VA, Watt, and power factor

VA: volt ampere
W: watt (joule/s, one joule per second)

pf: power factor(功率因素) , pf== W/VA



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FPL27Ex-N 省電燈管???
用"省電達靈"電力監測器(Power meter)量得 VA=41, W= 24,  pf==0.58


省電燈泡功率因素大約在0.55 ~ 0.6

每瓦發光效率大約55 ~ 70 lm

日光燈的功率因素低於0.5??
每瓦發光效率約81 lm



[ref]
http://www.mobile01.com/topicdetail.php?f=168&t=772594&last=8823003