In Electronics circuitry, the current flow is a requirement. And, For measuring current in a circuit, a sensor is required. A sensor that can measure and estimate the amount of current applied without altering the performance of the system. And, ACS712 of 20A which serves that purpose. There are also other versions of this module that can detect the current of 30A and 5A.
An Overview of ACS712
ACS712 Current Sensor includes a fully integrated, Hall-effect-based sensor IC. They based this ACS721 current module on the ACS712 sensor, which detects alternating and direct current. And, ACS712 detects the maximum current of 20A. We can read the present current signal through analog I/O ports of any microcontroller
Hardware Overview of ACS712
The module has two phoenix terminal connectors of green colors with mounting screws. Through these terminals, the wire has to be passed. While using, one has to make sure they connect the module in series with the load and be extra watchful to avoid shorts. On the other side of the module, there are three pins. The VCC to power the module requires 5V, the ground. And the analog pin to read.
Working Principle
The module includes the hall effect sensor which detects the coming current through the magnetic field generation. Once the module detects the current, it generated the voltage which is proportional to its magnetic field and hence it measures the current.
Features and Specifications of ACS712
Features
The low-noise analog signal path
▪ Device bandwidth is set via the new FILTER pin
▪ 5 μs output rise time in response to step input current
▪ 80 kHz bandwidth
▪ Total output error 1.5% at TA = 25°C
▪ Small footprint, low-profile SOIC8 package
▪ 1.2 mΩ internal conductor resistance
▪ 2.1 kV RMS minimum isolation voltage from pins 1-4 to pins 5-8
▪ 5.0 V, single-supply operation
▪ 66 to 185 mV/A output sensitivity
▪ Output voltage proportional to AC or DC currents
▪ Factory-trimmed for accuracy
▪ Extremely stable output offset voltage
▪ Nearly zero magnetic hysteresis
Specifications
- Supply Voltage: 4.5V~5.5V DC
- Measure Current Range: -20A~ 20A
- Sensitivity: 100mV/A
Pinouts of ACS712
Pin Number | Pin Name | Description |
1 | Vcc | Supply voltage typically requires 5V |
2 | Output | Outputs Analog voltage proportional to current |
3 | Ground | needs to be grounded to the system’s ground |
T1 | Wire In | We connect here the wire through which the current has to be measured |
T2 | Wire Out |
Applications of ACS712
Motor Speed Control
Because higher currents can damage the entire system, many industries adopt the idea of limiting current for motors. And, hence requires a current sensor.
Electrical load detection
Electrical load detection is a current transformer that controls the amount of current draw. That amount may vary from time to time depending on the different loads.
Switched-mode power supplies
A switched-mode power supply allows to turn ON or OFF the system for lower and higher frequencies and therefore, ACS712 is used in their application