This module is generating three different waveforms with a fixed frequency of 1kHz. The signals are triangle, square-wave and sine-wave and can go from 0V up to 20Vpp (20V peak to peak). As output I used a BNC connector.
The sine wave is generated in a Wien bridge with an opamp. This signal is fed through a comparator for generating the square wave and this is put through an integrator for making the triangle waveform. With the help of some potentiometers the output voltages are set to 2Vpp and a rotary switch is letting you choose the desired waveform. With the help of an inverting amplifier with a settable voltage gain between 0 and 10 the signal is controlling a push-pull amplifier in order to draw up to 2A from it.
And that’s it. Looks more complicated than it actually is but works like a charm.
And as usual here some pictures.