Desktop voice fan

As a student majoring in electronic information engineering, it is inevitable to manually solder some electrical boards frequently. Solder wire will be used in the process of soldering circuit boards, and a lot of smoke will be generated during the melting process of solder wire. For this reason, taking the opportunity of this invitational competition, I hand-made a desktop fan that can escape the heat in summer and absorb smoke during welding. It is based on the control of Anxin's offline voice module VC-02-CN, gets rid of button control, and can achieve stepless speed regulation, lighting control, etc.;
Boost boost circuit. Since the power supply voltage of the fan used this time is 12V, and 12V requires three 18650 batteries, which greatly increases the production cost. The MT3608Boost boost chip input voltage: 2V~24V output voltage: 28V switching frequency: 1.2MHz 2A fully meets the needs of this project.
Fan drive circuit. AO3400A NMOSFET is very small in size, the drive circuit is simple, and the overcurrent can reach 5.7A. It is a very easy-to-use MOS tube.
Charging circuit. In order to meet the needs of mobility, it is impossible to use wired connection while keeping the size small, so it is necessary to consider battery life and charging issues. TP4059 is a very good lithium battery charging chip, its charging current can reach 600mA, and it also has reverse connection protection for the positive and negative poles of the battery, and constant current/constant voltage linear control fully meets the design requirements.
Main control circuit. VC-02-CN is a very easy-to-use offline voice assistant with simple development and circuit, high recognition sensitivity, and serial port, PWM, IO and other advantages.