The circuit was conventionally designed with eight LED audio level meter made out of two low power quad op-amps which utilizes LM324. Volume Unit – an entity equal to a decibel for expressing the ...

This circuit senses AC audio voltage supplied to the car-radio loudspeakers and displays it as power using a LED bar graph, achieving at the same time an attractive visual effect. It is designed to ...

[Christian Doran] wanted some blinky goodness to go along with the tunes on his PSP. He built a VU meter circuit around a couple of LM324 op-amp chips and fit it into the UMD space on the back of the ...