Supporting the production of our national life "24V DC Cooling Fan" electric motors account for about 60 percent of all sectors of national and various types of machinery and electrical equipment. It is particularly worth mentioning is that most of the fan motors are present in a large horse-drawn trolley phenomenon, coupled with the changes in terms of production technology, the need for frequent adjustment of gas flow, pressure, temperature; many units still use behind the windshield or adjusting the opening degree of the valve plate to regulate the pressure of the gas flow pattern and temperature. "24V DC Cooling Fan" is actually by way of artificially increasing the resistance, but also a waste of energy and money to meet the cost of technology and working conditions of the gas flow regulator requirements. "24V DC Cooling Fan" backward adjustment, not only a waste of valuable energy, regulation accuracy is poor, difficult to meet the requirements of modern industrial production and services, very serious negative impact.