This circuit with a bargraph scale was found in a 90s Popular Electronics. The circuit measures the intensity of a sound in three scales. R14 works as a sensitivity adjustment.
Originally designed to analyze the shape of light pulses from a flash for photographic...
This CMOS oscillator circuit generates signals up to a few megahertz, depending on the capacitor value....
Generating sinusoidal signals from 1.5 to 15 kHz, this oscillator uses common complementary...