The **WADS-321-R** typically refers to a **Microwave Motion Sensor Switch** or a specific series of **Wall-Mount Occupancy Sensors**. These devices are designed to automate lighting by detecting movement through walls or objects using high-frequency electromagnetic waves. --- ### 1. Key Electronic Components The internal circuitry of a WADS-321-R sensor is divided into several functional blocks: | Component Type | Function | Details | | :--- | :--- | :--- | | **Microwave Module** | Signal Transceiver | Operates at 5.8GHz (C-band). It emits low-power waves and measures the Doppler shift of reflected waves. | | **Control IC (MCU)** | Logic Processing | An integrated circuit that processes the analog signal from the sensor and determines if the "threshold" for motion has been met. | | **Relay** | Power Switching | An electromechanical component that opens or closes the electrical circuit to the load (light bulb/fan). | | **Photosensor (LDR)** | Ambient Light Sensing | Detects if the room is already bright enough. If the lux level is high, it prevents the light from turning on despite motion. | | **Potentiometers** | User Adjustments | Small variable resistors (trimmers) used to manually set sensitivity, time delay, and lux levels. | --- ### 2. Technical Specifications The electronic performance of the unit usually follows these parameters: * **Operating Voltage:** 220V - 240V AC / 50Hz. * **Transmission Power:** < 0.2mW (extremely low, safe for human exposure). * **Detection Angle:** 180° (Wall mount) or 360° (Ceiling mount). * **Detection Range:** Adjustable from 2m to 15m. * **Time Delay:** Adjustable from 10 seconds to 12 minutes. --- ### 3. Circuit Operation Logic The device follows a specific electronic workflow to manage the connected load: 1. **Emission:** The **Microwave Module** continuously sends out high-frequency pulses. 2. **Detection:** When a moving object enters the field, the frequency of the reflected signal changes (**Doppler Effect**). 3. **Analysis:** The **MCU** filters out small movements (like insects or wind) and checks the **Photosensor**. 4. **Actuation:** If it is dark enough and motion is confirmed, the MCU sends a signal to the **Relay**, which clicks shut and completes the circuit to the light. 5. **Countdown:** The **Timer Circuit** resets every time motion is re-detected. --- ### 4. Installation Wiring (Typical) The electronic terminal block usually features three connections: ```text L (Line) --- Incoming Hot/Live Wire N (Neutral) --- Common Neutral Wire L' (Load) --- Switched Output to the Light/Device ``` ---