The **OBT15-R3-E2** is a high-performance subminiature photoelectric sensor manufactured by Pepperl+Fuchs. It operates on the **diffuse mode** principle, meaning it detects objects by reflecting light directly off the target back to the sensor. --- ### Technical Specifications Below are the primary electronic and operational characteristics: | Feature | Specification | | :--- | :--- | | **Detection Range** | 0 to 15 mm | | **Operating Voltage** | 10 ... 30 V DC | | **Output Type** | 1 PNP output, short-circuit protected, reverse polarity protected, open collector | | **Switching Type** | NO (Normally Open) / Light-ON | | **Switching Frequency** | approx. 1 kHz | | **No-load Supply Current** | < 10 mA | | **Light Source** | LED (modulated visible red light, 630 nm) | --- ### Key Electronic Components & Functions #### 1. The Optical System * **Transmitter:** Uses a visible red LED. The modulation of the light ensures the sensor can distinguish its own signal from ambient light interference. * **Receiver:** A sensitive photodiode that detects the intensity of reflected light. #### 2. Output Configuration (E2 Type) The "E2" suffix designates the specific output stage: * **PNP Logic:** When an object is detected, the sensor connects the output load to the positive supply voltage ($V+_{cc}$). * **Light-ON (NO):** The output is active (High) when the receiver "sees" the reflected light from a target. #### 3. Protection Circuitry The device includes integrated electronic protection to prevent damage during installation or fault conditions: * **Reverse Polarity Protection:** Prevents damage if the power supply wires are swapped. * **Short-Circuit Protection:** Protects the internal PNP transistor if the output is accidentally grounded or overloaded. --- ### Wiring Diagram (Typical) The sensor uses a standard 3-wire color code: ```text [ Brown ] ---- (+) 10-30V DC [ Blue ] ---- (-) 0V / Ground [ Black ] ---- (S) Output (PNP / Load) ``` --- ### Mechanical & Environmental Interface * **Housing:** Ultra-small R3 series design, ideal for tight spaces in robotic arms or precision machinery. * **Connection:** Usually comes with a fixed cable or a M8 metallic connector (depending on the specific sub-model). * **Status Indicator:** Equipped with a yellow LED to indicate switching state (ON/OFF).