Multivibrators and Schmitt circuits

Relevant key device information applied in this article: NE555 multivibrator and Schmidt circuit 1. Multivibrator (only required to know its working characteristics and uses) The working characteristics of the multivibrator are: The circuit is not stable state, but has two transient stable states; the circuit can automatically generate a rectangular wave output without an external trigger signal; the circuit works by switching back and forth between the two transient stable states. Its purpose is: to generate quantitative rectangular pulses. 2. Schmidt circuit Connect pins 2 and 6 in the 555 timing circuit to form a Schmidt circuit. As shown in Figure (1), the working characteristics of the Schmidt circuit are: There are two stable states, but these two stable states are maintained by the input signal, and the conversion also depends on the conversion of the input signal to achieve the output voltage and input The voltage has circuitous characteristics and strong anti-interference ability. The purpose of the Schmidt circuit is: shaping: turning a bad rectangular wave into a better rectangular wave; waveform conversion: converting triangle waves, sine waves and other waveforms into rectangular waves; the converted output waveform is the same as the input waveform ; Amplitude identification: It can detect the signal whose amplitude is greater than a certain value in the input signal.