The **S5-R91-NP** is a specific electronic component typically identified as a **Hall Effect Speed/Proximity Sensor**. It is widely used in industrial automation, automotive systems, and machinery for non-contact detection of rotating or moving metallic targets (specifically magnets). --- ### 1. Key Technical Specifications The following table highlights the general electrical and physical characteristics of this part: | Characteristic | Specification (Typical) | | :--- | :--- | | **Technology** | Hall Effect (Magnetic Field Sensing) | | **Output Type** | NPN (Normally Open / Normally Closed options) | | **Operating Voltage** | 5V - 24V DC (Standard range) | | **Sensing Distance** | 5mm to 10mm (Depending on magnet strength) | | **Housing Material** | Nickel-plated brass or Stainless Steel | | **Connection Type** | 3-wire (VCC, GND, Signal) | | **Operating Temp** | -25°C to +75°C | --- ### 2. Electronic Operating Principle The S5-R91-NP operates based on the **Hall Effect** phenomenon. Inside the sensor head, a thin semiconductor strip carries a current. When a magnetic field (from a target) approaches the sensor, it deflects the electrons, creating a voltage difference across the strip. #### Internal Circuitry Breakdown: * **Voltage Regulator:** Ensures the sensor can handle variations in the input DC voltage. * **Hall Element:** The primary transducer that detects the magnetic field. * **Schmitt Trigger:** Converts the analog signal from the Hall element into a clean, digital "ON/OFF" signal to prevent "chatter" or noise. * **NPN Transistor (Open Collector):** This is the output stage. When a magnet is detected, the transistor switches, pulling the signal line to **Ground (0V)**. --- ### 3. Wiring Configuration The device usually follows a standard industrial color-coding scheme: | Wire Color | Function | Description | | :--- | :--- | :--- | | **Brown** | VCC (+) | Connect to positive power supply (e.g., +12V or +24V). | | **Blue** | GND (-) | Connect to 0V / Common. | | **Black** | Out (Signal) | The NPN output. Requires a pull-up resistor if the PLC/Controller doesn't have one. | --- ### 4. Applications * **Speed Measurement:** Counting pulses from a magnet mounted on a rotating shaft/gear. * **Position Sensing:** Detecting the "home" position of a CNC machine or pneumatic cylinder. * **Security:** Proximity detection for doors or safety guards. ---