This speed governor uses PWM control technology to realize temperature control and speed regulation. The speed governor controls the fan speed according to the ambient temperature. The higher the temperature, the faster the speed. When the ambient temperature is lower than the set starting temperature, the governor controls the fan to stop running. Features:1. Dual working mode (fixed temperature range + adjustable temperature), supports various DC24V/12V fan access.2. With power supply reverse protection function, it can protect the controller and fan from damage when the negative pole is reversed.3. Using industrial-grade solutions, excellent performance, maximum drive current 2A/4A.4. Dynamic LED indicator, more intuitive and true understanding of the working status of the controller.5. The devices are basically SMD packaging, with high craftsmanship, small size, and space saving.6. The temperature sensor is equipped with connecting wires and mounting holes, which can detect the temperature of air and liquid.7. Product size: length 5.6xwidth 3.5xheight 1.8cm, the installation method is 4 M3 through holes. Notice:?The voltage of the DC power supply used must be the same as the voltage of the fan, and the current of the power supply must be greater than the total current of the fan.?The speed governor has a hysteresis circuit. The start temperature and the stop temperature of the fan are set by the difference of 2°C. For example, the set start temperature is 30°C. When the temperature is lower than 28°C, the fan will stop. After the fan stops, wait for the temperature to rise. The fan will not start until 30 degrees or more.?When multiple fans need to be connected, connect them in parallel directly to the fan's wiring port, but ensure that the total current of the fans does not exceed the rated current of the governor.Shipping list:1 PWM temperature control speed controller