Self made course courseware of remote control electric fan

There are several kinds of fans, including AC, DC, brushless and brush. The basic principle is the same. This product is a dc3v DC motor, which uses electromagnetic induction to drive the fan blade to rotate. The specific circuit design and mechanism design also have some differences according to different types. For example, DC brushless motor, its fan blade has rubber magnet, which is a permanent magnet. It is a rotor, a stator is a coil, and the circuit board is fixed on the coil, On the board, there is a sensor called Hall sensor. When the sensor senses the N-pole pole in the fan blade, it is converted into an electrical signal. The circuit adjusts the current direction from left to right (assuming that the stator generates thrust to make the fan blade rotate. When the fan blade turns to the S-pole, the sensor senses it and converts it into another electrical signal to make the current direction turn from right to left, Another thrust is generated to push the blades to keep running

Experiment purpose: through connecting circuit, learning the basic knowledge of series circuit, understanding the conditions of motor remote control, realizing the application of electricity in life

Experimental cognition:

Battery box: as the name suggests, the box for installing fixed battery is the battery power output device

Motor: it is composed of stator and rotor. DC motor is a motor that converts DC electric energy into mechanical energy. Because of its good speed regulation performance, it is widely used in electric drive. DC motor is divided into permanent magnet according to excitation mode

There are three kinds of self excitation, including parallel excitation, series excitation and compound excitation.

Triode: when the working state of triode is in the amplification area, the collector current and base current of triode are basically in a fixed proportion. The so-called amplification function of triode actually depends on this fixed proportion

The relation controls a large current (collector current) by a small current (base current).

Infrared diodes: circuit elements for triggering and switching on Circuits

Experimental equipment:

1. Prepare and know the experimental equipment: screw hole plate, battery box, switch, resistance, adjustable resistance, triode, motor, wire, screwdriver, diagonal pliers.

Experiment report:

Electronic remote control fan, is to use a two-way SCR to speed, like a dimmable lamp. It is characterized by low cost, small volume and light weight. The disadvantage is that the thyristor's conduction angle is used to adjust the voltage, and the output is not sinusoidal

Wave current, will produce a lot of harmonics, radio, audio and so on are greatly disturbed.

Expression knowledge: by inserting capacitance or inductance in series, the winding current of the motor is changed, thus the load capacity of the motor is changed. The load of the electric fan should be the same as that of the fan. The higher the speed, the greater the load, and the change of the load capacity of the motor

Now, the speed of the blades changes.