The **FD40002B** (often identified as FD400-02B) is typically a high-performance **Brushless DC (BLDC) Cooling Fan** commonly used in electronics cooling, server racks, and industrial power supplies. Below is a breakdown of its electronic components, specifications, and internal structure. --- ### 1. Key Technical Specifications | Parameter | Typical Value | | :--- | :--- | | **Voltage** | 12V DC (Standard) | | **Operating Voltage Range** | 10.2V – 13.8V | | **Current Draw** | ~0.08A to 0.15A (Depending on RPM variant) | | **Dimensions** | 40mm x 40mm x 10mm | | **Bearing Type** | Sleeve or Ball Bearing | | **Speed** | ~5000 - 7000 RPM | --- ### 2. Internal Electronic Parts The fan is more than just a motor; it contains an integrated PCB (Printed Circuit Board) located at the hub. #### A. The Brushless DC (BLDC) Motor Unlike traditional motors with brushes that wear out, the FD40002B uses an **electronic commutator**. It consists of: * **Stator:** Permanent copper windings that create an electromagnetic field. * **Rotor:** A circular permanent magnet attached to the fan blades. #### B. Hall Effect Sensor A small IC located on the PCB detects the position of the rotor’s magnets. This allows the controller to know exactly when to switch the polarity of the coils to keep the fan spinning. #### C. Driver IC (Integrated Circuit) This is the "brain" of the fan. It performs several functions: * **Commutation:** Switching the current between coils. * **Soft Start:** Gradually increasing speed to prevent current spikes. * **Locked Rotor Protection:** If the fan is obstructed, the IC cuts power to the coils to prevent the motor from burning out. #### D. Passive Components * **Capacitors:** Used for noise filtering to ensure the fan doesn't introduce electromagnetic interference (EMI) into the rest of the circuit. * **Diodes:** Provide reverse polarity protection (prevents damage if the wires are connected backwards). --- ### 3. Wiring Configuration The "02B" series typically follows a standard wiring color code: | Wire Color | Function | Description | | :--- | :--- | :--- | | **Red** | VCC (+) | Positive power supply (12V) | | **Black** | GND (-) | Negative/Ground | | **Yellow/White** | Tachometer (Optional) | Outputs a frequency signal to the motherboard to monitor RPM | --- ### 4. Common Applications * **Network Equipment:** Routers and switches. * **PC Hardware:** Northbridge/Southbridge cooling or small form factor cases. * **Medical Devices:** Compact cooling for diagnostic tools. * **3D Printers:** Used for cooling the hotend or the controller board. ---