[LectronFanModerator]

Hi all,

Did you enjoy the experiments with the Schmitt trigger so far ?
Well, here is another circuit that can be constructed with this very versatile module :

A monostable flipflop.
By pressing a switch, the flipflop switches and returns to its first state after a certain time.
We can build this circuit with discrete components, like explained in the manual, but we can also make use of the Schmitt trigger module.
Here’s the setup diagram :

By choosing different values for C2 and R2, we can change the timing.

A little explanation …

By pressing S1, we deliver a short negative pulse via C1 to the input of the Schmitt trigger.
R1 (2,2M) discharges the capacitor when the key is released.
The Schmitt trigger changes state and C2 starts to charge via R2, keeping the Schmitt trigger input low.
At a certain moment, the capacitor is charged and no current flows anymore to the input of the Schmitt trigger.

It will have returned back to its original state.

R3 makes sure that the input of the Schmitt trigger is not falsely activated.
R2 reduces the high charging current and protects the input of the Schmitt trigger for being damaged.

By adding an Emitter follower, you can use the light bulb to visualise.

Have fun !

 

 

• This topic was modified 3 years, 2 months ago by LectronFan.

[MichaelKeymaster]

Thanks so much Frank!  Another instructive but fun demonstration circuit 🙂

[Author]

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