An NPN Proximity Sensor is a type of proximity sensor that operates based on the principle of detecting the presence of objects without any physical contact. It works by sensing changes in the electromagnetic field or by detecting other environmental changes such as capacitance or inductance. The sensor can detect objects made of various materials, including metal, plastic, or liquids, depending on the specific type.
Key Features of an NPN Proximity Sensor:
-
Output Type: The "NPN" designation refers to the type of transistor output used by the sensor. When the sensor detects an object, it completes a circuit by sinking current to ground, resulting in a low (0V) output signal. In contrast, when no object is detected, the output is high (close to the supply voltage).
Three-Wire Configuration:
- Brown Wire (Positive Supply, often +12V or +24V)
- Blue Wire (Negative/Ground)
- Black Wire (Signal Output – when activated, this connects to ground)
Sensing Range: NPN proximity sensors have a specific range within which they can detect objects. This range varies depending on the sensor model, typically from a few millimeters to several centimeters.
Types of Detection:
- Inductive Proximity Sensors: These are typically used for detecting metal objects. They generate a magnetic field and detect changes when a metal object enters that field.
- Capacitive Proximity Sensors: These can detect both metallic and non-metallic objects by sensing changes in capacitance.
Applications:
- Automation and robotics
- Object detection and positioning
- Safety interlocks
- Conveyor systems
Power Supply:
Usually operates with a DC voltage, commonly in the range of 10V to 30V.
Operation Example:
When a metal object comes within the sensing range of an inductive NPN proximity sensor, the sensor detects this and pulls its output to ground (0V), allowing the connected control system to register that an object is present.
Package Included:
1x NPN Proximity Sensor