Research on the basic working principle of insect repeller using broadband ultrasonic technology

Probe domestic switch needle KG300B head diameter 3.0 normally closed switch needle total length is 5

Filter 18.432M

IC1 (555) and R1, R2, and C1 form an astable multi-harmonic oscillator with an oscillator frequency of f = 1.44 / (R1 + 2R2) C1. . Q0~Q9 sequentially generate high-level pulses to provide different charging resistors for the IC3 oscillator, so that the charging time constant of the IC3(555) multivibrator is different, and ultrasonic oscillation waves of different frequencies are generated.