The **ALR-044-R** is a high-performance, ultra-compact electronic liquid cooling fan controller and sensor hub, primarily used in advanced PC thermal management systems. It is manufactured by **Koolance**. Below is a detailed breakdown of its electronic components, specifications, and connectivity features. --- ### 1. Core Technical Specifications The device acts as a PWM (Pulse Width Modulation) signal relay and monitoring hub. | Feature | Specification | |:---|:---| | **Input Voltage** | 12V DC | | **Current Rating** | Up to 4.0A total (across all channels) | | **Output Channels** | 4 x 4-pin Fan/Pump Headers | | **Input Connection** | 1 x 4-pin PWM (Motherboard) + SATA Power | | **Speed Range** | 0 - 100% PWM Duty Cycle | | **Mounting** | Self-adhesive or screw-mount | --- ### 2. Key Electronic Components The ALR-044-R is more than just a simple splitter; it contains active circuitry to protect the host controller (usually the motherboard). #### A. Integrated Circuit (IC) Signal Buffer Unlike passive splitters that can degrade the PWM signal when multiple fans are connected, the ALR-044-R uses an internal **buffer/amplifier circuit**. This ensures that the PWM signal from the motherboard remains "clean" and readable for all four connected devices. #### B. Power Distribution Circuitry * **SATA Power Input:** To prevent drawing too much current from a single motherboard fan header (which are typically rated for 1A), the ALR-044-R pulls raw power directly from the PSU via a SATA connector. * **Decoupling Capacitors:** Small surface-mount capacitors are used to filter electronic noise, ensuring stable voltage delivery to sensitive pump motors or high-speed fans. #### C. Tachometer (RPM) Feedback Logic In PC electronics, only one RPM signal can be read by a single header. The ALR-044-R is wired to report the RPM of the device connected to **Header #1** back to the motherboard. Headers 2, 3, and 4 receive the PWM control signal but do not send speed data back to avoid signal conflict. --- ### 3. Connection Interface 1. **SATA Power (15-pin):** The primary source of 12V and Ground for the connected fans/pumps. 2. **PWM Input (4-pin):** Connects to the motherboard CPU_FAN or SYS_FAN header. It carries the PWM control signal and sends back RPM data. 3. **Fan Outputs (4-pin x 4):** Standard molex/KK-style connectors compatible with both 3-pin (DC controlled) and 4-pin (PWM controlled) fans. *Note: 3-pin fans will run at 100% speed since this is a PWM-specific controller.* --- ### 4. Safety and Protection Features * **Circuit Protection:** The board includes traces designed to handle up to 48 Watts of total power. * **Short Circuit Resistance:** High-quality PCB masking prevents accidental shorts if the back of the unit touches a metal chassis.