这四个字。先说“吃”正文理论知识以下是理论基础:人体三大营养物质:糖(碳水化合物)、蛋白质和脂肪。糖分为:单糖、双糖、多糖(馒头、面食、米饭。淀粉)。糖会促进胰岛素的分泌,胰岛素可以理解为一个搬运工,会影响脂肪的转换量; 所以,想减少脂肪的产生,就要减少胰岛素的分泌,就要减少吃碳水化合物。低糖高脂的减肥理念就是这个逻辑。 回答以下三个问题:1.食物是如何转换为我们身上的脂肪的?回答:食物 胰岛素搬运 优先糖原,其次脂肪。2.我们吃进去的脂肪会直接变成我们身上的脂肪吗?回答:这主要是取决于胰岛素,胰岛素分泌的多,就会发生,分泌的少,就不会发生。3.为什么大多数人小时候都不会发胖的现象,长大以后大多数人就会变成油腻大叔?回答:小孩的身体机能要比大人好很多,而且小时候的生活环境,碳水化合物没有像现在这么多,再加上中年人多少有这样或那样饭局或应酬。行动起来再说“动” 除了会吃,需要配合适当的运动,才能到达快速减肥的目的。短暂的运动,一时冲动,都是闹着玩。要让运动形成一种习惯,也就是说,改变你的生活习惯。我们总有这样的困难,那样的不行。 如果想改变, 那就必须得行。骑车是个不错的运动方式,尝试着走出机动车,单车有别样的美,跳绳也是一个不错的运动,以前老觉得跳绳是女孩子才做的运动其实,运动不分男女,试试看,也许你会爱上它。初步结果汇报我可不是光会说不会练,下面就是我的这几个月的体重报告, 加油,兄弟!以上就是我的减肥笔记,希望给予有需要的人参考! - 视频 -
我看《反恐24小时》24 Hours 影评、资源下载及在线观看
概述 看过越狱之后,就觉得美剧很过瘾,于是就搜索相关的美剧,《反恐24小时》被广大网友所推荐,就抱着试探的心里看了第一季的第一集,因手越狱的影响过深,老感觉根本无法和越狱相比,强忍这把第一集看完的时候,无法自拔,赶紧打开第二集,就这样一集一集的把24小时全部看完,共7季,每季有24集 - 音乐 - 看完之后,评论一下,其实24小时的紧张程度,我个人认为情急要比越狱还要紧张一些,但剧情构造没有越狱那么精密。大概剧情就是:美国有个专门的反恐机构 Counter Terrorist Unit,简称CTU,专门处理恐怖分子对美国政府或人民的恐怖袭击,故事就是按照这一方向展开的。很早以前就认为美国人比较崇尚个人英雄主义,比如:超人,蜘蛛侠,钢铁侠,很多侠。。。这部24小时更是明显的体现了这一观点,主演Jack Bauer有种打不死的小强精神,季季结尾都要死,季季开头有活过来了,随着剧情的变化很多演员都变了,就Jack Bauer从头演到位,因为从剧情上看,每次恐怖袭击,如果Jack Bauer不出面的话,其他人都是摆不平的,政府要遭威胁,平民百姓将要深受核弹,病毒一系列的袭击,所以这个英雄人物必须每场都要出来营救大家,而且还要很好的活下去。。。因为恐怖袭击仍在继续。 瞎扯归瞎扯,虽然不是很喜欢这种个人英雄主义,但电视剧还是要看的,其实整部电视剧从情节,枪战的场面上看还是很棒的,可以和越狱相媲美,我最喜欢看的就是当CTU出现内鬼时的情节,CTU的保安措施也是相当到位,反应迅速,任何人想从这个单位跑出去的机会几乎没有,CTU这个单位的规定和原则我都很喜欢,办事效率高, 说话比较直接,从不绕弯,也许这就是美国人的个性吧!下面我就把里边的几个演员评论一下吧:正文人物点评主角:Jack Bauer主演男一号 ,站在正义的一方,剧中的英雄,做事果断,很冷血,当然也有大爱的精神,为了平息恐怖袭击,他可以放弃自己的家庭,以及自己的生命。