The **MA25TBA-R** is a specialized high-performance cooling component, typically identifying a **DC Axial Fan** manufactured by **Sanyo Denki** (San Ace series). These fans are engineered for industrial applications requiring high reliability and significant airflow in a compact form factor. --- ### Technical Specifications The following table outlines the typical electrical and mechanical characteristics of the MA25TBA-R series: | Feature | Specification | | :--- | :--- | | **Type** | DC Axial Fan | | **Operating Voltage** | 12V DC (Standard) | | **Frame Size** | 120mm x 120mm x 25mm (Typical for MA series) | | **Bearing Type** | Dual Ball Bearing | | **Housing Material** | Aluminum or High-Temp Plastic (PBT) | | **Termination** | Lead Wires (Red/Black/Yellow) | | **Safety Certifications** | UL, CSA, TUV | --- ### Key Electronic Components & Features #### 1. Brushless DC (BLDC) Motor The core of the fan is a 3-phase or single-phase brushless motor. Unlike brushed motors, it uses electronic commutation to switch the polarity of the stator coils, reducing friction and EMI (Electromagnetic Interference). #### 2. Integrated Circuit (IC) Controller The "R" suffix often denotes a specific sensor or control output. The internal PCB contains: * **Hall Effect Sensor:** Detects the position of the permanent magnets on the rotor to synchronize switching. * **Locked Rotor Protection:** Automatically shuts down power if the blades are obstructed to prevent the motor coils from burning out. * **Auto-Restart:** Periodically attempts to spin the fan again once the obstruction is cleared. #### 3. Signal Output (Pulse/Tachometer) The "R" in the model number frequently indicates a **Sensor Output** (often a Tachometer or Pulse sensor). * **Yellow Wire:** Usually provides a square wave signal to the system's motherboard or controller to monitor the actual RPM. * **Alarm Signal:** Some variants use this to trigger a "Low Speed" or "Fan Fail" logic high/low signal. --- ### Typical Wiring Diagram ```markdown Wire Color | Function | Description -----------|---------------|---------------------------------- Red | VCC (+) | Positive Power Supply (12V) Black | GND (-) | Ground Yellow/Blue| Sensor Output | Tachometer (RPM) or Locked Rotor Alarm ``` ### Applications * **Server Enclosures:** Constant, high-reliability cooling for 24/7 operation. * **Power Supplies:** Heat dissipation for high-wattage industrial PSUs. * **Telecommunications:** Cooling for base stations and networking racks. ---