The **WJM-15WE-R** is a specific electronic component, typically categorized as a **Water Flow Sensor** or a **Flow Switch** used in industrial and consumer appliances like water heaters, vending machines, and water treatment systems. Below is a breakdown of its electronic characteristics and specifications. ### 1. Component Overview The device functions by converting the physical movement of water into an electrical signal that a microcontroller (like an Arduino or PLC) can interpret. | Feature | Specification (Typical) | | :--- | :--- | | **Type** | Hall Effect Flow Sensor / Paddle Switch | | **Output Type** | Pulse Signal (Square Wave) | | **Voltage Range** | DC 5V – 24V | | **Flow Range** | 1.0 – 15 L/min | | **Load Capacity** | $\leq$ 10 mA (DC 5V) | | **Connection Port** | Typically G1/2" or specialized quick-connect | --- ### 2. Internal Electronic Parts The WJM-15WE-R consists of three primary internal segments: * **The Magnetic Rotor:** A turbine wheel with an embedded permanent magnet. As water flows, the rotor spins at a speed proportional to the flow rate. * **The Hall Effect Sensor:** A solid-state semiconductor that detects the magnetic field changes. Every time the magnet passes the sensor, it generates a high/low pulse. * **Circuit Protection:** Most models include a resistor and a capacitor to stabilize the output signal and protect against minor voltage spikes. --- ### 3. Wiring Configuration The device usually features a 3-wire interface. The standard color coding is as follows: | Wire Color | Function | Description | | :--- | :--- | :--- | | **Red** | VCC | Positive Power Supply (5V-24V) | | **Black** | GND | Ground Connection | | **Yellow** | Signal (Out) | NPN Pulse Output Signal | --- ### 4. Technical Working Principle The relationship between the water flow and the frequency of the electrical pulses is defined by a "K-factor." ```python # Example logic for calculating flow rate in a microcontroller def calculate_flow(pulse_count, k_factor): # flow_rate = Frequency (Hz) / K-factor flow_rate = pulse_count / k_factor return flow_rate # Result in Liters per minute ``` --- ### 5. Application Precautions 1. **Mounting Orientation:** The sensor must be installed according to the arrow direction marked on the housing to ensure correct electronic pulse generation. 2. **Filtration:** Because the electronic rotor is sensitive, a filter should be used upstream to prevent particles from jamming the magnet. 3. **Signal Noise:** If using long cables (over 5 meters), it is recommended to use shielded cable to prevent electromagnetic interference (EMI) from distorting the pulse signal.