我个人认为,这种人天生就是当特工的料,他过不了那种平淡安定的生活,他的生活必须无时无刻的充满着危机感,他才如鱼得水,精力十足。也常常不安常理出牌,比较自我,无视规章制度,无视领导,甚至有时候把总统都不放在眼里。自己怎样想的,就按照自己想法来,比较庆幸的是他的想法往往是正确的,频繁的出现并且平息各种恐怖袭击,让我开始怀疑这是一个人还是一个神。Nina MyersNina是Jack的情妇,也是工作上的同事,这个女人后来被证实是安插在CTU的内鬼,她办事相当精明,对Jack也是相当了解,无论是正面角色还是反面角色,她都是个人物,尤其是最后他演反面人物,把Jack抓住的时候,Jack说了很多好话,说不计较她杀自己的妻子,都已经忘记了,也发誓要叛变CTU,要和Nina合作,她就让Jack吻她,证明给她看,接吻过后,她就知道Jack在说谎,虽然Jack很认真的吻。其实我想如果nina和jack是夫妻的话,那绝对是强悍组合,这个女人长得其实还是很漂亮的,身材也不错,只是她发起飙了很残忍。Tony AlmeidaTony算是一个沉得住气的男人,很多事情他有主见,拿得住事,也比较忠心,算是jack的一个好哥们吧。比起JACK,他就温柔的多,而且很善良,比较在乎关系和情感,曾经就为了爱情,置国家安全 而不顾。做事也比较果断,有句俗话说:英雄难过美人关,jack能过去,他过不去。呵呵,顺便报个料,其实他也暗恋Nina,似乎是。Michelle DesslerMichelle,CTU的出色干员,后来嫁给了Tony,这个女人我查资料说是个美国人,可是我老觉得她是亚洲人,可能是他的头发的颜色吧,有大将风范,做事果断,机灵。最让我感动的是,明知道楼里面有病毒,她第一个冲进去阻止,结果阻止失败,整个楼的人员全部被感染,她也是。明知道自己几个小时就会死掉,但仍然在维持秩序,继续工作。还有一次,她自己顺利的逃脱了恐怖分子的追捕,但Jack命令她跑回去,以便完成交易,她就把电话一甩,故意让恐怖分子抓住,这些种种事迹表明了这个女人有足够大的胸怀,遇事很冷静。David Palmer帕默总统,比较正直,声称:从不和恐怖分子谈判,也从不接受威胁。但事事难料啊,很多事情不是说自己不怎么样,就一定会不怎么样,即便是美国总统也不行,无论是对恐怖分子的威胁还是前夫人的威胁,他表现出来的确实符合他的原则,不妥协,不谈判,但其实内心里已经有坚持不下去的意思,虽然妥协的注意不是他出的,也不是他下令去执行的,但他至少默许了。所以说最终还是妥协了。我认为这个很正常。说明他还是爱护他的人民,之所以妥协就是为了不让人民受到伤害。Chloe O'Brian顶级解码员,CTU的骨干力量,只要和电脑的有关的事情,到她这里都能搞定。厉害的武林高手,到最后都是可以练到人剑合一,那她就是和电脑合一,她的性格也和电脑一样,只做逻辑判断,没有人物情感,她不分场合,不看情节,认为不对就会说出来,而且也从来不回避话题。相当直接的人。直肠子不记仇。唯一能让她说谎的,估计就是Jack了,因为在她心目中,jack也是个神。ChaseChase,CTU的新生外派特工,既是Jack的搭档,也是他的女婿。相当精干的特工,虽然他是JACK的配角,jacK才是那个英雄人物,但是CHASE的出色演出,丝毫不比JACK逊色。一个硬汉,在他面前就感觉JACK有点老了,呵呵!结尾人物就介绍到这来,因为24小时每季除了JACK,其他人物更换的比较频繁,我这来只介绍给我留下深刻印象的,来和大家分享!附件阿里云盘资源下载,在线观看, - 隐藏 - 看到的尽快保存起来,我不确保永久有效