Tiny Cooling Fan how to control speed

"Tiny Cooling Fan" by DC voltage and electromagnetic induction, the electrical energy into mechanical cooling fan blades so as to drive the rotation, this rotation has become a fan in DC fan. Cooling fan is running, with the case of heat is changed, a slower speeds, "Tiny Cooling Fan" will have less noise and consumes less energy. In most of the design requirements, the cooling fan speed operation in a few hours after the air temperature is usually lower than the maximum design temperature value. Under normal circumstances, low-speed operation of the "Tiny Cooling Fan" can be enough to complete its work. When the temperature changes slowly cooling fan, cooling fan speed changes are slow, will not suddenly change the cooling fan speed and noise. The reaction time depends mainly on the length of the sensor of its thermally-induced sensitivity.