Product details Sensing and controlling current flow is a fundamental requirement in a wide variety of applications including, over-current protection circuits, battery chargers, switching mode power supplies, digital watt meters, programmable current sources, etc. This ACS721 current module is based on ACS712 sensor, which can accurately detect AC or DC current. The maximum AC or DC that can be detected can reach 20A, and the present current signal can be read via analog I/O port of Arduino. Specifications Supply Voltage: 4.5V~5.5V DC Measure Current Range: -5A~ 20A 100 mV/A output sensitivity Output voltage proportional to AC or DC currents Total output error 1.5% at TA = 25°C Extremely stable output offset voltage Nearly zero magnetic hysteresis Low-noise analog signal path 5 µs output rise time in response to step input current 80 kHz bandwidth Module PCB Size : 30.5×1.7×19.5mm Weight: 4g.