Function introduction:
After this kit is successfully produced, as music or other sounds sound, the 5 LED lights will flash according to the rhythm of the sound (the speed of the sound). Get moving. It can be placed near the speaker, and you can feel the wonderful melody combination of sound and light, and let the light dance with the music!
Circuit principle:
The voice-activated LED melody light circuit consists of a power supply circuit, a microphone amplifier circuit, and an LED light-emitting indication circuit. The power supply is input by J1, and C1 is filtered for circuit use. MIC1 converts the sound signal into an electrical signal, which is coupled to Q1 for amplification via C2. The amplified signal is sent to the base of Q2, and Q2 drives the LED to emit light. The louder the sound, the higher the brightness of the LED.
Component list:
Frequently asked questions:
1. I didn’t pay attention to the positive and negative poles of the LED. The long leg is the positive pole.
2. The three resistors are not welded according to the markings on the board. Use a multimeter to measure or look at the resistor color ring reading.
3. The transistor is not inserted according to the shape on the board, resulting in the wrong direction.
4. The positive and negative poles of the microphone are incorrect, the long leg is positive, or the pin connected to the shell is negative.
5. The capacitance of the electrolytic capacitor is wrongly soldered. One is 1uf and the other is 47uf. Pay attention to the difference. The positive pole is long.
6. The positive and negative poles of the power supply are connected reversely. According to the mark on the board, the line corresponding to the + sign is the positive pole, and the line corresponding to the - sign is the negative pole.
7. Check the welding short circuit and virtual welding phenomenon. The power supply voltage is 3-5.5V. A stable power supply is required, and it is best to use a battery.
Appendix: Specific identification methods of four-ring and five-ring color ring resistors