Sound-activated circulating lantern circuit

Shown is a sound-controlled cyclic lantern circuit. HTD is a piezoelectric ceramic chip (sound transmitter). When sound is received, its signal
is amplified by VT1 and then added to the ⑤ pin of Icl. IC1 is a time base circuit. IC1 sends the signal to the @ pin of IC2. After counting and dividing,
Qo-Q9 sequentially outputs the trigger signal to trigger the bidirectional thyristor. When the bidirectional thyristor is turned on, the colored lamp will light up. IC2 will output the trigger pulse cyclically,
and the colored lamp will Looping light.