The **OBT30-R3-E2** is a high-performance miniature photoelectric sensor manufactured by Pepperl+Fuchs. It is designed for space-critical industrial automation applications. --- ### 1. Key Technical Specifications The electrical characteristics define how the sensor interacts with a Programmable Logic Controller (PLC) or other control circuits. | Feature | Specification | | :--- | :--- | | **Detection Principle** | Diffuse Mode (Background Evaluation) | | **Detection Range** | 0 to 30 mm | | **Operating Voltage** | 10 ... 30 V DC | | **Output Type** | PNP, Open Collector | | **Switching Type** | NO (Normally Open) / Light-ON | | **Current Consumption** | < 10 mA | | **Switching Frequency** | Approx. 1000 Hz | --- ### 2. Electronic Components & Functionality #### A. The Emitter (Light Source) The sensor utilizes a **modulated visible red LED**. * **Modulation:** The light is pulsed at a specific frequency. This allows the internal receiver to distinguish the sensor's own light from ambient light (like sunlight or overhead factory lamps), preventing false triggering. #### B. The Receiver & Logic The internal circuitry consists of a photodiode and a comparator circuit: * **Photoelectric Effect:** When light reflects off an object and hits the photodiode, it creates a small electrical current. * **Signal Processing:** The internal ASIC (Application-Specific Integrated Circuit) amplifies this signal. * **E2 Output (PNP):** The "E2" designation indicates a **PNP transistor output**. When an object is detected, the sensor connects the output wire to the positive supply voltage (+V). #### C. Protection Circuitry To ensure longevity in industrial environments, the electronics include: 1. **Reverse Polarity Protection:** Prevents damage if the power wires are connected backwards. 2. **Short Circuit Protection:** Protects the internal PNP transistor if the output wire is accidentally grounded. --- ### 3. Wiring Diagram (Electronic Interface) The sensor typically uses a 3-wire connection: ```markdown Wire Color | Function | Connection -----------|---------------|----------------------- Brown (BN) | +V | 10-30V DC Power Supply Blue (BU) | 0V (GND) | Ground Black (BK) | Output (PNP) | To PLC Input / Load ``` --- ### 4. Physical Dimensions and LED Indicators * **Status Indicators:** The rear of the sensor features a green LED (Power On) and a yellow LED (Switching State/Object Detected). * **Housing:** Ultra-small R3 series design, suitable for mounting on robotic grippers or inside small machinery.