The **NJM5N-R** refers to a high-performance, high-voltage proximity sensor manufactured by **Autonics**. This specific model belongs to the **NJ Series** (Rectangular Inductive Proximity Sensors), which are widely used in industrial automation for non-contact detection of metallic objects. --- ### Technical Specifications The following table outlines the primary electrical and mechanical characteristics of the NJM5N-R: | Feature | Specification Details | | :--- | :--- | | **Sensing Type** | Inductive (Metallic objects only) | | **Sensing Distance** | 5 mm | | **Power Supply** | 100-240VAC (50/60Hz) | | **Output Type** | AC 2-Wire (Normally Open - NO) | | **Current Consumption** | Leakage current < 2.5mA | | **Response Frequency** | 20 Hz | | **Indicator** | Red LED (Operation indicator) | | **Protection Circuit** | Surge protection circuit | | **Environmental Rating** | IP67 (Waterproof and Dustproof) | --- ### Key Components and Internal Structure The device operates using electromagnetic induction. Below are the core electronic parts found inside the sensor housing: 1. **Oscillator Circuit:** Generates a high-frequency magnetic field at the sensing face. When a metal object enters this field, eddy currents are induced in the object. 2. **Detection Circuit (Amplitude Detector):** Monitors changes in the oscillation amplitude caused by the metal object. 3. **Trigger Circuit (Schmitt Trigger):** Converts the analog change into a digital signal to ensure clean switching. 4. **Output Switching Element:** Since this is an AC 2-wire model, it typically utilizes a **Thyristor (SCR)** or **Triac** to switch the load. 5. **Surge Absorber:** A Varistor (MOV) is usually included to protect the internal circuitry from high-voltage spikes common in industrial AC lines. --- ### Connection Diagram (AC 2-Wire) The NJM5N-R is a "Series" load device. It must be connected in series with the load. ```text [ Brown Wire ] ---------- ( L1 / Phase ) | [ Load ] | [ Blue Wire ] ---------- ( L2 / Neutral ) ``` > **Warning:** Never connect the sensor directly to the power source without a load (e.g., a relay, motor starter, or PLC input), as this will cause an immediate short circuit and destroy the internal switching component. --- ### Application Use Cases * **Limit Sensing:** Detecting the end-of-travel for machinery arms. * **Counting:** High-speed counting of metal parts on a conveyor belt. * **Positioning:** Ensuring a metal jig is correctly seated before a process begins.