Instructions for use: J1 can change the control mode. When short circuit 1, 3 and 2, 4 of J1, the stronger the light, the higher the series voltage divider on R7. This voltage is added to the inverting input of the voltage comparator IC1A. When the voltage exceeds the voltage of the non-inverting input terminal, IC1A outputs low level, the transistor 8550 is turned on, the music chip and the 18 LED loop circuits are powered on and begin to sound and flicker. J2 is the speaker power switch, and the short-circuit cap of J2 is removed and it is in a mute state. Transistor V5 is a power amplifier, the audio signal of the music chip is amplified by V5; it drives the passive buzzer to sound; otherwise, if the pins 3, 5 and 4, 6 of J1 are short-circuited, the light will be darker and the resistance R7 The higher the series partial pressure of. This becomes dark control. Other connections of J1 are undefined. The adjustable resistor W1 can adjust the voltage of the non-inverting input terminal, so that the circuit responds to the appropriate light intensity and avoids excessive high and low. The music chip is a positive trigger and pin 2 is the trigger terminal. After connecting pin 2 to the power supply pin 1, the music chip can be played in a loop. Resistors R2, R4, and R6 are the current-limiting resistors of the light-emitting diodes, corresponding to different colors of light-emitting diodes, R2 for red, R4 for yellow, and R6. If the colors of the three groups of LEDs are the same, current-limiting resistors with the same resistance can be used. Since LEDs of different colors have different turn-on voltages, only one color of LEDs can be installed in the same group. For example, if L1-6 is a group, L1-6 can only install LEDs of one color. If the colors are mixed, Then the LED with high turn-on voltage will not emit light. Red LED turn-on voltage. Yellow is higher. If the red and yellow are installed in a group, the yellow LED will not emit light. Pay attention when installing.