Welcome guest voice greeting circuit diagram principle

Car Audio Crystal 3.2*2.5mm 3225 24M (24.000MHZ) 20PF 10PPM 20PPM 30PPM

Shunluo Inductance Power Inductor SWPA Series First Class Agent

Tantalum capacitor TR3C107K010C0100 original 2011+

SMD aluminum electrolytic capacitor

As shown in the figure, the time base circuit 555 and RP1, R2, C1, etc. form a multivibrator whose vibration frequency is f=1.44/(RP1+2R2)Cl. The vibration of the parameter is o.007 Hz, that is, each Oscillate once every 2 minutes or more (143 seconds), the duty ratio is l: l.
When the 3 feet of 555 are at a low level, the LEDs LED1 and LED2 emit light. IC2 uses the voice integrated circuit HFC5218, its trigger terminals TG1 and TG2 can be issued "Welcome!" and "Thank you!" when the high potential is triggered. When the population is welcoming, it can be issued by turning on the switch SA1. Welcome! "Welcome to the guest; at the exit, you can send a "Thank you!" by connecting SA2.
The oscillation period of the oscillation circuit can be adjusted by changing the charge and discharge time constant (RP1 + R2) Cl of the time base circuit.