[simpits-tech] Momentary on-off

[Gene Buckle]

*boggle*

Hey Jim, could you draw up a schematic of this and upload it to the
website?  Us slower types could use the help. :)

Great post!

g.


On Wed, 8 Oct 2003, Jim Sturcbecher wrote:

> Recipe as follows:
>
> 1 - Connect one side of the switch to ground.
>
> 2 -  Add a pullup resistor to VCC on the other switch contact. this
>       gives you a normally high output that goes to ground when the
>       button is pushed.
>
> 3 - Feed this signal via a RC network (series resistor, then cap to gnd)
>      to lose the switch-bounce noise.
>
> 4 - This then goes into a 74LS14 Schmitt trigger invertor.
>
> 5 - You will now have a nice clean high-going signal out of the invertor
>      when you push the button.
>
> 6 - Feed this to the clock input of a D-Type flip-flop (74LS74) which has
>      the /Q output connected back to the D input and both /SET and /CLR
>      connected to VCC.
>
> 7 - Now every time you press the button, the Q output of the flip-flop
> will
>      change state.
>
> Voila, one change-over switch from a single push-button. You can drive
> the leds from the Q output through a transistor to take the current.
>
> Serve and enjoy.
>
> Jim.
>
> At 8-10-03 18:57, you wrote:
>       Quick question:
>
>       I need to make a momentary pushbutton switch turn some LEDs
>       on and off. I.E. you push the button once, they turn on, you
>       push it again, they turn off. Any ideas?
>
>       Brian
>
>       PS - I've been having trouble lately with my messages coming
>       back from simpits-tech as undeliverable my first try. Anyone
>       else having this?
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