Brief description of heat dissipation DC cooling fan (1)
I believe that DC cooling fans are not unfamiliar to everyone. As a heat dissipation component in the digital electrical industry, we often see them, such as refrigerators, air conditioners, automobiles, water dispensers, air purifiers, etc. in our homes. It will exist inside. , If you say it can be seen everywhere, it can't be said. Although the components are small, they have great effects. Because of their small size, the capacity is so small that people ignore its importance. Below, the DC cooling fan manufacturer [Tongchi Automotive Air Conditioning Technology] will take you to understand the heat dissipation DC cooling fan DC cooling fan Because of the different power supply modes of motors, motors can be divided into two categories: DC motors and AC motors. The cooling fan motors used in general household appliances like refrigerator cars are all DC motors, with a power supply voltage of +12V, and a rotation speed between 1,000 and 10,000 revolutions per minute. A DC motor is a rotating machine that converts DC electrical energy into mechanical energy. It consists of three parts: stator, rotor and commutator. DC motors can be divided into two types: brushed DC motors and brushless DC motors. The structure of a brushed DC motor is composed of: the stator (ie, the main magnetic pole) is fixed on the cooling fan bracket and is the non-rotating part of the motor. There are more than two sets of coils in the rotor, which are wound by enameled wire, called windings. When a current flows through the winding, a magnetic field is generated, and the magnetic field and the magnetic field of the stator generate force. Since the stator is fixed, the rotor rotates under the action of force. The commutator is a special device of the DC motor, which is composed of many commutator segments, and the middle of every two adjacent commutator segments is an insulating sheet. The fixed brush is pressed by a spring on the surface of the commutator, so that the rotating armature winding can be connected with the external circuit. When the rotor rotates through a certain angle, the commutator connects the supply voltage to another pair of windings and continues to generate a magnetic field in this winding. It can be seen that due to the existence of the commutator, the electromagnetic torque received in the armature coil remains unchanged. Under the action of this electromagnetic torque, the armature can be rotated. The difference between a brushed DC cooling fan and a brushless DC cooling fan: DC The motor uses carbon brushes to achieve commutation. Due to the friction of the carbon brush, the life of the brush and even the motor is shortened. At the same time, the brushes will generate sparks during high-speed operation, which will also interfere with the surrounding electronic circuits. For this reason, people invented a DC motor without carbon brushes, which is usually called a brushless motor. The brushless motor uses the winding as the stator and the permanent magnet as the rotor (as shown in Figure 7), which is exactly the opposite of the brush motor in structure. The brushless motor uses an electronic circuit to switch the energization sequence of the windings to generate a rotating magnetic field and push the rotor to rotate.