Operation: use a 220V to 15V transformer, and then connect a ballast module, and then connect a 1000 or more capacitors to filter, and then a 7812 voltage regulator module, stabilized into 12V voltage output, and then connect a 470 or more capacitors can finally power the audio.
Low-voltage protection is the use of low-voltage protection relay to connect the two sides of the power supply, when there is a low-voltage phenomenon in the circuit, the relay will automatically cut off the power supply, thus playing a protective role.