Complementary symmetric astable multivibrator circuit diagram

Complementary Symmetric Astable Multivibrator

This circuit is familiar to electronics enthusiasts. It is a complementary symmetrical astable multivibrator. When the left and right components have the same value, the waveform duty cycle is 50%, and the two LEDs light up for the same time.

As shown in the figure, the oscillation frequency of the circuit is about 0.5 seconds, and the two LEDs will flash alternately. You can change the frequency by changing the two 100u capacitors.

Random Monostable

The first circuit is astable. With a slight modification, it can become a monostable circuit. This circuit is designed to be a random monostable and controlled by a button.

When the button is pressed, the circuit will oscillate at a high rate and illuminate both LEDs. When the button is released, one LED will remain illuminated, with a 50% randomness. Adjusting the 50k variable resistor will change the duty cycle, and thus the randomness.