Been trying to locate a reasonable CT and don't want to wait a month to receive one from Seeed in China. Came across this sensor from Phidgets that looks interesting:
Its quite a bit more cash but looks quite a bit easier to interface to the Arduino. Has anyone had any experience with this sensor or have any thoughts?
Cheers-
Brian
Re: Phidgets/Elkor 25A Current Sensor?
It depends how you intend to interpit the data.
Are you going to use one of the openenergymonitor sketches in the Arduino? if so, then this CT would not be suitable because it does not provide a AC waveform for the Arduino to analyze, instead it provides a 0 - 5v DC output.
The openenergymonitor sketch samples the waveform itself to produce really accurate results, and does not rely upon a steady DC voltage from the CT's.
Using a DC CT, may not be as accurate as the openenergymonitor systems as it will not be able to recognise changes in phase caused by reactive/resistive loads.
You will probably find that buying a straightforward AC CT would be cheaper as well. I paid £16 ($25) for two CT's, which have performed great.
Re: Phidgets/Elkor 25A Current Sensor?
Gotcha! Momentary lapse there as I forgot about the AC waveform sampling. I guess I was seduced by the apparent simplicity in it. Problem seems to be getting an AC CT here in the US. Sparkfun imports from China and are currently backordered. Seeed in China has them but it could be a month in transit and I don't want to wait that long. There's ebay but many of them seem to come from Hong Kong with equaly arduous transit times unless I want to go with a 100A version but that seems like an accuracy problem when all I want to measure is upwards of 20A....
Thanks!
Re: Phidgets/Elkor 25A Current Sensor?
Coolcomponents in the UK import some Seedstudio CT's. Shouldt take too long to post to the USA. http://www.coolcomponents.co.uk/catalog/product_info.php?cPath=36_61&products_id=677
We at openenergymonitor in North Wales, UK have a stock of 100A Seedstudio CT's.