Auto cooling fan also need protection
auto cooling fan at the time of use, impedance will have two functions, one is the impedance protection function, is a kind of thermal protection function were introduced as follows: the first one,
impedance protection: auto cooling fan is by dc voltage and electromagnetic induction, the electrical energy into mechanical energy to drive the blades rotating a cooling device. Auto cooling fan impeller and blade design, with auto cooling fan, air volume and air pressure and pressure collision resistance ability of the blades, serious point that affect the entire automotive cooling fan of the grade and quality. Therefore, in order to prevent motor loss in closed, impedance protection set motor coil impedance ( Ac resistance) , keep the motor temperature rise under burning temperature.
the second, thermal protection function: the motor loss in closed to prevent, on the motor temperature rise before burning temperature is reached, typically by hot components to cut off the fan without overheating protection, normal car radiator fan can only lock machine for 2 hours, with the temperature rising slowly, over time, the motor will be burnt, IC will be burned to death, it is also an important role in overheating protection. So relatively speaking, the product has the two characteristics, can have longer service life for the product.