I know this is something simple but i've done a little searching and can't find what i'm looking for and it's been a while since digital logic courses, but i can't work it up form scratch for the life of me....

I'm looking for digital logic circuit/gate that everything starts at 0 (low) and then if high is input, the output is high, but only for about 5 seconds, then the output goes low again, nomatter if the input stays high or goes low again.

I hope i explained it clearly, but basically the effect would be, press a button to turn on a LED or something for 5 seconds or so, if you hold the button down it goes for 5 seconds and turns off, if you press it and let go it will hold it for 5 seconds and turn off, either way once the led goes low it is ready to be turned on again.

Thanks
bonanz

 

Try looking for a 555 tutorial and you will find the circuit you need. As a hint try Monostable 555 circuit 8)

Ivancho

 

i need help to find a circuit :
set/reset circuit by presing one boton

 

Hi Luis,

Sounds like you mean a flip-flop circuit.

John

 

See this circuit:

Attached Thumbnails

 

 

im sorry the time
not a flip flop circuit but impulse relay circuit with one boton
i send a picture with a circuit like i want but this have two switches

Attached Files

TOUCH_SWITCH.zip (58.6 KB, 170 views)

 

Just a small modification for relay...

Attached Thumbnails

 

 

thanks Sebi your circuit works very well.