The simplest voice-controlled music lantern

The 220V alternating current is divided by Rl and R2, and VD
is half-wave rectified, and
a DC voltage of about 3V is obtained at both ends of the capacitor C. Adjust the potentiometer RP so that the transistor
VT is just in the on state. At this time,
the gate and cathode of the thyristor vs are short-
circuited by the ce pole of the transistor VT. vs has no trigger current and is in the off state.
The lantern not bright. B is a piezoelectric ceramic piece. After receiving the environmental
sound wave signal , it outputs a corresponding electrical signal. This electrical signal is added between the base and emitter of VT. The negative half cycle of the signal causes
the transistor to exit the conductive state, and its collector The electrode can control the gate potential of the silicon VS to rise, and the VS is turned on, and the colorful lights will light up. Therefore,
the colored lights can sparkle with the sound waves of the ambient music.
    Potentiometer RP can be used to adjust the sound control sensitivity. When RP is adjusted small, the conduction depth of transistor VT is shallow, and VT is easy to exit
the short conduction state, so the voice control sensitivity is high. On the contrary, when RP is increased, VT is deeply saturated. To exit the conduction state, a
larger input is required at the base. signal , dare voice control sensitivity is low.