Five-digit LED display audio power indication circuit diagram made with FD502

As shown in the figure, a five-digit LED display is used as an audio power indication circuit. This circuit consists of a level meter driver FD502 and a five-digit LED display. This circuit can take out the positive amplitude changes of the audio signal to form a DC level, and then measure the changes in the DC level, thereby indicating the audio power. If the audio signal is too low, you can change FD502 to FD501, and then drive the LED after preamplification. FD502 and FD501 are domestic integrated circuits. FD501 has one preamplifier and five comparators inside, while FD502 has no preamplifier.