Multivibrator calculator based on NE555 / Stack of Circuits

Calculation of the time-consuming components of a multivibrator

This calculator will help you calculate the frequency and fill factor of the multivibrator signals based on the NE555 timer chip. A circuit for generating rectangular pulses can be built on the basis of the NE555 timer chip. A multivibrator is a relaxation generator that produces a rectangular signal. The word "relaxation" means that the elements that make up the multivibrator do not have the ability to resonate. The figure below shows the NE555-based multivibrator circuit. The circuit uses external timing components: $R_A$ , $R_B$ , $C$ , and the amplitude of the output signal is equal to the supply voltage of the chip, which can be 5-12 Volts. The formulas for calculating the signal parameters are presented below:

f = \frac{1}{ln(2) * C * (R_A + 2R_B)}

T_{high} = ln(2) * C * (R_A + R_B)

T_{low} = ln(2) * C * R_B

D = \frac{T_{high}}{T_{low} + T_{high}} = \frac{R_A + R_B}{R_A + 2R_B}