#565 Single-Shot Trigger
A debounced single-shot pulse generator with inverted amd non-inverted output designed for use on a breadboard.
This little module is for those breadboard occassions where when one needs a debounced pulse - or possibly an inverted pulse for active low logic.
It uses a 555 timer in monostable mode to debounced a pushbutton, emitting a pulse of trigger a pulse of at least 22ms (R1=20k and C1=1uF).
A CD4049 is used to buffer and invert the outputs (inverted amd non-inverted) so that it can match any required load.
First testing the circiut on a breadboard:
Making it a “Breadboard Bling” Module
I went for dead-bug stlye on a small piece of protoboard in order to keep the module small (I don’t have SMD versions of these chips on hand).
A scope trace of the pushbutton (CH2 - Blue) and the triggered and debounced 555 output (CH1 - Yellow):
The outputs from the CD4049 on a trigger pulse:
- CH1 - Yellow: non-inverted output
- CH2 - Blue: inverted output (offset -3.5V)