The LJ12A3-4-Z/BX Inductive Proximity Sensor is a device that can detect metallic objects without touching them with a detection distance of 4mm. It has a red LED indicator for nearby object detection and operates with an input voltage of 6-36V DC or 5V DC. The output is a digital signal that connects to the ground when a metal object is detected. The LJ12A3 is designed for use with CNC machines and 3D printers and has M12 threading for easy installation. The sensor is NPN Normally Open (NO) and comes with a nut and M12 mounting bracket.

 

Package Includes:

• 1 x LJ12A3-4-Z/BX Inductive Proximity Sensor

 

Features:

• Detects metallic objects without touching them: The sensor uses electromagnetic induction to detect metallic objects without making physical contact.
• Detection distance: The sensor has a detection distance of 4mm, which makes it suitable for measuring the distance to metallic objects.
• High precision: The sensor can detect large metal fields with high precision, making it ideal for use in industrial applications.
• Red LED indicator: The sensor has a small red detection LED that lights up when a metallic object is detected, making it easy to monitor its operation.
• NPN Normally Open (NO): The sensor is NPN Normally Open (NO), which means that when nothing is detected, the resistance on the black wire is high. When detected, the resistance is low and connects to the ground.
• Supply voltage: The sensor is designed to work with a supply voltage range of 6-36V DC or 5V DC.
• Output current: The DC type of the sensor has a maximum output current of 300mA, while the AC type has a maximum output current of 400mA.
• Standard detected object: The LJ12A3 can detect mild steel with a size of 12x12x1mm.
• Response frequency: The sensor has a response frequency of 500Hz.
• M12 threading: The sensor has M12 threading, which makes it easy to install on a 3D printer or CNC machine.
• IP65 rating: The sensor has an IP65 rating, which means it is dust-tight and can withstand water jets from any direction, making it suitable for use in harsh environments.
• Operating temperature: The sensor can operate in a temperature range of -25 to 70 °C (-13 to 158 °F), making it suitable for use in various industrial applications.
• Reverse connection protection: The sensor has reverse connection protection, which prevents damage to the sensor if the power supply is connected incorrectly.

 

Description:

The LJ12A3-4-Z/BX Inductive Proximity Sensor is a type of sensor that is commonly used in industrial applications. It is designed to detect metallic objects without making physical contact with them, which makes it ideal for use in environments where physical contact is not possible or desirable. The LJ12A3-4-Z/BX Sensor has a detection distance of 4mm and can detect large metal fields with high precision. It can be used to precisely measure the distance to a metallic object, such as an aluminum heated bed in a 3D printer or CNC machine. The sensor emits a small red detection LED that indicates the presence of a nearby object. The LJ12A3-4-Z/BX Sensor is NPN Normally Open (NO), which means that when nothing is detected, the resistance on the black wire is high. When detected, the resistance is low and connects to the ground. The sensor has M12 threading and comes with a nut for easy installation on your 3D printer or CNC machine. This proximity sensor has a supply voltage range of 6-36Vdc or 5Vdc and can handle a maximum output current of 300mA (DC) or 400mA (AC). It has an IP65 rating, making it resistant to dust and water.

 

Principle of Work:

The LJ12A3-4-Z/BX Inductive Proximity Sensor uses electromagnetic induction to detect metallic objects without touching them. The sensor consists of a coil of wire that generates a high-frequency magnetic field around it. When a metallic object comes into the range of this magnetic field, it interacts with the field and disturbs it. This disturbance induces a current in the metallic object, which generates a secondary magnetic field. The secondary magnetic field interacts with the coil in the sensor and produces a change in the magnetic field. This change is detected by the sensor, which sends a digital signal to the output, indicating the presence of the metallic object. The proximity sensor is designed to detect metallic objects only and will not work with non-metallic objects. The LJ12A3 proximity sensor has a detection distance of 4mm, and its sensitivity can be adjusted by adjusting the setting distance. The sensor has a red LED indicator that lights up when it detects a metallic object, making it easy to monitor its operation. The LJ12A3 is an NPN Normally Open (NO) sensor, which means that when nothing is detected, the resistance on the black wire is high. When a metallic object is detected, the resistance becomes low and connects to the ground. The LJ12A3 is designed to work with a supply voltage range of 6-36V DC or 5V DC and has a response frequency of 500Hz.

