### E3F2-R2Z1 Photoelectric Sensor Overview The **E3F2-R2Z1** is a member of the OMRON E3F2 series. It is a **cylindrical M18-sized photoelectric sensor** designed for industrial automation tasks. Specifically, the "R2Z1" designation indicates it is a **Retro-reflective** model using an AC power supply. --- ### Technical Specifications The following table outlines the core electronic and physical characteristics of the E3F2-R2Z1: | Feature | Specification | | :--- | :--- | | **Sensor Type** | Retro-reflective (requires a reflector) | | **Sensing Distance** | 0.1 to 2 meters (standard) | | **Supply Voltage** | 24 to 240 VAC (50/60 Hz) | | **Output Type** | Thyristor (AC Switching) | | **Operation Mode** | Light-ON | | **Current Consumption** | 2.5 mA max at 240 VAC | | **Control Output** | 5 to 200 mA (Load current) | | **Response Time** | 30 ms maximum | | **Indicator** | Light indicator (Red LED) | | **Housing Material** | Plastic (PBT) / Brass (Nickel-plated) | | **Connection Method** | Pre-wired cable (2 meters) | --- ### Electronic Components & Functionality 1. **Optical System:** * **Emitter:** Uses an Infrared LED (typically 850-880nm) to pulse light towards a reflector. * **Receiver:** A photodiode or phototransistor tuned to the specific frequency of the emitter to prevent interference from ambient light. 2. **Circuitry (AC Design):** * **Power Supply:** Contains a built-in rectifier and regulator to convert 24-240V AC into low-voltage DC for the internal logic. * **Output Switch:** Uses a **Thyristor (SCR/Triac)** rather than a transistor (NPN/PNP). This allows it to switch AC loads directly, but it requires a minimum holding current to remain active. 3. **Retro-reflective Principle:** * The emitter and receiver are in the same housing. * The beam travels to a reflector and back. * When an object breaks the beam, the sensor detects the drop in light intensity and changes the output state. --- ### Wiring Diagram (2-Wire AC) Since this is an AC 2-wire sensor, it is wired in series with the load. ```text [Line (L)] ----------- (Brown Wire) [ SENSOR ] (Blue Wire) ----------- [ LOAD ] ----------- [Neutral (N)] ``` > **Warning:** Never connect the two wires of an AC sensor directly across the power supply without a load, as this will result in a short circuit and destroy the internal thyristor. --- ### Key Application Notes * **Leakage Current:** Because the sensor is powered through the load, there is a small "leakage current" (approx. 2.5mA) even when the sensor is OFF. Ensure the load (like a small relay) won't be triggered by this current. * **Reflector Required:** This sensor will not work without a corner-cube reflector (e.g., OMRON E39-R1). * **Protection Rating:** Usually IP67, making it resistant to water and dust in industrial environments.