tag 标签: gun

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  • 热度 3
    2025-4-13 16:52
    735 次阅读|
    0 个评论
    【拆解】+MASSAGE GUN 筋膜枪拆解
    MASSAGE GUN 筋膜枪拆解 今天给车子做保养,厂家送了一个筋膜枪。产品拿在手里还是挺有分量的。标价108元。通过海鲜市场一搜索,几十元不等,而且还是爆款。不多说,我们就来看看里面用了什么料,到底值几个钱。 外观篇 首先给它来个开箱照,从外观看,确实还是很精致,一点都不逊色品牌产品。 从箱中取出筋膜枪,沉甸甸的。附上产品的各方位视角 产品的全家福 我装上球头,使用了一番,还真不赖,有不同的敲击速度和根据力度调节不同的档位。 拆解篇 拿出我的螺丝套装,对产品开始进行拆解,首先拧下端部的十字螺丝钉 刚开始不了解结构,一顿撬,没找到入口点。后来发现头部是可以旋的,分解后取下枪头, 然后取下黑色橡皮套和灰色衬套。橡皮套里有四个钢珠。感觉是个阻尼套一样,枪体结构跟这个皮套前后运动。我拿着橡皮套试了下,有些许阻力。不像是轴承更像阻尼,缓解电机运行的刚性。同时保持枪头的直线运行。 接着用手一掰上壳体,筋膜枪内部的部件呈现在眼前。 电机偏心结构像驴拉磨一样带动杆前后运动,一块小线路板支持锂电池充电,指示灯控制,按键控制,电机控制等功能。取下电池和电机,留下线路板底座 拧下线路板上的螺丝,线路板的正反两面就看到了。 电路分析篇 线路板正反面如下图 电源 :丝印为7550-1,通过半导小芯输入丝印号,app弹出各种厂家的物料,我选择一款打开规格书,这是一款150mA输出,5v输出的线性稳压器。给MCU和指示灯供电 查看规格书参数,它输入电压最大是36v,当然最小值肯定要比输出的5V要大,不然不会稳压至5v. 从上表看出输出精度为2%(大部分LDO都是这种参数),静态功耗还是很低的(没有EN,纯粹不带载能力),电流为150mA。我们尽量使用其50%以下,不然LDO发热会很大同时会影响压降。最后这个压降有点离谱了(100mA的负载)竟然达到了0.5v。 MOS管 :丝印为50N03, 同样通过半导小芯输入丝印号,app弹出各种厂家的物料,我选择一款打开规格书,这是一款Nmos。控制电机,旁边的二极管为续流作用,防止电机反电动势。 它大致的功能就是开关控制直流有刷电机,MCU输出PWM控制Nmos的栅极来控制电机的转速。 MCU: 由于丝印打磨,无法知道其MCU型号,大致的功能就是接收外部的按键信号,内部程序计数按键次数,通过次数得知当前档位,然后MCU输出控制不同的LED做指示灯。告知用户当前档位。 电池: 电源采用电池供电(18650),电池参数如下:为两节锂电池串联,输出7.4v给LDO供电。容量为800mAh 电机: 由于螺丝无法拧下来,无法拆解电机部分,从形状大型大致猜测其电机应该是扭矩比较大的电机。引线只有两根,应该是输入直流有刷电机。所以运行噪音比较大。 电路框图 最后组装还原,产品继续使用。 成本分析 组成 外壳 电机 线路板 其他 总价 单价 2元 10元 3元 2元 预估17元 个人就产品做了简单的成本预估,仅供参考 个人点评 这款产品外观设计还是很精致的产品也很有分量,看不出来廉价的感觉。但是合计成本后确实这一块的利润还是很大的,在咸鱼买20+元还是有赚头的。商业化的产品,只要量上去的,还是很可观的。基本损坏都是电路上的器件损坏,比如长时间工作等等。 对于电路设计没什么点评的,都是低成本的物料,线路板都是用的极薄了,很脆的感觉。 1、在PCB布局上尽量做下螺丝接地,螺丝孔改为金属化孔,更有利于EMC. 2、大功率器件做好散热,大块覆铜或者露铜处理,保证产品的可靠运行。
  • 热度 10
    2014-8-1 16:03
    1409 次阅读|
    0 个评论
    I’ve always had a thing with tools. Over the years I’ve reviewed lots of firmware and hardware engineering devices, from IDEs to scopes. But here are a few of the more traditional tools that I find really useful. Half a century ago my Dad gave me an old aluminum-case Craftsman drill. It was old when I got it, yet despite awful abuse it lasted for many years. Alas, that brand has not stood the test of time. Since then I’ve gone through many other drills. Some burned up. Others wore out. I still have a few corded drills (one on the boat, one in my home shop, a rarely-used but occasionally crucial 90 degree angle drill, and a hammer drill) but now the cordless versions are my go-to tools. Early versions were awful with too little power and short life between charges. My current favorite is a Makita XFD01 I’ve had for about 6 or 7 years. It’s an 18 V Li-ion model that seems to run forever before the battery drains, and it has an enormous amount of power. Better: it came with two batteries and a charger that only takes 20 minutes. The one downside is the cost of batteries, which run a ridiculous $70 each. Three have failed over the years; two of those just last week. Turns out Home Depot sells the entire kit - drill, charger and battery pair – for $120, less than the cost a pair of cells. It seems most Li-ion tool batteries are very expensive. We have a Black Decker weed whacker that holds a charge for only ten or twenty minutes of use. A spare battery is $89. Yikes!   I used to use the Makita to drive screws. The basement flooded last year and in a fit of over-engineering I decided to put in a DriCore floor, where the wood is suspended above the cement by corrugated plastic. That meant driving a lot of Tap-cons. A friend recommended the Bosch PS41 12 volt impact driver, which is small, fits the hand perfectly, and is quite lightweight. It, too, came with a pair of batteries, but a single charge keeps it going and going. Having one bit in the Makita to drill the pilot hole, another in the hammer drill to break into the concrete, and a Philips driver in the Bosch greatly sped up the flooring project. Today I use the impact driver nearly daily on other projects in the shop. With a small adapter it will even drive sockets, though not with the oomph one gets from a socket wrench. I do wish it could store one bit. 90% of the time I’m driving Philips screws, but those occasional flat heads need a different bit.   