 

Pinout of the Module:

 

• VCC: Module power supply – 6-36 V (Brown)
• GND: Ground (Blue)
• OUT: Digital output (Black)

 

Applications:

• 3D printing: The sensor is often used to detect the position of an aluminum heated bed in a 3D printer. This allows for precise leveling of the bed and ensures accurate printing.
• CNC machines: The sensor is used in CNC machines to detect the position of metal objects such as workpieces and tools. This allows for accurate machining and reduces the risk of collision.
• Robotics: The sensor can be used in robots to detect the presence of metallic objects in their path. This allows for safe and efficient movement in industrial environments.
• Conveyor systems: The sensor can be used in conveyor systems to detect metallic objects such as cans, bottles, and metal parts. This allows for efficient sorting and handling of materials.
• Security systems: The sensor can be used in security systems to detect the presence of metallic objects such as weapons or other dangerous items.

 

Circuit:

The resistors used are 10KΩ.

• Arduino:

  • VCC to VCC
  • GND to GND
  • A2 to Out

• Inductive Proximity Sensor:

  • VCC to VCC
  • GND to GND
  • Out to A2

• Battery:

  • GND to GND
  • VCC to VCC

 

Library:

The module does not need a Library to function with Arduino

 

Code:

The following code is written to read the status of an inductive proximity sensor connected to pin 2 of an Arduino board, and display the result on the serial monitor:

 
const int Pin = 2;

void setup() {
  pinMode(Pin, INPUT);
  Serial.begin(9600);
}

void loop() {
  int sensorValue = digitalRead(Pin);
  if (sensorValue == HIGH) {
    Serial.println("no Object");
    delay(500);
  } else {
    Serial.println("Object Detected");
    delay(500);
  }
}

• We define a constant variable called Pin, which is set to the value 2. This variable is used later in the code to refer to the pin connected to the sensor.
• The setup() function runs once at the beginning of the program. Here, we configure the pin as an input using the pinMode() function, and initialize the serial communication at a baud rate of 9600 using the Serial.begin() function. This allows us to send data to and from the Arduino board through the USB cable.
• The loop() function runs repeatedly as long as the Arduino is powered on. Here, we read the state of the sensor using the digitalRead() function, which returns either HIGH or LOW depending on whether the sensor detects an object or not. If the sensor detects nothing, the sensorValue variable will be set to HIGH, so we print the message "no Object" to the serial monitor using the Serial.println() function. If the sensor detects an object, the sensorValue variable will be set to LOW, so we print the message "Object Detected" to the serial monitor. In either case, we add a delay of 500 milliseconds using the delay() function to prevent the program from executing too quickly.

 

Technical Details:

• Detection distance: 4mm
• Setting distance: 0-3.2 mm
• Supply voltage: 6-36Vdc, 5Vdc; 90-250Vac, 36Vac, 380Vac, 50/60Hz
• Output current DC type: 300mA max; AC Type: 400mA
• Standard detected object: Mild steel (12x12x1mm)
• Sensing object Magnetic metals (if it is not magnetic metals, the sensing distance
• would decrease)
• Response frequency: 500Hz
  Matched mounting bracket: M12 mounting bracket
• Output indication: Red LED
• Short-circuit protection: No
• Reverse connection protection: Yes
• Insulation resistance: 50MΩ min (between charging part and housing)
• Dielectric strength: 1000Vac, 1min (between charging part and housing)
• IP Rating: IP65
• Operating temperature: -25 to 70 °C (13 to 158 °F)

 

Resources:

Link 1

 

Comparisons:

• The LJ12A3-4-Z/BX Inductive Proximity Sensor and Photoelectric/Infrared Proximity Sensor are two different types of proximity sensors that work in different ways and have different applications.
• The LJ12A3-4-Z/BX Inductive Proximity Sensor uses electromagnetic fields to detect metallic objects without touching them. It has a detection range of 4mm and is capable of detecting large metal fields with high precision. It is commonly used in industrial applications such as CNC machines and 3D printers.
• On the other hand, Photoelectric/Infrared Proximity Sensors use light to detect the presence of an object. They emit a beam of light and detect the reflected light to determine the distance to the object. They are commonly used in applications such as automatic doors, security systems, and vending machines.
• One major difference between the two types of sensors is the detection range. While the LJ12A3-4-Z/BX Inductive Proximity Sensor has a range of 4mm, the detection range of Photoelectric/Infrared Proximity Sensors can vary from a few millimeters to several meters depending on the model.
• Another difference is the nature of the object being detected. The LJ12A3-4-Z/BX Inductive Proximity Sensor is specifically designed to detect metallic objects, while Photoelectric/Infrared Proximity Sensors can detect a wide range of objects, including non-metallic objects.
• In terms of usage, the LJ12A3-4-Z/BX Inductive Proximity Sensor is typically used in applications where precise detection of metallic objects is required, such as in industrial automation. Photoelectric/Infrared Proximity Sensors, on the other hand, are used in a variety of applications where the detection of objects is required, such as in security systems or robotics.
• While both types of sensors are used for proximity detection, they operate on different principles and have different applications. The choice of the sensor depends on the specific needs of the application, the type of object being detected, and the required detection range.