Pulse shaper generating sharp edge square wave - uses rectified AC input to operated Schmitt trigger that controls electronic switch

摘要

The pulse shaper converts a periodic voltage into a rectangular voltage. The alternating input (UE) is applied both to an electronic switch (3) e.g. an op. amp. or a CMOS gate with buffer, and to a rectifier (1). The switch has a steep transition slope. The rectifier controls a Schmitt trigger (2) whose own output operates the switch, thereby causing the input to appear at the output (UA) with steep leading and trailing edges. When the input voltage drops below a given level the electronic switch is disabled, i.e. the trigger fails to operate. The shapes may be used between a quartz oscillator and digital circuitry in a CW system.