This signal generator circuit is ideal for electronic enthusiasts looking for a sine and square wave generator in the audio frequency range. It is also an instructional tool that can be used to display waveforms on an oscilloscope.

The circuit is based on a Wien-Bridge oscillator, which provides a sinusoidal output. The square wave is then derived from this sinusoidal output.

It has two independent outputs, one for sine wave and the other for square wave. The circuit can produce frequencies from approximately 40Hz to 2.5KHz or from 2.5KHz to 10KHz depending on the position of the range select switch. The sine level can be adjusted from 0 to 2V peak-to-peak through a trimmer potentiometer. The square wave output provides two separate fixed level outputs, one at 5V and the other at 9V.