split-core current transducer/sensor

hi, for a project about a power monitoring interface i need small split-core transducers, the ones you can clamp on a cable to measure the current. any suggestions where i can buy small and cheap ones ?

I guess you could wind your own if you have to have small and cheap. Does your application allow you to use a more modern approach?

For example, devices from: www.allegromicro.com like the ACS712.

yea, i could probably do that but the clamp-on would be hard i guess. i need a more practical solution for the prototype. allegros sensors are not transducers, right? i have to actually wire it ; i need something like these ones http://amploc.com/store/index.html but with a clamp.

I see. I've always been lucky enough to place the sensor at either the source or the load.

allegros sensors are not transducers, right?

No, a transducer is something that turns some effect into an electrical signal. These are transducers as are the amploc ones you mentioned. Yes with the Allegro you have to wire it in serise with the current you are measuring, maybe that is what you don't like.

The problem with the split core type is that you have to have a lot of turns in the coil to pick up the small induced currents made even smaller by the two gaps where to core splits. This is a lot of turns of very thin wire and they are even then not particularly sensitive, so that makes them expensive.

What current range are you looking to measure?

thanks for the correction ,and yes i dont want to wire it in, it has to be removable and practical. accuracy is not too important. the range is up to 25-30 amps.

As already posted, current clamps tend on the expensive side. Here is one of Flukeā€™s cheaper ones.

Lefty