It is a circuit developed for lighting lamps according to the severity of music or sound broadcast. In the given circuit, the values of the resistors and capacitors connected to the G terminal of the three thyristors are different. In this case, each thyristor has a different value of transmission. The current of the bass frequencies below 400 Hz is SCR1, the current of the medium frequency signals between 400 Hz and 2 kHz is SCR2, and the current of high frequency signals above 2 kHz is SCR3.
According to the value of the incoming audio frequency signals, the thyristors pass through. In this way, the lamps blink according to the rhythm of the music and a beautiful appearance is obtained. The transformer in charge is the output of the old type lamp radios. The 4 W terminals of the transformer are connected to the output of the anfin, and the 5 kW secondary terminals are connected to the electronic circuit. Nowadays, optocoupler models that work better with this unit have been developed.