Produces a very sharp almost perfect triangular wave from a square wave input and at 50% duty cycle. Even works at pretty high frequencies such as 100KHz without loosing its shape, or becoming distorted. Very dependent upon the size of the capacitor and/or current source though. If you want a higher frequency at full amplitude, then use a smaller cap while shortening the period of the square wave input; do the opposite for lower frequencies... Or you can try to adjust the base resistors to control the constant current value, but that’s gonna require much more patience. Note though: don’t adjust the cap too low or high, cause otherwise it’ll begin to either clip the peaks of the triangular wave, or it’ll start to look square.
