Typical relaxation oscillator and its output voltage waveform

Typical relaxation oscillator and its output voltage waveform

The sawtooth wave signal generator is actually an extension and application of the relaxation oscillator. The figure shows a typical relaxation oscillator . If
the input terminal of the operational amplifier switches between ten/- voltages, there will be a triangular wave signal at the output terminal. This feature can be used to form the required
oscillation circuit.
    When the switch is switched to position 1, a negative voltage is applied, so The output is a positive slope voltage: when the switch is switched to position 2,
the output is a negative slope voltage. If the switch
switches back and forth at regular intervals, the output is a triangle wave consisting of alternating positive and negative ramp voltages.