Voice controlled running water lamp

Principle: Q1 and its peripheral circuits form a simple amplifier circuit. The MIC converts the sound signal into an electrical signal, which is coupled to Q1 through C3 for amplification. A voltage signal with high and low changes is formed at the collector of Q1. The voltage with sufficient amplitude is sent to the CD4017 for counting. At the input end (pin 14), every time a pulse arrives, the high level output of Q0-9 of the counter moves one bit in sequence, lighting up the corresponding light-emitting diode, thereby creating the feeling of flowing water. L11 is connected to the 4017 counting output terminal CO. When L1-5 lights up, the CO terminal of 4017 outputs a high level and lights up L11. When L6-10 lights up, the CO terminal outputs a low level and L11 does not light up. If you think L11 is unsightly, you don’t need to install it, and it won’t affect the circuit operation at all.