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樓主會唔會量產
平平地賣俾我地益下我地呢

Offer

I will use ADE7753 to build a A/C wattmeter




Apparent Energy, RMS Voltage & RMS Current
Active Energy
Reactive Energy
Power Quality Supervisory

[ 本帖最後由 Offer 於 2009-4-26 22:43 編輯 ]

funghome

搵下有冇5個人會DIY呢舊野
買個CIRCUIT TRAMSFORMER返黎分

ktktkt

相信樓主係唔會量產嘅

阿死

支持本土原創

jackli

樓主, 兩隻唔該

SilentAged

重想要兩隻添。

jwong852

原帖由 YES_MAN 於 2009-4-26 18:44 發表


一只ADC唔準咩，voltage assume 正弦波
因為line voltage一定係50Hz好準確，
detect voltage cross-over point, 用table乘個current reading
咁得唔得, 用少粒ADC

呢個係"偷雞"o既做法, 你(好多大陸廠都習慣)要偷雞, 無話唔得. 不過誤差隨時>10%.

AC唔係100%正弦波, 失真隨時有10%, 一般削峰好嚴重, 因為整流電路都在Vpeak時取電.
用示波器睇下AC波型, 就知有幾差. 我要求係誤差<1%. 無法唔用2粒ADC.

Offer

原帖由 jwong852 於 2009-4-26 22:30 發表


呢個係"偷雞"o既做法, 你(好多大陸廠都習慣)要偷雞, 無話唔得. 不過誤差隨時>10%.

AC唔係100%正弦波, 失真隨時有10%, 一般削峰好嚴重, 因為整流電路都在Vpeak時取電.
用示波器睇下AC波型, 就知有幾差. 我要求係誤差

如果用ADE7753加埋好D的CT可以做到Class 1 合IEC要求,好多電力公司D電錶都係用佢

[ 本帖最後由 Offer 於 2009-4-26 22:45 編輯 ]

jwong852

原帖由 Offer 於 2009-4-26 19:52 發表
I will use AD7753 to build a A/C wattmeter




Apparent Energy, RMS Voltage & RMS Current
Active Energy
Reactive Energy
Power Quality Supervisory

YES, ADE7753 is a good and professional single phase metering IC and is quite cheap, <RMB20 from Shenzhen.

My project is not for commercial production, just use on-hand ready available components. If I will develop a commercial wattmeter, ADE7753 is a good candidate.