The Current Sensor ACS712 offers a cost-effective and precise solution for AC or DC current detection in industrial, commercial, and communications systems. Motor control, load detection and management, switched-mode power supplies, and overcurrent fault protection are examples of typical applications.

Package Includes:

• 1x RobotDYN ACS712 Current Sensor 20A Version

Features:

• Chip ACS712ELC-20A 5V
• 5VDC operating voltage e.g. from the MCU
• Operating voltage with LED 
• Pin 5V power supply, on-board power indicator;
• The module can measure the positive and negative 30 amps, corresponding to the analog output of 100 mV/A;
• No test current through the output voltage is VCC / 2;
• The low-noise analog signal path
• Device bandwidth is set via the new FILTER pin
• Stable output offset voltage.
• Near zero magnetic hysteresis
• High DC PSRR enables use with low-accuracy power supplies or batteries (3 to 4.5 V operation)

Description:

The RobotDYN ACS712 is a 5V hall effect current sensor that is based on the ACS712ELC-20 chip, which can detect AC and DC current signals reliably. It can measure both positive and negative 20 amps and has a 100 mV/A analog output. The hall effect, which also allows the sensor to produce voltage proportionate to the current flowing through it, enables the sensor to produce a voltage that is directly proportional to the magnetic field it generates when current passes through it.

Principle of Work:

ASC712 is based on the Hall Effect. Internally, a copper strip connects the IP+ and IP- pins. When current runs through this copper wire, a magnetic field is created, which the Hall Effect sensor detects. Working RobotDYN ACS712 Current Sensor Interfacing with Arduino The magnetic field is converted into voltage by the Hall Effect sensor. The input and output are totally segregated in this manner.

RobotDYN ACS712 Model	Optimized Current Range	Output Sensitivity
ACS712 ELC-20	+/- 20A	100 mV/A

Pinout of the Board:

 

Applications:

1. Electrical load detection and management
2. Switched-mode power supplies (SMPS)
3. Protection for over-current

Circuit:

• The current flowing from a 12V power supply to a 12V DC lamp will be measured. As a result, the wiring diagram looks like this.
• 12V DC GND source connected to the GND of the Load 
• 12V DC VCC connected to the current terminal of the module the other terminal connected to the VCC input of the Load
• VCC of the Module connected to the 5V Arduino Pin 
• GND of the Module connected to the GND Arduino Pin 
• OUT of the Module connected to the A0 Arduino Pin

Library: 

You can download the ACS712 library here. Just download the library extract from your Arduino library folder and restart the Arduino. Once it’s done, you can use the code below.

Code:

This code is going to print the current passing the sensor on the Serial Monitor.

#include "ACS712.h"
RobotDYN ACS712 sensor(ACS712_20A, A0);
void setup() {
 Serial.begin(9600);
 sensor.calibrate();
}
void loop() {
 float I = sensor.getCurrentAC();
//ignoring the value below 0.09
 if (I < 0.09) {
 I = 0;
 }
 Serial.println(I);
 delay(300);
}

Technical Details:

• Measuring range ± 20A / DC
• Analog output 100 mV/A
• no current flows - output voltage is ~ VCC / 2
• 1.2 mΩ internal conductor resistance
• Total output error of 1.5% at TA = 25°C
• 80kHz bandwidth
• Dimensions PCB: L x W x H approx. 27.5 x 11.6 x 14 mm

Resources:

Tutorial1

Tutorial 2

Comparisons:

There are three variants of the RobotDYN ACS712 Sensor based on the range of its current sensing. The optimized ranges are +/-5A, +/-20A, and +/-30A. these 3 variants are different not only from the current point of view but also all have the same IC but with a different configuration, so when you want to measure a higher current you will sacrifice some of the resolutions depending on the variant, the output sensitivity also varies as follows:

RobotDYN ACS712 Model	Optimized Current Range	Output Sensitivity
ACS712 ELC-05	+/- 5A	185 mV/A
ACS712 ELC-20	+/- 20A	100 mV/A
ACS712 ELC-30	+/- 30A	66 mV/A