Introduction
Thank you for choosing the OwlTree PC039b 4 Pin 12V PWM Fan Controller. This manual provides essential information for the safe and efficient use of your fan controller, including setup, operation, maintenance, and troubleshooting. Please read this manual thoroughly before using the product and retain it for future reference.
Product Overview
Components Included
- 1 x OwlTree 4 Pin 12V PWM Fan Speed Controller
- 1 x USB-Type C Power Cable
- 1 x 4Pin 5 Way PWM Fan Splitter Hub

Image: The OwlTree 4 Pin 12V PWM Fan Controller, USB-Type C power cable, and the 4Pin 5 Way PWM Fan Splitter Hub are included in the package.
Key Features
- Wide Compatibility: Compatible with most 12V PWM fans and pumps. Suitable for cooling applications in routers, small hosts, soft routing setups, and other DIY projects.
- 5V Type-C Input: Utilizes a Type-C female port for power input, compatible with standard 5V Type-C chargers.
- 12V PWM Output: Features a built-in DC-DC boost circuit to convert 5V input to 12V output for PWM fans. Speed regulation is achieved via PWM signals.
- Integrated Solution: Combines power supply and speed control in one unit for convenient use.
- Fan Splitter Hub: Includes a 4-pin 5-way fan splitter hub, allowing multiple fans to be connected and controlled simultaneously.
- Adjustable Speed: Offers a PWM duty cycle range of 0-100% for precise fan speed control.
Safety Information
- Power Supply: Always use a 5V Type-C power adapter. Ensure the charger's total power output exceeds the combined total power consumption of all connected fans for optimal performance and to achieve full fan speed.
- Fan Compatibility: This controller is designed exclusively for 4-pin 12V PWM fans. It is not compatible with 3-pin or 2-pin fans. Connecting incompatible fans may result in damage to the fans or the controller.
- Maximum Output: The maximum output power (15-18W, 1.2-1.5A) is determined by the capability of your 5V Type-C power adapter.
- Installation: Ensure all connections are secure before applying power. Avoid short circuits.
- Environment: Do not expose the device to moisture, extreme temperatures, or corrosive environments.
Setup Instructions
- Connect Fans to Splitter Hub: Connect your 4-pin 12V PWM fans to the 4Pin 5 Way PWM Fan Splitter Hub. The hub allows you to connect up to five fans.
- Connect Splitter Hub to Controller: Connect the 4-pin cable from the splitter hub to the 4-pin output socket on the OwlTree fan controller.
- Connect Power Cable: Insert one end of the provided USB-Type C cable into the Type-C input port on the fan controller.
- Connect Power Source: Plug the other end of the USB-Type C cable into a compatible 5V Type-C power adapter (not included). Ensure the power adapter is capable of supplying sufficient current for all connected fans.
- Verify Connections: Double-check all connections to ensure they are firm and correctly oriented.

Image: Connection diagram illustrating how to connect multiple 4-pin PWM fans to the splitter hub, which then connects to the OwlTree controller. The controller is powered by a 5V USB-C charger.

Image: The controller accepts 5V input via a Type-C port and provides 12V output for 4-pin PWM fans. Compatible power sources include A-port and C-port charging heads, routers, power banks, notebooks, and desktop computers.
Setup Demonstration Video
Video: This video demonstrates the connection and operation of the fan speed controller with multiple fans, showing how to adjust fan speed.
Operating Instructions
Once the controller is properly connected and powered, you can adjust the fan speed using the integrated rotary knob.
- To Increase Speed: Turn the knob clockwise.
- To Decrease Speed: Turn the knob counter-clockwise.
- To Turn Off: Continue turning the knob counter-clockwise until the fans stop.

Image: The rotary knob controls fan speed. Turn clockwise to increase speed, and counter-clockwise to decrease speed or turn off the fans.
Maintenance
- Cleaning: Use a dry, soft cloth to clean the exterior of the controller. Do not use liquid cleaners or solvents.
- Storage: Store the device in a cool, dry place away from direct sunlight and moisture when not in use.
- Inspection: Periodically check cables and connections for any signs of wear or damage.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Fans not spinning or spinning slowly. |
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| Intermittent fan operation. |
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| Controller not responding. |
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Specifications
| Feature | Detail |
|---|---|
| Model Number | PC039b |
| Brand | OwlTree |
| Input Voltage | 5V (via Type-C USB) |
| Output Voltage | 12V (for 4-pin PWM fans) |
| Max Output Power | 15-18W |
| Max Output Current | 1.2-1.5A |
| Fan Compatibility | 4-pin 12V PWM fans only (not compatible with 3-pin/2-pin fans) |
| Speed Adjustment | PWM duty cycle 0-100% (rotary knob) |
| Dimensions (Controller) | Approx. 47.5mm x 22mm x 18mm |
| Item Weight | 2.89 ounces (0.08 Kilograms) |
| Color | Black |

Image: Physical dimensions of the OwlTree fan controller.

Image: Dimensions of the included 4-pin 5-way fan splitter hub and the USB-Type C power cable.
Warranty and Support
For warranty information or technical support, please refer to the product packaging or contact OwlTree customer service directly. Contact details can typically be found on the manufacturer's official website or through your point of purchase.