ACS712 Current Sensor Module +-- 20A

This current sensor board is based on the Allegro ACS712ELCTR-20A bi-directional hall-effect current sensor chip that detects positive and negative flowing currents in the range of minus 20 Amps to positive 20 Amps. The board operates at 5V DC and the current flow through the sensor is converted to an output voltage starting at 1/2Vcc (or 2.5V) for no current flow and moves up 100mV per amp for positive current or down -100mV per amp for negative current.

For Example:

• The output voltage at +2 amps would be (2.5V + (0.1 * 2)) = 2.7 V
  
• The output voltage at -5 amps would be (2.5V - (0.1 * 5)) = 2.0 V

Specifications

• VCC: 5V DC Nominal
  
• Measurement Range: -20 to +20 A
  
• Voltage at 0A: VCC/2 (Nominally 2.5V DC)
  
• Scale Factor: 100 mV per A
  
• Dimensions:
  
  • Length: 31.73 mm (1.24")
    
  • Width: 13.25 mm (0.52")
    
  • Height: 14 mm (0.55")

Hook Up Diagram

(Click on image to view full size)

Resources

• ACS712 Datasheet (PDF file)
  
• ACS712 Example Arduino Sketch (Zip file)