USB Fan Speed Governor for Quiet USB Fans - Compact Inline Speed Controller Key benefits - Gives precise, quiet speed control for common 5.0 V USB fans, making workspaces and sleeping areas more comfortable. - Stepless voltage output lets you set airflow continuously from low to high for personalized cooling instead of fixed fan steps. - Simple plug and play design works with USB chargers, power banks, and computer USB ports for fast setup. What this controller does and why you need it - Converts a USB power source into an adjustable output so you can dial fan speed to your preferred airflow without noisy on off cycling. - Helps reduce fan noise and energy use by allowing lower settings when full power is not needed, and higher airflow when you need stronger cooling. - Compact inline module with a rotary knob that also functions as an on off switch for easy, one handed operation. Main features - Compatibility: Designed for the most common 5.0 V USB fans on the market. Use with USB power supplies, power banks, and computer USB ports. - Input and output ranges: Input DC 4 to 12 V. Output DC 2.5 to 8.0 V for stepless speed adjustment. - Rated power: 5 W. Do not exceed this rated power to avoid overload. - Knob control: Turn clockwise to increase airflow, turn counterclockwise to reduce airflow. Built in switch operation on the knob. - Two types of fan behavior supported: Standard 5 V direct-drive fans respond directly to the governor. Fans that include an internal two-gear step-up circuit require the fan to be set to a single gear before using the governor for reliable speed control. How to use - Plug the governor male USB plug into a USB power source such as a phone charger, power bank, or computer USB port. - Plug the USB fan into the governor output socket. - Rotate the knob to switch on and adjust airflow. Clockwise increases airflow, counterclockwise decreases it. - For fans with a two-gear internal circuit, set the fan to the appropriate single gear before adjusting the governor, otherwise speed adjustment may not work correctly. - A Micro USB 5.0 V adapter may be used as the power source as long as the input and output limits are observed. Practical use scenarios - Office desk: Connect a small USB desk fan to the governor and keep airflow quiet during focused work while adjusting speed to reduce distraction. - Dormitory or bedroom: Plug the fan into a power bank on bedside tables to provide gentle cooling for sleeping and increase airflow when needed without constant noise. - Portable cooling while traveling: Use with a portable power bank to control fan speed precisely when working in cafes or on trains. Safety and important notes - Maximum rated power is 5 W. Do not connect fans or loads that exceed this rating to avoid damage. - Input voltage must remain within DC 4 to 12 V. Output voltage varies between DC 2.5 and 8.0 V under control. - For two-gear fans, set the fan to a single gear before using the governor to ensure proper speed control. - This unit is intended for use with USB fans and similar small DC motors only. Technical summary - Function: USB inline speed governor for 5.0 V USB fans. - Input: DC 4 to 12 V. - Output: DC 2.5 to 8.0 V stepless adjustment. - Rated power: 5 W. - Control: Rotary knob with integrated on off switch. - Typical applications: office, dormitory, bedroom, travel. This compact, easy to use USB fan speed governor provides flexible, quiet control of common USB fans while protecting the fan with clear input and power limits.