我們都聽過這樣的建議：為了解決問題，對電子裝置進行電源迴圈，但電源迴圈是否比簡單地拔掉電源插頭再插回去好呢？今天的超級使用者問答帖子回答了一位好奇的讀者的問題。

今天的問答環節是由SuperUser提供的，SuperUser是Stack Exchange的一個分支，是一個由社群驅動的問答網站分組。

照片由Ben Daines（Flickr）提供。

問題

超級使用者讀者cqm想知道是否有任何可量化的證據支援電力迴圈電子裝置，而不是簡單地拔掉插頭再插回去：

Is there any quantifiable evidence to support power cycling routers for 10 seconds (or any arbitrary amount of time) instead of just unplugging and plugging them back in?

This is related to troubleshooting a mi**ehaving router. The theory is based on ‘things’ needing to be cleared from memory and that this could take a few seconds. This is also a theory related to electronics from over a decade ago, and I am sure it was equally as anecdotal then.

As a person allergic to anecdotes, I became curious when I realized that I had never investigated this issue. Is there any quantifiable reason to support power cycling routers for 10 seconds (or any arbitrary amount of time) instead of just unplugging and plugging them back in?

是否有任何可量化的證據支援電力迴圈電子裝置與簡單的拔出/重新**？

答案

超級使用者貢獻者Enis P.Aginic和Wes Sayeed為我們提供了答案。首先，Enis P.Aginic：

Yes, there is. Any electronics device will have capacitors that will store energy even after you unplug it. You may have noticed that when you unplug a monitor or TV, the little diode will take another second or two to discharge remaining energy from the capacitors in the form of electricity and stop glowing.

This residual energy may not allow memory chips to wipe and you may have problems once your router starts again.

As for sources, well it is really common sense to someone with basic electronics knowledge, like the sky is blue and water is wet, so I recommend reading about capacitors to see what they do and you will understand it.

The point is that electronics components are far from perfect and any interference may produce unpredictable results.

接著是韋斯·賽義德的回答：

Ten seconds is an arbitrarily long amount of time, but yes, it does take time for electronic devices to discharge themselves completely because of the capacitance of the circuits within. Some of this capacitance is intentional, some of it is not.

It is impossible to say exactly how much time is needed, as the bleed-off of that capacitance varies with environmental factors like temperature, humidity, and background EMI generated by nearby electronics. The RAM in your computer, for example, can take minutes to fully discharge.

But there is a shortcut. If the router has a button of any kind on it (WPS button or a reset button), this will usually discharge any residual electrical charge immediately. This is because the button places a load on the circuit(s) holding the charge and there is no power going into the device.

In fact, in the old days of parallel ports, this used to be a guaranteed way to correct a stubborn printer. Unplug the printer, unplug the computer, and unplug the parallel cable. Then hit the power button on both devices. Then plug everything back in. Worked every time. Parallel SCSI busses had this problem too sometimes.

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