20A 1, current sensor chip: ACS712ELC-20A; 2, pin 5V power supply, on-board power indicator; 3, the module can measure the positive and negative 20 amps, corresponding to the analog output 66mV / A; 4, there is no the detection current through, the output voltage is VCC / 2; 5, PCB board size: 31 (mm) x13 (mm);