simple sawtooth generator

62 simple sawtooth generator Relt 81 P1 250k Sawtooth generators are frequently required in most branches of elec- tronics. We therefore feature a new design for a circuit which makes use of components which can be found in almost every box of goodies (or "rubbish" to unbelievers!). The basic version of the circuit as shown in figure 1 uses a 9 V battery as supply. The circuit itself can be readily understood: capacitor Cl is linearly charged by constant current source Ti, R1, Pl. Transistors T2 and T3 are used as substitute for a silicon controlled rectifier (SCR) and if you bear this in mind, the circuit is somewhat easier to understand. The "SCR" is not, as usual, fired by a pulse. Instead, the "gate" is biased by voltage divider R3/D2 and once the "anode to cathode" voltage ex- R2 C + I22n 83412.1 C 834122 c 9V T C2 D1 1N4148IDUS BC 557B r2 1.4V 2 loop 35V 02 3V3 400 m W * seelext a A ceeds this bias, the "SCR" conducts. Cl then discharges rapidly through the "SCR" and current...