Using this circuit diagram can be a very simple triangular wave signal generator. The circuit is an usual rectangular-triangular oscillator used. A Schmitt trigger converts a triangular wave in one rectangular, used to charge and discharge a capacitor continuously through currernt sources. Positive current source T1 ensure charge and negative current source T2 discharge.
Trigger output alternating commands conduction of T1 and T2. If the output of IClb is logical 1 T2 conduct if is logical 0 T1 conduct.