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data acquisition from current transformer

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esons

Electrical
Jan 13, 2008
1
Hello everyone, I am beginner in data acquistion, is there anyone can help me to build a low cost low speed 16 channel 8 bit A/D converter, the input signal is from panel curent transformer ( 20/5 A, 50/5 A, etc ). I only need 1 conversion per secon for each channel, with the precision of +/- 0.5 A. The data will be captured by pc, the distance between pc and signal source (input signal cable) about 50 m.
thank you
 
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"Build"? As in producing a PCB, putting components on it and write a program?

If this is for a single application, that would be a very expensive excersise. There are many other roads to choose from. Like LabView, a PLC with analogue front end, the little LabJack U12 and many more. I would have a deep look at the LabJack. It has eight channels and you can connect two to one PC, easily. Cost is next to nothing. I have used it for multi-channel acquisition at 50 readings/second. No sweat. Resolution is a lot better than you need. I think that is not a problem ;-)
Google "LabJack U12"

Gunnar Englund
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
 
If the current transformer is the usual (basic) sort with an AC voltage output, then wouldn't you need to take enough samples to determine the AC voltage? In other words, more than a single conversion once per second.

 
I used a NI USB-6008 and a current transformer to monitor ac currents on a power supply. It has 4 differential/ 8 single ended analog inputs @ 12 bit. 2 analog outs and several digital I/O. The included software allows you to save the data to excell files for easy manipulation. At $160 I thought it was well worth it. You can do the same thing with a PIC or similar micro.,but buy the time you buy a programmer and write the code you will have spent several hours. All depends on how much your time is worth.

 
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