You can build a Citroën 2CV from scratch with entirely new parts - almost - because someone somewhere makes what you need.
About the only mechanical component you can't buy is the gearbox "bucket", presumably because nobody ever breaks those. You can actually get various gearbox upgrades for them which is worth it if you daily one, because the mainshaft nut can slacken off and get you jammed in gear.
Well, I know from my own experience of driving some really quite nice modern EVs they are a far bigger risk to pedestrians than my own car, a 30-year-old Range Rover.
It's really simple.
The Range Rover has you quite high up in the air, and has really big windows with nothing that gets in the way.
The Kia Niro EV that I drive most often has you sitting with your shoulders about level with the bottom of the window, a big long bonnet in front of a steeply-raked windscreen, huge A pillars so you can't see for about 15° either side of the car, and most of your view of pedestrian crossings blocked by a giant "blob" in the upper centre of the windscreen for all the cameras and sensors for things like lane assist.
The only vehicle I regularly use with better visibility of other road users - including pedestrians - than the Range Rover is my bicycle.
The Kia with all its sensors and beepers and flashers and things is like driving a Daimler Ferret through its little periscope.
I don't know how people can drive EVs. They're so stressful.
Those of us who grew up in the 8-bit era would have just typed it in, carefully, in silence, with no-one allowed to enter or leave the room until we were done ;-)
I neither want nor need anything beeping away because it thinks that someone might be driving in the lane beside me, which is what seems to freak the Kias out the most.
I don't want it to suddenly panic brake from 70mph to 30mph because it saw the shadow of the car I'm overtaking on the road.
The Kia Niro EVs I drive at work have something that apparently detects driver fatigue. I don't know what sets it off but it starts beeping at fire alarm levels and makes the huge LCD constantly flash up warnings, usually before I've even left the yard. There doesn't appear to be a way to turn it off or stop it, so you just have to put up with a constant "BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING BING" for the whole journey.
It's very hard to do that when every few seconds some new alarm goes off and some big red flashing warning on the TV screen that's blocking your view of the road comes on.
Both of your points were the very first things I thought reading this.
A Sallen-Key filter is trivially easy to design if you work within certain constraints - a 2-pole Butterworth filter has the feedback capacitor exactly twice the value of the "second" capacitor to ground, if both resistors are the same value. If you pick 10kΩ for both resistors, 1nF for the feedback cap, and 470pF for the cap to ground, then you'll get pretty damn near a Butterworth response (Q of 0.707, maximally flat in the passband and then as fast a transition as possible to the stopband) at around 23kHz.
This is perfect.
And guess what? If you want to scale the cutoff, just scale the component values! If you use 15kΩ resistors you get 15kHz, if you use 22kΩ you get 10kHz, and so on. The minor error in Q will not be audible.
当您首先将其放入时，黄铜套环将最大的输出齿轮锁定到轴上，该轴由最小的输入齿轮驱动，因此您得到了很大的减速，依此类推 - 看看自行车上的拨链器，这是相同的想法。
有一个在杆上滑动的半圆形叉，该杆上刻有凹口，弹簧上的滚珠轴承卡入其中。当您将变速箱挂入档位时，您感觉到的咔哒声就是它跳入该档位。
但那个凹口和豌豆大小的滚珠轴承就是将其固定到位的全部！
因此，您可以稍微松开油门，这样变速箱就不会受到张力，轻轻推动轴，它就会弹出空档。
如果您以一档启动，您可以加快一些速度，将其调至空档，然后如果您小心地获得正确的转速，则可以将其调至二档。我不建议在您打算长期保留的汽车上尝试此操作，它对变速箱的磨损相当严重，但您将能够做到这一点 - 前几次会发出一些可怕的噪音，直到您习惯为止 - 并在回家或到车库的路上将启动和停止以及换档保持在最低限度。
因此，现在如果您的离合器拉线断裂，您知道您实际上可以摆脱暴风雪并回家，或者至少可以到达更安全的地方。