IC2 uses the voice integrated circuit HFC5212, which has a "beep, please pay attention" voice signal. The integrated circuit adopts a level, does not maintain the trigger mode, and once it is powered and triggered, it immediately plays the statement of the memory. Its working voltage V"DD=2.4~6V is to ensure its reliable operation. R3 and DW voltage regulator circuits are used in the circuit. The voltage is regulated by 2CW52 and the voltage is +3.7V. The peripheral circuit of HFC5212 is simple and external. Resistor R4, which adjusts the size of R4, changes its pronunciation pitch and rhythm. 180W Desktop Power Adapter,19V180W Desktop Charger,4V7.5A 180W Power Adapter,24V7.5A180W Switching Power Supply Guangdong Mingxin Power Technologies Co.,Ltd. , https://www.mxpowersupply.com