A current sensor is a device that detects electric current (AC or DC) in a wire, and generates a signal proportional to that current. The generated signal could be analog voltage or current or even a digital output. The generated signal can be then used to display the measured current in an ammeter, or can be stored for further analysis in a data acquisition system, or can be used for the purpose of control.

The sensed current and the output signal can be:

• Alternating current input,
  • analog output, which duplicates the wave shape of the sensed current.
  • bipolar output, which duplicates the wave shape of the sensed current.
  • unipolar output, which is proportional to the average or RMS value of the sensed current.
• Direct current input,
  • unipolar, with a unipolar output, which duplicates the wave shape of the sensed current
  • digital output, which switches when the sensed current exceeds a certain threshold

Technologies

• Hall effect IC sensor.
• Transformer or current clamp meter, (suitable for AC current only).
• Fluxgate Transformer Type, (suitable for AC and/or DC current).
• Resistor, whose voltage is directly proportional to the current through it.
• Fiber optic current sensor, using an interferometer to measure the phase change in the light produced by a magnetic field.
• Rogowski coil, electrical device for measuring alternating current (AC) or high speed current pulses.

The Hall Effect current sensor is a type of current sensor which is based on the Hall Effect phenomenon discovered by Edwin Hall in 1879.

Hall Effect current sensors can measure all types of current signals (i.e. AC, DC, or pulsating current).

These sensors are currently being used widely in many industries because of their vast applications and the type of output they provide, which can be manipulated and can be used for various application.

See also

• Current shunt
• List of sensors