## Schmitt trigger VS simple inverter

Schmitt trigger is special logical element adjusted to work with analog input signals. The primary purpose of Schmitt triggers were restoring the shape of digital signals. Because of transmission line effect digital shape transforms from square to trapezoid or triangle or more complex signal. Of course during transmission signals become noisy and distorted. Schmitt trigger is a comparator circuit but inside it is a positive feedback what results in hysteresis and memory effect. Comparing to simple logical elements Schmitt triggers have two threshold levels. Between these threshold values U1 and U2 the state of output doesn’t change what is so called a hysteresis. Such effect stabilizes output against rapid triggering by noise. Bellow is two characteristics compared of simpel logical inverter and Schmitt trigger inverter: We see that Schmitt trigger characteristics is more complex -the output signal threshold depends on direction of input voltage rise/drop. When input signal is rising…

## Logical elements and their classification

Logical elements are circuits that perform logical operations. Logical elements are used in digital circuits and are used to express Boolean algebra. The system of logical operations were defined by George Boole an English mathematician in 1848. Firs logical element was used by Erenfest in 1910. It was calculator made of telephone relays… Let’s go to now days and clarify what is logical algebra. In logical algebra there are only two values: â€œTrueâ€ or â€œFalseâ€ they are identified as numbers 1 â€“ for â€œtrueâ€ and â€œ0â€ – for â€œfalseâ€. Because there are two digits used, so this is why digital electronics is called as it is – â€œDigital Electronicsâ€ – the electronics which operates with two digits. Logical operations may be as follows: Logical negation – Â¬A (in different sources negation has various markings like Ä€); Logical OR â€“ C=A + B (in other literature you may find C=AUB); Logical…