Inexpensive, clip-on current transducer?

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1

I saw the PowerHouse eMonitor on Ask This Old House, and it looks like a very neat setup. It uses small, relatively inexpensive current transducers ($20 each) to measure each line. They clip over the wire just like a clamp-on ammeter, as seen below.

http://www.energycircle.com/shop/emonitor-accessories.html

Have you seen any other sources for these in the 15-20A range? And pretty accurate? Considering the cost of transducers, their packages actually are pretty reasonably priced… I’d just rather create something myself.

2

http://www.seeedstudio.com/depot/noninvasive-ac-current-sensor-100a-max-p-547.html?cPath=144_154&zenid=900b6b12c45c328877802ec726ac789b

http://www.seeedstudio.com/depot/noninvasive-ac-current-sensor-30a-max-p-519.html?cPath=144_154&zenid=900b6b12c45c328877802ec726ac789b

3

Or here:

http://iteadstudio.com/store/index.php?main_page=index&cPath=4&sort=20a&page=2

shipping time to US is about the same Singapore vs Hong Kong

4

If you’re creating your own PCB with switching relais etc, you could implement a hall effect current sense IC on the PCB for each line.

F.e.:
http://be02.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=6807554