## E3JK-R2M22M Photoelectric Sensor Overview The **E3JK-R2M22M** is a high-performance, long-distance retro-reflective photoelectric sensor manufactured by Omron. It is widely used in industrial automation for object detection due to its built-in amplifier and multi-voltage power supply capabilities. --- ### 1. Technical Specifications | Feature | Specification | | :--- | :--- | | **Sensing Method** | Retro-reflective (requires a reflector) | | **Sensing Distance** | 2.5 meters (using E39-R1 reflector) | | **Supply Voltage** | 24 to 240 VAC / 24 to 240 VDC (Universal) | | **Output Type** | Relay Output (SPDT - Single Pole Double Throw) | | **Control Output** | 3A at 250 VAC / 30 VDC | | **Light Source** | Red LED (Visible) | | **Operation Mode** | Light-ON / Dark-ON (Selectable via switch) | | **Response Time** | 20 ms maximum | | **Connection** | Pre-wired (standard 2m cable) | --- ### 2. Key Electronic Components & Internal Design The E3JK-R2M22M is distinct because it integrates several complex electronic stages into a compact housing: * **Integrated Power Supply:** It contains a bridge rectifier and voltage regulator, allowing it to accept both AC and DC voltages (24V to 240V). This eliminates the need for a separate DC power supply. * **Transmitter (Emitter):** Uses a high-intensity Red LED. The pulse-modulated light helps the sensor distinguish its own signal from ambient light. * **Receiver (Photodiode):** Features a high-sensitivity phototransistor tuned to the frequency of the emitter's pulse. * **Built-in Relay:** Unlike many industrial sensors that use NPN/PNP transistors, this model uses a mechanical relay. This allows it to switch larger loads directly, though it has a slower response time (20ms) compared to solid-state sensors. * **Polarizing Filter:** It includes a polarizing filter which ensures that only light reflected from the specialized reflector is detected, preventing false triggers from shiny metal objects. --- ### 3. Wiring Diagram (Relay Output) The sensor typically uses a 5-wire configuration. Below is a representation of the wiring logic: ```text Power Supply Lines: 1. Brown -> L1 / (+) [24-240V AC/DC] 2. Blue -> N / (-) [24-240V AC/DC] Relay Contact Lines: 3. White -> Common (COM) 4. Black -> Normally Open (NO) 5. Gray -> Normally Closed (NC) ``` --- ### 4. Application Advantages 1. **Versatility:** The universal voltage input makes it a "one-size-fits-all" spare part for maintenance teams. 2. **Ease of Alignment:** The visible red beam allows for quick physical alignment with the reflector without specialized tools. 3. **Large Load Handling:** The 3A relay output can directly drive small motors, solenoids, or light towers without an intermediate relay. 4. **Durability:** Rated IP64 (typical for E3JK series), providing protection against dust and splashes. ---