點解係純太陽光下睇唔到風扇像在倒轉運行既錯覺?

呢啲係由於交流電既周波數既問題, 交流電每秒50Hz可以令到繞綫牛日光燈和LED每秒閃爍100次, 但是抽氣扇每秒1450轉就會比日光燈每秒閃爍100次慢了一點, 所以就會造成掉轉轉既錯覺。

只有用鎢絲電燈泡（Incandescent light bulb）用陽光來照就沒事了。

如果在發電廠内工作就會見到發電機停頓既錯覺，非常危險。

如果你一定要用繞綫牛日光燈，試試用超前滯後電路 Lead lag Circuit 或可解決，我用電子牛都可以解決。


2012-01-21 21:18:43 補充：
對不起，打錯字 ：

抽氣扇每分鐘1450轉

Because the frequency of sun light is much higher than the fan revolution speed, so we cannot see the rotation shadow of 'fan turbine' under sun light. However, the flash frequency of fluorescent lamp is nearly same as the revolution speed of fan , thus we can see the rotation shadow of 'fan turbine' . No relation with our brain and eye !!

Human brain receive signal that has a certain speed, not frequency !

human vision will not 'pause' , but we cannot see the object with a tremendous high moving speed !

你見到的會是反方向因為那實在轉得太快,腦部處理圖像時間相差更大.

其實你望着車輪也會"倒轉運行", 唔關光的事。

2012-01-17 11:24:27 補充：
參見[ http://hk.knowledge.yahoo.com/question/question?qid=7011120200496 ]

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