Hi Sean

Current may reach 200 Amps so is it possible to use shunt resistor? if so
from where can I get it and how much it would be?
Thanks

Mohamed Elegairy

E-mail : egairy@iname.com
ICQ     :       14668366



-----Original Message-----
From: Sean Breheny <shb7@CORNELL.EDU>
To: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
Date: 07 February 1999 23:23
Subject: Re: Power factor?


>Hi Mohamed,
>
>How much current will your power factor meter have to handle?
>
>There are standard shunts available (small value power resistors) which
>have a very accurate resistance and develop a small but certain amount of
>voltage across them in proportion to the current going through them. You
>can then amplify this voltage with an op amp and detect its zero crossing,
>as well. However, in order to choose the right kind of shunt, you have to
>know how much current it needs to handle.
>
>Sean
>
>
>At 10:55 PM 2/7/99 +0200, you wrote:
>>Hi
>>I want to use PIC16F84 to measure power factor witch is (as I know ) the
>>angle between
>>voltage and current. I know how to detect voltage angle (zero crossing )
but
>>how to do it for the current should I use current transformer? any other
>>idea.
>>
>>Thanks in advance
>>
>|
>| Sean Breheny
>| Amateur Radio Callsign: KA3YXM
>| Electrical Engineering Student
>\--------------=----------------
>Save lives, please look at http://www.all.org
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