Smart Ammeters

UPDATE : 2017-09-07





Currently, most ammeters use mutual inductors. Their working principle is: according to the principle of electromagnetic induction, the ammeter can produce electromagnetic fields on current coil and voltage coil and form driving torque on the aluminum disk once powered on and its driving gear drives its counter to count. The higher the current voltage, the higher the driving torque, and the faster the counting, the more the electricity is used.

According to new stipulations of state grid, all new smart ammeters must be equipped with electricity stealing prevention functions. The electricity stealing prevention scheme is provided for new smart ammeters as thus, i.e. use Hall magnetic sensors to detect the electricity stealing magnetic fields applied by stealers from the outside. When anyone tries to apply an external magnetic field to destroy counter of the ammeter, the Hall sensor can detect such external magnetic field and the anti-stealing system can act at once to play the role of electricity stealing prevention.

As we cannot foresee from which magnetic pole the stealer tries to steal electricity, non-polar Hall switching circuit with micro power consumption or non-polar conventional Hall switching circuit shall be used.

LiBrave is now working on non-polar conventional Hall switching circuit to meet market demands.

Preview:Brushless DC Motor