The **PRU-11-R** is an inductive proximity sensor manufactured by **Autonics**. It is a cylindrical, 3-wire DC type sensor designed for non-contact detection of metallic objects. --- ### 1. Technical Specifications Table | Parameter | Specification | | :--- | :--- | | **Model Number** | PRU-11-R | | **Sensing Side** | Upper (Round Cylinder) | | **Sensing Distance** | 2 mm | | **Power Supply** | 12-24V DC | | **Output Type** | PNP NO (Normally Open) | | **Hysteresis** | Max. 10% of sensing distance | | **Frequency** | 1.5 kHz | | **Protection Circuit** | Surge, Reverse Polarity, Overcurrent | | **Material** | Brass (Nickel Plated) | | **Cable Type** | Oil-resistant PVC cable | --- ### 2. Core Electronic Components The internal circuitry of the PRU-11-R consists of several critical electronic stages: * **Oscillator Circuit:** Generates a high-frequency electromagnetic field at the sensing face. When a metal object enters this field, eddy currents are induced in the object, absorbing energy from the oscillator. * **Trigger Circuit (Schmitt Trigger):** Monitors the amplitude of the oscillations. When the amplitude drops below a specific threshold (due to the presence of metal), the trigger changes its state. * **Output Switching Transistor:** Since this is a **PNP** type, it uses a bipolar junction transistor (BJT) to switch the "Load" to the positive rail (VCC) when activated. * **LED Indicator:** A Red LED is integrated into the housing to provide visual confirmation of the output state. --- ### 3. Wiring Configuration The PRU-11-R follows the standard industrial color coding for 3-wire DC sensors: ```markdown Brown [+] ----> Positive Power Supply (12-24VDC) Blue [-] ----> Negative Power Supply (0V) Black [OUT] --> Output Signal (Connects to PLC Input or Relay) ``` --- ### 4. Key Features 1. **Inductive Sensing:** Only detects ferrous and non-ferrous metals; immune to dust, water, and oil. 2. **IP67 Rating:** The electronics are fully encapsulated, making the sensor dust-tight and capable of withstanding immersion in water. 3. **High-Speed Response:** The 1.5 kHz switching frequency allows it to be used in high-speed counting or RPM monitoring applications.