Actual Resolution of ACS712: How small can we measure
The ACS712 is very popular ic used to measure alternating current (ac). It comes in three variants which can measure ±5, ±20 and ±30 peak to peak current. Following specifications are important for calculation of minimum current that can be measured by ACS712. Part Number Optimized Range, Ip (A) Sensitivity (Typ) (mV/A) ACS712ELCTR-05B-T ±5 185 ACS712ELCTR-20A-T ±20 100 ACS712ELCTR-30A-T ±30 66 Here, consider ADC resolution of an Arduino 10-bit, which is 1024 in decimal. Mostly, ADC reference voltage for Arduino is set to 5V. So, minimum voltage can be measured by Arduino is, 5/1024 = 4.88mV Therefore, actual minimum current can be measured by Arduino (considering ACS712ELCTR-20A-T) is, (4.88) / (100) = 0.0488 A peak-peak = 48.8 mA peak-peak The RMS value of minimum current can be measured by Arduino (considering ACS712ELCTR-20A-T ) is, (48.8 mA peak-peak) / (√2) = 34.5 mA Results: Table: minimum peak-...