Current Transformers question

Hello,
I am trying to monitor my electrical power consumption. for my proof of concept I am using a LEM AT 10 B5. It is perfect because the output is between 0-5V. BUT it is very expensive. Do you have any advice regarding another component ?
I tried a AC1020 from Talema but it was not a success.

I don't want to add any external power for the sensor, the Arduino board is powered by the USB cable.

Thanks for your feedback.

Regards

Fabien

Check out seeed labs.or iteadstudio, either sells current transformers at very low cost.

http://www.devicecraft.com/haefcuse.html these are pretty neat current sensors. i have 2 of them, they even provide schematics and values so you can re-scale the output to whatever you want. pretty neat, or you can wrap a wire inside them multiple times to scale the range. all they need is +5 volts, ground, and the output is an analog output that varies between 2.5 volts and +5 or gnd. just keep in mind that if you are measuring current in an AC line, the current is going to be oscillating at whatever operating frequency you're working at, so if you just take current measurements whenever, you will get very wrong values. (also note, i am not affiliated with that company, i just like their product)

I use these, working for some time now and all good.

http://www.ebay.com/itm/SCT-013-030-3-5mm-Output-Split-core-Current-Transformer-/190600906690?pt=AU_B_I_Electrical_Test_Equipment&hash=item2c60b307c2

http://www.ebay.com/itm/20mA-Output-8V-Mutual-Inductor-Current-Transformer-Red-/270851414915?pt=BI_Circuit_Breakers_Transformers&hash=item3f10009b83

http://www.ebay.com/itm/5mA-Output-Leading-Wire-Type-Current-Transformer-Red-/390365278115?pt=BI_Circuit_Breakers_Transformers&hash=item5ae3956fa3

how to connect them?
check here
http://openenergymonitor.org/emon/node/58

Hello
Many thnaks for your answer, yes the purpose is to measure an AC current :frowning:
I will have a look at "your" site

Regards

Fabien