Description
nciple: This circuit consists of a triode amplifier circuit and a level indicator circuit. The microphone sends the received sound to the triode Q1 through C3 for amplification and then sends it to the signal input terminal (pin 8) of the KA2284. The KA2284 drives 5 groups of light-emitting diodes to display on and off. The louder the sound, the more LEDs light up, and the quieter the sound, the fewer LEDs light up. The circuit board has mesh holes so that the outside can be easily seen from the inside. And the LEDs on the circuit board shine outwards and do not irradiate the eyes, has no impact on vision at all.




