Current sensor

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

The sensed current and the output signal can be:

• AC 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
• DC 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).
• 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.

See also

• Current shunt
• List of sensors