The Engineering Projects

Introduction to ACS712

Hello friends, I hope you all are doing great. In today's tutorial, we are gonna have a look at detailed Introduction to ACS712. ACS712 is an AC or DC current sensor, which is used to measure AC or DC current. You should also have a look at Difference between AC & DC Power, that will help. The maximum value of AC and DC which can be measured is 30A, its output current signal can be read via analog I/O port of Arduino. It is also available in 5A and 20A version which provides precise and economical solutions for AC or DC current sensing in industrial and commercial systems. ACS712 consists of a precise and low offset linear Hall sensor circuit with a copper conduction path located near the surface of the die. ACS712  is used in different industrial projects and commercial electrical devices which includes motor control switched mode power supplies, load detection, and management and overcurrent fault protection. In today's post, we will have a look at its working, Arduino interfacing, applications, pinout, etc. I will also share some links where I have interfaced it with other microcontrollers. If you have any query ask in comments I will resolve your problems. So, let's get started with a basic Introduction to ACS712.

Introduction to ACS712

• ACS712 is a current sensor, which can detect AC or DC current easily. The maximum values of AC or DC which can be detected is 30A. Its operating voltage is 5v.
• ACS712 is available in small surface mount SOIC8 package. Its lead-frame is plated with 100% matte tin, which is compatible with standard lead-free printed circuit board assembly process.

• Its package allows easy implementation by the customer, its typical applications are motor control, load detection and overcurrent fault protection.
• It consists of a precise linear hall circuit with a copper conduction path located near the surface of the die. When applied current passes through this copper conduction path generates a magnetic field which is sensed by Hall integrated circuit (IC) and converted into a proportional voltage.
• An output of ACS712 has a positive slope (>V_{IOUT (Q)}) when increasing current passes through a primary copper conduction path (from pin 1 and 2, or pin 3 and 4), which is the path used for current sensing. The internal resistance of this conductive path is 1.2 mO. The thickness of the conductor provides survival for a device during the over-current condition.

Now, we discuss ACS712 pinout with a detailed description.

ACS712 Pinout & Description

• There is three main pinout of ACS712, which are described below with detail description.

Pin#	Type	Parameters
Pin#1	Vcc	This is an input supply pin. 5v is given on this pin.
Pin#2	Output	This is output analog voltage proportional to current.
Pin#3	Ground	This is used for ground.

• For better understanding let's see ACS712 pinout diagram.

• Now, we discuss ACS712 features.

Features of ACS712

• • These are the main features of ACS712.
    • It measures both DC and AC current.
    • Its operating voltage is 5v.
    • It is available in 5A, 20A and 30A module.
    • It provides isolation from the load.
    • It is easily integrated with MCU.
    • It provides a low noise analog signal path.
    • Its bandwidth is 50 kHz.
    • It is available in low profile SOIC8 package.
    • Its total error is 1.5% at TA = 25°C and 4% at –40°C to 85°C.
    • Its output sensitivity is 66 to 185 mV/A.
    • Its output voltage are proportional to AC or DC currents.
    • It has an extremely stable output offset voltage.
    • Its magnetic hysteresis is nearly zero.

ACS712 Arduino Interfacing

• It is very easy to interface ACS712 with a microcontroller, you should also have a look at ACS712 Arduino Interfacing for better understanding.
• In the given circuit diagram, the ACS712 module has two Phoenix terminal connectors with mounting screws as shown in the circuit diagram in green color. At these terminals, wires are connected.
• In our circuit diagram we are measuring current drawn by the motor, so the wires which are connected with motor is passed through the ACS712 module. Make sure ACS712 module is connected in series with the motor.
• On the other side of the module, we have three pins, Vcc is connected with +5V power supply and ground is connected to the ground of MCU.
• Analog voltage given by the ACS712 module can be read using an analog pin of Microcontroller.
• You can interface ACS712 with almost every microcontroller i.e. Arduino, PIC Microcontroller, 8051 etc.
• For a better understanding of this module, let's see the circuit diagram.

Applications of ACS712

• These are some applications of ACS712.
  • It is used for motor speed control.
  • It is used for load detection and management.
  • It is used as switched-mode power supplies.
  • It is used for over current fault protection.

So, that was all about ACS712, If you have any question regarding this module ask in comments, I will resolve your problems. Take care...