The **SVB-4WF-R** is a specific electronic module, typically identified as a **4-Channel Wi-Fi Relay Module**. These devices are widely used in IoT (Internet of Things) applications, smart home automation, and industrial remote control. Below is a detailed breakdown of its electronic components and specifications. --- ### 1. Technical Specifications The module is designed to interface high-voltage appliances with low-voltage digital control signals via Wi-Fi. | Component / Feature | Specification | | :--- | :--- | | **Microcontroller** | Usually based on **ESP8266** or **ESP32** (AI-Thinker/Espressif) | | **Operating Voltage** | DC 5V or DC 7V-32V (Wide range input) | | **Relay Channels** | 4 Independent Channels | | **Max Switching Load** | 10A / 250V AC or 10A / 30V DC (per channel) | | **Connectivity** | 2.4GHz Wi-Fi (802.11 b/g/n) | | **Control Modes** | Inching (Momentary), Self-locking (Toggle), Interlock | --- ### 2. Key Electronic Parts Breakdown #### A. The Wi-Fi Core (ESP Series) The heart of the SVB-4WF-R is a Wi-Fi-enabled SoC (System on Chip). It handles the wireless handshake with your router and processes incoming commands from apps (like eWeLink, Tuya, or MQTT brokers). #### B. Electromagnetic Relays * **Function:** Act as an electrically operated switch. * **Isolation:** They provide galvanic isolation, meaning the low-voltage Wi-Fi circuit is physically separated from the high-voltage (220V) load for safety. #### C. Power Management Circuit * **Buck Converter/Regulator:** Converts the input voltage (e.g., 12V or 24V) down to the **3.3V** required by the Wi-Fi chip. * **Optocouplers (Optional in some versions):** Often used to further isolate the GPIO pins of the microcontroller from the relay coils to prevent EMF interference. #### D. User Interface Components * **Push Buttons:** Usually labeled S1-S4 for manual toggling and a "Config" button for Wi-Fi pairing. * **LED Indicators:** * **Power LED:** Indicates the board has electricity. * **Status/Wi-Fi LED:** Blinks during pairing, stays solid when connected. * **Relay LEDs:** Light up when a specific relay is energized (closed). --- ### 3. Wiring Configuration The relay outputs typically provide **Dry Contact** (Voltage-Free) terminals: 1. **COM (Common):** The center terminal. 2. **NO (Normally Open):** Connects to COM when the relay is ON. 3. **NC (Normally Closed):** Connects to COM when the relay is OFF. --- ### 4. Application Logic The device supports three primary electronic behaviors: * **Self-locking:** One click turns it ON; another click turns it OFF. * **Inching:** Turns ON for a brief period (e.g., 0.5 seconds) and then automatically turns OFF (useful for garage doors). * **Interlock:** Turning one relay ON automatically turns the others OFF (useful for motor direction control).