Current sensor up to 30A based on the Allegro ACS712 IC. The hall effect sensor is capable of making current readings up to values of about 30A, both positive and negative. The load to be measured is connected in series on the terminal block, as in a normal tester. The reading is returned as an analog signal proportional to the current. The sensor provides a 66mV output for each A read. The 3 pins on the opposite side of the terminal blocks are Vcc, GND and the OUT pin (analog signal).