ACS712 Current Sensor Module (5A Max)

The ACS712 Current Sensor Module is a fully integrated linear current sensor that uses its conductor to calculate and measure the current applied in the circuit. It uses indirect sensing in which the integrated hall effect sensor detects the incoming AC or DC current through its magnetic field generation and then generates a voltage proportional to measure the current. It is used in a wide range of applications since it is applicable to detect AC and DC current, such as motor speed control, electrical load detection and power supplies. 

The maximum AC or DC that can be detected can reach 5A, and the present current signal can be read via the analog I / O port of Arduino. There are also the 20A and 30A versions for your choice.