>> I am rather new to PIC development but I am learning 
>> fast. I would like to
>> build a circuit to measure the amount of AC current in 
>> AMPs flowing through
>> a wire. Any suggestions on how to measure the current 
>> without directly
>> connecting to the wire which will be carrying up to 
>> 125vac @ 30 amps.
>>
>> Can the PIC ADC be used for this purpose? Eventually I 
>> would like to drive an
>> LCD with the value in amps.


> How about something like:
>
> http://www.allegromicro.com/en/Products/Part_Numbers/0754/index.asp


A Hall sensor as above is an excellent solution. It can cost 
somewhat more than good enough solutions in many cases but 
for 1 off jobs is liable to be far more flexible and useful 
than most others.

It allows

    Non contact
    AC or DC
    Pre calibrated by the manufacturer


Here is one of the above from Digikey


        http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=620-1106-ND


In stock, $US5.50 in 1.s
Of the ones they list this is arguably one of the best as it 
has higher sensitivity than most (40 mV/A) and 100A range. 
Some have lower values of both. It also has a good 
temperature range -40 /+150.

Good datasheet & mini-app note

    http://www.allegromicro.com/en/Products/Part_Numbers/0754/0754-050.pdf

There are potentially more accurate solutions, but few 
easier ones to use.



            Russell McMahon







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