Electronic circuits > Audio > Audio level meter (vumeter)
Audio level meter (vumeter)This circuit uses just one IC and a very few number of external components.
It displays the audio level in terms of 10 LEDs. The input voltage can vary from
12V to 20V, but suggested voltage is 12V.
The LM3915 is a monolithic integrated circuit that senses analog voltage
levels and drives ten LEDs providing a logarithmic 3 dB/step analog display.
LED current drive is regulated and programmable, eliminating the need for
current limiting resistors.
The IC contains an adjustable voltage reference and an accurate ten-step
voltage divider. The high-impedance input buffer accepts signals down to ground
and up to within 1.5V of the positive supply. Further, it needs no protection
against inputs of ±35V. The input buffer drives 10 individual comparators
referenced to the precision divider. Accuracy is typically better than 1 dB.
Published on: 2004-08-21 (3833 reads)
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