With a simple transformer connected to the output of an amplifier of more than 5 W it is possible to cause a small fluorescent lamp to blink in the rhythm of the music.
Even weak bulbs that no longer work normally in the power grid will blink in the rhythm of the music when used in this circuit.
Its operation is simple: the low audio output voltage of an amplifier, when applied to the transformer, appears as high voltage in the other winding, then lighting the lamp that will flash in the music peaks.
The transformer used may be any of 6 to 12 V with a current of 200 to 500 mA and a primary of 110 V or 220 V.
To use this unit, however, the reader must take special care not to force the amplifier and cause damage to your circuit.
So if the output of the channels is 4 ohms, we should use 8 speakers plus the indicated circuit. If it is 2 ohms, we should use 4 speakers plus the indicated circuit.
Note that in this circuit, the luminous power corresponds to the sound power that is developed in the loudspeaker which means that we will have certain loss in the maximum volume of sound that the amplifier can give.
In figure 1 we have the complete diagram of the apparatus.
The final appearance of the assembly that does not require a chassis or other component support member is shown in Figure 2.
The circuit is connected to the output of any amplifier with a minimum power of 5 W.
To try the device, simply open the volume and check the point at which the lamp starts blinking.
Material list
T1 - Transformer - see text
L1- Fluorescent 5 to 40 W lamp
Miscellaneous: wires, solder, screw terminals.
