并非所有电缆似乎都是相等的,但我从来没有到底为什么这么多(廉价)电缆我尝试只收费 - 没有数据。任何人都知道为什么?某些引脚未连接?
我知道将较长的电缆或汽车到USB转换器无法传输足够的手机的电源来注册而不是充电,但我得到相反的。我不认为我是一个人(Nexus One Users的同样的问题这里)
并非所有电缆似乎都是相等的,但我从来没有到底为什么这么多(廉价)电缆我尝试只收费 - 没有数据。任何人都知道为什么?某些引脚未连接?
我知道将较长的电缆或汽车到USB转换器无法传输足够的手机的电源来注册而不是充电,但我得到相反的。我不认为我是一个人(Nexus One Users的同样的问题这里)
Not all cables seem to be created equal but I've never got to the bottom of why so many (cheap) cables I try only charge - no data. Anyone know why? Certain pins not connecting?
I do know that longer cables or car to usb converters fail to transmit enough power for the phone to register and not charging but I'm getting the opposite. I don't think I am alone (same problem for Nexus One users here)
广泛地说,如果您有一个只连接引脚1&amp的"USB" 电缆; 4那么你将获得电力,没有数据(最好的购买是销售电缆,就像通用USB充电电缆一样,不确定是否仍然是这样)。同样,如果您只有2&amp的电缆; 3,您将获得数据但没有权力。如果你很奇怪,这里是一个wikipedia页面,标准 USB引脚突出。
注意:Micro使用与USB a相同的引脚。
Broadly speaking, if you have a "USB" cable that only connects pins 1 & 4 then you will get power and no data (Best Buy was selling cables like that as Universal USB Charging Cables a while back, not sure if they still do). Likewise, if you have a cable with only 2 & 3, you will get data but no power. If you're curious, here's a Wikipedia page with the standard USB Pinout.
Note: Micro uses the same pinout as USB A.
随着Devnul3表示,仅电源电缆是USB电缆,其中数据引脚未连接。它们存在的主要原因是因为只有需要2个连接而不是4(而且因为您不需要担心在数据线上保留非常高频信号的质量,因此它们可以毫不疑问地更便宜)。
本说,有电源电缆对"全饰" USB电缆的情况有用的情况:当您希望从某个随机USB连接器向您的某处充电时。正如众所周知的一样,USB连接器可以用于用户预期的许多东西,因此如果您使用"普通" USB电缆,您可能最终不知不觉地提供对设备的权限访问权限。
iow当您从USB连接器充电时,您没有理由信任,只有电源的电缆不仅更便宜,但它也有点更安全。
As devnul3 says, a power-only cable is a USB cable where the data pins are not connected. The main reason they exist is because they can be made ever so slightly cheaper by virtue of only needing 2 connections instead of 4 (and also because you don't need to worry about preserving the quality of the very high frequency signals on the data lines).
This said, there are cases where a power-only cable is preferable to a "fully featured" USB cable: when you want to charge your device from some random USB connector somewhere. As is becoming more widely known, a USB connector can be used for many things besides the ones the user expects, so if you use a "normal" USB cable, you may end up unwittingly providing priviledged access to your device.
IOW when you're charging from a USB connector that you have no reason to trust, a power-only cable is not only ever-so-slightly cheaper, but it's also a bit safer.
抱歉不同意其他答案,但这些假设是错误的:
Sorry to disagree with the other answers, but those assumptions are simply wrong:
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