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ACS712 Current Sensor Module (20A)

User’s Manual V1.0 1|Page

Contents 1.

Introduction ............................................................................................................................. 3

2.

Pin Definition ........................................................................................................................... 4

3.

Sample Hardware Installation and Sample Source Code ........................................................ 5

4.

Result ....................................................................................................................................... 7

5.

Warranty ................................................................................................................................ 10

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1. Introduction The current sensor module is a device that is used for making current measurements. This sensor comes with three pins, there are VCC, GND and OUT. When current flow is detected by the sensor, it wills give an analog output signal (voltage) that decrease linearly with sensed current. This sensor can be used in a wide variety of applications including, over-current protection circuits, battery chargers, switching mode power supplies, digital watt meters, programmable current sources, etc.

Specifications:  Input voltage : DC 5V  Output : Analog  Version : 20 Ampere(A)  Sensitivities : 100mV/A  Measuring current range up to ±20A

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2. Pin Definition

GND OUT VCC

2 Pins Connector

LED Indicator

Pin

Description

Function

VCC

+5V

Connect to +5V

GND

Ground

Connect to Ground

OUT

Analog Output

 

2 Pins Connector

Interface Pin

Connect in series to the load.

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Connect to analog pin of the microcontroller. When the flowed current is increasing  the voltage measured by the sensor will be decreases.

3. Sample Hardware Installation and Sample Source Code Diagram below shows the hardware connection between Current Sensor Module and Arduino UNO. Besides Arduino UNO, it may interface with any microcontroller such as PIC and etc. Load and external power supply must be connected in series with the current sensor module in order to measure the output.

  

VCC  Arduino 5V GND  Arduino GND OUT  Arduino pin A0

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USB Jack +5V

To obtain the result, please get the sample source code and burn it into Arduino.

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4. Result This example is done by observing the output current in ampere (A) by using DC motor as the load. Small rubber toy tire is attached on the shaft of the motor so that it will be easier to stop the motor from rotating. Before observing the result, the calibration is needed to eliminate the OFFSET. Picture below shows the output when the load is not connected (open circuit). In this example, the LCD screen shows an OFFSET value about 0.073A, where it is supposed to be a 0.000A through the current sensor during an open circuit.

So, in order to calibrate the sensor, the OFFSET value has to be changed in the source code as shown in picture below. Later, this offset value will be subtracted inside source code.

In this example, the OFFSET is changed to 0.073.

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After subtracting with the OFFSET value, the LCD screen is displaying 0.000A when the sensor and DC motor is unconnected.

After the DC motor is connected, the output current is increasing. The current sensor is measuring the flow of current in this closed circuit.

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When the external force (by using hand) is applied to the motor in order to stop the tire from rotating, the current flow to motor will be increased to oppose the applied force by hand. It causes the current value to increase.

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5. Warranty    

Product warranty is valid for 1 month. Warranty only applies to manufacturing defect. Damaged caused by misuse is not covered under warranty. Warranty does not cover shipping cost for both ways.

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