Monostable Multivibrator

A monstable multivibrator knows exactly one state where he remains. This occurs, everytime the circuit has cycled. The left transistor is dominant, because it is no longer controlled by a capacitor, but directly via a push-button. When the push button is not pressed, the green LED lights up. If the button is pressed, the yellow LED lights up and the green gets off. When the push button is released immediately, the yellow LED lights up for a short time, and the green one remains dark at this time. Holding down the button for longer time, the yellow LED lights up until the button is released. At the same time the green LED remains dark until the time dened by the capacitor has expired. Now the stable state is reached and the green LED lights up permanently. By pressing the push button repeatedly pulses can be created, this is called triggering. Trigger signals are used to generate pulses. Attention: The green is glowing also in the off condition as a small amount of current ows through the 10 kOhm resistor into the base of the rst transistor which is enough. This example is perfect for experimenting! You can use a lot of different bricks, for changing some effects.