You’d think something as old as the trusty combination wrench would have been perfected in the Dark Ages, but about a decade ago I discovered ratcheting wrenches at Sears. I have two sets now: one like those in the picture, and another where the box-end swivels up and down. While these don’t replace traditional wrenches (as they are slightly bulkier and won’t go into a tightly-constrained space) they are a huge time-saver. The fellow who designed our sailboat back in the 70s also designed the Pride of Baltimore, but he must have been a madman. The engine is easy to work on if you weigh 20 pounds and are two feet tall. Working in the blind on some barely-accessible bolt makes me glad to have the wrenches. I bought a set for my son for Christmas. He informed me I had given him the same tools the year before! When looking for our current house I had promised Marybeth we’d have a tub. Yet the place we finally bought didn’t have one, so we did a major rebuild making one large bathroom from two small ones. She now has the tub and I get brownie points every time she uses it. Knowing there were a number of other projects looming I bought a Porter Cable FR350A nail gun for the project. Swinging a hammer hour after hour is harder now than 30, 20, or even ten years ago, and the air-powered nail gun, while heavy, sure is a muscle-saver. Besides, it’s just plain fun to shoot nails, and I admit to disabling the safety with a friend and banging off a few nails in the back yard. Since then it has seen use on a number of jobs. It’s a little finicky, requiring adjustment occasionally so it sets nails at the proper depth. The tool stops firing when there are three or four nails left, but slip in another bandolier behind them and every nail gets used. The nail gun mostly goes unused, pulled out only when there’s serious construction going on. But last week a furious thunderstorm plopped a neighbor’s tree onto our barn. We’ve decided to pull the building down and build anew, so the tool will be getting a lot of use. I’d like to get a similar screw gun, one that takes a bandolier of fasteners, but have not found such a product. A friend demonstrated one for setting drywall screws, but it was far less convenient as a nail gun.   I hate hiring workmen. Some perverted gene drives me to think that if I own something, I should be able to take care of it. Occasionally that fails. We had some very large dead trees I was determined to take down but The Boss prohibited it. Watching the pros do the deed was humbling as they have a large bag of tricks garnered from years of experience. But when we do start a major project I use it as an opportunity to buy pretty much any tool that will aid the effort. The overall cost is much lower than using contractors, and the tools always prove useful on a future bit of work. I rarely buy cheap tools as they nearly always disappoint. One exception is a Poulan 4218 chain saw, an inexpensive Home Depot purchase that I rationalized would be OK because I’d rarely use the thing. A few years later we moved to a house in the woods, which we heat with five or six cords a year. And I bought a small sawmill. Many weekends the neighbors have to suffer through the whine of my saw. The pros laugh at Poulans, calling them “pull-ons” due to their hard-to-start reputation. Mine has been incredibly reliable (though, like for most small engines, ethanol in gas is always a headache). It’s terrible at ripping and is not powerful enough or big enough for a lot of the logs I process now, so a Stihl MS362 got added to the line-up. The Stihl is a phenomenal – and expensive - machine. But once in a while, like when it vapor-locked this weekend, the Poulan comes out and proves its worth. Alas, over the decades most of the cheap stuff has been exactly that: cheap sometimes to the point of ticking me off. Another philosophical point about tools: I always get extras. Extra bits, blades, whatever might get consumed or need sharpening. I have a half dozen chains for each of the saws, because it’s far faster to swap one than break out the file. At night, after a day using the tools, sometimes with an adult beverage at hand, I’ll sharpen everything so the tools are ready for the next day. With plenty of spares on hand there’s never a panic to replace a chain or other consumable that wears out. I keep an eye out for sales and replenish at a discount. What about your collection? What are your favorite tools?
