Voice-activated music lantern circuit (3)

It is a voice-activated music lantern with another connection method . Its circuit is relatively simple, the cost is low, and the effect
is very good. The gate tube VT3 forms
the main circuit of the lantern F, VT1 and VT2 form the return circuit, and
the 220V alternating current is rectified by VD and R. After step-down, VS
voltage stabilization and C, filtering, a stable DC
voltage of about 12V is output to supply power to the control circuit. Microphone B picks up the sound wave signal
of the indoor environment and converts it into an electrical signal, which is amplified by the transistor VT1. The amplified signal is translated into RP and C and flows into the base of VT? (RP is the sound-activated sensitivity deletion potentiometer) . VT2 is connected as an unbiased follower, and the music signal VT2 emitter is rectified as the chip bias voltage, thereby changing the size of the output current of the VT2 emitter , and this current is directed to the thyristor VT3. f J pole, change the conduction angle of VT3, so that the colorful light string E connected in series in its anode circuit flashes with the rhythm of indoor music m. The LED flashes with electricity and doubles as a power indicator.