shingzhk

原帖由 low238 於 2009-9-10 03:04 發表

真係同個名好岩FEEL
兩支野放落要度個野度一頭一尾

唔係咖,樓主話想度[電器],電壓就唔度都知220V peak
要度Current就祝佢好運啦
w就....,要度r都可以理解,但要度呢3樣
我就真係
[???????????????????????//]

[ 本帖最後由 shingzhk 於 2009-9-10 11:24 編輯 ]

Leopard

認真
樓主知唔知 V=IR 同P=VI 係乜
???????????????????????

stephenwong

AC 220V from your socket is NOT 220V peak-to-peak ah!

220V is an rms value, which equals to 220 x 1.414 = 325V peak and 650V peak-to-peak.

That's my understanding.

Stephen Wong @ Hong Kong

shingzhk

原帖由 stephenwong 於 2009-9-10 11:17 發表
AC 220V from your socket is NOT 220V peak-to-peak ah!

220V is an rms value, which equals to 220 x 1.414 = 325V peak and 650V peak-to-peak.

That's my understanding.

Stephen Wong @ Hong Kong

OK,係我搞錯
原本想打Peak Value 220V ,P2P係440V (點知原來係rms)

shingzhk

原帖由 so? 於 2009-9-10 12:40 發表
我買來量電器既電功率w
我見萬用表$20有交易
功率表就要$100
我承認貪平
完

唔係話緊你貪唔貪平
根本係2個作用,萬用錶常用黎度DC電路既Resister, Voltage, current(低),好少少既有得度埋cap
基本上係for circuit checking / debug ,一般人買左都冇乜用
功率計既話,鴨記最平果隻(好似得一隻),都要$230左右

Leopard

其實你唔驚死的話可以用錶串聯拖板的live入你件電器度A
然後再用個A數乘電壓
前題係確定你件電器唔過2200W, 然後就係你相信個錶真係MAX頂到AC10A
呢D咁高手的行為, 我就唔敢做嘞

stephenwong

Use a clam meter, or a wattage meter.

Stephen Wong @ Hong Kong

Leopard

唔洗回我, 我只係因應佢問DMM來答, 亦講明危險
and clam is 蝌蚪
clampmeter 才是鉗錶