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This is a breakout board for the fully integrated Hall Effect based linear ACS712 current sensor. The sensor gives precise current measurement for both AC and DC signals. Thick copper conductor and signal traces allows for survival of the device up to 5 times overcurrent conditions.
The ACS712 outputs an analog voltage output signal that varies linearly with sensed current. The device requires 5VDC for VCC and a couple of filter capacitors.
Project description, more information and ordering can be found at https://www.sparkfun.com/products/8882
ACS712 Datasheet: http://www.sparkfun.com/datasheets/BreakoutBoards/0712.pdf
Wiring Example: http://wiring.org.co/learning/basics/currentacs712.html