USB Fan Speed Controller with On/Off Switch, Adjustable 5V for Laptop Cooler(A)

Compact DC 4-12V USB Fan Speed Controller with Switch - 5 W Description A compact, portable speed controller for USB-powered fans and small cooling modules such as laptop and phone coolers. Provides stepless adjustment of fan speed through a simple knob with built-in on/off switch, supporting a wide range of DC input voltages for flexible use in different scenarios. Key benefits - Precise airflow control: Stepless output from 2.5 V to 7.5 V lets you fine-tune airflow for comfort and noise reduction. - Broad compatibility: Accepts DC 4 to 12 V input, so it works with standard USB 5 V sources and other DC supplies within the range. - Quiet operation: Designed for low-noise performance to keep workspaces and sleeping areas comfortable. - Portable and simple: Small size and one-knob operation make it easy to carry and use without tools or setup. - Low power draw: Rated for 5 W operation to match small USB fans and cooling modules; use within rated power to avoid overload. Features - Input voltage: DC 4 to 12 V. - Output voltage: DC 2.5 to 7.5 V (stepless). - Rated power: 5 W. Do not overload. - Control method: Rotary knob increases speed when turned clockwise and decreases speed when turned counterclockwise; knob includes on/off function. - Compatibility note: Works with single-speed USB fans and fans that use an internal two-speed boost board. For fans with a two-speed setting, set the fan to the first speed before using this controller to ensure proper adjustment. - Low-noise design and compact housing for easy placement on desks, in bags, or near devices. Typical use scenarios - Desktop work: Reduce fan noise and fine-tune airflow on a USB desk fan while working or studying. - Mobile device cooling: Control airflow for phone cooling modules during gaming or heavy charging to balance cooling and sound level. - Travel and portable power: Pair with a portable power bank or a DC adapter to adjust fan speed on the go, whether in a hotel room, vehicle, or shared workspace. What is included - Speed controller x 1. Important notes - Use only within the specified input voltage range DC 4 to 12 V. - Rated power is 5 W; do not exceed this rating to avoid damage. - If a connected fan has a two-speed internal boost board, switch that fan to its first speed before attempting to adjust speed with this controller. This controller provides straightforward, stepless fan speed control for USB-powered fans and small coolers while keeping installation and operation simple.