  • 热度 13
    2013-1-22 16:12
    1590 次阅读|
    0 个评论
    My friend Jay Dowling just gave me a link  to this training video on YouTube. The presenter is showing the use of an electrostatic gun to verify the ability of electronic components and products to survive encounters with electrostatic discharge. Unfortunately, the presenter doesn't seem to know which end of an electrostatic gun is the "sharp end," although he soon finds out... If you read the comments associated with this video you will see that some people think this is all staged (in which case the presenter must have an unnatural fascination with self-inflicted pain), while others think his actions were unintentional, but the film's editor left them in for laughs. And lest you think that the presenter in the above video could not possibly be as inept as he appears to be, may I invite you to watch this video . Suffice it to say that I don't believe anyone can watch this without wincing and exclaiming "Oooohhhh" at least once... But back to the first video – what do you think – ineptitude of the first order or staged?
  • 热度 16
    2013-1-22 16:10
    1519 次阅读|
    0 个评论
    My friend Jay Dowling just led me to a training video on YouTube. The presenter is showing the use of an electrostatic gun to verify the ability of electronic components and products to survive encounters with electrostatic discharge. Unfortunately, the presenter doesn't seem to know which end of an electrostatic gun is the "sharp end," although he soon finds out... If you read the comments associated with this video you will see that some people think this is all staged (in which case the presenter must have an unnatural fascination with self-inflicted pain), while others think his actions were unintentional, but the film's editor left them in for laughs. And lest you think that the presenter in the above video could not possibly be as inept as he appears to be, may I invite you to watch this video . Suffice it to say that I don't believe anyone can watch this without wincing and exclaiming "Oooohhhh" at least once... But back to the first video – what do you think – ineptitude of the first order or staged?  
  • 热度 35
    2012-6-14 21:20
    4283 次阅读|
    13 个评论
    本人在戴尔工作期间,曾经遇到过这样一个奇怪的现象:某种型号的台式电脑在升级Intel新的Cedar Mill和 Presler CPU后,在EMC实验室做认证测试时发生ESD测试死机现象,但老款的Prescott CPU测试时却没有发现任何问题。但是,当我在戴尔内部实验室对此款机型测试时,无论用哪种CPU,而且无论如何测试,ESD都不会有问题。但当这台电脑送到EMC实验室重新做ESD实验时,前面的死机现象又会重新出现,而且死机也是跟CPU有关。 我们首先发现EMC实验室的ESD Gun的型号为EM Test公司的ESD P30,而我们实验室的型号为EM Test Dito。在EMC实验室里更换Dito ESD Gun后,同一台电脑也没有发现任何问题。 由此看来,ESD的结果除了跟CPU有关外,应该还跟两只都已校准通过的ESD Gun 有关。因为这个案例的出现,戴尔专门修改ESD测试流程,并指定EM TEST Dito ESD Gun为戴尔ESD测试标准用Gun. 后面我还会专门撰写一篇有关ESD Gun的分析文章。 让我们再来看ESD跟CPU的关系。我们分析Intel新的Cedar Mill和 Presler CPU是采用最新的65nm,而老款的Prescott CPU是95nm工艺。新款的CPU频率更高,速度更快,但对干扰信号也更敏感。由于ESD信号的频谱很宽,频谱高频部分高达GHZ以上。如果CPU工作频率恰好与ESD干扰频率重合的话,ESD肯定会干扰到CPU的正常工作。 由于我们无法要求Intel去修改CPU设计及工艺流程,Intel Cedar Mill和 Presler CPU也必须通过测试才能拿到认证上市,唯一的办法还是修改设计,在PCB排版或者结构设计上想办法。 由于此次只是升级CPU,台式机的结构上也很难做什么改变,最终只能在PCB排版上想办法。经过近一个月的艰苦努力,我们终于发现PCB排版上的问题,并最终通过版图升级将此ESD问题彻底解决。此解决方案最终也被纳入戴尔EMC设计流程控制文件。后面我也会专门写一篇与此有关的文章。(对不起,敏感词限制,只能用GUN)