I understand that voltage is relative to ground, so that can be negative.
However, I'm currently looking at current-sensors (ACS712 current sensor) and in the performance characteristics table, it specifies the Optimized Accuracy Range
.
In the case of this sensor, it's being specified in Amps, ranging from -5 A
to +5 A
I can't find anything explaining how you could have a negative amperage. As far as I know, electric current is the rate of flow of electric charge within a (part of a) circuit.
How could the flow of charge sensed by the sensor be negative?
Best Answer
I prefer to disagree. A voltage is against a reference point. Often that reference point is ground but not always.
Taken the above into account your current is defined the same way.
Take a pin/port of a component or circuit. You can now define the current going into that port/pin as positive from which it follows that if current comes out of that port/pin the current is negative.