detect small changes in magnetic field consuming very low current??

[pradhan.mcis]

Hi,


How to detect small changes in magnetic field consuming very low current. Any suggestion would be appreciated and helpful.

Thanks

 

[jiripolivka]

As you do not define any quantity it is difficult to respond. To detect small changes of a DC magnetic field you can use no current but a suitable coil across which the changes will induce a corresponding voltage.

 

[BradtheRad]

A compass is a mechanical way to do the job. It detects the earth's magnetic field, which is weak compared to everyday magnets.

To detect electronically...

A hall effect sensor comes to mind. (As opposed to a hall effect switch.)

You may need an extra-sensitive device. You may need to amplify its signal. It may or may not work for small changes as well as you hope.