555 square wave triangle wave generator circuit diagram

As shown in the figure, this is a stable square wave and triangle wave generating circuit. The characteristics of this circuit are: the frequencies of the square wave and the triangle wave are almost equal, and the positive and negative amplitudes are symmetrical; the positive and negative slopes of the triangle wave are not affected by the amplitude change, and the positive and negative slopes can be adjusted separately. In addition, the output waveform will not change when the baseline level is adjusted. Operational amplifier A2 is an integrator, which is driven by the output square wave of operational amplifier A1. The amplitude of the square wave is fixed at 5V by two Zener diodes D1 and D2. Potentiometer R3 adjusts the positive slope of the triangle wave, R2 adjusts the negative slope of the triangle wave, and R5 adjusts the amplitude of the triangle wave. If only the same positive and negative slopes are required, D3, D4 and R2 can be omitted. Operational amplifier A1 is a comparator. The reference voltage is adjusted by potentiometer R4, which determines the baseline level of the output, but does not affect the amplitude and slope. The maximum operating frequency is determined by the conversion rate of the operational amplifier, the maximum output current and the switching speed of the diode.
Triangle wave amplitude:

Square wave amplitude: (determined by diodes D1 and D2)