Detection small AC currents remotely?

[frankqt]

I like to detect current passing through a wire. I have only a very small opening (15-20mm diameter) that access to wire so using a current transformer is not feasible. I can touch the bare wire. (I can touch with a tip of a scope probe) The wire carries 1 - 10A and 220V. I am looking for a non-contact or contact way of understanding the current. 10% accuracy is good enough.


Any pointers?

Thanks

 

[FvM]

The term current transformer doen't imply a particular size. It's surely possibly to make a current transformer fitting the restricted room, but possibly not easy as it may involve opening the magnetical path. Some available small oscilloscope current probes possibly fit the situation.

There are also special open path probes like this New Aim I-prober 520 positional current probe for PCB track current measurement

Finally, a Rogowski coil can be used for AC measurements where no other probe fits. Commercial products are available, but they can be easily self designed. **broken link removed**

 

[RF_Jim]

I like to detect current passing through a wire. I have only a very small opening (15-20mm diameter) that access to wire so using a current transformer is not feasible. I can touch the bare wire. (I can touch with a tip of a scope probe) The wire carries 1 - 10A and 220V. I am looking for a non-contact or contact way of understanding the current. 10% accuracy is good enough.


Any pointers?

Thanks

If you don't have funds for an I-prober as recommended above, perhaps a simple Hall Effect sensor (IC) can be used?

Hall Effect Sensor - Northwestern Mechatronics Wiki

If one can measure a known amount of current, passing through a given test wire, one can calibrate the sensor of use on any other wire with an unknown current though the measurement of the magnetic field created around the wire by the current flow.

Jim

 

[suresh_kvja]

Hi,

Please go through the link. I think this circuit will help you detect current.
**broken link removed**

Thanks,
Suresh.

I like to detect current passing through a wire. I have only a very small opening (15-20mm diameter) that access to wire so using a current transformer is not feasible. I can touch the bare wire. (I can touch with a tip of a scope probe) The wire carries 1 - 10A and 220V. I am looking for a non-contact or contact way of understanding the current. 10% accuracy is good enough.


Any pointers?

Thanks

 

[FvM]

I think this circuit will help you detect current.

It hardly can. It's a voltage (E-field) rather than current (H-field) detector.