The **E2AB** series (specifically produced by Omron) refers to a family of **Inductive Proximity Sensors**. These are electronic components used in industrial automation to detect the presence of metallic objects without physical contact. --- ## 1. Core Technical Specifications The E2AB series is designed for standard industrial environments and is often used as a cost-effective alternative to high-end series while maintaining reliability. | Feature | Description | | :--- | :--- | | **Sensing Type** | Inductive (detects ferrous metals like Iron/Steel) | | **Housing Material** | Nickel-plated brass or Stainless steel | | **Connection Type** | M12, M18, or M30 cylindrical sizes | | **Operating Voltage** | 10 to 30 VDC | | **Output Type** | PNP or NPN (Normally Open / Normally Closed) | | **Mounting** | Shielded (flush) or Unshielded (non-flush) | --- ## 2. Key Internal Components The functionality of an E2AB sensor relies on four primary internal stages: 1. **Oscillator Coil:** Located at the sensing face. It generates a high-frequency electromagnetic field. 2. **Schmitt Trigger:** A circuit that monitors the amplitude of the oscillations. When a metal object enters the field, it induces eddy currents, causing the oscillation to dampen. The Schmitt trigger detects this drop. 3. **Output Amplifier:** Converts the low-level signal from the trigger into a high-current output (typically 100mA to 200mA) to drive a PLC input or a relay. 4. **Protection Circuits:** Most E2AB models include reverse polarity protection and short-circuit protection to prevent damage during installation. --- ## 3. Sensing Distance vs. Size The sensing range is directly proportional to the diameter of the sensor head: | Model Size | Sensing Distance (Shielded) | | :--- | :--- | | **M12** | 2.0 mm to 4.0 mm | | **M18** | 5.0 mm to 8.0 mm | | **M30** | 10.0 mm to 15.0 mm | --- ## 4. Wiring Configuration The standard wiring for an E2AB DC 3-wire sensor follows international color codes: ```markdown - Brown: VCC (+10 to 30V) - Blue: GND (0V) - Black: Output Signal (Load) ```