Simple Schmitt Trigger Circuit Diagram

This is a Simple Schmitt Trigger Circuit Diagram. Schmitt trigger is a comparator circuit with hysteresis, implemented by applying positive feedback to the non-inverting input of a comparator. In this circuit By replacing the common-emitter resistor in a conventional Schmitt by a zener diode the hysteresis normally associated with these circuits is eliminated. 

Simple Schmitt Trigger Circuit Diagram